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Swagger

Swagger-First Development

Swagger Auto Generation

Please see the Swagger2Feature page for more information

WADL

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CXF JAX-RS supports (Web Application Description Language|http://www.w3.org/Submission/wadl] (WADL).
Users can use WADL documents to generate the initial code and have WADL auto-generated on demand.

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Overview

WADL is a resource-centric description language which has been designed to facilitate the modeling, description and testing of
RESTful Web applications. Please check the official page for more information, this section provides a brief overview of main WADL constructs.

Basic example

A top level WADL document element is called "application". Usually it may contain a "grammars" section and "resources" element with one or more top-level "resource" elements, with each one representing a specific root resource, for example:

<application xmlns="http://wadl.dev.java.net/2009/02" xmlns:ns="http://superbooks">
 <grammars>
  <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" 
        xmlns:tns="http://superbooks" attributeFormDefault="unqualified" elementFormDefault="unqualified" 
        targetNamespace="http://superbooks">
    <xs:element name="thebook" type="tns:book"/>
    <xs:complexType name="book">
        <xs:sequence>
            <xs:element minOccurs="0" ref="tns:thechapter"/>
            <xs:element name="id" type="xs:int"/>
        </xs:sequence>
    </xs:complexType>
  </xs:schema>
 </grammars>
 <resources base="http://localhost:8080/">
   <resource path="/bookstore/{id}">
     <param name="id" style="template"/>
     <method name="GET">
      <response>
       <representation mediaType="application/xml" element="ns:thebook"/>
      </response>
    </method>
   </resource>
   <resource path="/books">
      <resource path="/bookstore/{id}">
        <param name="id" style="template"/>
        <method name="GET">
          <response>
           <representation mediaType="application/xml" element="ns:thebook"/>
          </response>
        </method>
      </resource>
   </resource>
 </resources>  
</application>

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Also note that the resource with the "/books" path has another child resource with the "/bookstore/{id}" path, but it could've had a "/books/bookstore/{id}" path instead and no child resource.

WADL with references

Basic WADL example in the previous section shows a "grammars" section with the inlined schema, as well as a "resource" description with the "/bookstore/{id}" path listed twice, as an immediate child of the "resources" and as a child of the "resource" element with the "/books" path.

Note that inlined schemas can be included instead by referencing external schemas. Likewise, most of WADL element declarations such as "resource", "method", "representation", etc can be shared by using the same document or external references. Here is how the basic example can be simplified with the help of references:

<application xmlns="http://wadl.dev.java.net/2009/02" xmlns:ns="http://superbooks">
 <grammars>
   <include href="schemas/book.xsd"/>
 </grammars>

 <resource_type id="bookResource">
     <param name="id" style="template"/>
     <method name="GET">
       <response>
        <representation mediaType="application/xml" element="ns:thebook"/>
       </response>
    </method>
 </resource_type>

 <resources base="http://localhost:8080/">
   <resource path="/bookstore/{id}" type="#bookResource"/>
   <resource path="/books">
      <resource path="/bookstore/{id}" type="#bookResource"/>

   <!-- 
     or 
     <resource path="/books/bookstore/{id}" type="#bookResource"/>
   --> 
   </resource> 
 </resources>  
</application>

Note that a book.xsd schema resource located in the 'schemas' path relative to the location of this WADL document is referenced using wadl:include element. Abstract resource type "bookResource" is declared as an immediate child of wadl:application and is linked to concrete resource elements using a "#bookResource" reference.

Sharing declarations between multiple WADLs

WADL references allow for having WADL documents with abstract declarations only and concrete WADLs referencing them, thus making it possible to reuse resource declarations in different web application descriptions.

For example, the following baseApplication.wadl documents describes an abstract "bookResource" resource:

<application xmlns="http://wadl.dev.java.net/2009/02" xmlns:ns="http://superbooks">
 <grammars>
   <include href="schemas/book.xsd"/>
 </grammars>

 <resource_type id="bookResource">
     <param name="id" style="template"/>
     <method name="GET">
       <response>
        <representation mediaType="application/xml" element="ns:thebook"/>
       </response>
    </method>
 </resource_type>
</application>

and this WADL document links to the abstract resource by using an external WADL reference with a "baseResource" fragment.

