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spring-integration/docs/src/reference/docbook/ip.xml
2010-11-22 18:11:28 -05:00

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<?xml version="1.0" encoding="UTF-8"?>
<chapter xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="ip"
xmlns:xlink="http://www.w3.org/1999/xlink">
<title>TCP and UDP Support</title>
<para>
Spring Integration provides Channel Adapters for receiving and sending messages over internet protocols. Both UDP
(User Datagram Protocol)
and TCP (Transmission Control Protocol) adapters are provided. Each adapter provides for one-way communication
over the underlying protocol.
In addition, simple inbound and outbound tcp gateways are provided. These are used when two-way communication is
needed.
</para>
<section id="ip-intro">
<title>Introduction</title>
<para>
Two flavors each of UDP inbound and outbound channel adapters are provided <classname>UnicastSendingMessageHandler</classname>
sends a datagram packet to a single destination. <classname>UnicastReceivingChannelAdapter</classname> receives
incoming datagram packets. <classname>MulticastSendingMessageHandler</classname> sends (broadcasts) datagram packets to
a multicast address. <classname>MulticastReceivingChannelAdapter</classname> receives incoming datagram packets
by joining to a multicast address.
</para>
<para>
TCP inbound and outbound channel adapters are provided <classname>TcpSendingMessageHandler</classname>
sends messages over TCP. <classname>TcpReceivingChannelAdapter</classname> receives messages over TCP.
</para>
<para>
An inbound TCP gateway is provided; this allows for simple request/response processing. While
the gateway can support any number of connections, each connection can only process serially. The thread
that reads from the socket waits for, and sends, the response before reading again. If the connection factory
is configured for single use connections, the connection is closed after the socket times out.
</para>
<para>
An outbound TCP gateway is provided; this allows for simple request/response processing.
If the associated connection factory is configured for single use connections, a new connection is
immediately created for each new request. Otherwise, if the connection is in use,
the calling thread blocks on the connection until either a response is received or a timeout
or I/O error occurs.
</para>
<para>
The TCP and UDP inbound channel adapters, and the TCP inbound gateway, support the "error-channel" attribute.
This provides the same basic functionality as described in <xref linkend="gateway-proxy"/>.
</para>
</section>
<section id="udp-adapters">
<title>UDP Adapters</title>
<para>
<programlisting language="xml"><![CDATA[ <ip:udp-outbound-channel-adapter id="udpOut"
host="somehost"
port="11111"
multicast="false"
channel="exampleChannel" />]]></programlisting>
A simple UDP outbound channel adapter.
<tip>
When setting multicast to true, provide the multicast address in the host
attribute.
</tip>
</para>
<para>
UDP is an efficient, but unreliable protocol. Two attributes are added to improve reliability. When check-length is
set to true, the adapter precedes the message data with a length field (4 bytes in network byte order). This enables
the receiving side to verify the length of the packet received. If a receiving system uses a buffer that is too
short the contain the packet, the packet can be truncated. The length header provides a mechanism to detect this.
</para>
<para>
<programlisting language="xml"><![CDATA[ <ip:udp-outbound-channel-adapter id="udpOut"
host="somehost"
port="11111"
multicast="false"
check-length="true"
channel="exampleChannel" />]]></programlisting>
An outbound channel adapter that adds length checking to the datagram packets.
<tip>
The recipient of the packet must also be configured to expect a length to precede the
actual data. For a Spring Integration UDP inbound channel adapter, set its
<classname>check-length</classname> attribute.
</tip>
</para>
<para>
The second reliability improvement allows an application-level acknowledgment protocol to be used. The receiver
must send an acknowledgment to the sender within a specified time.
</para>
<para>
<programlisting language="xml"><![CDATA[ <ip:udp-outbound-channel-adapter id="udpOut"
host="somehost"
port="11111"
multicast="false"
check-length="true"
acknowledge="true"
ack-host="thishost"
ack-port="22222"
ack-timeout="10000"
channel="exampleChannel" />]]></programlisting>
An outbound channel adapter that adds length checking to the datagram packets and waits for an acknowledgment.
<tip>
Setting acknowledge to true implies the recipient of the packet can interpret the header added to the packet
containing acknowledgment data (host and port). Most likely, the recipient will be a Spring Integration inbound
channel adapter.
</tip>
<tip>
When multicast is true, an additional attribute min-acks-for-success specifies
how many acknowledgments must be received within the ack-timeout.
</tip>
</para>
<para>
For even more reliable networking, TCP can be used.
</para>
<para>
<programlisting language="xml"><![CDATA[ <ip:udp-inbound-channel-adapter id="udpReceiver"
channel="udpOutChannel"
port="11111"
receive-buffer-size="500"
multicast="false"
check-length="true" />]]></programlisting>
A basic unicast inbound udp channel adapter.
</para>
<para>
<programlisting language="xml"><![CDATA[ <ip:udp-inbound-channel-adapter id="udpReceiver"
channel="udpOutChannel"
port="11111"
receive-buffer-size="500"
multicast="true"
multicast-address="225.6.7.8"
check-length="true" />]]></programlisting>
A basic multicast inbound udp channel adapter.
</para>
</section>
<section id="connection-factories">
<title>TCP Connection Factories</title>
<para>
For TCP, the configuration of the underlying connection is provided using a
Connection Factory. Two types of connection factory are provided; a
client connection factory and a server connection factory. Client connection
factories are used to establish outgoing connections; Server connection factories
listen for incoming connections.
</para>
<para>
A client connection factory is used
by an outbound channel adapter but a reference to a client connection factory
can also be provided to an inbound channel adapter and that adapter will receive
any incoming messages received on connections created by the outbound adapter.
