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new 3448385 CAMEL-16861: Polished bean language
3448385 is described below
commit 344838585b99f2fe99df3bcc452cb39cc9a238c1
Author: Claus Ibsen <[email protected]>
AuthorDate: Mon Sep 13 16:47:53 2021 +0200
CAMEL-16861: Polished bean language
---
.../org/apache/camel/language/bean/bean.json | 4 +-
.../camel-bean/src/main/docs/bean-language.adoc | 148 ++++++---------------
docs/components/modules/languages/nav.adoc | 2 +-
3 files changed, 45 insertions(+), 109 deletions(-)
diff --git
a/components/camel-bean/src/generated/resources/org/apache/camel/language/bean/bean.json
b/components/camel-bean/src/generated/resources/org/apache/camel/language/bean/bean.json
index f4c5ca0..645f237 100644
---
a/components/camel-bean/src/generated/resources/org/apache/camel/language/bean/bean.json
+++
b/components/camel-bean/src/generated/resources/org/apache/camel/language/bean/bean.json
@@ -2,8 +2,8 @@
"language": {
"kind": "language",
"name": "bean",
- "title": "Bean method",
- "description": "Call a method of the specified Java bean passing the
Exchange, Body or specific headers to it.",
+ "title": "Bean Method",
+ "description": "Calls a Java bean method.",
"deprecated": false,
"firstVersion": "1.3.0",
"label": "language,core,java",
diff --git a/components/camel-bean/src/main/docs/bean-language.adoc
b/components/camel-bean/src/main/docs/bean-language.adoc
index 97a4ebc..2f8fd4e 100644
--- a/components/camel-bean/src/main/docs/bean-language.adoc
+++ b/components/camel-bean/src/main/docs/bean-language.adoc
@@ -1,35 +1,27 @@
[[bean-language]]
-= Bean method Language
+= Bean Method Language
//THIS FILE IS COPIED: EDIT THE SOURCE FILE:
:page-source: components/camel-bean/src/main/docs/bean-language.adoc
-:docTitle: Bean method
+:docTitle: Bean Method
:artifactId: camel-bean
-:description: Call a method of the specified Java bean passing the Exchange,
Body or specific headers to it.
+:description: Calls a Java bean method.
:since: 1.3
:supportLevel: Stable
include::{cq-version}@camel-quarkus:ROOT:partial$reference/languages/bean.adoc[opts=optional]
*Since Camel {since}*
-The purpose of the Bean Language is to be able to implement an
-xref:manual::expression.adoc[Expression] or
xref:manual::predicate.adoc[Predicate] using
-a simple method on a bean. The bean name is resolved using a
xref:manual::registry.adoc[Registry], such as the
-xref:ROOT:spring-summary.adoc[Spring] *`ApplicationContext`*, then a method is
-invoked to evaluate the xref:manual::expression.adoc[Expression] or
-xref:manual::predicate.adoc[Predicate]. If no method name is provided then one
-is chosen using the rules for xref:manual::bean-binding.adoc[Bean Binding];
-using the type of the message body and using any annotations on the bean
-methods.
+The Bean language is used for calling a method on an existing Java bean.
-The xref:manual::bean-binding.adoc[Bean Binding] rules are used to bind the
-xref:{eip-vc}:eips:message.adoc[Message] Exchange to the method parameters; so
you can
-annotate the bean to extract headers or other expressions such as
-xref:xpath-language.adoc[XPath] or xref:xquery-language.adoc[XQuery] from the
message.
+Camel adapts to the method being called via
xref:manual::bean-binding.adoc[Bean Binding].
+The binding process will for example automatic convert the message payload to
the parameter
+of type of the first parameter in the method. The binding process has a lot
more features so
+it is recommended to read the xref:manual::bean-binding.adoc[Bean Binding]
documentation for mor details.
-== Bean Language options
+== Bean Method options
// language options: START
-The Bean method language supports 5 options, which are listed below.
+The Bean Method language supports 5 options, which are listed below.
@@ -44,21 +36,25 @@ The Bean method language supports 5 options, which are
listed below.
|===
// language options: END
+== Examples
-[[BeanLanguage-UsingBeanExpressionsinJava]]
-== Using Bean Expressions in Java
+In the given route below, we call a Java Bean Method with `method`, where
"myBean"
+is the id of the bean to use (lookup from
xref:manual::registry.adoc[Registry]),
+and "isGoldCustomer" is the name of the method to call.
-[source,syntaxhighlighter-pre]
+[source,java]
----
from("activemq:topic:OrdersTopic")
.filter().method("myBean", "isGoldCustomer")
.to("activemq:BigSpendersQueue");
----
-[[BeanLanguage-UsingBeanExpressionsinSpringXML]]
-== Using Bean Expressions in Spring XML
+TIP: It is also possible to omit the method name, then Camel would have to
choose the best suitable
+method to use; this process is a little bit complex, so it is good practice to
specify the method name,
-[source,syntaxhighlighter-pre]
+And in XML DSL
+
+[source,xml]
----
<route>
<from uri="activemq:topic:OrdersTopic"/>
@@ -69,26 +65,9 @@ from("activemq:topic:OrdersTopic")
</route>
----
-[WARNING]
-====
- **Bean Attribute Now Deprecated**
-
-The *`bean`* attribute of the method expression element is now
-deprecated. Use the *`ref`* attribute instead.
