Arun Gupta, Miles to go ...

TOTD #56: Simple RESTful Web service using Jersey and Embeddable GlassFish - Text and JSON output

Jersey is the open source, production quality, JAX-RS (JSR 311) Reference Implementation for building RESTful Web services in the GlassFish community. It also provides an API that allows developers to extend Jersey to suite their requirements.

1. Create a simple web app using Maven as:
   
   

   ~/samples/jersey >mvn archetype:generate -DarchetypeCatalog=http://download.java.net/maven/2 [INFO] Scanning for projects... [INFO] Searching repository for plugin with prefix: 'archetype'. [INFO] ------------------------------------------------------------------------ [INFO] Building Maven Default Project [INFO]    task-segment: [archetype:generate] (aggregator-style) [INFO] ------------------------------------------------------------------------ [INFO] Preparing archetype:generate [INFO] No goals needed for project - skipping [INFO] Setting property: classpath.resource.loader.class => 'org.codehaus.plexus.velocity.ContextClassLoaderResourceLoader'. [INFO] Setting property: velocimacro.messages.on => 'false'. [INFO] Setting property: resource.loader => 'classpath'. [INFO] Setting property: resource.manager.logwhenfound => 'false'. [INFO] [archetype:generate] [INFO] Generating project in Interactive mode [INFO] No archetype defined. Using maven-archetype-quickstart (org.apache.maven.archetypes:maven-archetype-quickstart:1.0) Choose archetype: 1: remote -> jersey-quickstart-grizzly (Archetype for creating a RESTful web application with Jersey and Grizzly) 2: remote -> jersey-quickstart-webapp (Archetype for creating a Jersey based RESTful web application WAR packaging) Choose a number:  (1/2): 2 [INFO] snapshot com.sun.jersey.archetypes:jersey-quickstart-webapp:1.0.1-SNAPSHOT: checking for updates from jersey-quickstart-webapp-repo Define value for groupId: : org.glassfish.samples Define value for artifactId: : helloworld-webapp Define value for version:  1.0-SNAPSHOT: : Define value for package: : org.glassfish.samples Confirm properties configuration: groupId: org.glassfish.samples artifactId: helloworld-webapp version: 1.0-SNAPSHOT package: org.glassfish.samples  Y: : [INFO] ---------------------------------------------------------------------------- [INFO] Using following parameters for creating OldArchetype: jersey-quickstart-webapp:1.0.1-SNAPSHOT [INFO] ---------------------------------------------------------------------------- [INFO] Parameter: groupId, Value: org.glassfish.samples [INFO] Parameter: packageName, Value: org.glassfish.samples [INFO] Parameter: package, Value: org.glassfish.samples [INFO] Parameter: artifactId, Value: helloworld-webapp [INFO] Parameter: basedir, Value: /Users/arungupta/samples/jersey [INFO] Parameter: version, Value: 1.0-SNAPSHOT [INFO] ********************* End of debug info from resources from generated POM *********************** [INFO] OldArchetype created in dir: /Users/arungupta/samples/jersey/helloworld-webapp [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESSFUL [INFO] ------------------------------------------------------------------------ [INFO] Total time: 21 seconds [INFO] Finished at: Mon Nov 24 14:09:27 PST 2008 [INFO] Final Memory: 12M/30M [INFO] ------------------------------------------------------------------------

2. Edit the generated "pom.xml" to add dependencies on GlassFish plugin
1. Add the following plugin in the "pom.xml" under <build>/<plugins>:
   
   

   <plugin>                 <groupId>org.glassfish</groupId>                 <artifactId>maven-glassfish-plugin</artifactId>             </plugin>

2. Add the following plugin repositories:
   
   

   <pluginRepositories>         <pluginRepository>             <id>maven2-repository.dev.java.net</id>             <name>Java.net Repository for Maven</name>             <url>http://download.java.net/maven/2/</url>             <layout>default</layout>         </pluginRepository>         <pluginRepository>             <id>maven-repository.dev.java.net</id>             <name>Java.net Maven 1 Repository (legacy)</name>             <url>http://download.java.net/maven/1</url>             <layout>legacy</layout>         </pluginRepository>     </pluginRepositories>

3. Optionally, if the generated dependencies in "pom.xml" as shown below:
   
   

   <dependency>             <groupId>org.glassfish.distributions</groupId>             <artifactId>web-all</artifactId>             <version>10.0-build-20080430</version>             <scope>test</scope>         </dependency>         <dependency>             <groupId>org.glassfish.embedded</groupId>             <artifactId>gf-embedded-api</artifactId>             <version>1.0-alpha-4</version>             <scope>test</scope>         </dependency>

   
   are changed to:
   
   

   <dependency>             <groupId>org.glassfish.distributions</groupId>             <artifactId>web-all</artifactId>             <version>10.0-SNAPSHOT</version>             <scope>test</scope>         </dependency>         <dependency>            <groupId>org.glassfish.embedded</groupId>            <artifactId>glassfish-embedded-all</artifactId>            <version>3.0-Prelude-SNAPSHOT</version>         </dependency>

   
   then the latest version of Embedded GlassFish APIs are used.
4. Also optionally, if you want to run against Jersey 1.0 bits then change the following property from "1.0.1-SNAPSHOT" to "1.0".
   
