用maven建立可执行jar？

Question

我正在尝试使用maven为一个名为"logmanager"的小型家庭项目生成一个可执行jar,就像这样:

如何使用Maven创建具有依赖关系的可执行JAR？

我将那里显示的代码段添加到pom.xml中,然后运行mvn assembly:assembly.它在logmanager/target中生成两个jar文件:logmanager-0.1.0.jar和logmanager-0.1.0-jar-with-dependencies.jar.当我双击第一个jar时出现错误:

Could not find the main class: com.gorkwobble.logmanager.LogManager. Program will exit.

当我双击jar-with-dependencies.jar时出现稍微不同的错误:

Failed to load Main-Class manifest attribute from: C:\EclipseProjects\logmanager\target\logmanager-0.1.0-jar-with-dependencies.jar

我复制并粘贴了路径和类名,并检查了POM中的拼写.我的主要类从eclipse启动配置启动.有人可以帮我弄清楚为什么我的jar文件不会运行？另外,为什么有两个罐开始？如果您需要更多信息,请与我们联系.

这是完整的pom.xml,供参考:

<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.gorkwobble</groupId>
  <artifactId>logmanager</artifactId>
  <name>LogManager</name>
  <version>0.1.0</version>
  <description>Systematically renames specified log files on a scheduled basis. Designed to help manage MUSHClient logging and prevent long, continuous log files.</description>
  <build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>2.2</version>
            <!-- nothing here -->
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-assembly-plugin</artifactId>
            <version>2.2-beta-4</version>
            <configuration>
              <descriptorRefs>
                <descriptorRef>jar-with-dependencies</descriptorRef>
              </descriptorRefs>
              <archive>
                <manifest>
                  <mainClass>com.gorkwobble.logmanager.LogManager</mainClass>
                </manifest>
              </archive>
            </configuration>
            <executions>
              <execution>
                <phase>package</phase>
                <goals>
                  <goal>single</goal>
                </goals>
              </execution>
            </executions>
          </plugin>
          <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
              <source>1.6</source>
              <target>1.6</target>
            </configuration>
          </plugin>
    </plugins>
  </build>
  <dependencies>
    <!-- commons-lang -->
    <dependency>
        <groupId>commons-lang</groupId>
        <artifactId>commons-lang</artifactId>
        <version>2.4</version>
    </dependency> 

    <!-- Quartz scheduler -->
    <dependency>
        <groupId>opensymphony</groupId>
        <artifactId>quartz</artifactId>
        <version>1.6.3</version>
    </dependency>
    <!-- Quartz 1.6.0 depends on commons collections -->
    <dependency>
      <groupId>commons-collections</groupId>
      <artifactId>commons-collections</artifactId>
      <version>3.1</version>
    </dependency>
    <!-- Quartz 1.6.0 depends on commons logging -->
    <dependency>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
      <version>1.1</version>
    </dependency>
    <!-- Quartz 1.6.0 requires JTA in non J2EE environments -->
    <dependency>
      <groupId>javax.transaction</groupId>
      <artifactId>jta</artifactId>
      <version>1.1</version>
      <scope>runtime</scope>
    </dependency>

    <!-- junitx test assertions -->
    <dependency>
        <groupId>junit-addons</groupId>
        <artifactId>junit-addons</artifactId>
        <version>1.4</version>
        <scope>test</scope>
    </dependency>

    <!-- junit dependency; FIXME: make this a separate POM -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.1</version>
    </dependency>

  </dependencies>
  <dependencyManagement>
  </dependencyManagement>
</project>

Answer 1

实际上,我认为你提到的问题中给出的答案是错误的(UPDATE - 20101106:有人修复了它,这个答案指的是编辑之前的版本),这至少部分解释了为什么你遇到了麻烦.

它在logmanager/target中生成两个jar文件:logmanager-0.1.0.jar和logmanager-0.1.0-jar-with-dependencies.jar.

第一个是在package阶段期间生成的logmanager模块的JAR jar:jar(因为模块具有类型的包装jar).第二个是由assembly:assembly当前模块及其依赖项生成的程序集,并且应该包含它们(如果使用了描述符jar-with-dependencies).

当我双击第一个jar时出现错误:

Could not find the main class: com.gorkwobble.logmanager.LogManager. Program will exit.

