我想用Maven创建简单的Jersey 2 Client应用程序(服务器应用程序也已实现并运行)。
我的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代码
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);
}
}
我通过命令 mvn package 构建app,一切都通过了。然后,我通过 java -cp target / RestClient-1.0-SNAPSHOT.jar com.client.App 运行app,然后发生错误:
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
似乎没有包含库,因为projeckt的文件树看起来:
.
├── 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
我在哪里弄错了?感谢。
答案 0 :(得分:3)
您需要将依赖项从本地repo复制到您的项目中(或者任何地方,无论您想要-cp到哪里)。为此,您可以使用maven-dependency-plugin。只需将其添加到<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>
上述插件配置的作用是将所有依赖项复制到target/lib
。
将jar作为可执行文件运行的最简单方法是通过Maven在Class-Path
中设置MANIFEST.MF
。为此,我们可以使用maven-jar-plugin。所以将其添加到<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>
此外,您需要删除Jersey客户端依赖项的<scope>provided</scope>
。使用此范围,Maven不会将jar添加到类路径中。
执行此操作后,您只需运行java -jar your-jar.jar
,而无需-cp任何内容,因为所有jar都在Manifest中指定。它应该看起来像
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
答案 1 :(得分:1)
您已根据提供标记了您的球衣依赖关系,因此它不会包含在输出中,因为当提供依赖关系时,假定它在环境中可用(例如,由应用程序服务器提供)。 / p>
尝试从Maven依赖项中删除<scope>provided</scope>
,或在运行程序时使用-cp
参数在类路径中包含jersey jar。
答案 2 :(得分:0)
您可以做的另一件事是将依赖项打包到胖罐中。 maven-assembly-plugin会自动为你完成。
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>YOUR MAIN CLASS HERE</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
如果您需要更复杂的基本模式,您可以创建自定义程序集规范,其中所有依赖项都包含在jar中。
还有maven-shade-plugin,它也更易于配置。
另一个有用的工具是:
mvn dependency:tree -Dverbose
准确了解您的依赖关系。