5c0c55409b
Add strategy interfaces - obtaining ServerSocketFactory and SocketFactory - post processing ServerSockets and Sockets - obtaining initialized SSLContext Provide SSL and non-SSL implementations of the strategies, to serve up the appropriate socket factories, and do nothing in the post processing methods. The postprocessors allow the user to modify sockets after configured attributes have been applied but before the sockets are used. This is particularly useful with SSL in case additional SSL options need to be applied. Docs Polishing JavaDocs Polishing Javadocs, polishing Polishing Polishing INT-2153 Polishing PR Review White Space INT-2513 Polishing Fixed method names.
1686 lines
76 KiB
XML
1686 lines
76 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<chapter xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="ip"
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xmlns:xlink="http://www.w3.org/1999/xlink">
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<title>TCP and UDP Support</title>
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<para>
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Spring Integration provides Channel Adapters for receiving and sending messages over internet protocols. Both UDP
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(User Datagram Protocol)
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and TCP (Transmission Control Protocol) adapters are provided. Each adapter provides for one-way communication
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over the underlying protocol.
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In addition, simple inbound and outbound tcp gateways are provided. These are used when two-way communication is
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needed.
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</para>
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<section id="ip-intro">
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<title>Introduction</title>
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<para>
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Two flavors each of UDP inbound and outbound channel adapters are provided <classname>UnicastSendingMessageHandler</classname>
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sends a datagram packet to a single destination. <classname>UnicastReceivingChannelAdapter</classname> receives
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|
incoming datagram packets. <classname>MulticastSendingMessageHandler</classname> sends (broadcasts) datagram packets to
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a multicast address. <classname>MulticastReceivingChannelAdapter</classname> receives incoming datagram packets
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by joining to a multicast address.
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</para>
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<para>
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TCP inbound and outbound channel adapters are provided <classname>TcpSendingMessageHandler</classname>
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sends messages over TCP. <classname>TcpReceivingChannelAdapter</classname> receives messages over TCP.
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</para>
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<para>
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An inbound TCP gateway is provided; this allows for simple request/response processing. While
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the gateway can support any number of connections, each connection can only process serially. The thread
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that reads from the socket waits for, and sends, the response before reading again. If the connection factory
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is configured for single use connections, the connection is closed after the socket times out.
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</para>
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<para>
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An outbound TCP gateway is provided; this allows for simple request/response processing.
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If the associated connection factory is configured for single use connections, a new connection is
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immediately created for each new request. Otherwise, if the connection is in use,
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the calling thread blocks on the connection until either a response is received or a timeout
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or I/O error occurs.
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</para>
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<para>
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The TCP and UDP inbound channel adapters, and the TCP inbound gateway, support the "error-channel" attribute.
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This provides the same basic functionality as described in <xref linkend="gateway-proxy"/>.
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</para>
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</section>
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<section id="udp-adapters">
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<title>UDP Adapters</title>
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<para>
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<programlisting language="xml"><![CDATA[ <int-ip:udp-outbound-channel-adapter id="udpOut"
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host="somehost"
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port="11111"
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multicast="false"
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channel="exampleChannel" />]]></programlisting>
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A simple UDP outbound channel adapter.
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<tip>
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When setting multicast to true, provide the multicast address in the host
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attribute.
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</tip>
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</para>
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<para>
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UDP is an efficient, but unreliable protocol. Two attributes are added to improve reliability. When check-length is
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set to true, the adapter precedes the message data with a length field (4 bytes in network byte order). This enables
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the receiving side to verify the length of the packet received. If a receiving system uses a buffer that is too
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short the contain the packet, the packet can be truncated. The length header provides a mechanism to detect this.
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</para>
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<para>
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<programlisting language="xml"><![CDATA[ <int-ip:udp-outbound-channel-adapter id="udpOut"
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host="somehost"
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port="11111"
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multicast="false"
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check-length="true"
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channel="exampleChannel" />]]></programlisting>
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An outbound channel adapter that adds length checking to the datagram packets.
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<tip>
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The recipient of the packet must also be configured to expect a length to precede the
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actual data. For a Spring Integration UDP inbound channel adapter, set its
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<classname>check-length</classname> attribute.
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</tip>
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</para>
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<para>
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The second reliability improvement allows an application-level acknowledgment protocol to be used. The receiver
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must send an acknowledgment to the sender within a specified time.
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</para>
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<para>
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<programlisting language="xml"><![CDATA[ <int-ip:udp-outbound-channel-adapter id="udpOut"
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host="somehost"
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port="11111"
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multicast="false"
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check-length="true"
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acknowledge="true"
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ack-host="thishost"
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ack-port="22222"
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ack-timeout="10000"
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channel="exampleChannel" />]]></programlisting>
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An outbound channel adapter that adds length checking to the datagram packets and waits for an acknowledgment.
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<tip>
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Setting acknowledge to true implies the recipient of the packet can interpret the header added to the packet
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containing acknowledgment data (host and port). Most likely, the recipient will be a Spring Integration inbound
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channel adapter.
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</tip>
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<tip>
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When multicast is true, an additional attribute min-acks-for-success specifies
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how many acknowledgments must be received within the ack-timeout.
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</tip>
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</para>
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<para>
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For even more reliable networking, TCP can be used.
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</para>
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<para>
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<programlisting language="xml"><![CDATA[ <int-ip:udp-inbound-channel-adapter id="udpReceiver"
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channel="udpOutChannel"
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port="11111"
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receive-buffer-size="500"
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multicast="false"
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check-length="true" />]]></programlisting>
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A basic unicast inbound udp channel adapter.
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</para>
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<para>
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<programlisting language="xml"><![CDATA[ <int-ip:udp-inbound-channel-adapter id="udpReceiver"
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channel="udpOutChannel"
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port="11111"
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receive-buffer-size="500"
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multicast="true"
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multicast-address="225.6.7.8"
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check-length="true" />]]></programlisting>
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A basic multicast inbound udp channel adapter.
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</para>
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<para>
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By default, reverse DNS lookups are done on inbound packets to convert IP addresses to
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hostnames for use in message headers.
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In environments where DNS is not configured, this can cause delays.
|
|
This default behavior can be overridden by setting the <literal>lookup-host</literal>
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attribute to "false".
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</para>
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</section>
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<section id="connection-factories">
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<title>TCP Connection Factories</title>
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<para>
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For TCP, the configuration of the underlying connection is provided using a
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Connection Factory. Two types of connection factory are provided; a
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client connection factory and a server connection factory. Client connection
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factories are used to establish outgoing connections; Server connection factories
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listen for incoming connections.
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</para>
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<para>
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A client connection factory is used
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by an outbound channel adapter but a reference to a client connection factory
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can also be provided to an inbound channel adapter and that adapter will receive
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any incoming messages received on connections created by the outbound adapter.
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</para>
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<para>
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A server connection factory is used by an inbound channel adapter or gateway (in fact
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the connection factory will not function without one). A reference to a server
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connection factory can also be provided to an outbound adapter; that adapter
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can then be used to send replies to incoming messages to the same connection.
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<tip>
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<para>Reply messages will only be routed to the connection if the reply contains
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the header ip_connection_id that was inserted into the original message by
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the connection factory.</para></tip>
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<tip>
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<para>
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This is the extent of message correlation performed when sharing connection
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factories between inbound and outbound adapters. Such sharing allows for
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asynchronous two-way communication over TCP. Only payload information is
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transferred using TCP; therefore any message correlation must be performed
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by downstream components such as aggregators or other endpoints.
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For more information refer to <xref linkend="ip-correlation" />.
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</para>
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</tip>
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</para>
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<para>
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A maximum of one adapter of each type may be given a reference to a connection
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factory.
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</para>
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<para>
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Connection factories using <classname>java.net.Socket</classname> and
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<classname>java.nio.channel.SocketChannel</classname> are provided.
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</para>
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<para>
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<programlisting language="xml"><![CDATA[
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<int-ip:tcp-connection-factory id="server"
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type="server"
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port="1234"
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/>]]></programlisting>
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A simple server connection factory that uses <classname>java.net.Socket</classname>
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connections.
