RESTful Services using Jersey 2.0

Jersey is an implementation of JAX-RS specification which provide API's for developing and exposing applications designed following principles of REST architectural style.

Jersey is now part of glassfish that means the upgrade 2.0 is provided from glassfish and has lot of changes shipped with it compared to Jersey 1.0. Here's the migration guide.

Though above migration guide will help. My development involves using Oracle JDeveloper so I haven't really got a chance to use the migration steps myself so I'm making some hand written code again to get a feel of Jersey 2.0 and also along the way I'll try to document needed changes for anyone else going my path.

This document includes code that can be used by Java and Oracle ADF developers. Let's roll into code now:

Maven dependencies for the maven people:

pom.xml:

<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd;

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.rdev.jersey</groupId>

    <artifactId>Jersey2Demo</artifactId>

    <version>0.0.1-SNAPSHOT</version>

    <packaging>war</packaging>

    <repositories>

        <repository>

            <id>maven2-repository.java.net</id>

            <name>Java.net Repository for Maven</name>

            <url>http://download.java.net/maven/2/</url>

            <layout>default</layout>

        </repository>

    </repositories>

    <properties>

        <jersey2.version>2.19</jersey2.version>

        <jaxrs.version>2.0.1</jaxrs.version>

    </properties>

    <dependencies>

        <!-- JAX-RS -->

        <dependency>

            <groupId>javax.ws.rs</groupId>

            <artifactId>javax.ws.rs-api</artifactId>

            <version>${jaxrs.version}</version>

        </dependency>

        <!-- Jersey 2.19 -->

        <dependency>

            <groupId>org.glassfish.jersey.containers</groupId>

            <artifactId>jersey-container-servlet</artifactId>

            <version>${jersey2.version}</version>

        </dependency>

        <dependency>

            <groupId>org.glassfish.jersey.core</groupId>

            <artifactId>jersey-server</artifactId>

            <version>${jersey2.version}</version>

        </dependency>

        <dependency>

            <groupId>org.glassfish.jersey.core</groupId>

            <artifactId>jersey-client</artifactId>

            <version>${jersey2.version}</version>

        </dependency>

    </dependencies>

    <build>

        <finalName>Jersey2Demo</finalName>

        <plugins>

            <plugin>

                <artifactId>maven-compiler-plugin</artifactId>

                <configuration>

                    <source>1.7</source>

                    <target>1.7</target>

                </configuration>

            </plugin>

        </plugins>

    </build>

</project>

JDeveloper 12.2.1.3: (***** JDeveloper/ADF Developers only****)

web.xml:

<!DOCTYPE web-app PUBLIC

 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"

 "http://java.sun.com/dtd/web-app_2_3.dtd" >

  

<web-app>

  

  <display-name>Archetype Created Web Application</display-name>

    

  <servlet>

        <servlet-name>jersey-serlvet</servlet-name>

        <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>

        <init-param>

             <param-name>jersey.config.server.provider.packages</param-name>

             <param-value>com.rdev.jersey</param-value>

        </init-param>

        <load-on-startup>1</load-on-startup>

    </servlet>

   

    <servlet-mapping>

        <servlet-name>jersey-serlvet</servlet-name>

        <url-pattern>/rest/*</url-pattern>

    </servlet-mapping>

      

</web-app>

Notice the package changes from com.sun.jersey.* to org.glassfish.jersey.*

Now let's write the resource class:

HelloResource.java:

package com.rdev.jersey;




import javax.ws.rs.GET;

import javax.ws.rs.Path;




@Path("/hello")

public class HelloResource{

     @GET

     public String getHelloWorld(){

         return "Hello World from Jersey 2!";

     }

}

So steps needed for migration for simple resources as above would be:

1. change the dependencies in pom.xml.
2. ServletContainer changes in web.xml.
3. package import changes if any.

Happy Coding ✌