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INT-3133: Add <spel-property-accessors> Support

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* Add <spel-property-accessors> to configure a list of beans
that implement `org.springframework.expression.PropertyAccessor`
* Add `SpelPropertyAccessorRegistrar` to manage a list of PropertyAccessors
for Integration infrastructure
* Refactoring for `SpelFunctionRegistrar` and `IntegrationEvaluationContextFactoryBean`
to fix the issue when there is no `SpelFunctionRegistrar`(`SpelPropertyAccessorRegistrar`)
in the child AC, but there is one in the parent.
Previously the inheritance did't work for that reason.
* Now parent/child logic moved to `IntegrationEvaluationContextFactoryBean`
* Add documentation

JIRA: https://jira.springsource.org/browse/INT-3133

INT-3133: Rebasing, polishing and documentation

INT-3133: PropertyAccessors override support

* `@Ignore` `SOLingerTests#finReceivedNioLinger()` test

INT-3133: Change JavaDoc link to 3.0.0.RC1

Polishing

- Remove duplicate check - last bean def wins
- Doc Polishing
This commit is contained in:
Artem Bilan
2013-09-06 10:49:53 +03:00
committed by Gary Russell
parent 00d9ba50ef
commit 19dd45a98a
16 changed files with 419 additions and 26 deletions
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101
src/reference/docbook/spel.xml
View File