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</para>
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<para>
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<programlisting language="xml"><![CDATA[
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<int-ip:tcp-connection-factory id="server"
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type="server"
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port="1234"
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using-nio="true"
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/>]]></programlisting>
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A simple server connection factory that uses <classname>java.nio.channel.SocketChannel</classname>
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connections.
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</para>
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<para>
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<programlisting language="xml"><![CDATA[
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<int-ip:tcp-connection-factory id="client"
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type="client"
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host="localhost"
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port="1234"
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single-use="true"
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so-timeout="10000"
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/>]]></programlisting>
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A client connection factory that uses <classname>java.net.Socket</classname>
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connections and creates a new connection for each message.
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</para>
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<para>
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<programlisting language="xml"><![CDATA[
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<int-ip:tcp-connection-factory id="client"
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type="client"
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host="localhost"
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port="1234"
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single-use="true"
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so-timeout="10000"
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using-nio=true
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/>]]></programlisting>
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A client connection factory that uses <classname>java.nio.channel.Socket</classname>
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connections and creates a new connection for each message.
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</para>
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<para>
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TCP is a streaming protocol; this means that some structure has to be provided to data
|
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transported over TCP, so the receiver can demarcate the data into discrete messages.
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Connection factories are configured to use (de)serializers to convert between the message
|
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payload and the bits that are sent over TCP. This is accomplished by providing a
|
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deserializer and serializer for inbound and outbound messages respectively.
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A number of standard (de)serializers are provided.
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</para>
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<para>
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The <classname>ByteArrayCrlfSerializer</classname>,
|
|
converts a byte array to a stream of bytes followed by carriage
|
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return and linefeed characters (\r\n). This is the default (de)serializer and can be used with
|
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telnet as a client, for example.
|
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</para>
|
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<para>
|
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The <classname>ByteArrayStxEtxSerializer</classname>,
|
|
converts a byte array to a stream of bytes preceded by an STX (0x02) and
|
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followed by an ETX (0x03).
|
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</para>
|
|
<para>
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The <classname>ByteArrayLengthHeaderSerializer</classname>,
|
|
converts a byte array to a stream of bytes preceded by a binary
|
|
length in network byte order (big endian). This a very efficient deserializer
|
|
because it does not have to parse every byte looking for a termination
|
|
character sequence. It can also be used for payloads containing binary data;
|
|
the above serializers only support text in the payload. The default size of
|
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the length header is 4 bytes (Integer), allowing for messages up to 2**31-1
|
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bytes. However, the length header can be a single byte (unsigned) for
|
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messages up to 255 bytes, or an unsigned short (2 bytes) for messages up to
|
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2**16 bytes. If you need any other format for the header, you can subclass
|
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this class and provide implementations for the readHeader and writeHeader
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methods. The absolute maximum data size supported is 2**31-1 bytes.
|
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</para>
|
|
<para>
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The <classname>ByteArrayRawSerializer</classname>,
|
|
converts a byte array to a stream of bytes and adds no additional message
|
|
demarcation data; with this (de)serializer, the end of a message is indicated
|
|
by the client closing the socket in an orderly fashion. When using this serializer,
|
|
message reception will hang until the client closes the socket, or a timeout occurs;
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|
a timeout will NOT result in a message. When this serializer is being used, and the client
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is a Spring Integration application, the client must use a connection factory that is
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configured with single-use=true - this causes the adapter to close the socket after sending
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the message; the serializer will not, itself, close the connection. This serializer
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should only be used with connection factories used by channel adapters (not gateways), and the
|
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connection factories should be used by either an inbound or outbound adapter, and not both.
|
|
</para>
|
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<para>
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Each of these is a subclass of
|
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<classname>AbstractByteArraySerializer</classname> which implements both
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<classname>org.springframework.core.serializer.Serializer</classname> and
|
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<classname>org.springframework.core.serializer.Deserializer</classname>.
|
|
For backwards compatibility, connections using any subclass of
|
|
<classname>AbstractByteArraySerializer</classname> for serialization
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will also accept a String which will be converted to a byte array first.
|
|
Each of these (de)serializers converts an input stream containing the
|
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corresponding format to a byte array payload.
|
|
</para>
|
|
<para>
|
|
To avoid memory exhaustion due to a badly behaved client (one that does not adhere to
|
|
the protocol of the configured serializer), these serializers impose a maximum message
|
|
size. If the size is exceeded by an incoming message, an exception will be thrown.
|
|
The default maximum message size is 2048 bytes, and can be increased by setting the
|
|
<classname>maxMessageSize</classname> property. If you are using the default (de)serializer
|
|
and wish to increase the maximum message size, you must declare it as an explicit bean
|
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with the property set and configure the connection factory to use that bean.
|
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</para>
|
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<para>
|
|
The final standard serializer is
|
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<classname>org.springframework.core.serializer.DefaultSerializer</classname> which can be
|
|
used to convert Serializable objects using java serialization.
|
|
<classname>org.springframework.core.serializer.DefaultDeserializer</classname> is provided for
|
|
inbound deserialization of streams containing Serializable objects.
|
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</para>
|
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<para>
|
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To implement a custom (de)serializer pair, implement the
|
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<classname>org.springframework.core.serializer.Deserializer</classname> and
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<classname>org.springframework.core.serializer.Serializer</classname> interfaces.
|
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</para>
|
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<para>
|
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If you do not wish to use
|
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the default (de)serializer (<classname>ByteArrayCrLfSerializer</classname>), you must supply
|
|
<classname>serializer</classname> and
|
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<classname>deserializer</classname> attributes on the connection factory (example below).
|
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</para>
|
|
<para>
|
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<programlisting language="xml"><![CDATA[
|
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<bean id="javaSerializer"
|
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class="org.springframework.core.serializer.DefaultSerializer" />
|
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<bean id="javaDeserializer"
|
|
class="org.springframework.core.serializer.DefaultDeserializer" />
|
|
|
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<int-ip:tcp-connection-factory id="server"
|
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type="server"
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port="1234"
|
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deserializer="javaDeserializer"
|
|
serializer="javaSerializer"
|
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/>]]></programlisting>
|
|
A server connection factory that uses <classname>java.net.Socket</classname>
|
|
connections and uses Java serialization on the wire.
|
|
</para>
|
|
<para>
|
|
For full details of the attributes available on connection factories, see the
|
|
reference at the end of this section.
|
|
</para>
|
|
<para>
|
|
By default, reverse DNS lookups are done on inbound packets to convert IP addresses to
|
|
hostnames for use in message headers.
|
|
In environments where DNS is not configured, this can cause connection delays.
|
|
This default behavior can be overridden by setting the <literal>lookup-host</literal>
|
|
attribute to "false".
|
|
</para>
|
|
<para>
|
|
<note>
|
|
<title>TCP Caching Client Connection Factory</title>
|
|
<para>
|
|
As noted above, TCP sockets cam be 'single-use' (one request/response)
|
|
or shared. Shared sockets do not perform well with outbound gateways,
|
|
in high-volume environments,
|
|
because the socket can only process one request/response at a time.
|
|
</para>
|
|
<para>
|
|
To improve performance, users could use collaborating channel adapters
|
|
instead of gateways, but that requires application-level message
|
|
correlation. See <xref linkend="ip-correlation" />for more information.
|
|
</para>
|
|
<para>
|
|
Spring Integration 2.2 introduced a caching client connection factory,
|
|
where a pool of shared sockets is used, allowing a gateway to
|
|
process multiple concurrent requests with a pool of shared
|
|
connections.
|
|
</para>
|
|
</note>
|
|
</para>
|
|
<note>
|
|
<para>
|
|
It is possible to modify the creation of and/or attributes of sockets - see
|
|
<xref linkend="ssl-tls"/>. As is noted there, such modifications are possible whether
|
|
or not SSL is being used.
|
|
</para>
|
|
</note>
|
|
</section>
|
|
<section id="ip-interceptors">
|
|
<title>TCP Connection Interceptors</title>
|
|
<para>
|
|
Connection factories can be configured with a reference to a
|
|
<classname>TcpConnectionInterceptorFactoryChain</classname>. Interceptors can be used
|
|
to add behavior to connections, such as negotiation, security, and other setup.
|
|
No interceptors are currently provided by the framework but, for an example,
|
|
see the <classname>InterceptedSharedConnectionTests</classname> in the source
|
|
repository.
