f30da932e8
This is a significant update to the build system, including the changes listed below. README.md has been updated with instructions on the most important day-to-day commands. - Eliminate buildSrc submodule In favor of using the new bundlor and docbook-reference plugins. The net effect is a large reduction in number of lines of build code. Common docbook resources, stylesheets, etc are stored directly in the docbook plugin. This means that --recursive is no longer required when cloning and there will never be a need to use `git submodule` commands. README files have been updated to reflect. Use of the new bundlor plugin also means the removal of template.mf files from the source tree in favor of an inline approach. See build.gradle for details. Bundlor 'import templates' are built up programmatically and kept physically close to gradle dependency declarations, leading to more convenience when changing these values and hopefully fewer errors / version inconsistencies over time. Certain tests depended on the presence of template.mf files, all of which have recently been removed from the source tree in favor of the new bundlor plugin which allows for inlining bundlor configuration within the Gradle build script. These tests now create temp files using the java.io.File API instead. - Upgrade to Gradle 1.0-milestone-6 The m6 release is significantly faster when resolving dependencies and has a number of valuable new features over the earlier m3 version. Review the release notes for Gradle 1.0-milestone-6 online for full details. - Switch to repo.springsource.org repository Previously the project build declared as many repositories as necessary to resolve all project dependencies. Now depending on a single 'virtual repository' defined within the SpringSource Artifactory instance at http://repo.springsource.org. Currently, the virtual repository in use is 'libs-milestone', which allows for the resolution of all "milestone-or-better" versions of all S2 and third-party dependencies. Should snapshot dependencies become required, this value may be changed from 'libs-milestone' to 'libs-snapshot'. To build only against GA releases, change the value to 'libs-release'. - New build plan(s) Spring Integration build plans have been updated to use the Artifactory Bamboo plugin and publish to repo.springsource.org. Build plans have names like 2.1.x to reflect the version under development, not necessarily the name of the branch, as this may change over time and across major releases. - Improve release process As mentioned above, Spring Integration will now use the Artifactory Bamboo plugin to publish releases and also use Artifactory's support for pushing builds directly into Maven Central via oss.sonatype.org. Generate poms that contain all necessary fields for onboarding at Maven central (scm, developers, organization, licenses, etc). Generate -source and -javadoc poms to comply with Maven Central onboarding rules (and for general good practice anyway). Generation of PGP signatures, sha1 and md5 checksums are all handled automatically by Artifactory. These are also requirements for automated entry into Maven Central. - Remove source-level pom generation Automatic generation of Maven poms suitable for use in building Spring Integration is no longer supported. Generation and publication of poms for the purpose of dependency management remains supported. Sonar support has to date depended on these poms, but will be switched over to use the Gradle Sonar plugin shortly. - Eliminate docs subproject Move docs/src to the root of the project and eliminate docs as a formal subproject. This simplifies the build in a number of ways, including removing the need for distinguishing between 'subprojects' and 'javaprojects' as well as allowing users to build both 'api' and 'reference' docs without qualifying with a ':docs' prefix. Also rename the src/info directory to src/dist to better reflect that these files are packaged with the distribution. For example, the readme.txt there is really the distribution readme, distinct from the README.md at the root of the project which is for building from source, etc.
96 lines
5.5 KiB
XML
96 lines
5.5 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
|
|
<chapter xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="resource"
|
|
xmlns:xlink="http://www.w3.org/1999/xlink">
|
|
<title>Resource Support</title>
|
|
|
|
<section id="resource-intro">
|
|
<title>Introduction</title>
|
|
<para>
|
|
The <emphasis>Resource Inbound Channel Adapter</emphasis> builds upon Spring's <classname>Resource</classname> abstraction to
|
|
support greater flexibility across a variety of actual types of underlying resources, such as a file, a URL,
|
|
or a class path resource. Therefore, it's similar to but more generic than the
|
|
<emphasis>File Inbound Channel Adapter</emphasis>.
|
|
</para>
|
|
</section>
|
|
|
|
<section id="resource-inbound-channel-adapter">
|
|
<title>Resource Inbound Channel Adapter</title>
|
|
<para>
|
|
The <emphasis>Resource Inbound Channel Adapter</emphasis> is a polling adapter that creates a <classname>Message</classname>
|
|
whose payload is a collection of <classname>Resource</classname> objects.
|
|
</para>
|
|
<para>
|
|
<classname>Resource</classname> objects are resolved based on the pattern specified using the <code>pattern</code> attribute.