<application xmlns="http://wadl.dev.java.net/2009/02" xmlns:ns="http://superbooks">
 
 <resources base="http://localhost:8080/">
   <resource path="/bookstore/{id}" type="baseApplication.wadl#bookResource"/>
   <resource path="/books">
      <resource path="/bookstore/{id}" type="baseApplication.wadl#bookResource"/>
   </resource> 
 </resources>  
</application>

New: Starting from CXF 2.5.0 and 2.4.4 all WADL elements may link to top-level local declarations, see this example.

WADL-first Development

CXF 2.4.1 introduces a wadl2java code generator and cxf-wadl2java-plugin Maven plugin which can be used to generate server and client JAX-RS code and speed up the transition between modeling and implementation stages.

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Code generator expects WADL resource and method elements to have "id" attributes set which can provide hints on how to name generated classes and methods. For example:

<application xmlns="http://wadl.dev.java.net/2009/02" xmlns:ns="http://superbooks">
 <grammars>
  <include href="schemas/book.xsd"/>
 </grammars>
 <resources base="http://localhost:8080/">
   <resource path="/bookstore/{id}" id="org.apache.cxf.jaxrs.systest.BookStore">
     <param name="id" style="template"/>
     <method name="GET" id="getBook">
      <response>
       <representation mediaType="application/xml" element="ns:thebook"/>
      </response>
    </method>
   </resource>
 </resources>  
</application>

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Classes generated from schemas will have a package name derived from a given schema target namespace by default. wadltojava tool lets customize it as well.

wadl2java command line tool

Running wadltojava from the command line will produce:

wadl2java -p <package-name> -sp <[schema-namespace =]package-name>* 
          -tMap <schema-type = java-type>* -repMap <media-type = java-type>*
          -resource <resource-name> -b <binding-file-name>* -catalog <catalog-file-name> 
          -d <output-directory> -compile -classdir <compile-classes-directory> -interface -impl 
          -noTypes -inheritResourceParams -generateEnums -supportMultipleXmlReps -async<methodNames>*javaDocs
          -generateResponseIfHeadersSet -generateResponseForMethods<methodNames>* -async<methodNames>* -xjc<xjc-arguments>* 
          -rx <library> -authentication <name:password> -validate -h -v -verbose -quiet <wadl>

Note 'tMap', 'repMap', 'noTypes' and 'inheritResourceParams' options are supported starting from CXF 2.6.3, 'noVoidForEmptyResponses' - from 2.6.4, '-async' - from 2.7.1, '-xjc' - from 2.7.4,

'generateResponseForMethods' and 'generateResponseIfHeadersSet' - from 2.7.12/3.0.0, 'validate' - from 2.7.13/3.2.0/3.1.0, 'javaDocs' - from 3.1.4, 'authentication' - from 3.1.14/3.2.1, 'rx' - from 3.2.13/3.3.6.

The options are reviewed in the The options are reviewed in the following table.

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The 'repMap' option is similar and provides a mapping between the representations of a given media type and Java type. For example, if one has to process different XML representations in one method, a mapping like '-repMap application/xml=javax.xml.transform.Source' will work, affecting declarations like "<wadl:representation mediaTpe='application/xml'". Similarly CXF org.apache.cxf.jaxrs.ext.multipart.MultipartBody class can be linked to 'multipart/form-data' representations, etc.

JAXB customizations

At the moment it is possible to apply external JAXB customizations to WADL grammars however it is not possible yet to restrict a given customization to a specific WADL document or explicitly inlined schema. Linking binding to external schemas works, for example, the following bindings file can be used:

The 'generateResponseForMethods' and 'async' options accept a comma separated list of method names, providing a single '*' (no quotes) as a method name will get these options affecting all of the generated methods.

In some cases, example when describing JSON arrays, you may want to have an explicit collection of types defined in schema generated. In this case use -tMap or -repMap option with a value such as "List..MyType".