|
|
</para>
|
|
<para>
|
|
The <classname>HelloWorldInterceptor</classname> used in the test case works as follows:
|
|
</para>
|
|
<para>
|
|
When configured with a client connection factory,
|
|
when the first message is sent over a connection that is intercepted, the interceptor
|
|
sends 'Hello' over the connection, and expects to receive 'world!'. When that occurs,
|
|
the negotiation is complete and the original message is sent; further messages
|
|
that use the same connection are sent without any additional negotiation.
|
|
</para>
|
|
<para>
|
|
When configured with a server connection factory, the interceptor requires the first
|
|
message to be 'Hello' and, if it is, returns 'world!'. Otherwise it throws an exception causing
|
|
the connection to be closed.
|
|
</para>
|
|
<para>
|
|
All <classname>TcpConnection</classname> methods are intercepted.
|
|
Interceptor instances are created for each connection by an interceptor factory.
|
|
If an interceptor is stateful, the factory should create a new instance for each connection.
|
|
Interceptor
|
|
factories are added to the configuration of an interceptor factory chain, which is provided
|
|
to a connection factory using the <classname>interceptor-factory</classname> attribute.
|
|
Interceptors must implement the <classname>TcpConnectionInterceptor</classname> interface;
|
|
factories
|
|
must implement the <classname>TcpConnectionInterceptorFactory</classname> interface. A
|
|
convenience class <classname>AbstractTcpConnectionInterceptor</classname> is provided
|
|
with passthrough methods; by extending this class, you only need to implement those
|
|
methods you wish to intercept.
|
|
</para>
|
|
<para>
|
|
<programlisting language="xml"><![CDATA[<bean id="helloWorldInterceptorFactory"
|
|
class="org.springframework.integration.ip.tcp.connection.TcpConnectionInterceptorFactoryChain">
|
|
<property name="interceptors">
|
|
<array>
|
|
<bean class="org.springframework.integration.ip.tcp.connection.HelloWorldInterceptorFactory"/>
|
|
</array>
|
|
</property>
|
|
</bean>
|
|
|
|
<int-ip:tcp-connection-factory id="server"
|
|
type="server"
|
|
port="12345"
|
|
using-nio="true"
|
|
single-use="true"
|
|
interceptor-factory-chain="helloWorldInterceptorFactory"
|
|
/>
|
|
|
|
<int-ip:tcp-connection-factory id="client"
|
|
type="client"
|
|
host="localhost"
|
|
port="12345"
|
|
single-use="true"
|
|
so-timeout="100000"
|
|
using-nio="true"
|
|
interceptor-factory-chain="helloWorldInterceptorFactory"
|
|
/>]]></programlisting>
|
|
Configuring a connection interceptor factory chain.
|
|
</para>
|
|
</section>
|
|
<section id="tcp-adapters">
|
|
<title>TCP Adapters</title>
|
|
<para>
|
|
TCP inbound and outbound channel adapters that utilize the above connection
|
|
factories are provided. These adapters have attributes
|
|
<classname>connection-factory</classname> and <classname>channel</classname>.
|
|
The channel attribute specifies the channel on which messages arrive at an
|
|
outbound adapter and on which messages are placed by an inbound adapter.
|
|
The connection-factory attribute indicates which connection factory is to be used to
|
|
manage connections for the adapter. While both inbound and outbound adapters
|
|
can share a connection factory, server connection factories are always 'owned'
|
|
by an inbound adapter; client connection factories are always 'owned' by an
|
|
outbound adapter. One, and only one, adapter of each type may get a reference
|
|
to a connection factory.
|
|
</para>
|
|
<para>
|
|
<programlisting language="xml"><![CDATA[
|
|
<bean id="javaSerializer"
|
|
class="org.springframework.core.serializer.DefaultSerializer" />
|
|
<bean id="javaDeserializer"
|
|
class="org.springframework.core.serializer.DefaultDeserializer" />
|
|
|
|
<int-ip:tcp-connection-factory id="server"
|
|
type="server"
|
|
port="1234"
|
|
deserializer="javaDeserializer"
|
|
serializer="javaSerializer"
|
|
using-nio="true"
|
|
single-use="true"
|
|
/>
|
|
|
|
<int-ip:tcp-connection-factory id="client"
|
|
type="client"
|
|
host="localhost"
|
|
port="#{server.port}"
|
|
single-use="true"
|
|
so-timeout="10000"
|
|
deserializer="javaDeserializer"
|
|
serializer="javaSerializer"
|
|
/>
|
|
|
|
<int:channel id="input" />
|
|
|
|
<int:channel id="replies">
|
|
<int:queue/>
|
|
</int:channel>
|
|
|
|
<int-ip:tcp-outbound-channel-adapter id="outboundClient"
|
|
channel="input"
|
|
connection-factory="client"/>
|
|
|
|
<int-ip:tcp-inbound-channel-adapter id="inboundClient"
|
|
channel="replies"
|
|
connection-factory="client"/>
|
|
|
|
<int-ip:tcp-inbound-channel-adapter id="inboundServer"
|
|
channel="loop"
|
|
connection-factory="server"/>
|
|
|
|
<int-ip:tcp-outbound-channel-adapter id="outboundServer"
|
|
channel="loop"
|
|
connection-factory="server"/>
|
|
|
|
<int:channel id="loop" />]]></programlisting>
|
|
In this configuration, messages arriving in channel 'input'
|
|
are serialized over connections created by 'client' received
|
|
at the server and placed on channel 'loop'. Since 'loop' is
|
|
the input channel for 'outboundServer' the message is simply
|
|
looped back over the same connection and received by
|
|
'inboundClient' and deposited in channel 'replies'. Java
|
|
serialization is used on the wire.
|
|
</para>
|
|
<para>
|
|
Normally, inbound adapters use a type="server" connection
|
|
factory, which listens for incoming connection requests.
|
|
In some cases, it is desireable to establish the connection
|
|
in reverse, whereby the inbound adapter connects to an
|
|
external server and then waits for inbound messages on that
|
|
connection.
|
|
</para>
|
|
<para>
|
|
This topology is supported by using <emphasis>client-mode="true"</emphasis>
|
|
on the inbound adapter. In this case, the connection factory must
|
|
be of type 'client' and must have <emphasis>single-use</emphasis>
|
|
set to false.
|
|
</para>
|
|
<para>
|
|
Two additional attributes are used to support this mechanism:
|
|
<emphasis>retry-interval</emphasis> specifies (in milliseconds)
|
|
how often the framework will attempt to reconnect after a
|
|
connection failure. <emphasis>scheduler</emphasis> is used to
|
|
supply a <classname>TaskScheduler</classname> used to
|
|
schedule the connection attempts, and to test that the connection is
|
|
still active.
|
|
</para>
|
|
<para>
|
|
For an outbound adapter, the connection is normally established
|
|
when the first message is sent. <emphasis>client-mode="true"</emphasis>
|
|
on an outbound adapter will cause the connection to be established
|
|
when the adapter is started. Adapters are automatically started
|
|
by default. Again, the connection factory must be of type client
|
|
and have <emphasis>single-use</emphasis> set to false and
|
|
<emphasis>retry-interval</emphasis> and
|
|
<emphasis>scheduler</emphasis> are also supported. If a connection
|
|
fails, it will be re-established either by the scheduler or
|
|
when the next message is sent.
|
|
</para>
|
|
<para>
|
|
For both inbound and outbound,
|
|
if the adapter is started, you may force the adapter to establish
|
|
a connection by sending a <control-bus /> command:
|
|
<classname>@adapter_id.retryConnection()</classname> and examine the
|
|
current state with <classname>@adapter_id.isConnected()</classname>.
|
|
</para>
|
|
</section>
|
|
<section id="tcp-gateways">
|
|
<title>TCP Gateways</title>
|
|
<para>
|
|
The inbound TCP gateway <classname>TcpInboundGateway</classname>
|
|
and outbound TCP gateway <classname>TcpOutboundGateway</classname>
|
|
use a server and client connection factory respectively. Each connection
|
|
can process a single request/response at a time.
|
|
</para>
|
|
<para>
|
|
The inbound gateway, after constructing a message with the incoming payload and sending
|
|
it to the requestChannel, waits for a response and sends the payload
|
|
from the response message by writing it to the connection.
