Can I get application.wadl file using RESTeasy?

Question

I need to get WADL file for RESTful service. I know that in case using jersey it's available as http://localhost:8080/application.wadl. But I use RESTeasy.

Can I do the same in my framework case?

Answer 1

Latest versions:

Quoting Chapter 49. RESTEasy WADL Support:

Chapter 49. RESTEasy WADL Support

49.1. RESTEasy WADL Support for Servlet Container
49.2. RESTEasy WADL support for Sun JDK HTTP Server
49.3. RESTEasy WADL support for Netty Container
49.4. RESTEasy WADL Support for Undertow Container

RESTEasy has its own support to generate WADL for its resources, and it supports several different containers. The following text will show you how to use this feature in different containers.

49.1. RESTEasy WADL Support for Servlet Container

RESTEasy WADL uses ResteasyWadlServlet to support servlet container. It can be registered into web.xml to enable WADL feature. Here is an example to show the usages of ResteasyWadlServlet in web.xml:

<servlet>
  <servlet-name>RESTEasy WADL</servlet-name>
  <servlet-class>org.jboss.resteasy.wadl.ResteasyWadlServlet</servlet-class>
</servlet>

<servlet-mapping>
  <servlet-name>RESTEasy WADL</servlet-name>
  <url-pattern>/application.xml</url-pattern>
</servlet-mapping>

The preceding configuration in web.xml shows how to enable ResteasyWadlServlet and mapped it to /application.xml. And then the WADL can be accessed from the configured URL:

/application.xml

---

Workaround for Older versions

There is a workaround: a maven plugin called maven-wadl-plugin by the jersey folks that also works to generate WADL for services coded using RESTEasy.

Here's how to use it.

1. Add this to your pom.xml:

<build>
<plugins>
    <plugin>
        <groupId>com.sun.jersey.contribs</groupId>
        <artifactId>maven-wadl-plugin</artifactId>      
        <version>1.17</version>
        <executions>
            <execution>
                <id>generate</id>
                <goals>
                    <goal>generate</goal>
                </goals>
                <phase>${javadoc-phase}</phase>
            </execution>
        </executions>
        <configuration>
            <wadlFile>${project.build.outputDirectory}/application.wadl
            </wadlFile>
            <formatWadlFile>true</formatWadlFile>
            <baseUri>http://example.com:8080/rest</baseUri>
            <packagesResourceConfig>
                <param>com.example.rs.resource</param>
            </packagesResourceConfig>
            <wadlGenerators>
                <wadlGeneratorDescription>
                    <className>com.sun.jersey.server.wadl.generators.WadlGeneratorApplicationDoc
                    </className>
                    <properties>
                        <property>
                            <name>applicationDocsFile</name>
                            <value>${basedir}/src/main/doc/application-doc.xml</value>
                        </property>
                    </properties>
                </wadlGeneratorDescription>
                <wadlGeneratorDescription>
                    <className>com.sun.jersey.server.wadl.generators.WadlGeneratorGrammarsSupport
                    </className>
                    <properties>
                        <property>
                            <name>grammarsFile</name>
                            <value>${basedir}/src/main/doc/application-grammars.xml</value>
                        </property>
                    </properties>
                </wadlGeneratorDescription>
            </wadlGenerators>
        </configuration>
    </plugin>
</plugins>
</build>

Pay attention to the baseUri and packagesResourceConfig elements. You have to change them to reflect your project's configuration. You may also want to change the plugin's version (I used 1.17).

2. Create a /doc folder and add some files.

Create the src/main/doc/ folder and create the two files below.

File: application-doc.xml

Content:

<?xml version="1.0" encoding="UTF-8"?>
<applicationDocs targetNamespace="http://wadl.dev.java.net/2009/02">
    <doc xml:lang="en" title="A message in the WADL">This is added to the start of the generated application.wadl</doc>
</applicationDocs>

File: application-grammars.xml

Content:

<?xml version="1.0" encoding="UTF-8" ?>
<grammars xmlns="http://wadl.dev.java.net/2009/02" />

3. Run the maven command.

Go to the project folder and run the following command:

$ mvn compile com.sun.jersey.contribs:maven-wadl-plugin:generate

The files \target\classes\application.wadl (the WADL itself) and \target\classes\xsd0.xsd (the schema of the resources - it's used by the application.wadl) should be generated.

Edit and use them as you wish.

PS.: Bear in mind that this is a very simple use of the maven-wadl-plugin. It can do a lot more. To know it better, please refer to the zip file in http://search.maven.org/remotecontent?filepath=com/sun/jersey/samples/generate-wadl/1.12/generate-wadl-1.12-project.zip