The reactive extensions support is limited to Java 8 standard library APIs only, which essentially means CompletionStage / CompletableFuture are supported at the moment. Please note that the void / one-way methods are not generated with CompletionStage / CompletableFuture and kept unchanged.

JAXB customizations

At the moment it is possible to apply external JAXB customizations to WADL grammars however it is not possible yet to restrict a given customization to a specific WADL document or explicitly inlined schema. Linking binding to external schemas works, for example, the following bindings file can be used:

<jaxb:bindings version="2.0"
	xmlns:jaxb="http://java.sun.com/xml/ns/jaxb"
	xmlns:xs="http://www.w3.org/2001/XMLSchema"
	schemaLocation="schemas/book.xsd"
	node="//xs:complexType[@name='book2']/xs:sequence/xs

<jaxb:bindings version="2.0"
	xmlns:jaxb="http://java.sun.com/xml/ns/jaxb"
	xmlns:xs="http://www.w3.org/2001/XMLSchema"
	schemaLocation="schemas/book.xsd"
	node="//xs:complexType[@name='book2']/xs:sequence/xs:element[@name='id']">
	<jaxb:property name="book2Id"/>
</jaxb:bindings>

wadl2java Maven plugin

If you need the code generated during Maven build then the following plugin can be used:

<groupId>org.apache.cxf</groupId>
<artifactId>cxf-wadl2java-plugin</artifactId>
<version>2.4.1</version>

Add this plugin to the build section of your project's pom and specify a 'wadl2java' goal, for example:

<build>
        <plugins>
            <plugin>
                <groupId>org.apache.cxf</groupId>
                <artifactId>cxf-wadl2java-plugin</artifactId>
                <version>2.4.1</version>
                <executions>
                    <execution>
                        <id>generate-sources</id>
                        <phase>generate-sources</phase>
                        <configuration>
                            <sourceRoot>${basedir}/target/generated/src/main/java</sourceRoot>
                            <wadlOptions>
                                <wadlOption>
                                    <wadl>${basedir}/src/test/resources/wadl/bookstoreImport.xml</wadl>
                                    <impl>true</impl>
                                    
                                    <packagename>org.apache.cxf.systest.jaxrs.codegen.service</packagename>
                                    <schemaPackagenames>
                                       <schemaPackagename>http://superbooks=org.apache.cxf.systest.jaxrs.codegen.schema</schemaPackagename>
                                    </schemaPackagenames>
                                    
                                </wadlOption>
                            </wadlOptions>
                        </configuration>
                        <goals>
                            <goal>wadl2java</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

...

CXF will generate artifacts in the <sourceRoot> directory. Configuration arguments which are included inside the <wadlOption> element are used to pass arguments to the tooling and correspond to the options outlined in the wadltojava section, they can be specified explicitly, as above, or using an "extraargs" wrapper, for example:

<wadlOptions>
	<wadlOption>
		<wadl>$\{basedir}/src/main/wadl/bookStore.wadl</wsdl>
                <extraargs>
                    <extraarg>-impl</extraarg>
                    <extraarg>-verbose</extraarg>
                </extraargs>
	</wadlOption>
</wadlOptions>

Integration

Two options are available to developers who wish to integrate CXF JAX-RS WADLToJava code generator.
First option is to pass the collected options directly to a wadltojava process.

Another approach is to use org.apache.cxf.tools.wadlto.jaxrs.JAXRSContainer class shipped with the cxf-tools-wadlto-jaxrs module:

<groupId>org.apache.cxf</groupId>
<artifactId>cxf-tools-wadlto-jaxrs</artifactId>
<version>2.4.1</version>

Please see CXF source for more details and org.apache.cxf.tools.wadlto.jaxrs.JAXRSContainerTest in particular.

External WADL documents and JAXRS endpoints.