|
|
</para>
|
|
<para>
|
|
<note>
|
|
<para>
|
|
For the inbound gateway, care must be taken to retain, or populate, the
|
|
<emphasis>ip_connnection_id</emphasis> header because it is used to
|
|
correlate the message to a connection. Messages that originate at the
|
|
gateway will automatically have the header set. If the reply is
|
|
constructed as a new message, you will need to set the header. The
|
|
header value can be captured from the incoming message.
|
|
</para>
|
|
</note>
|
|
</para>
|
|
<para>
|
|
As with inbound adapters, inbound gateways normally use a
|
|
type="server" connection
|
|
factory, which listens for incoming connection requests.
|
|
In some cases, it is desireable to establish the connection
|
|
in reverse, whereby the inbound gateway connects to an
|
|
external server and then waits for, and replies to, inbound
|
|
messages on that connection.
|
|
</para>
|
|
<para>
|
|
This topology is supported by using <emphasis>client-mode="true"</emphasis>
|
|
on the inbound gateway. In this case, the connection factory must
|
|
be of type 'client' and must have <emphasis>single-use</emphasis>
|
|
set to false.
|
|
</para>
|
|
<para>
|
|
Two additional attributes are used to support this mechanism:
|
|
<emphasis>retry-interval</emphasis> specifies (in milliseconds)
|
|
how often the framework will attempt to reconnect after a
|
|
connection failure. <emphasis>scheduler</emphasis> is used to
|
|
supply a <classname>TaskScheduler</classname> used to
|
|
schedule the connection attempts, and to test that the connection is
|
|
still active.
|
|
</para>
|
|
<para>
|
|
If the gateway is started, you may force the gateway to establish
|
|
a connection by sending a <control-bus /> command:
|
|
<classname>@adapter_id.retryConnection()</classname> and examine the
|
|
current state with <classname>@adapter_id.isConnected()</classname>.
|
|
</para>
|
|
<para>
|
|
The outbound gateway, after sending a message over the connection, waits for a response and
|
|
constructs a response message and puts in on the reply channel.
|
|
Communications over the connections are single-threaded. Users should be aware that only one
|
|
message can be handled at a time and, if another thread attempts to send
|
|
a message before the current response has been received, it will block until
|
|
any previous requests are complete (or time out).
|
|
If, however, the client connection factory is configured for single-use connections
|
|
each new request gets its own connection and is processed immediately.
|
|
</para>
|
|
<para>
|
|
<programlisting language="xml"><![CDATA[
|
|
<int-ip:tcp-inbound-gateway id="inGateway"
|
|
request-channel="tcpChannel"
|
|
reply-channel="replyChannel"
|
|
connection-factory="cfServer"
|
|
reply-timeout="10000"
|
|
/>]]></programlisting>
|
|
A simple inbound TCP gateway; if a connection factory configured with the default
|
|
(de)serializer is used, messages will be \r\n delimited data and the gateway can be
|
|
used by a simple client such as telnet.
|
|
</para>
|
|
<para>
|
|
<programlisting language="xml"><![CDATA[
|
|
<int-ip:tcp-outbound-gateway id="outGateway"
|
|
request-channel="tcpChannel"
|
|
reply-channel="replyChannel"
|
|
connection-factory="cfClient"
|
|
request-timeout="10000"
|
|
reply-timeout="10000"
|
|
/>]]></programlisting>
|
|
A simple outbound TCP gateway.
|
|
</para>
|
|
</section>
|
|
<section id="ip-correlation">
|
|
<title>TCP Message Correlation</title>
|
|
<section>
|
|
<title>Overview</title>
|
|
<para>
|
|
One goal of the IP Endpoints is to provide communication with systems other
|
|
than another Spring Integration application. For this reason, only
|
|
message payloads are sent
|
|
and received. No message correlation is provided by the framework,
|
|
except when using the gateways, or collaborating channel adapters on the
|
|
server side. In the paragraphs below we discuss the various
|
|
correlation techniques available to applications. In most cases, this
|
|
requires specific application-level correlation of messages, even when
|
|
message payloads contain some natural correlation data (such as an order
|
|
number).
|
|
</para>
|
|
</section>
|
|
<section>
|
|
<title>Gateways</title>
|
|
<para>
|
|
The gateways will automatically correlate messages. However, an outbound
|
|
gateway should only be used for relatively low-volume use.
|
|
When the connection factory is configured for a single shared connection
|
|
to be used for all message pairs ('single-use="false"'),
|
|
only one message can be processed at a time.
|
|
A new message will have to wait until the reply to the previous message has
|
|
been received.
|
|
When a connection factory is configured for each new message to use a new connection
|
|
('single-use="true"'), the above restriction does not apply.
|
|
While this may give higher throughput
|
|
than a shared connection environment, it comes with the overhead of opening
|
|
and closing a new connection for each message pair.
|
|
</para>
|
|
<para>
|
|
Therefore, for high-volume messages, consider using a collaborating pair of
|
|
channel adapters. However, you will need to provide collaboration logic.
|
|
</para>
|
|
<para>
|
|
Another solution, introduced in Spring Integration 2.2, is to use a
|
|
<classname>CachingClientConnectionFactory</classname>, which allows
|
|
the use of a pool of shared connections.
|
|
</para>
|
|
</section>
|
|
<section>
|
|
<title>Collaborating Outbound and Inbound Channel Adapters</title>
|
|
<para>
|
|
To achieve high-volume throughput (avoiding the pitfalls of using gateways
|
|
as mentioned above) you may consider configuring a pair of collaborating
|
|
outbound and inbound channel adapters.
|
|
Collaborating adapters can also be used (server-side or client-side) for
|
|
totally asynchronous communication (rather than with request/reply semantics).
|
|
On the server side, message
|
|
correlation is automatically handled by the adapters because the inbound
|
|
adapter adds a header allowing the outbound adapter to determine which
|
|
connection to use to send the reply message.
|
|
</para>
|
|
<para>
|
|
<note>
|
|
<para>
|
|
On the server side, care must be taken to populate the
|
|
<emphasis>ip_connnection_id</emphasis> header because it is used to
|
|
correlate the message to a connection. Messages that originate at the
|
|
inbound adapter will automatically have the header set. If you wish to
|
|
construct other messages to send, you will need to set the header. The
|
|
header value can be captured from an incoming message.
|
|
</para>
|
|
</note>
|
|
</para>
|
|
<para>
|
|
On the client side,
|
|
the application will have to provide its own correlation logic, if needed.
|
|
This can be done in a number of ways.
|
|
</para>
|
|
<para>
|
|
If the message payload has some natural correlation data, such as a
|
|
transaction id or an order number, AND there is no need to retain any
|
|
information (such as a reply channel header) from the original outbound message,
|
|
the correlation is simple and would done at the application level in any case.
|
|
</para>
|
|
<para>
|
|
If the message payload has some natural correlation data, such as a
|
|
transaction id or an order number, but there is a need to retain some
|
|
information (such as a reply channel header) from the original outbound message,
|
|
you may need to retain a copy of the original outbound message (perhaps
|
|
by using a publish-subscribe channel) and use an aggregator to recombine
|
|
the necessary data.
|
|
</para>
|
|
<para>
|
|
For either of the previous two paragraphs, if the payload has no natural
|
|
correlation data, you may need to provide a transformer upstream of the
|
|
outbound channel adapter to enhance the payload with such data. Such a
|
|
transformer may transform the original payload to a new object containing
|
|
both the original payload and some subset of the message headers. Of course,
|
|
live objects (such as reply channels) from the headers can not be
|
|
included in the transformed payload.
|
|
</para>
|
|
<para>
|
|
If such a strategy is chosen you will need to ensure the connection factory
|
|
has an appropriate serializer/deserializer pair to handle such a payload,
|
|
such as the <classname>DefaultSerializer/Deserializer</classname> which use java
|
|
serialization, or a custom serializer and deserializer.