|
|
The collection of resolved <classname>Resource</classname> objects is then sent as a payload within a
|
|
<classname>Message</classname> to the adapter's channel. That is one major difference between <emphasis>Resource Inbound Channel Adapter</emphasis>
|
|
and <emphasis>File Inbound Channel Adapter</emphasis>; the latter buffers File objects and sends a single <classname>File</classname> object per
|
|
<classname>Message</classname>.
|
|
</para>
|
|
<para>
|
|
Below is an example of a very simple configuration which will find all files ending with the 'properties'
|
|
extension in the <code>foo.bar</code> package available on the classpath and will send them as
|
|
the payload of a Message to the channel named '<code>resultChannel</code>':
|
|
|
|
<programlisting language="xml"><![CDATA[<int:resource-inbound-channel-adapter id="resourceAdapter"
|
|
channel="resultChannel"
|
|
pattern="classpath:foo/bar/*.properties">
|
|
<int:poller fixed-rate="1000"/>
|
|
</int:resource-inbound-channel-adapter>]]></programlisting>
|
|
</para>
|
|
<para>
|
|
The <emphasis>Resource Inbound Channel Adapter</emphasis> relies on the
|
|
<classname>org.springframework.core.io.support.ResourcePatternResolver</classname> strategy interface to resolve the provided pattern.
|
|
It defaults to an instance of the current <classname>ApplicationContext</classname>. However you may provide a reference to an instance
|
|
of your own implementation of <classname>ResourcePatternResolver</classname> using the <code>pattern-resolver</code> attribute:
|
|
<programlisting language="xml"><![CDATA[<int:resource-inbound-channel-adapter id="resourceAdapter"
|
|
channel="resultChannel"
|
|
pattern="classpath:foo/bar/*.properties"
|
|
pattern-resolver="myPatternResolver">
|
|
<int:poller fixed-rate="1000"/>
|
|
</int:resource-inbound-channel-adapter>
|
|
|
|
<bean id="myPatternResolver" class="org.example.MyPatternResolver"/>]]></programlisting>
|
|
</para>
|
|
<para>
|
|
You may have a use case where you need to further filter the collection of resources
|
|
resolved by the <classname>ResourcePatternResolver</classname>. For example, you may want to prevent resources
|
|
that were resolved already from appearing in a collection of resolved resources ever again. On the other hand
|
|
your resources might be updated rather often and you <emphasis>do</emphasis> want them to be picked up again.
|
|
In other words there is a valid use case for defining an additional filter as well as disabling filtering altogether.
|
|
You can provide your own implementation of the <classname>org.springframework.integration.util.CollectionFilter</classname>
|
|
strategy interface:
|
|
<programlisting language="java"><![CDATA[public interface CollectionFilter<T> {
|
|
|
|
Collection<T> filter(Collection<T> unfilteredElements);
|
|
|
|
}]]></programlisting>
|
|
|
|
As you can see the <classname>CollectionFilter</classname> receives a collection of un-filtered elements
|
|
(which would be <classname>Resource</classname> objects in this case), and it returns a collection of
|
|
filtered elements of that same type.
|
|
|
|
</para>
|
|
<para>
|
|
If you are defining the adapter via XML but you do not specify a filter reference, a default implementation of
|
|
<classname>CollectionFilter</classname> will be used by the <emphasis>Resource Inbound Channel Adapter</emphasis>.
|
|
The implementation class of that default filter is <classname>org.springframework.integration.util.AcceptOnceCollectionFilter</classname>.
|
|
It remembers the elements passed in the previous invocation in order to avoid returning those elements more than once.
|
|
</para>
|
|
<para>
|
|
To inject your own implementation of <classname>CollectionFilter</classname> instead, use the <code>filter</code> attribute.
|
|
<programlisting language="xml"><![CDATA[<int:resource-inbound-channel-adapter id="resourceAdapter"
|
|
channel="resultChannel"
|
|
pattern="classpath:foo/bar/*.properties"
|
|
filter="myFilter">
|
|
<int:poller fixed-rate="1000"/>
|
|
</int:resource-inbound-channel-adapter>
|
|
|
|
<bean id="myFilter" class="org.example.MyFilter"/>]]></programlisting>
|
|
|
|
If you don't need any filtering and want to disable even the default <classname>CollectionFilter</classname> strategy,
|
|
simply provide an empty value for the filter attribute (e.g., <code>filter=""</code>)
|
|
</para>
|
|
</section>
|
|
|
|
</chapter>
|