Jersey 2 client with maven
I want to create simple Jersey 2 Client app with Maven (Server app is also implemented and runs).
My 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.client</groupId>
<artifactId>RestClient</artifactId>
<packaging>jar</packaging>
<version>1.0-SNAPSHOT</version>
<name>RestClient</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.core</groupId>
<artifactId>jersey-client</artifactId>
<version>2.13</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
java code
package com.client;
import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.client.Entity;
import javax.ws.rs.core.GenericType;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.client.WebTarget;
import javax.ws.rs.core.Response;
import javax.ws.rs.client.Invocation.Builder;
public class App
{
public static void main( String[] args )
{
Client client = ClientBuilder.newClient();
WebTarget target = client.target("http://localhost:8080").path("simple-service-webapp/rest/myresource");
Builder builder = target.request();
//Response response = builder.get();
String result = builder.get(String.class);
System.out.println(target.getUri().toString());
System.out.println("Result=" + result);
}
}
I build app by command mvn package and everything pass. Then, I run app by java -cp target/RestClient-1.0-SNAPSHOT.jar com.client.App and then error occurs:
Exception in thread "main" java.lang.NoClassDefFoundError: javax/ws/rs/client/ClientBuilder
at com.client.App.main(App.java:20)
Caused by: java.lang.ClassNotFoundException: javax.ws.rs.client.ClientBuilder
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 1 more
It seems that libraries are not included, because files tree of projeckt looks:
.
├── pom.xml
├── src
│ ├── main
│ │ └── java
│ │ └── com
│ │ └── client
│ │ └── App.java
│ └── test
│ └── java
│ └── com
│ └── client
│ └── AppTest.java
└── target
├── classes
│ └── com
│ └── client
│ └── App.class
├── generated-sources
│ ├── annotations
│ └── test-annotations
├── maven-archiver
│ └── pom.properties
├── RestClient-1.0-SNAPSHOT.jar
├── surefire
├── surefire-reports
│ ├── com.client.AppTest.txt
│ └── TEST-com.client.AppTest.xml
└── test-classes
└── com
└── client
└── AppTest.class
Where did I mistake? Thanks.
Answer
You need to copy the dependencies to from your local repo into you project (or anywhere really, wherever you want to -cp to). For this, you can use the maven-dependency-plugin. Just add this to the <plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.9</version>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>package</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/lib</outputDirectory>
<overWriteReleases>false</overWriteReleases>
<overWriteSnapshots>false</overWriteSnapshots>
<overWriteIfNewer>true</overWriteIfNewer>
</configuration>
</execution>
</executions>
</plugin>
What the above plugin configuration will do is copy all the dependencies to target/lib.
The easiest way to run the jar as an executable is to also set the Class-Path in the MANIFEST.MF, through Maven. For that we can use the maven-jar-plugin. So add this to the <plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.5</version>
<configuration>
<archive>
<index>true</index>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
<mainClass>com.client.App</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
Also you will need to get rid of the <scope>provided</scope> for the Jersey client dependency. With this scope, Maven will not add the jars to the classpath.
After doing this, you can simply run java -jar your-jar.jar, without the need to -cp anything, as all the jars are specified in the Manifest. It should look something like
Manifest-Version: 1.0
Archiver-Version: Plexus Archiver
Built-By: XxxxXxxxx
Class-Path: lib/jersey-client-2.13.jar lib/jersey-common-2.13.jar lib/
javax.annotation-api-1.2.jar lib/jersey-guava-2.13.jar lib/osgi-resou
rce-locator-1.0.1.jar lib/javax.ws.rs-api-2.0.1.jar lib/hk2-api-2.3.0
-b10.jar lib/hk2-utils-2.3.0-b10.jar lib/aopalliance-repackaged-2.3.0
-b10.jar lib/javax.inject-2.3.0-b10.jar lib/hk2-locator-2.3.0-b10.jar
lib/javassist-3.18.1-GA.jar
Created-By: Apache Maven 3.0.5
Build-Jdk: 1.8.0_20
Main-Class: com.client.App