|
|
The <classname>ByteArray*Serializer</classname> options
|
|
mentioned in <xref linkend="connection-factories" />,
|
|
including the default <classname>ByteArrayCrLfSerializer</classname>,
|
|
do not support such payloads,
|
|
unless the transformed payload is a <classname>String</classname> or
|
|
<classname>byte[]</classname>,
|
|
</para>
|
|
<para>
|
|
<note>
|
|
<para>
|
|
Before the 2.2 release,
|
|
when a <emphasis>client</emphasis> connection factory was used by
|
|
collaborating channel
|
|
adapters, the <emphasis>so-timeout</emphasis> attribute defaulted
|
|
to the default reply timeout (10 seconds). This meant that if
|
|
no data were received by the inbound adapter for this period of
|
|
time, the socket was closed.
|
|
</para>
|
|
<para>
|
|
This default behavior was not appropriate in a truly asynchronous
|
|
environment, so it now defaults to an infinite timeout.
|
|
You can reinstate the previous default behavior by setting the
|
|
<emphasis>so-timeout</emphasis> attribute on the client connection
|
|
factory to 10000 milliseconds.
|
|
</para>
|
|
</note>
|
|
</para>
|
|
</section>
|
|
</section>
|
|
<section id="note_nio">
|
|
<title>A Note About NIO</title>
|
|
<para>
|
|
Using NIO (see <classname>using-nio</classname> in
|
|
<xref linkend="ip-endpoint-reference" />)
|
|
avoids dedicating a thread to read from each socket. For a small number
|
|
of sockets, you will likely find that <emphasis>not</emphasis> using NIO,
|
|
together with an async handoff (e.g. to a <classname>QueueChannel</classname>),
|
|
will perform as well as, or better than, using NIO.
|
|
</para>
|
|
<para>
|
|
Consider using NIO when handling a large number of connections. However, the use
|
|
of NIO has some other ramifications. A pool of threads (in the task executor) is
|
|
shared across all the sockets; each incoming message is assembled and sent to the
|
|
configured channel as a separate unit of work on a thread selected from that pool.
|
|
Two sequential
|
|
messages arriving on the <emphasis>same</emphasis> socket <emphasis>might</emphasis>
|
|
be processed by different threads. This means that the order in which the messages are
|
|
sent to the channel is indeterminate; the strict ordering of the messages arriving on the
|
|
socket is not maintained.
|
|
</para>
|
|
<para>
|
|
For some applications, this is not an issue; for others it is. If strict ordering
|
|
is required, consider setting <classname>using-nio</classname> to false
|
|
and using async handoff.
|
|
</para>
|
|
<para>
|
|
Alternatively, you may choose to insert a resequencer downstream of the inbound endpoint to
|
|
return the messages to their proper sequence. Set <emphasis>apply-sequence</emphasis>
|
|
to true on the connection factory, and messages arriving on a TCP connection will
|
|
have <emphasis>sequenceNumber</emphasis> and <emphasis>correlationId</emphasis> headers
|
|
set. The resequencer uses these headers to return the messages to their proper
|
|
sequence.
|
|
</para>
|
|
<para><emphasis>Pool Size</emphasis></para>
|
|
<para>
|
|
When using NIO, it is important to understand how threads are used, in order set the pool-size
|
|
appropriately. One thread from the pool is used to handle all socket events (e.g. data is
|
|
ready to be read). This thread is not available for other tasks. When data are ready to be
|
|
read, this thread dispatches the actual I/O to another thread from the pool, which reads
|
|
from the channel and writes the data to a temporary buffer; if this read is the start of
|
|
a new message, a third thread is used to read from that buffer to assemble the data into
|
|
a message.
|
|
</para>
|
|
<para>
|
|
If there is not enough room in the temporary buffer to receive the newly read data, the
|
|
reader thread will block until the assembler thread consumes some data. If the pool is
|
|
exhausted, this will cause a deadlock, until another thread becomes available. The temporary
|
|
buffer is currently 1024 bytes. In the simplest case, with one connection, and data greater
|
|
than 1024 bytes, a pool-size of 2 will cause this deadlock to occur because a thread will
|
|
never be made available.
|
|
</para>
|
|
<para>
|
|
For this reason, when using NIO, the pool-size should be set to a minimum of 3. This does not
|
|
mean you have to reserve 2 threads for each socket because, aside from the selector thread,
|
|
the threads in the pool are shared across all the connections. The actual pool-size needed
|
|
will depend on a number of factors including the number of active connections, how
|
|
much utilization there is on those connections, and how long message processing takes when
|
|
a new message is received.
|
|
</para>
|
|
</section>
|
|
<section id="ssl-tls">
|
|
<title>SSL/TLS Support</title>
|
|
<section>
|
|
<title>Overview</title>
|
|
<para>
|
|
Secure Sockets Layer/Transport Layer Security is supported. When using NIO, the JDK 5+
|
|
<classname>SSLEngine</classname> feature is used to handle handshaking after the
|
|
connection is established. When not using NIO, standard
|
|
<classname>SSLSocketFactory</classname> and <classname>SSLServerSocketFactory</classname> objects are
|
|
used to create connections. A number of strategy interfaces are provided to allow
|
|
significant customization; default implementations of these interfaces provide for
|
|
the simplest way to get started with secure communications.
|
|
</para>
|
|
</section>
|
|
<section>
|
|
<title>Getting Started</title>
|
|
<para>
|
|
Regardless of whether NIO is being used, you need to configure the
|
|
<classname>ssl-context-support</classname> attribute on the connection factory.
|
|
This attribute references a <bean/> definition that describes the location
|
|
and passwords for the required key stores.
|
|
</para>
|
|
<para>
|
|
SSL/TLS peers require two keystores each; a keystore containing private/public key
|
|
pairs identifying the peer; a truststore, containing the public keys for peers that
|
|
are trusted. See the documentation for the <classname>keytool</classname> utility
|
|
provided with the JDK. The essential steps are
|
|
</para>
|
|
<para>
|
|
<orderedlist>
|
|
<listitem><para>Create a new key pair and store in a keystore.</para></listitem>
|
|
<listitem><para>Export the public key.</para></listitem>
|
|
<listitem><para>Import the public key into the peer's truststore.</para></listitem>
|
|
</orderedlist>
|
|
</para>
|
|
<para>
|
|
Repeat for the other peer.
|
|
</para>
|
|
<note>
|
|
<para>
|
|
It is common in test cases to use the same key stores on both peers, but this should
|
|
be avoided for production.
|
|
</para>
|
|
</note>
|
|
<para>
|
|
After establishing the key stores, the next step is to indicate their locations to the
|
|
<classname>TcpSSLContextSupport</classname> bean, and provide a reference to that bean
|
|
to the connection factory.
|
|
</para>
|
|
<para><programlisting language="xml"><![CDATA[ <bean id="sslContextSupport"
|
|
class="o.sf.integration.ip.tcp.connection.support.DefaultTcpSSLContextSupport">
|
|
<constructor-arg value="client.ks"/>
|
|
<constructor-arg value="client.truststore.ks"/>
|
|
<constructor-arg value="secret"/>
|
|
<constructor-arg value="secret"/>
|
|
</bean>
|
|
|
|
<ip:tcp-connection-factory id="clientFactory"
|
|
type="client"
|
|
host="localhost"
|
|
port="1234"
|
|
ssl-context-support="sslContextSupport"]]></programlisting>
|
|
</para>
|
|
<para>
|
|
The <classname>DefaulTcpSSLContextSupport</classname> class also has an optional
|
|
'protocol' property, which can be 'SSL' or 'TLS' (default).
|
|
</para>
|
|
<para>
|
|
The keystore file names (first two constructor arguments) use the Spring <classname>Resource</classname>
|
|
abstraction; by default the files will be located on the classpath, but this can be overridden by using
|
|
the <classname>file:</classname> prefix, to find the files on the filesystem instead.
|
|
</para>
|
|
</section>
|
|
<section>
|
|
<title>Advanced Techniques</title>
|
|
<para>
|
|
In many cases, the configuration described above is all that is needed to enable secure
|
|
communication over TCP/IP. However, a number of strategy interfaces are provided to
|
|
allow customization and modification of socket factories and sockets.