@@ -35,8 +35,8 @@
<title>SpEL Evaluation Context Customization</title>
<para>
Starting with Spring Integration 3.0, it is possible to add additional
<interfacename>PropertyAccessor</interfacename>s to the SpEL evaluation context.
In fact, the framework provides one such accessor,
<interfacename>PropertyAccessor</interfacename>s to the SpEL evaluation contexts used by
the framework. The framework provides
the <classname>JsonPropertyAccessor</classname> which can be used (read-only) to access fields from
a <classname>JsonNode</classname>, or JSON in a <classname>String</classname>. Or you can create your
own <interfacename>PropertyAccessor</interfacename> if you have specific needs.
@@ -47,10 +47,11 @@
expression used throughout the framework.
</para>
<para>
To configure your custom accessors and functions, add an
<classname>IntegrationEvaluationContextFactoryBean</classname> with
<code>id="integrationEvaluationContext"</code>
to your application context, with the appropriate configuration; for example:
The following configuration shows how to directly configure the
<classname>IntegrationEvaluationContextFactoryBean</classname> with custom property accessors
and functions. However, for convenience, namespace support is provided for both, as
described in the following sections, and the framework will automatically configure
the factory bean on your behalf.
</para>
<programlisting language="xml"><![CDATA[<beans:bean id="integrationEvaluationContext"
class="org.springframework.integration.config.IntegrationEvaluationContextFactoryBean">
@@ -92,8 +93,8 @@
<para>
Namespace support is provided for easy addition of SpEL custom functions.
You can specify <code>&lt;spel-function/&gt;</code> components to provide
<ulink url="http://static.springsource.org/spring-framework/docs/current/spring-framework-reference/html/expressions.html#expressions-ref-functions">
custom SpEL functions</ulink> to the <interfacename>EvaluationContext</interfacename> used throughout the framework.
<ulink url="http://static.springsource.org/spring-framework/docs/current/spring-framework-reference/html/expressions.html#expressions-ref-functions"
>custom SpEL functions</ulink> to the <interfacename>EvaluationContext</interfacename> used throughout the framework.
Instead of configuring the factory bean above, simply add one or more of these components
and the framework will automatically add them to the default <emphasis>integrationEvaluationContext</emphasis>
factory bean.
@@ -123,7 +124,7 @@
<classname>StandardEvaluationContext</classname> instance,
and it is configured with the default
<interfacename>PropertyAccessor</interfacename>s, <interfacename>BeanResolver</interfacename>
and the custom function.
and the custom functions.
</listitem>
<listitem>
That <interfacename>EvaluationContext</interfacename> instance is injected into the
@@ -136,13 +137,85 @@
SpEL functions declared in a parent context are also made available in any child context(s). Each
context has its own instance of the <emphasis>integrationEvaluationContext</emphasis> factory bean
because each needs a different <interfacename>BeanResolver</interfacename>, but the function
declarations are inherited (and can be overridden if needed by declaring a SpEL function with
the same name. The functions themselves are processed by the framework - they do not appear
as beans in the application context.
declarations are inherited and can be overridden if needed by declaring a SpEL function with
the same name.
</note>
</para>
<para>
Spring Integration provides some standard functions, which are registered with the application
context automatically on start up:
<itemizedlist>
<listitem>
<emphasis role="bold">#jsonPath</emphasis> - to evaluate a 'jsonPath' on some provided object. This function
invokes <code>JsonPathUtils.evaluate(...)</code>. This static method delegates to the
<ulink url="http://code.google.com/p/json-path">Jayway JsonPath library</ulink>. The following shows
some usage examples:
<programlisting language="xml"><![CDATA[<transformer expression="#jsonPath(payload, '$.store.book[0].author')"/>
<filter expression="#jsonPath(payload,'$..book[2].isbn') matches '\d-\d{3}-\d{5}-\d'"/>
<splitter expression="#jsonPath(payload, '$.store.book')"/>
<router expression="#jsonPath(payload, headers.jsonPath)">
<mapping channel="output1" value="reference"/>
<mapping channel="output2" value="fiction"/>
</router>]]></programlisting>
#jsonPath also supports the third optional parameter - an array of
<ulink url="https://github.com/jayway/JsonPath/blob/master/json-path/src/main/java/com/jayway/jsonpath/Filter.java"
><classname>com.jayway.jsonpath.Filter</classname></ulink>, which could be provided by a reference to a
bean or bean method, for example.
<note>
Using this function requires the Jayway JsonPath library (json-path.jar) to be on
the classpath; otherwise the <emphasis>#jsonPath</emphasis>
SpEL function won't be registered.
</note>
For more information regarding JSON see 'JSON Transformers' in <xref linkend="transformer"/>.
</listitem>
<!--<listitem>
<emphasis>#xpath</emphasis> - TBD
</listitem>
<listitem>
<emphasis>#request</emphasis> - TBD
</listitem>
<listitem>
<emphasis>#auth</emphasis> - TBD
</listitem>-->
</itemizedlist>
</para>
</section>
<section id="spel-property-accessors">
<title>PropertyAccessors</title>
<para>
Namespace support is provided for the easy addition of SpEL custom
<ulink url="http://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/expression/PropertyAccessor.html"
><interfacename>PropertyAccessor</interfacename></ulink>
implementations. You can specify the <code>&lt;spel-property-accessors/&gt;</code> component to provide a list of
custom <interfacename>PropertyAccessor</interfacename>s to the <interfacename>EvaluationContext</interfacename>
used throughout the framework. Instead of configuring the factory bean above, simply add one or more of these
components, and the framework will automatically add the accessors to the default
<emphasis>integrationEvaluationContext</emphasis> factory bean:
</para>
<programlisting language="xml"><![CDATA[<int:spel-property-accessors>
<bean id="jsonPA" class="org.springframework.integration.json.JsonPropertyAccessor"/>
<ref bean="fooPropertyAccessor"/>
</int:spel-property-accessors>
]]></programlisting>
<para>
With this sample, two custom <interfacename>PropertyAccessor</interfacename>s will be injected to the
<interfacename>EvaluationContext</interfacename> in the order that they are declared.
</para>
<para>
<note>
At this time, <interfacename>PropertyAccessor</interfacename>s are not inherited and must be
declared as described above in each context.
Custom <interfacename>PropertyAccessor</interfacename>s declared in a parent context are also made available
in any child context(s). They are placed at the end of result list (but before the default
<classname>org.springframework.context.expression.MapAccessor</classname> and
<classname>org.springframework.expression.spel.support.ReflectivePropertyAccessor</classname>).
If a <interfacename>PropertyAccessor</interfacename> with the same bean id is declared in a child context(s),
it will override the parent accessor. Beans declared within a <code>&lt;spel-property-accessors/&gt;</code>
must have an 'id' attribute.
The final order of usage is: the accessors in the current context,
in the order in which they are declared, followed by any from parent contexts, in order, followed
by the <classname>MapAccessor</classname> and finally the <classname>ReflectivePropertyAccessor</classname>.
</note>
</para>
</section>

4
src/reference/docbook/transformer.xml
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@@ -350,6 +350,10 @@ public class Foo {
<int-amqp:inbound-channel-adapter ... message-converter="jsonConverterWithPOType" ... />]]></programlisting>
</important>
<para>
In addition to JSON Transformers Spring Integration provides out-of-the-box <emphasis>#jsonPath</emphasis>
SpEL function. For more information see <xref linkend="spel"/>.
</para>
</section>
<section id="transformer-annotation">

9
src/reference/docbook/whats-new.xml
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@@ -110,6 +110,15 @@
component is introduced. For more information see <xref linkend="spel-functions" />.
</para>
</section>
<section id="3.0-spel-property-accessors">
<title>SpEL PropertyAccessors Support</title>
<para>
To customize the SpEL <interfacename>EvaluationContext</interfacename> with
<interfacename>PropertyAccessor</interfacename> implementations
the new <code>&lt;spel-property-accessors/&gt;</code> component is introduced.
For more information see <xref linkend="spel-property-accessors" />.
</para>
</section>
</section>
<section id="3.0-general">