我正在尝试使用JDK 6（在Eclipse Luna，Java EE版中）使用Maven 3.2.5构建，并且我不断收到以下错误：
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/maven/cli/MavenCli : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:401)
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:254)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
at org.codehaus.plexus.classworlds.launcher.Launcher.getMainClass(Launcher.java:144)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:266)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
经过调查，Maven下载了为JDK 7编译的plexus-classworlds-2.5.2-sources.jar，这就是问题的原因。 Maven 3.2.5应该与JDK 6一起工作，所以我不明白发生了什么。
这里是pom.xml：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>fr.sacem.fwk</groupId>
<artifactId>frmwk-parent</artifactId>
<version>5.3.13</version>
</parent>
<artifactId>sacem-fwkweb</artifactId>
<packaging>jar</packaging>
<name>Sacem Framework Web</name>
<description>Socle technique de la Sacem</description>
<dependencies>
<!-- FwkCore -->
<dependency>
<groupId>fr.sacem.fwk</groupId>
<artifactId>sacem-fwkcore</artifactId>
<version>${project.version}</version>
</dependency>
<!-- Wesso -->
<dependency>
<groupId>fr.sacem.admap</groupId>
<artifactId>wesso-api</artifactId>
<version>3.5.0</version>
</dependency>
<!-- Apache Commons -->
<dependency>
<groupId>commons-beanutils</groupId>
<artifactId>commons-beanutils</artifactId>
</dependency>
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
</dependency>
<dependency>
<groupId>commons-collections</groupId>
<artifactId>commons-collections</artifactId>
</dependency>
<dependency>
<groupId>commons-dbcp</groupId>
<artifactId>commons-dbcp</artifactId>
</dependency>
<dependency>
<groupId>commons-digester</groupId>
<artifactId>commons-digester</artifactId>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
</dependency>
<dependency>
<groupId>commons-jxpath</groupId>
<artifactId>commons-jxpath</artifactId>
</dependency>
<dependency>
<groupId>commons-lang</groupId>
<artifactId>commons-lang</artifactId>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</dependency>
<dependency>
<groupId>commons-net</groupId>
<artifactId>commons-net</artifactId>
</dependency>
<dependency>
<groupId>commons-pool</groupId>
<artifactId>commons-pool</artifactId>
</dependency>
<!--
<dependency>
<groupId>commons-resources</groupId>
<artifactId>commons-resources</artifactId>
<version>X.Y.Z</version>
</dependency>
-->
<dependency>
<groupId>commons-validator</groupId>
<artifactId>commons-validator</artifactId>
</dependency>
<!-- Gestion des Logs -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</dependency>
<!-- POI -->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-contrib</artifactId>
</dependency>
<!-- Struts -->
<dependency>
<!--
<groupId>struts</groupId>
-->
<groupId>fr.sacem.struts</groupId>
<artifactId>struts</artifactId>
</dependency>
<dependency>
<groupId>xerces</groupId>
<artifactId>xercesImpl</artifactId>
</dependency>
<!-- JUnit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>fr.sacem.fwk</groupId>
<artifactId>fwkunit</artifactId>
<scope>test</scope>
</dependency>
<!-- API JavaEE
<dependency>
<groupId>javaee</groupId>
<artifactId>javaee-api</artifactId>
<scope>provided</scope>
</dependency>
-->
<!-- API Servlet -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<scope>provided</scope>
</dependency>
<!-- API JSP -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jsp-api</artifactId>
<scope>provided</scope>
</dependency>
<!-- API JTA -->
<dependency>
<groupId>javax.transaction</groupId>
<artifactId>jta</artifactId>
<scope>provided</scope>
</dependency>
<!-- YUI Compressor -->
<dependency>
<groupId>com.yahoo.platform.yui</groupId>
<artifactId>yuicompressor</artifactId>
<version>2.4.7</version>
<scope>provided</scope>
<type>jar</type>
</dependency>
</dependencies>
<properties>