如果您应用了作为参考发布的链接的建议配置,那么您配置了jar插件以生成可执行工件,如下所示:

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-jar-plugin</artifactId>
    <configuration>
      <archive>
        <manifest>
          <addClasspath>true</addClasspath>
          <mainClass>com.gorkwobble.logmanager.LogManager</mainClass>
        </manifest>
      </archive>
    </configuration>
  </plugin>

所以logmanager-0.1.0.jar确实是可执行的但是1.这不是你想要的(因为它没有所有的依赖关系)和2.它不包含com.gorkwobble.logmanager.LogManager(这是错误所说的,检查jar的内容).

当我双击jar-with-dependencies.jar时出现稍微不同的错误:

Failed to load Main-Class manifest attribute from: C:\EclipseProjects\logmanager\target\logmanager-0.1.0-jar-with-dependencies.jar

同样,如果您按照建议配置了程序集插件,那么您可以这样:

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-assembly-plugin</artifactId>
    <configuration>
      <descriptorRefs>
        <descriptorRef>jar-with-dependencies</descriptorRef>
      </descriptorRefs>
    </configuration>
  </plugin>

有了这个设置,logmanager-0.1.0-jar-with-dependencies.jar包含的类从当前模块和它的依赖,但根据错误,它META-INF/MANIFEST.MF 并不包含一个Main-Class条目(其可能不一样MANIFEST.MF在日志管理-0.1.0.jar).jar实际上不可执行,这也不是你想要的.

所以,我的建议是configuration从maven-jar-plugin中删除元素并配置maven-assembly-plugin,如下所示:

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-jar-plugin</artifactId>
    <version>2.2</version>
    <!-- nothing here -->
  </plugin>
  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-assembly-plugin</artifactId>
    <version>2.2-beta-4</version>
    <configuration>
      <descriptorRefs>
        <descriptorRef>jar-with-dependencies</descriptorRef>
      </descriptorRefs>
      <archive>
        <manifest>
          <mainClass>org.sample.App</mainClass>
        </manifest>
      </archive>
    </configuration>
    <executions>
      <execution>
        <phase>package</phase>
        <goals>
          <goal>single</goal>
        </goals>
      </execution>
    </executions>
  </plugin>

当然,替换org.sample.App你想要执行的类.小小的奖励,我已经assembly:single到了package阶段,所以你不必再跑assembly:assembly了.刚运行mvn install,组装将在标准构建期间生成.

因此,请使用上面给出的配置更新您的pom.xml并运行mvn clean install.然后,cd进入target目录并再试一次:

java -jar logmanager-0.1.0-jar-with-dependencies.jar

如果您收到错误,请用它更新您的问题并发布META-INF/MANIFEST.MF文件的内容和您的相关部分pom.xml(插件配置部分).还请发布以下结果:

java -cp logmanager-0.1.0-jar-with-dependencies.jar com.gorkwobble.logmanager.LogManager

证明它在命令行上运行正常(无论eclipse在说什么).

编辑:对于Java 6,您需要配置maven-compiler-plugin.将其添加到您的pom.xml:

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
      <source>1.6</source>
      <target>1.6</target>
    </configuration>
  </plugin>

Answer 2

Pascal Thivent的答案也帮助了我. 但是如果您在<pluginManagement>元素中管理插件,则必须在插件管理之外再次定义程序集,否则如果运行,依赖项不会打包在jar中mvn install.

<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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>jar</packaging>


    <build>
        <pluginManagement>
            <plugins>

                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.1</version>
                    <configuration>
                        <source>1.6</source>
                        <target>1.6</target>
                    </configuration>
                </plugin>

                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-assembly-plugin</artifactId>
                    <version>2.4</version>
                    <configuration>
                        <archive>
                            <manifest>
                                <mainClass>main.App</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>

            </plugins>

        </pluginManagement>

        <plugins> <!-- did NOT work without this  -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
            </plugin>
        </plugins>

    </build>


    <dependencies>
       <!--  dependencies commented out to shorten example -->
    </dependencies>

</project>

Answer 3

如果您不希望在程序包上执行程序集目标,则可以使用next命令:

mvn package assembly:single

这里的包是关键字.