|
|
</para>
|
|
<para>
|
|
<itemizedlist>
|
|
<listitem><para><classname>TcpSSLContextSupport</classname></para></listitem>
|
|
<listitem><para><classname>TcpSocketFactorySupport</classname></para></listitem>
|
|
<listitem><para><classname>TcpSocketSupport</classname></para></listitem>
|
|
</itemizedlist>
|
|
</para>
|
|
<para><programlisting language="java"><![CDATA[public interface TcpSSLContextSupport {
|
|
|
|
SSLContext getSSLContext() throws Exception;
|
|
|
|
}]]></programlisting>
|
|
</para>
|
|
<para>
|
|
Implementations of this interface are responsible for creating an SSLContext.
|
|
The sole implementation provided by the framework is the
|
|
<classname>DefaultTcpSSLContextSupport</classname> described above. If you require
|
|
different behavior, implement this interface and provide the connection factory with
|
|
a reference to a bean of your class' implementation.
|
|
</para>
|
|
<para><programlisting language="java"><![CDATA[public interface TcpSocketFactorySupport {
|
|
|
|
ServerSocketFactory getServerSocketFactory();
|
|
|
|
SocketFactory getSocketFactory();
|
|
|
|
}
|
|
]]></programlisting>
|
|
</para>
|
|
<para>
|
|
Implementations of this interface are responsible for obtaining references to
|
|
<classname>ServerSocketFactory</classname> and <classname>SocketFactory</classname>.
|
|
Two implementations are provided; the first is <classname>DefaultTcpNetSocketFactorySupport</classname>
|
|
for non-SSL sockets (when no 'ssl-context-support' attribute is defined); this simply
|
|
uses the JDK's default factories. The second implementation is
|
|
<classname>DefaultTcpNetSSLSocketFactorySupport</classname>; this is used, by default,
|
|
when an 'ssl-context-support' attribute is defined; it uses the <classname>SSLContext</classname>
|
|
created by that bean to create the socket factories.
|
|
</para>
|
|
<note>
|
|
<para>
|
|
This interface only applies if <classname>using-nio</classname> is "false"; socket factories
|
|
are not used by NIO.
|
|
</para>
|
|
</note>
|
|
<para><programlisting language="java"><![CDATA[public interface TcpSocketSupport {
|
|
|
|
void postProcessServerSocket(ServerSocket serverSocket);
|
|
|
|
void postProcessSocket(Socket socket);
|
|
|
|
]]></programlisting>
|
|
</para>
|
|
<para>
|
|
Implementations of this interface can modify sockets after they are created, and after
|
|
all configured attributes have been applied, but before the sockets are used. This applies
|
|
whether or not NIO is being used. For example,
|
|
you could use an implementation of this interface to modify the supported cipher suites on
|
|
an SSL socket, or you could add a listener that gets notified after SSL handshaking is
|
|
complete. The sole implementation provided by the framework is the
|
|
<classname>DefaultTcpSocketSupport</classname> which does not modify the sockets in
|
|
any way
|
|
</para>
|
|
<para>
|
|
To supply your own implementation of <classname>TcpSocketFactorySupport</classname> or
|
|
<classname>TcpSocketSupport</classname>, provide the connection factory with references to
|
|
beans of your custom type using the <classname>socket-factory-support</classname> and
|
|
<classname>socket-support</classname> attributes, respectively.
|
|
</para>
|
|
</section>
|
|
</section>
|
|
<section id="ip-endpoint-reference">
|
|
<title>IP Configuration Attributes</title>
|
|
<para>
|
|
<table id="connection-factory-attributes">
|
|
<title>Connection Factory Attributes</title>
|
|
<tgroup cols="5">
|
|
<colspec align="left" />
|
|
<colspec colnum="1" colname="col1" colwidth="1*"/>
|
|
<colspec colnum="2" colname="col2" colwidth="0.4*" align="center"/>
|
|
<colspec colnum="3" colname="col3" colwidth="0.4*" align="center"/>
|
|
<colspec colnum="4" colname="col4" colwidth="1*"/>
|
|
<colspec colnum="5" colname="col5" colwidth="2*"/>
|
|
<thead>
|
|
<row>
|
|
<entry align="center">Attribute Name</entry>
|
|
<entry align="center">Client?</entry>
|
|
<entry align="center">Server?</entry>
|
|
<entry align="center">Allowed Values</entry>
|
|
<entry align="center">Attribute Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry>type</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry>client, server</entry>
|
|
<entry>Determines whether the connection factory is a client or server.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>host</entry>
|
|
<entry>Y</entry>
|
|
<entry>N</entry>
|
|
<entry></entry>
|
|
<entry>The host name or ip address of the destination.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>port</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>The port.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>serializer</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>An implementation of <classname>Serializer</classname> used to serialize
|
|
the payload. Defaults to <classname>ByteArrayCrLfSerializer</classname></entry>
|
|
</row>
|
|
<row>
|
|
<entry>deserializer</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>An implementation of <classname>Deserializer</classname> used to deserialize
|
|
the payload. Defaults to <classname>ByteArrayCrLfSerializer</classname></entry>
|
|
</row>
|
|
<row>
|
|
<entry>using-nio</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry>true, false</entry>
|
|
<entry>Whether or not connection uses NIO. Refer to the java.nio
|
|
package for more information.
|
|
See <xref linkend="note_nio" />.
|
|
Default false.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>using-direct-buffers</entry>
|
|
<entry>Y</entry>
|
|
<entry>N</entry>
|
|
<entry>true, false</entry>
|
|
<entry>When using NIO, whether or not the connection uses direct buffers.
|
|
Refer to <classname>java.nio.ByteBuffer</classname> documentation for
|
|
more information. Must be false if using-nio is false. </entry>
|
|
</row>
|
|
<row>
|
|
<entry>apply-sequence</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry>true, false</entry>
|
|
<entry>When using NIO, it may be necessary to resequence messages. When this
|
|
attribute is set to true, <emphasis>correlationId</emphasis> and
|
|
<emphasis>sequenceNumber</emphasis> headers will be added to
|
|
received messages.
|
|
See <xref linkend="note_nio" />.
|
|
Default false.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-timeout</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>Defaults to 0 (infinity), except for
|
|
server connection factories with single-use="true".
|
|
In that case, it
|
|
defaults to the default reply timeout (10 seconds).
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-send-buffer-size</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>See <classname>java.net.Socket. setSendBufferSize()</classname>.
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-receive-buffer- size</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>See <classname>java.net.Socket. setReceiveBufferSize()</classname>.
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-keep-alive</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry>true, false</entry>
|
|
<entry>See <classname>java.net.Socket. setKeepAlive()</classname>.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-linger</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>Sets linger to true with supplied value.
|
|
See <classname>java.net.Socket. setSoLinger()</classname>.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-tcp-no-delay</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry>true, false</entry>
|
|
<entry>See <classname>java.net.Socket. setTcpNoDelay()</classname>.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-traffic-class</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>See <classname>java.net.Socket. setTrafficClass()</classname>.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>local-address</entry>
|
|
<entry>N</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>On a multi-homed system, specifies an IP address
|
|
for the interface to which the socket will be bound.
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>task-executor</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Specifies a specific Executor to be used for socket handling. If not supplied, an internal
|
|
pooled executor will be used. Needed on some platforms that require the use of specific
|
|
task executors such as a WorkManagerTaskExecutor. See pool-size for thread
|
|
requirements, depending on other options.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>single-use</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry>true, false</entry>
|
|
<entry>Specifies whether a connection can be used for multiple messages.
|
|
If true, a new connection will be used for each message.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>pool-size</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>Specifies the concurrency. For tcp, not using nio, specifies the
|
|
number of concurrent connections supported by the adapter. For tcp,
|
|
using nio, it should be set to a minimum of 3; see 'Pool Size' in
|
|
<xref linkend="note_nio" />.
|
|
It only applies in this sense if task-executor is not configured.
|
|
However, pool-size is also used for the server socket backlog,
|
|
regardless of whether an external task executor is used. Defaults to 5.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>lookup-host</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry>true, false</entry>
|
|
<entry>
|
|
Specifies whether reverse lookups are done on IP addresses to convert to host names
|
|
for use in message headers. If false, the IP address is used instead. Defaults to true.
