用maven建立可执行jar?
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06-07-2019 - |
题
我正在尝试为名为<!> quot; logmanager <!>的小型家庭项目生成一个可执行jar。使用maven,就像这样:
我将那里显示的片段添加到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.
双击jar-with-dependencies.jar时出现略有不同的错误:
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。
以下是完整的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>
解决方案
实际上,我认为答案是在问题只是错误(更新 - 20101106:有人修复了它,此答案指的是编辑前的版本)这至少部分解释了为什么会遇到麻烦。
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package
阶段期间由jar:jar
生成的logmanager模块的JAR(因为该模块具有类型jar
的包装)。第二个是由assembly:assembly
生成的程序集,应该包含当前模块及其依赖项中的类(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,则配置了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(因为它没有所有依赖项)和2.它不包含com.gorkwobble.logmanager.LogManager
(这是错误所说的,检查jar的内容。)
双击jar-with-dependencies.jar时出现略有不同的错误:
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>
使用此设置,logmanager-0.1.0-jar-with-dependencies.jar
包含当前模块和其依赖项中的类,但根据错误,META-INF/MANIFEST.MF
不包含Main-Class
条目(它可能与logmanager-0.1.0.jar中的MANIFEST.MF不同)。 jar实际上是不可执行文件,这也不是你想要的。
所以,我的建议是从maven-jar-plugin中删除configuration
元素并配置像这样的maven-assembly-plugin:
<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,将org.sample.App
替换为您要执行的类。小小的奖励,我已经assembly:single
到mvn install
阶段,所以你不必再运行mvn clean install
了。只需运行target
,即可在标准构建期间生成程序集。
因此,请使用上面给出的配置更新您的pom.xml并运行pom.xml
。然后,cd进入<=>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<=>文件的内容和<=>(插件配置部分)的相关部分。另请发布结果:
java -cp logmanager-0.1.0-jar-with-dependencies.jar com.gorkwobble.logmanager.LogManager
证明它在命令行上正常工作(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>
其他提示
Pascal Thivent 的答案也帮助了我。
但如果您在<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,否则如果您运行mvn install
,则依赖项不会打包在jar中。
<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>
如果您不想在程序包上执行程序集目标,可以使用下一个命令:
mvn package assembly:single
此处包是关键字。
右键单击该项目并提供maven build,maven clean,maven generate resource和maven install.jar文件将自动生成。