External WADL documents can be linked to from jaxrs:server endpoints using newly introduced "docLocation" attribute, for example:

<jaxrs:server address="/rest" docLocation="wadl/bookStore.wadl">
   <jaxrs:serviceBeans>
      <bean class="org.bar.generated.BookStore"/> 
   </jaxrs:serviceBeans>
</jaxrs:server>

If external WADL documents include external schemas and jaxrs endpoints need to have the schema validation enabled, then those schemas can be referenced in the jaxrs:schemaLocations section as well.

WADL Auto Generation at Runtime

Note that in CXF 3.0.0 WADL Generator code has been moved to

<dependency>
  <groupId>org.apache.cxf</groupId>
  <artifactId>cxf-rt-rs-service-description</artifactId>
  <version>3.0.0-milestone1</version>
</dependency>

...

CXF 2.4.0: org.apache.cxf.jaxrs.ext.Description and org.apache.cxf.jaxrs.ext.xml.XMLName have been moved to org.apache.cxf.jaxrs.model.wadl package given that their purpose is to improve the WADL generation. Also, org.apache.cxf.jaxrs.model.wadl.WadlElement has been renamed to 'ElementClass'.

Documenting resource classes and methods in generated WADL

WADL documents can include doc fragments.

Users may want to use Description annotations which can be attached to resource classes and methods.

Note that starting from CXF 2.4.0, Description annotations can be applied to input parameters. Additionally, a method-level Descriptions annotation can have a collection of categorized Description annotations, with each Description targeting a specific WADL element by setting its 'target' property to one of the DocTarget values. For example, one can use a Descriptions annotation to document the response representation of a particular resource method, as well as add documentation fragments to WADL wadl:method/wadl:request and wadl:method/wadl:response elements:

@POST
@Path("books/{bookid}")
@Descriptions({ 
   @Description(value = "Adds a new book", target = DocTarget.METHOD),
   @Description(value = "Requested Book", target = DocTarget.RETURN),
   @Description(value = "Request", target = DocTarget.REQUEST),
   @Description(value = "Response", target = DocTarget.RESPONSE),
   @Description(value = "Resource", target = DocTarget.RESOURCE)
})
public Book addBook(@Description("book id") @PathParam("id") Long id, @Description("New Book") Book book) {...}

Every unique @Path value adds a new 'resource' element to the generated WADL, thus the last Description annotation in the @Descriptions array ensures the doc extension is also added to the 'resource' element. Note that multiple resource methods having different HTTP methods but sharing the same @Path value will have the same parent 'resource' element representing this shared path fragment, in this case a Description with the DocTarget.RESOURCE target will be ignored unless it is added to the first resource method with this shared @Path:

@POST
@Path("books/{bookid}")
@Description(value = "Resource", target = DocTarget.RESOURCE),
public Book addBook(@Description("book id") @PathParam("id") Long id, @Description("New Book") Book book) {...}

@GET
@Path("books/{bookid}")
public Book addBook(@Description("book id") @PathParam("id") Long id) {...}

Customizing WADL Generation

Support for Javadoc

In CXF 3.0.0 one can get the Javadoc documentation copied to WADL being auto-generated at runtime.

orgOne can register a custom WadlGenerator as a jaxrs:provider. The custom generator can extend the default
org.apache.cxf.jaxrs.model.wadl.WadlGenerator or register a default one with one of the following properties set.

• wadlNamespace: default is "http://wadl.dev.java.net/2009/02", the earlier one is "http://research.sun.com/wadl/2006/10".
• singleResourceMultipleMethods: default is 'true', for example, if a resource class has multiple methods supported at the same path such as "/" (GET, POST, etc) then WADL will list them all as the child nodes of a single resource element.
• useSingleSlashResource: default is false, for example, if you have a root resource class with a path "root" and a resource method with a path "" or "/" then a WADL resource representing the root will not have a child resource representing this resource method (it would do if a resource method had a more specific path such as "bar").

Starting from CXF 2.4.1 and 2.3.5 the following properties are also supported:

• applicationTitle: can be used to create an application title.
• namespacePrefix: defaut is 'prefix', it can be set to other value such as 'ns'.
• ignoreForwardSlash: can be used to enforce that resource path values do not start from '/'
• addResourceAndMethodIds: WadlGenerator will add "id" attributes to wadl:resource and wadl:method elements

An ElementClass annotation can help with representing JAX-RS Response elements in the generated WADL.

