error with a jersey restful maven project

Question

I downloaded the project from mkyong's website. I'm facing issue running the project. I'm not sure what is wrong. I'm doing this the first time, so please help me. If this works, I want to add hibernate to this project.

I tried to deploy this in Glassfish server and Wildfly 10. Didn't work in either of the servers

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/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.mkyong.common</groupId>
    <artifactId>RESTfulExample</artifactId>
    <packaging>war</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>RESTfulExample Maven Webapp</name>
    <url>http://maven.apache.org</url>

    <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>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.8.2</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.glassfish.jersey.core</groupId>
            <artifactId>jersey-server</artifactId>
            <version>2.22.1</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet-core</artifactId>
            <version>2.22.1</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet</artifactId>
            <version>2.22.1</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-json-jackson</artifactId>
            <version>2.22.1</version>
        </dependency>



    </dependencies>

    <build>
        <finalName>RESTfulExample</finalName>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

HelloWorldService.java

package com.mkyong.rest;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.core.Response;

@Path("/hello")
public class HelloWorldService {

    @GET
    @Path("/{param}")
    public Response getMsg(@PathParam("param") String msg) {

        String output = "Jersey say : " + msg;

        return Response.status(200).entity(output).build();

    }

}

web.xml

<web-app id="WebApp_ID" version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    <display-name>Restful Web Application</display-name>

    <servlet>
    <servlet-name>jersey-serlvet</servlet-name>
    <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
    <init-param>
        <param-name>com.sun.jersey.config.property.packages</param-name>
        <param-value>com.mkyong.rest</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>

Answer 1

You are using Jersey 1.x configuration for Jersey 2.x dependencies. It won't work. The two major versions have no compatibility whatsoever. 2.x configuration looks more like

<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.mkyong.rest
        </param-value>
    </init-param>
</servlet>
<servlet-mapping>
    <servlet-name>jersey-serlvet</servlet-name>
    <url-pattern>/rest/*</url-pattern>
</servlet-mapping>

See more at Servlet-based Deployment.

A few other things:

• You are already using Maven. No need to put jars into the WEB-INF/lib yourself.

• If you are using Glassfish, you should put all the Jersey dependencies you are using in a provided <scope>

  <dependency>
      <groupId>org.glassfish.jersey.containers</groupId>
      <artifactId>jersey-container-servlet</artifactId>
      <version>2.22.1</version>
      <scope>provided</scope>
  </dependency>
  

  The reason is that Glassfish already uses Jersey as the JAX-RS implementation, but it uses an older version (with GF 4.1 its 2.10.4). You don't want a different version to cause conflicts. If you want to upgrade Jersey in Glassfish, you can check out Updating Jersey 2 in GlassFish 4

• If you want to use Wildfly, it already uses RESTeasy as JAX-RS implementation. To use Jersey you should disable RESTeasy. Not completely sure the best way to go about doing that. You may need to do some googling.

• If you were to just use a plain servlet container like Tomcat, you can leave the dependencies as is, without <scope>provided</scope>, as Tomcat doesn't have a JAX-RS implementation.