   

   <properties>         <jersey-version>1.0</jersey-version>     </properties>

3. Run the application
1. The generated source code is:
   
   

   package org.glassfish.samples; import javax.ws.rs.GET; import javax.ws.rs.Path; import javax.ws.rs.Produces; // The Java class will be hosted at the URI path "/helloworld" @Path("/myresource") public class MyResource {         // The Java method will process HTTP GET requests     @GET     // The Java method will produce content identified by the MIME Media     // type "text/plain"     @Produces("text/plain")     public String getIt() {         return "Hi there!";     } }

   
   Invoking "mvn glassfish:run" starts the embedded GlassFish and shows the following output:
   
   

   ~/samples/jersey/helloworld-webapp >mvn glassfish:run [INFO] Scanning for projects... [INFO] Searching repository for plugin with prefix: 'glassfish'. [INFO] ------------------------------------------------------------------------ [INFO] Building helloworld-webapp Jersey Webapp [INFO]    task-segment: [glassfish:run] [INFO] ------------------------------------------------------------------------ [INFO] Preparing glassfish:run [INFO] [resources:resources] [INFO] Using default encoding to copy filtered resources. [INFO] [compiler:compile] [INFO] Compiling 1 source file to /Users/arungupta/samples/jersey/helloworld-webapp/target/classes [INFO] [glassfish:run] Nov 24, 2008 2:36:05 PM com.sun.enterprise.v3.server.AppServerStartup run INFO: HK2 initialized in 229 ms Nov 24, 2008 2:36:05 PM com.sun.enterprise.v3.server.AppServerStartup run INFO: com.sun.enterprise.naming.impl.ServicesHookup@2470b02c Init done in 237 ms Nov 24, 2008 2:36:05 PM com.sun.enterprise.v3.server.AppServerStartup run INFO: com.sun.enterprise.v3.server.Globals@13b3d787 Init done in 239 ms Nov 24, 2008 2:36:05 PM com.sun.enterprise.v3.server.AppServerStartup run INFO: com.sun.enterprise.v3.server.SystemTasks@61bedd7d Init done in 244 ms Nov 24, 2008 2:36:05 PM com.sun.enterprise.v3.server.AppServerStartup run INFO: com.sun.enterprise.v3.services.impl.HouseKeeper@2b9f7952 Init done in 245 ms Nov 24, 2008 2:36:05 PM com.sun.enterprise.v3.server.AppServerStartup run INFO: com.sun.enterprise.v3.services.impl.CmdLineParamProcessor@5249d560 Init done in 248 ms JMXMP connector server URL = service:jmx:jmxmp://localhost:8888 Nov 24, 2008 2:36:05 PM com.sun.enterprise.v3.services.impl.GrizzlyProxy start INFO: Listening on port 8080 Nov 24, 2008 2:36:06 PM com.sun.enterprise.v3.server.AppServerStartup run INFO: com.sun.enterprise.v3.services.impl.GrizzlyService@1baa56a2 startup done in 551 ms Nov 24, 2008 2:36:06 PM com.sun.enterprise.v3.services.impl.ApplicationLoaderService postConstruct INFO: loader service postConstruct started at 1227566166208 Nov 24, 2008 2:36:06 PM com.sun.enterprise.v3.server.AppServerStartup run INFO: Application Loader startup done in 740 ms Nov 24, 2008 2:36:06 PM com.sun.enterprise.v3.server.AppServerStartup run INFO: Glassfish v3 started in 740 ms Nov 24, 2008 2:36:07 PM com.sun.enterprise.web.WebModuleContextConfig authenticatorConfig SEVERE: webModuleContextConfig.missingRealm Nov 24, 2008 2:36:07 PM com.sun.jersey.api.core.PackagesResourceConfig init INFO: Scanning for root resource and provider classes in the packages:   org.glassfish.samples Nov 24, 2008 2:36:07 PM com.sun.jersey.api.core.PackagesResourceConfig init INFO: Root resource classes found:   class org.glassfish.samples.MyResource Nov 24, 2008 2:36:07 PM com.sun.jersey.api.core.PackagesResourceConfig init INFO: Provider classes found: Hit ENTER for redeploy

   
   Notice how GlassFish v3 starts up in sub-second (740 ms in this case).
   
2. "http://localhost:8080/helloworld-webapp" shows the following output:
   
   
3. Clicking on "Jersey resource" redirects to "http://localhost:8080/helloworld-webapp/webresources/myresource" and shows the following output:
   
   
4. Change the output representation to produce JSON representation
1. Add a new JAXB bean:
   
   

   package org.glassfish.samples; import javax.xml.bind.annotation.XmlRootElement; /**  * @author arungupta  */ @XmlRootElement public class Greeting {     public String greeting;     public Greeting() { }     public Greeting(String greeting) {         this.greeting = greeting;     } }

2. Change the method implementation in MyResource as:
   
   

   //    @Produces("text/plain")     @Produces("application/json")     public Greeting getIt() {         return new Greeting("Hi there!");     }

3. And now "http://localhost:8080/helloworld-webapp/webresources/myresource" shows the following output:
   
   
   
   Notice the output is now in JSON format.
5. Optionally a WAR file can be created using the command:
   
   

   mvn clean package

   
   and the WAR file is generated in "target/helloworld-webapp.war". If Jersey is installed using GlassFish v3 Update Center then you can use "maven-assembly-plugin" to customize packaging of WAR and drastically reduce the size.
   

Posted by Arun Gupta in webservices  |  Comments[16]