Representing explicit JAXB collections

Starting from CXF 2.5.5 and 2.6.2 it is possible to get explicit collections represented in generated WADL grammar sections and have WADL representations linking to these schema elements. Note it is only possible for JAXB collections, for example:

...

@GET
@Path("books")
@org.apache.cxf.jaxrs.model.wadl.XMLName("{http://books}books")
public List<Book> getBooks() {...}

Given the above example, WADLGenerator will attempt to add a 'books' element to the generated schema with the targetNamespace set to "http://books". This 'books' element will have a sequence of elements linking to a type representing the "Book" class.

Representing external schemas and non JAXB types

By default, the WADL grammar section will be properly generated if resource methods accept or return JAXB types.

Even when you do use JAXB, the JAXB types may have been generated from the external schema so having WadlGenerator attempting to recreate the original schema may not work well. To have a generated WADL referencing the original schema(s) please set a 'schemaLocations' list property (programmatically or from Spring) :

...

WadlGenerator wg = new WadlGenerator();
wg.setSchemaLocations(Collections.singletonList("classpath:/book.xsd"));

In this case the grammar section will have the 'book.xsd' schema inlined. If this schema imports other schemas then the imports with relative URIs will be replaced by the absolute URIs based on the current endpoint's base address. For example, if the endpoint address is "http://somehost/bar" and the 'book.xsd' imports "foo/book1.xsd" then the published WADL will contain an "http://somehost/bar/foo/book1.xsd". At the moment a custom RequestHandler filter will have to be registered to serve resources such as "http://somehost/bar/foo/book1.xsd" which can 'calculate' which resource is required get the absolute request URI and comparing it with the base URI, possibly with the help of the injected JAXRS UriInfo context. Alternatively, resources such as book1.xsd may be served by CXFServlet itself (see the Redirection with CXFServlet)

TODO : add ignoreImports flag so that users can list root and imported schemas in "schemaLocations" and have them all inlined.

Note that the root schema such as "book.xsd" is inlined - you can have it referenced only by setting an 'externalLinks' list property. This will work very well when the "book.xsd" is indeed available at the external URI, but this property can also be used to avoid the local schemas being inlined. Moreover, the use of JAXB will not be required. The result will look like this:

...

<wadl:grammars>
<wadl:include href="http://books.xsd"/>
</wadl:grammars>

Note that "schemaLocations" and "externalLinks" properties differ in that the schemas referenced by the former one are inlined.

You can also customize the way schema elements are referenced. When WadlGenerator creates WADL representation elements (representing resource method input or output types) it will be able to link to schema elements provided a given type is actually a JAXB one, so the result may look like this :

...

<!-- 
  thebook2 element is declared in a schema inlined in or referenced from the grammar section
  prefix1 is bound to that schema's target namespace and is declared at the wadl:application element 
-->
<representation mediaType="application/xml" element="prefix1:thebook2"/>

JavaDocProvider implements org.apache.cxf.jaxrs.model.wadl.DocumentationProvider and can be set as WADLGenerator "documentationProvider" property.

JavaDocProvider can be customized with URL or relative String path pointing to the generated Javadoc jar, so this jar can be shipped in the application war or located elsewhere.

JavaDocProvider parses the generated Javadoc HTML pages and scrapes the documentation. See Java to Wadl section on the alternative approach for supporting Javadoc.

Customizing WADL Generation

One can register a custom WadlGenerator as a jaxrs:provider. The custom generator can extend the default
org.apache.cxf.jaxrs.model.wadl.WadlGenerator or register a default one with one of the following properties set.

