用 Maven2构建一个可运行的 jar

我对 Maven 的咒语比较陌生，但是我正在尝试用 Maven 构建一个命令行可运行的 jar。我已经设置了我的依赖项，但是当我运行 mvn install并尝试运行 jar 时，会发生两件事情。首先，没有找到主类，这是可以纠正的。当我纠正这个问题时，我会在运行时遇到错误，说明无法找到类。

Maven 没有将我的依赖项库打包在 jar 中，因此我无法将 jar 作为独立应用程序运行。我该怎么纠正呢？

98786 次浏览
小开

Maven is not packaging your dependencies inside your jar file, because you don't usually do this with Java programs.

Instead you deliver the dependencies together with your jar file and mention them in the Class-Path header of the Manifest.

To go this route, you'll need to enable the addClasspath property (documented here) for the maven-jar-plugin.

If you really want to include all your dependencies in your jar file, then you can use the Maven Assembly plugin to create a jar-with-dependencies.

小开
最佳答案

The easiest way to do this would be to create an assembly using the maven-assembly-plugin and the predefined jar-with-dependencies descriptor. You'll also need to generate a manifest with a main-class entry for this uber jar. The snippet below shows how to configure the assembly plugin to do so:

<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>

Then, to generate the assembly, just run:

mvn assembly:assembly

If you want to generate the assembly as part of your build, simply bind the assembly:single mojo to the package phase:

<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>

And simply run:

mvn package
小开

I Agree with Joachim Sauer,

Instead of using jar-with-dependency you should configure the jar plugin like that in your pom.xml:

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<configuration>
<archive>
<index>true</index>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>[mainClassFullName]</mainClass>
</manifest>
<manifestEntries>
<mode>development</mode>
<url>${project.url}</url>
<key>value</key>
</manifestEntries>
</archive>
</configuration>
</plugin>

And use this assembly configuration to add the jar dependencies to you assembly:

<assembly xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0 http://maven.apache.org/xsd/assembly-1.1.0.xsd">
<id>zip-with-jars</id>
<formats>
<format>zip</format>
</formats>
<includeBaseDirectory>false</includeBaseDirectory>
<dependencySets>
<dependencySets>
<dependencySet>
<outputDirectory>/</outputDirectory>
<useProjectArtifact>true</useProjectArtifact>
<unpack>false</unpack>
<scope>runtime</scope>
</dependencySet>
</dependencySets>
</dependencySets>
</assembly>
小开

This is what I would do for small projects. Most of the time you don't want one huge jar.

to build: mvn clean dependency:copy-dependencies package

to execute (in target dir): java -cp myjar.jar:./dependency/* com.something.MyClass

小开

Just add the below code in pom.xml and Run as: maven:install . The jar will be created in target folder of eclipse which can be used as "java -jar Hello.jar" . but make sure that name of main class is given com.abc.HelloWorld.java

<build>
<plugins>
<plugin>
<groupid>org.apache.maven.plugins</groupid>
<artifactid>maven-shade-plugin</artifactid>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<finalname>HelloW</finalname>
<transformers>
<transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<manifestentries>
<main-class>com.abc.HelloWorld.java</main-class>
<build-number>1</build-number>
</manifestentries>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
</plugins>


</build>
小开

I have a spring boot application, and the jar created by maven package can be run without setting up additional plugins.

Inside my pom.xml:

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.6.12</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>

https://spring.io/projects/spring-boot


提交答案