-
-====
-
-[[BeanLanguage-WritingtheExpressionBean]]
-== Writing the Expression Bean
+The bean could be implemented as follows:
-The bean in the above examples is just any old Java Bean with a method
-called *`isGoldCustomer()`* that returns some object that is easily
-converted to a *`boolean`* value in this case, as its used as a
-predicate.
-
-Example:
-
-[source,syntaxhighlighter-pre]
+[source,java]
----
public class MyBean {
public boolean isGoldCustomer(Exchange exchange) {
@@ -97,96 +76,53 @@ public class MyBean {
}
----
-We can also use the xref:manual::bean-integration.adoc[Bean Integration]
-annotations.
-
-Example:
+How this method uses `Exchange` in the method signature. You would often not
do that,
+and use non Camel types. For example by using `String` then Camel will
automatic
+convert the message body to this type when calling the method:
-[source,syntaxhighlighter-pre]
+[source,java]
----
public boolean isGoldCustomer(String body) {...}
----
-or
+=== Using Annotations for bean integration
-[source,syntaxhighlighter-pre]
+You can also use the xref:manual::bean-integration.adoc[Bean Integration]
+annotations, such as `@Header`, `@Body` etc
+
+[source,java]
----
public boolean isGoldCustomer(@Header(name = "foo") Integer fooHeader) {...}
----
-So you can bind parameters of the method to the Exchange, the
+So you can bind parameters of the method to the `Exchange`, the
xref:{eip-vc}:eips:message.adoc[Message] or individual headers, properties,
the body
or other expressions.
-[[BeanLanguage-Non-RegistryBeans]]
-== Non-Registry Beans
+=== Non-Registry Beans
-The xref:bean-language.adoc[Bean Language] also supports invoking beans
-that isn't registered in the xref:manual::registry.adoc[Registry]. This is
-usable for quickly to invoke a bean from Java DSL where you don't need
-to register the bean in the xref:manual::registry.adoc[Registry] such as the
-xref:ROOT:spring-summary.adoc[Spring] *`ApplicationContext`*. Camel can
instantiate
-the bean and invoke the method if given a class or invoke an already
-existing instance.
+The Bean Method Language also supports invoking beans
+that isn't registered in the xref:manual::registry.adoc[Registry].
-Example:
+Camel can instantiate the bean and invoke the method if given a class
+or invoke an already existing instance.
-[source,syntaxhighlighter-pre]
+[source,java]
----
from("activemq:topic:OrdersTopic")
- .filter().expression(BeanLanguage(MyBean.class, "isGoldCustomer"))
+ .filter().method(MyBean.class, "isGoldCustomer")
.to("activemq:BigSpendersQueue");
----
-The 2nd parameter *`isGoldCustomer`* is an optional parameter to
-explicit set the method name to invoke. If not provided Camel will try
-to invoke the most suitable method. If case of ambiguity Camel will
-thrown an Exception. In these situations the 2nd parameter can solve
-this problem. Also the code is more readable if the method name is
-provided. The 1st parameter can also be an existing instance of a Bean
-such as:
+The 1st parameter can also be an existing instance of a Bean such as:
-[source,syntaxhighlighter-pre]
+[source,java]
----
-private MyBean my;
-
-from("activemq:topic:OrdersTopic")
- .filter().expression(BeanLanguage.bean(my, "isGoldCustomer"))
- .to("activemq:BigSpendersQueue");
-----
-
-In *Camel 2.2*: you can avoid the *`BeanLanguage`* and have it just as:
-
-[source,syntaxhighlighter-pre]
-----
-private MyBean my;
-
-from("activemq:topic:OrdersTopic")
- .filter().expression(bean(my, "isGoldCustomer"))
- .to("activemq:BigSpendersQueue");
-----
-
-Which also can be done in a bit shorter and nice way:
-
-[source,syntaxhighlighter-pre]
-----
-private MyBean my;
+private MyBean my = ...;
from("activemq:topic:OrdersTopic")
.filter().method(my, "isGoldCustomer")
.to("activemq:BigSpendersQueue");
----
-[[BeanLanguage-OtherExamples]]
-== Other Examples
-
-We have some test cases you can look at if it'll help
-
-*
https://github.com/apache/camel/blob/main/core/camel-core/src/test/java/org/apache/camel/processor/MethodFilterTest.java[MethodFilterTest]
-is a JUnit test case showing the Java xref:manual::dsl.adoc[DSL] use of the
bean
-expression being used in a filter
-*
https://github.com/apache/camel/blob/main/components/camel-spring/src/test/resources/org/apache/camel/spring/processor/aggregator.xml[aggregator.xml]
-is a Spring XML test case for the
xref:{eip-vc}:eips:aggregate-eip.adoc[Aggregator] which
-uses a bean method call to test for the completion of the aggregation.
-
include::{page-component-version}@camel-spring-boot::page$bean-starter.adoc[]
diff --git a/docs/components/modules/languages/nav.adoc
b/docs/components/modules/languages/nav.adoc
index 9b43525..90c163d 100644
--- a/docs/components/modules/languages/nav.adoc
+++ b/docs/components/modules/languages/nav.adoc
@@ -2,7 +2,7 @@
// make edits in docs/*nav.adoc.template files instead
* xref:languages:index.adoc[Languages]
-** xref:bean-language.adoc[Bean method]
+** xref:bean-language.adoc[Bean Method]
** xref:constant-language.adoc[Constant]
** xref:csimple-language.adoc[CSimple]
** xref:datasonnet-language.adoc[DataSonnet]