• wadlNamespace: default is "http://wadl.dev.java.net/2009/02", the earlier one is "http://research.sun.com/wadl/2006/10".
• singleResourceMultipleMethods: default is 'true', for example, if a resource class has multiple methods supported at the same path such as "/" (GET, POST, etc) then WADL will list them all as the child nodes of a single resource element.
• useSingleSlashResource: default is false, for example, if you have a root resource class with a path "root" and a resource method with a path "" or "/" then a WADL resource representing the root will not have a child resource representing this resource method (it would do if a resource method had a more specific path such as "bar").

Starting from CXF 2.4.1 and 2.3.5 the following properties are also supported:

• applicationTitle: can be used to create an application title.
• namespacePrefix: defaut is 'prefix', it can be set to other value such as 'ns'.
• ignoreForwardSlash: can be used to enforce that resource path values do not start from '/'
• addResourceAndMethodIds: WadlGenerator will add "id" attributes to wadl:resource and wadl:method elements

An ElementClass annotation can help with representing JAX-RS Response elements in the generated WADL.

Representing explicit JAXB collections

Starting from CXF 2.5.5 and 2.6.2 it is possible to get explicit collections represented in generated WADL grammar sections and have WADL representations linking to these schema elements. Note it is only possible for JAXB collections, for example:

@GET
@Path("books")
@org.apache.cxf.jaxrs.model.xml.XMLName("{http://books}books")
public List<Book> getBooks() {...}

Given the above example, WADLGenerator will attempt to add a 'books' element to the generated schema with the targetNamespace set to "http://books". This 'books' element will have a sequence of elements linking to a type representing the "Book" class.

Representing external schemas and non JAXB types

By default, the WADL grammar section will be properly generated if resource methods accept or return JAXB types.

Even when you do use JAXB, the JAXB types may have been generated from the external schema so having WadlGenerator attempting to recreate the original schema may not work well. To have a generated WADL referencing the original schema(s) please set a 'schemaLocations' list property (programmatically or from Spring) :

WadlGenerator wg = new WadlGenerator();
wg.setSchemaLocations(Collections.singletonList("classpath:/book.xsd"));

In this case the grammar section will have the 'book.xsd' schema inlined. If this schema imports other schemas then the imports with relative URIs will be replaced by the absolute URIs based on the current endpoint's base address. For example, if the endpoint address is "http://somehost/bar" and the 'book.xsd' imports "foo/book1.xsd" then the published WADL will contain an "http://somehost/bar/foo/book1.xsd". At the moment a custom RequestHandler filter will have to be registered to serve resources such as "http://somehost/bar/foo/book1.xsd" which can 'calculate' which resource is required get the absolute request URI and comparing it with the base URI, possibly with the help of the injected JAXRS UriInfo context. Alternatively, resources such as book1.xsd may be served by CXFServlet itself (see the Redirection with CXFServlet)

TODO : add ignoreImports flag so that users can list root and imported schemas in "schemaLocations" and have them all inlined.

Note that the root schema such as "book.xsd" is inlined - you can have it referenced only by setting an 'externalLinks' list property. This will work very well when the "book.xsd" is indeed available at the external URI, but this property can also be used to avoid the local schemas being inlined. Moreover, the use of JAXB will not be required. The result will look like this:

<wadl:grammars>
<wadl:include href="http://books.xsd"/>
</wadl:grammars>

Note that "schemaLocations" and "externalLinks" properties differ in that the schemas referenced by the former one are inlined.

You can also customize the way schema elements are referenced. When WadlGenerator creates WADL representation elements (representing resource method input or output types) it will be able to link to schema elements provided a given type is actually a JAXB one, so the result may look like this :

<!-- 
  thebook2 element is declared in a schema inlined in or referenced from the grammar section
  prefix1 is bound to that schema's target namespace and is declared at the wadl:application element 
-->
<representation mediaType="application/xml" element="prefix1:thebook2"/>

If no JAXB is used then you can attach an XMLName annotation to method input or output types. Alternatively, you can register an instance of ElementQNameResolver with the WadlGenerator which will be used for creating wadl:representation/@element values.