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>interceptor-factory-chain</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>See <xref linkend="ip-interceptors"/> </entry>
|
|
</row>
|
|
<row>
|
|
<entry>ssl-context-support</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>See <xref linkend="ssl-tls"/> </entry>
|
|
</row>
|
|
<row>
|
|
<entry>socket-factory-support</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>See <xref linkend="ssl-tls"/> </entry>
|
|
</row>
|
|
<row>
|
|
<entry>socket-support</entry>
|
|
<entry>Y</entry>
|
|
<entry>Y</entry>
|
|
<entry></entry>
|
|
<entry>See <xref linkend="ssl-tls"/> </entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
<table id="ip-ib-adapter-attributes">
|
|
<title>UDP Inbound Channel Adapter Attributes</title>
|
|
<tgroup cols="3">
|
|
<colspec align="left" />
|
|
<colspec colnum="1" colname="col1" colwidth="1*"/>
|
|
<colspec colnum="2" colname="col4" colwidth="1*"/>
|
|
<colspec colnum="3" colname="col5" colwidth="2*"/>
|
|
<thead>
|
|
<row>
|
|
<entry align="center">Attribute Name</entry>
|
|
<entry align="center">Allowed Values</entry>
|
|
<entry align="center">Attribute Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry>port</entry>
|
|
<entry></entry>
|
|
<entry>The port on which the adapter listens.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>multicast</entry>
|
|
<entry>true, false</entry>
|
|
<entry>Whether or not the udp adapter uses multicast.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>multicast-address</entry>
|
|
<entry></entry>
|
|
<entry>When multicast is true, the multicast address to which the adapter
|
|
joins.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>pool-size</entry>
|
|
<entry></entry>
|
|
<entry>Specifies the concurrency. Specifies how many packets can
|
|
be handled concurrently.
|
|
It only applies if task-executor is not configured.
|
|
Defaults to 5.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>task-executor</entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Specifies a specific Executor to be used for socket handling. If not supplied, an internal
|
|
pooled executor will be used. Needed on some platforms that require the use of specific
|
|
task executors such as a WorkManagerTaskExecutor. See pool-size for thread
|
|
requirements.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>receive-buffer-size</entry>
|
|
<entry></entry>
|
|
<entry>The size of the buffer used to receive DatagramPackets.
|
|
Usually set to the MTU size. If a smaller buffer is used than the
|
|
size of the sent packet, truncation can occur. This can be detected
|
|
by means of the check-length attribute..</entry>
|
|
</row>
|
|
<row>
|
|
<entry>check-length</entry>
|
|
<entry>true, false</entry>
|
|
<entry>Whether or not a udp adapter expects a data length field in the
|
|
packet received. Used to detect packet truncation.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-timeout</entry>
|
|
<entry></entry>
|
|
<entry>See <classname>java.net.DatagramSocket</classname>
|
|
setSoTimeout() methods for more information.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-send-buffer-size</entry>
|
|
<entry></entry>
|
|
<entry>Used for udp acknowledgment packets. See <classname>java.net.DatagramSocket</classname>
|
|
setSendBufferSize() methods for more information.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-receive-buffer- size</entry>
|
|
<entry></entry>
|
|
<entry>See <classname>java.net.DatagramSocket</classname>
|
|
setReceiveBufferSize() for more information.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>local-address</entry>
|
|
<entry></entry>
|
|
<entry>On a multi-homed system, specifies an IP address
|
|
for the interface to which the socket will be bound.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>error-channel</entry>
|
|
<entry></entry>
|
|
<entry>If an Exception is thrown by a downstream
|
|
component, the MessagingException message containing the exception
|
|
and failed message is sent to this channel.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>lookup-host</entry>
|
|
<entry>true, false</entry>
|
|
<entry>
|
|
Specifies whether reverse lookups are done on IP addresses to convert to host names
|
|
for use in message headers. If false, the IP address is used instead. Defaults to true.
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
<table id="ip-ob-adapter-attributes">
|
|
<title>UDP Outbound Channel Adapter Attributes</title>
|
|
<tgroup cols="3">
|
|
<colspec align="left" />
|
|
<colspec colnum="1" colname="col1" colwidth="1*"/>
|
|
<colspec colnum="2" colname="col4" colwidth="1*"/>
|
|
<colspec colnum="3" colname="col5" colwidth="2*"/>
|
|
<thead>
|
|
<row>
|
|
<entry align="center">Attribute Name</entry>
|
|
<entry align="center">Allowed Values</entry>
|
|
<entry align="center">Attribute Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry>host</entry>
|
|
<entry></entry>
|
|
<entry>The host name or ip address of the destination. For multicast udp
|
|
adapters, the multicast address.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>port</entry>
|
|
<entry></entry>
|
|
<entry>The port on the destination.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>multicast</entry>
|
|
<entry>true, false</entry>
|
|
<entry>Whether or not the udp adapter uses multicast.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>acknowledge</entry>
|
|
<entry>true, false</entry>
|
|
<entry>Whether or not a udp adapter requires an acknowledgment from the destination.
|
|
when enabled, requires setting the following 4 attributes.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>ack-host</entry>
|
|
<entry></entry>
|
|
<entry>When acknowledge is true, indicates the host or ip address to which the
|
|
acknowledgment should be sent. Usually the current host, but may be
|
|
different, for example when Network Address Transaction (NAT) is
|
|
being used.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>ack-port</entry>
|
|
<entry></entry>
|
|
<entry>When acknowledge is true, indicates the port to which the
|
|
acknowledgment should be sent. The adapter listens on this port for
|
|
acknowledgments.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>ack-timeout</entry>
|
|
<entry></entry>
|
|
<entry>When acknowledge is true, indicates the time in milliseconds that the
|
|
adapter will wait for an acknowledgment. If an acknowledgment is not
|
|
received in time, the adapter will throw an exception.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>min-acks-for- success</entry>
|
|
<entry></entry>
|
|
<entry>Defaults to 1. For multicast adapters, you can set this to a larger
|
|
value, requiring acknowledgments from multiple destinations.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>check-length</entry>
|
|
<entry>true, false</entry>
|
|
<entry>Whether or not a udp adapter includes a data length field in the
|
|
packet sent to the destination.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>time-to-live</entry>
|
|
<entry></entry>
|
|
<entry>For multicast adapters, specifies the time to live attribute for
|
|
the <classname>MulticastSocket</classname>; controls the scope
|
|
of the multicasts. Refer to the Java API
|
|
documentation for more information.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-timeout</entry>
|
|
<entry></entry>
|
|
<entry>See <classname>java.net.DatagramSocket</classname>
|
|
setSoTimeout() methods for more information.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-send-buffer-size</entry>
|
|
<entry></entry>
|
|
<entry>See <classname>java.net.DatagramSocket</classname>
|
|
setSendBufferSize() methods for more information.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>so-receive-buffer- size</entry>
|
|
<entry></entry>
|
|
<entry>Used for udp acknowledgment packets. See <classname>java.net.DatagramSocket</classname>
|
|
setReceiveBufferSize() methods for more information.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>local-address</entry>
|
|
<entry></entry>
|
|
<entry>On a multi-homed system, for the UDP adapter, specifies an IP address
|
|
for the interface to which the socket will be bound for reply messages.
|
|
For a multicast adapter it is also used to determine which interface
|
|
the multicast packets will be sent over.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>task-executor</entry>
|
|
<entry></entry>
|
|
<entry>
|
|
Specifies a specific Executor to be used for acknowledgment handling. If not supplied, an internal
|
|
single threaded executor will be used. Needed on some platforms that require the use of specific
|
|
task executors such as a WorkManagerTaskExecutor. One thread will be dedicated to handling
|
|
acknowledgments (if the acknowledge option is true).</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
<table id="tcp-ib-adapter-attributes">
|
|
<title>TCP Inbound Channel Adapter Attributes</title>
|
|
<tgroup cols="3">
|
|
<colspec align="left" />
|
|
<colspec colnum="1" colname="col1" colwidth="1*"/>
|
|
<colspec colnum="2" colname="col2" colwidth="1*"/>
|
|
<colspec colnum="3" colname="col3" colwidth="3*"/>
|
|
<thead>
|
|
<row>
|
|
<entry align="center">Attribute Name</entry>
|
|
<entry align="left">Allowed Values</entry>
|
|
<entry align="center">Attribute Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry>channel</entry>
|
|
<entry></entry>
|
|
<entry>The channel to which inbound messages will be sent.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>connection-factory</entry>
|
|
<entry></entry>
|
|
<entry>If the connection factory has a type 'server', the factory is 'owned'
|
|
by this adapter. If it has a type 'client', it is 'owned' by an
|
|
outbound channel adapter and this adapter will receive any
|
|
incoming messages on the connection created by the
|
|
outbound adapter.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>error-channel</entry>
|
|
<entry></entry>
|
|
<entry>If an Exception is thrown by a downstream
|
|
component, the MessagingException message containing the exception
|
|
and failed message is sent to this channel.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>client-mode</entry>
|
|
<entry>true, false</entry>
|
|
<entry>
|
|
When true, the inbound adapter will act as a client, with respect to establishing
|
|
the connection and then receive incoming messages on that connection. Default = false.
|
|
Also see <emphasis>retry-interval</emphasis> and <emphasis>scheduler</emphasis>.
|
|
The connection factory must be of type 'client' and have <emphasis>single-use</emphasis>
|
|
set to false.