</para>
<para>
A server connection factory is used by an inbound channel adapter or gateway (in fact
the connection factory will not function without one). A reference to a server
connection factory can also be provided to an outbound adapter; that adapter
can then be used to send replies to incoming messages to the same connection.
<tip>
<para>Reply messages will only be routed to the connection if the reply contains
the header ip_connection_id that was inserted into the original message by
the connection factory.</para></tip>
<tip>
<para>This is the extent of message correlation performed when sharing connection
factories between inbound and outbound adapters. Such sharing allows for
asynchronous two-way communication over TCP. Only payload information is
transferred using TCP; therefore any message correlation must be performed
by downstream components such as aggregators or other endpoints.
For more information refer to
<xref linkend="ip-correlation">TCP Message Correlation</xref></para></tip>
</para>
<para>
A maximum of one adapter of each type may be given a reference to a connection
factory.
</para>
<para>
Connection factories using <classname>java.net.Socket</classname> and
<classname>java.nio.channel.SocketChannel</classname> are provided.
</para>
<para>
<programlisting language="xml"><![CDATA[
<ip:tcp-connection-factory id="server"
type="server"
port="1234"
/>]]></programlisting>
A simple server connection factory that uses <classname>java.net.Socket</classname>
connections.
</para>
<para>
<programlisting language="xml"><![CDATA[
<ip:tcp-connection-factory id="server"
type="server"
port="1234"
using-nio="true"
/>]]></programlisting>
A simple server connection factory that uses <classname>java.nio.channel.SocketChannel</classname>
connections.
</para>
<para>
<programlisting language="xml"><![CDATA[
<ip:tcp-connection-factory id="client"
type="client"
host="localhost"
port="1234"
single-use="true"
so-timeout="10000"
/>]]></programlisting>
A client connection factory that uses <classname>java.net.Socket</classname>
connections and creates a new connection for each message.
</para>
<para>
<programlisting language="xml"><![CDATA[
<ip:tcp-connection-factory id="client"
type="client"
host="localhost"
port="1234"
single-use="true"
so-timeout="10000"
using-nio=true
/>]]></programlisting>
A client connection factory that uses <classname>java.nio.channel.Socket</classname>
connections and creates a new connection for each message.
</para>
<para>
TCP is a streaming protocol; this means that some structure has to be provided to data
transported over TCP, so the receiver can demarcate the data into discrete messages.
Connection factories are configured to use (de)serializers to convert between the message
payload and the bits that are sent over TCP. This is accomplished by providing a
deserializer and serializer for inbound and outbound messages respectively.
Four standard (de)serializers are provided; the first is <classname>ByteArrayCrlfSerializer</classname>,
which can convert a byte array to a stream of bytes followed by carriage
return and linefeed characters (\r\n). This is the default (de)serializer and can be used with
telnet as a client, for example. The second is is <classname>ByteArrayStxEtxSerializer</classname>,
which can convert a byte array to a stream of bytes preceded by an STX (0x02) and
followed by an ETX (0x03). The third is <classname>ByteArrayLengthHeaderSerializer</classname>,
which can convert a byte array to a stream of bytes preceded by a 4 byte binary
length in network byte order. Each of these is a subclass of
<classname>AbstractByteArraySerializer</classname> which implements both
<classname>org.springframework.core.serializer.Serializer</classname> and
<classname>org.springframework.core.serializer.Deserializer</classname>.
For backwards compatibility, connections using any subclass of
<classname>AbstractByteArraySerializer</classname> for serialization
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
corresponding format to a byte array payload. The fourth standard serializer is
<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.
To implement a custom (de)serializer pair, implement the
<classname>org.springframework.core.serializer.Deserializer</classname> and
<classname>org.springframework.core.serializer.Serializer</classname> interfaces. If you do not wish to use
the default (de)serializer (<classname>ByteArrayCrLfSerializer</classname>), you must supply
<classname>serializer</classname> and
<classname>deserializer</classname> attributes on the connection factory (example below).
</para>
<para>
<programlisting language="xml"><![CDATA[
<bean id="javaSerializer"
class="org.springframework.core.serializer.DefaultSerializer" />
<bean id="javaDeserializer"
class="org.springframework.core.serializer.DefaultDeserializer" />
<ip:tcp-connection-factory id="server"
type="server"
port="1234"
deserializer="JavaDeserializer"
serializer="javaSerializer"
/>]]></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>
</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 just 2 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>
</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>
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[
<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[
<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>
</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. 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. On the client side, however,
the application will have to provide its own correlation logic. 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">Connection Factories</xref>,
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>
</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 the tcp adapter is using NIO. Refer to the java.nio
package for more information. 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 tcp adapter 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>so-timeout</entry>
<entry>Y</entry>
<entry>Y</entry>
<entry></entry>
<entry>See <classname>java.net.Socket</classname>
setSoTimeout() methods for more information.</entry>
</row>
<row>
<entry>so-send-buffer-size</entry>
<entry>Y</entry>
<entry>Y</entry>
<entry></entry>
<entry>See <classname>java.net.Socket</classname>
setSendBufferSize() methods for more information.</entry>
</row>
<row>
<entry>so-receive-buffer- size</entry>
<entry>Y</entry>
<entry>Y</entry>
<entry></entry>
<entry>See <classname>java.net.Socket</classname>
setReceiveBufferSize() methods for more information.</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, specifies the number of tcp fragments that are concurrently
reassembled into complete messages.
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>interceptor-factory-chain</entry>
<entry>Y</entry>
<entry>Y</entry>
<entry></entry>
<entry>Documentation to be supplied.</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>
</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>
</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>
</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.</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>
</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.</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>