Changing the base address

Starting from CXF 2.6.2 it is possible to affect the base address specified in the auto-generated WADL (in wadl:resources/@base attribute).
WADLGenerator can be indirectly configured by setting a jaxrs:server/@publishedEndpointUrl attribute, similarly to the way CXF WSDL generator can be configured by setting a jaxws:endpoint/@publishedEndpointUrl attribute.

java2wadl Maven plugin

CXF 3.0.0 and 2.7.11 introduce java2wadl plugin for generating WADL at the build time:

<groupId>org.apache.cxf</groupId>
<artifactId>cxf-java2wadl-plugin</artifactId>
<version>3.0.0</version>

Add this plugin to the build section of your project's pom, for example:

<build>
     <plugins>
            
       <plugin>
                <groupId>org.apache.cxf</groupId>
                <artifactId>cxf-java2wadl-plugin</artifactId>
                <version>3.0.0</version>
                <executions>
                    <!-- Enable if support for Javadoc is required, not supported in CXF 2.7.11 -->
                    <!--
                    <execution>
                        <id>parsejavadoc</id>
                        <phase>generate-sources</phase>
                        <goals>
                            <goal>parsejavadoc</goal>
                        </goals>
                    </execution>
                    -->
                    <execution>
                        <id>process-classes</id>
                        <phase>process-classes</phase>
                        <goals>
                            <goal>java2wadl</goal>
                        </goals>
                        <configuration>
                            <classResourceNames>
                                    <classResourceName>a.b.c.CustomerService</classResourceName>
                            </classResourceNames>
                            <!-- Enable if support for Javadoc is required, not supported in CXF 2.7.11 -->
                            <!--
                            <docProvider>org.apache.cxf.maven_plugin.javatowadl.ResourceMapJavaDocProvider</docProvider>
                            -->
                            <attachWadl>true</attachWadl>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

Note that Javadoc can be properly supported by enabling the "parsejavadoc" execution and a docProvider property.

WADL Transformations

Starting from CXF 3.0.4 it is possible to configure WADLGenerator with a 'stylesheetReference' property pointing to a local XSLT template. 

If an 'applyStylesheetLocally' property is disabled (default) then a generated WADL XML representation will include an XML XSLT processing instruction pointing to a template with the browser downloading it in the next step and doing the transformation itself. Otherwise WADLGenerator will attempt to do a local transformation before returning a response to the browser.

This feature can help with further enhancing the generated WADL XML with some simple transformations (example, adding some information to WADL XML that is not possible to get from the annotated JAX-RS resources) or convert it to HTML

If no JAXB is used then you can attach an XMLName annotation to method input or output types. Alternatively, you can register an instance of ElementQNameResolver with the WadlGenerator which will be used for creating wadl:representation/@element values.

Changing the base address

Starting from CXF 2.6.2 it is possible to affect the base address specified in the auto-generated WADL (in wadl:resources/@base attribute).
WADLGenerator can be indirectly configured by setting a jaxrs:server/@publishedEndpointUrl attribute, similarly to the way CXF WSDL generator can be configured by setting a jaxws:endpoint/@publishedEndpointUrl attribute.

Service listings and WADL queries

Links to WADL instances for RESTful endpoints are available from {base endpointaddress}/services, in addition to SOAP endpoints if any.

For example, given

Base address : 'http://localhost:8080'
WAR name : 'store'
CXFServlet : '/books/*'
jaxrs:server/@address = '/orders'

...

For example, if the following 2 root resource classes has been registered with this endpoint:

@Path("/fiction") 
public class FictionBookOrders {
}
@Path("/sport") 
public class SportBookOrders {
}

...

You can easily customize what Content-Type is set by either using a WadlGenerator 'defaultMediaType' property or using the extension mappings and adding a .wadl at the end of request URI instead of using a _wadl query: "http://localhost:8080/store/books/orders/fiction.wadl", where extensions will map a 'wadl' to 'application/vnd.sun.wadl+xml' or indeed to 'application/xml'.

WADL in JSON format

Use a "?_wadl&_type=json" or something like "fiction.wadl", where extensions will map a 'wadl' to 'application/json' in order to get a WADL JSON representations, please see this blog entry for more information.

...