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>retry-interval</entry>
|
|
<entry></entry>
|
|
<entry>
|
|
When in <emphasis>client-mode</emphasis>, specifies the number of milliseconds
|
|
to wait between connection attempts, or after a connection failure. Default 60,000
|
|
(60 seconds).
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>scheduler</entry>
|
|
<entry>true, false</entry>
|
|
<entry>
|
|
Specifies a <classname>TaskScheduler</classname> to use for managing the
|
|
<emphasis>client-mode</emphasis> connection. Defaults to a
|
|
<classname>ThreadPoolTaskScheduler</classname> with a pool size of `.
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
<table id="tcp-ob-adapter-attributes">
|
|
<title>TCP Outbound Channel Adapter Attributes</title>
|
|
<tgroup cols="3">
|
|
<colspec align="left" />
|
|
<colspec colnum="1" colname="col1" colwidth="1*"/>
|
|
<colspec colnum="2" colname="col2" colwidth="1*"/>
|
|
<colspec colnum="3" colname="col3" colwidth="3*"/>
|
|
<thead>
|
|
<row>
|
|
<entry align="center">Attribute Name</entry>
|
|
<entry align="left">Allowed Values</entry>
|
|
<entry align="center">Attribute Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry>channel</entry>
|
|
<entry></entry>
|
|
<entry>The channel on which outbound messages arrive.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>connection-factory</entry>
|
|
<entry></entry>
|
|
<entry>If the connection factory has a type 'client', the factory is
|
|
'owned' by this adapter. If it has a type 'server', it is 'owned'
|
|
by an inbound channel adapter and this adapter will attempt
|
|
to correlate messages to the connection on which an
|
|
original inbound message was received. </entry>
|
|
</row>
|
|
<row>
|
|
<entry>client-mode</entry>
|
|
<entry>true, false</entry>
|
|
<entry>
|
|
When true, the outbound adapter will attempt to establish the connection as
|
|
soon as it is started. When false, the connection is established when
|
|
the first message is sent. Default = false.
|
|
Also see <emphasis>retry-interval</emphasis> and <emphasis>scheduler</emphasis>.
|
|
The connection factory must be of type 'client' and have <emphasis>single-use</emphasis>
|
|
set to false.
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>retry-interval</entry>
|
|
<entry></entry>
|
|
<entry>
|
|
When in <emphasis>client-mode</emphasis>, specifies the number of milliseconds
|
|
to wait between connection attempts, or after a connection failure. Default 60,000
|
|
(60 seconds).
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>scheduler</entry>
|
|
<entry>true, false</entry>
|
|
<entry>
|
|
Specifies a <classname>TaskScheduler</classname> to use for managing the
|
|
<emphasis>client-mode</emphasis> connection. Defaults to a
|
|
<classname>ThreadPoolTaskScheduler</classname> with a pool size of `.
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
<table id="tcp-ib-gateway-attributes">
|
|
<title>TCP Inbound Gateway Attributes</title>
|
|
<tgroup cols="3">
|
|
<colspec align="left" />
|
|
<colspec colnum="1" colname="col1" colwidth="1*"/>
|
|
<colspec colnum="2" colname="col2" colwidth="1*"/>
|
|
<colspec colnum="3" colname="col3" colwidth="3*"/>
|
|
<thead>
|
|
<row>
|
|
<entry align="center">Attribute Name</entry>
|
|
<entry align="left">Allowed Values</entry>
|
|
<entry align="center">Attribute Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry>connection-factory</entry>
|
|
<entry></entry>
|
|
<entry>The connection factory must be of type server. </entry>
|
|
</row>
|
|
<row>
|
|
<entry>request-channel</entry>
|
|
<entry></entry>
|
|
<entry>The channel to which incoming messages will be sent.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>reply-channel</entry>
|
|
<entry></entry>
|
|
<entry>The channel on which reply messages may arrive. Usually replies will
|
|
arrive on a temporary reply channel added to the inbound message
|
|
header</entry>
|
|
</row>
|
|
<row>
|
|
<entry>reply-timeout</entry>
|
|
<entry></entry>
|
|
<entry>The time in milliseconds for which the gateway will wait for a reply.
|
|
Default 1000 (1 second).</entry>
|
|
</row>
|
|
<row>
|
|
<entry>error-channel</entry>
|
|
<entry></entry>
|
|
<entry>If an Exception is thrown by a downstream
|
|
component, the MessagingException message containing the exception
|
|
and failed message is sent to this channel;
|
|
any reply from that flow will then be returned as a response by
|
|
the gateway.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>client-mode</entry>
|
|
<entry>true, false</entry>
|
|
<entry>
|
|
When true, the inbound gateway will act as a client, with respect to establishing
|
|
the connection and then receive (and reply to) incoming messages on that connection.
|
|
Default = false.
|
|
Also see <emphasis>retry-interval</emphasis> and <emphasis>scheduler</emphasis>.
|
|
The connection factory must be of type 'client' and have <emphasis>single-use</emphasis>
|
|
set to false.
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>retry-interval</entry>
|
|
<entry></entry>
|
|
<entry>
|
|
When in <emphasis>client-mode</emphasis>, specifies the number of milliseconds
|
|
to wait between connection attempts, or after a connection failure. Default 60,000
|
|
(60 seconds).
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>scheduler</entry>
|
|
<entry>true, false</entry>
|
|
<entry>
|
|
Specifies a <classname>TaskScheduler</classname> to use for managing the
|
|
<emphasis>client-mode</emphasis> connection. Defaults to a
|
|
<classname>ThreadPoolTaskScheduler</classname> with a pool size of `.
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
<table id="tcp-ob-gateway-attributes">
|
|
<title>TCP Outbound Gateway Attributes</title>
|
|
<tgroup cols="3">
|
|
<colspec align="left" />
|
|
<colspec colnum="1" colname="col1" colwidth="1*"/>
|
|
<colspec colnum="2" colname="col2" colwidth="1*"/>
|
|
<colspec colnum="3" colname="col3" colwidth="3*"/>
|
|
<thead>
|
|
<row>
|
|
<entry align="center">Attribute Name</entry>
|
|
<entry align="left">Allowed Values</entry>
|
|
<entry align="center">Attribute Description</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry>connection-factory</entry>
|
|
<entry></entry>
|
|
<entry>The connection factory must be of type client. </entry>
|
|
</row>
|
|
<row>
|
|
<entry>request-channel</entry>
|
|
<entry></entry>
|
|
<entry>The channel on which outgoing messages will arrive.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>reply-channel</entry>
|
|
<entry></entry>
|
|
<entry>Optional. The channel to which reply messages may be sent if the
|
|
original outbound message did not contain a reply channel header.
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry>reply-timeout</entry>
|
|
<entry></entry>
|
|
<entry>The time in milliseconds for which the gateway will wait for a reply.
|
|
Default: 10000 (10 seconds).</entry>
|
|
</row>
|
|
<row>
|
|
<entry>request-timeout</entry>
|
|
<entry></entry>
|
|
<entry>If a single-use connection factory is not being used, The time in milliseconds
|
|
for which the gateway will wait to get access to the shared connection.</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
</para>
|
|
</section>
|
|
</chapter>
|