<project.build.sourceEncoding>ISO-8859-1</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<frmwk.project.build.sourceEncoding>${project.build.sourceEncoding}</frmwk.project.build.sourceEncoding>
<frmwk.project.copyright>Copyright 2002-2015 SACEM.</frmwk.project.copyright>
<frmwk.web.directory.build>${basedir}/build</frmwk.web.directory.build>
<frmwk.web.directory.source.java>${basedir}/WEB-INF/sources/java/dev</frmwk.web.directory.source.java>
<frmwk.web.directory.classes>${frmwk.web.directory.build}/classes</frmwk.web.directory.classes>
<frmwk.web.directory.test.sources>${basedir}/WEB-INF/sources/java/tests</frmwk.web.directory.test.sources>
<frmwk.web.directory.test.config>${basedir}/WEB-INF/config</frmwk.web.directory.test.config>
<frmwk.web.directory.test.resources>${basedir}/WEB-INF/ressources</frmwk.web.directory.test.resources>
<frmwk.web.directory.test.classes>${frmwk.web.directory.build}/test-classes</frmwk.web.directory.test.classes>
<frmwk.web.directory.deploy>${basedir}/WEB-INF/deploiement</frmwk.web.directory.deploy>
<frmwk.web.directory.templates>${frmwk.web.directory.deploy}/script/templates</frmwk.web.directory.templates>
<frmwk.resources.jsp>${project.artifactId}-${project.version}-jsp</frmwk.resources.jsp>
<frmwk.resources.tools.yuicompressor>${maven.dependency.com.yahoo.platform.yui.yuicompressor.jar.path}</frmwk.resources.tools.yuicompressor>
</properties>
<build>
<directory>${frmwk.web.directory.build}</directory>
<sourceDirectory>${frmwk.web.directory.source.java}</sourceDirectory>
<resources>
<resource>
<directory>${frmwk.web.directory.source.java}</directory>
<filtering>false</filtering>
<includes>
<include>**/*.xml</include>
<include>**/*.properties</include>
</includes>
</resource>
</resources>
<outputDirectory>${frmwk.web.directory.classes}</outputDirectory>
<testSourceDirectory>${frmwk.web.directory.test.sources}</testSourceDirectory>
<testResources>
<testResource>
<directory>${frmwk.web.directory.test.resources}</directory>
<filtering>true</filtering>
<includes>
<include>**/*</include>
</includes>
</testResource>
<testResource>
<directory>${frmwk.web.directory.test.config}</directory>
<filtering>false</filtering>
<includes>
<include>**/*</include>
</includes>
</testResource>
</testResources>
<testOutputDirectory>${frmwk.web.directory.test.classes}</testOutputDirectory>
<plugins>
<!-- - - - - - - - - - - - - - - - - -
JAVADOC
- - - - - - - - - - - - - - - - - -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-javadoc-plugin</artifactId>
<configuration>
<javadocExecutable>${frmwk.javadoc.executable}</javadocExecutable>
<docfilessubdirs>true</docfilessubdirs>
<locale>fr_FR</locale>
<version>true</version>
<author>true</author>
<use>true</use>
<private>false</private>
<doctitle>${project.name} ${project.version}</doctitle>
<windowtitle>${project.name} ${project.version}</windowtitle>
<header><b>${project.name} ${project.version}</b></header>
<bottom>${frmwk.project.copyright}</bottom>
<stylesheetfile>${frmwk.web.directory.templates}/javadoc-stylesheet/stylesheet.css</stylesheetfile>
</configuration>
<executions>
<execution>
<id>attach-javadocs</id>
<goals>
<goal>jar</goal>
</goals>
</execution>
</executions>
</plugin>
<!-- - - - - - - - - - - - - - - - - -
COMPILATION JAVA 1.6
- - - - - - - - - - - - - - - - - -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${frmwk.compile.source}</source>
<target>${frmwk.compile.target}</target>
<verbose>${frmwk.compile.verbose}</verbose>
<debug>${frmwk.compile.debug}</debug>
<encoding>${frmwk.project.build.sourceEncoding}</encoding>
<showDeprecation>${frmwk.compile.deprecation}</showDeprecation>
<optimize>${frmwk.compile.optimize}</optimize>
<fork>${frmwk.compile.fork}</fork>
<executable>${frmwk.compile.executable}</executable>
<compilerVersion>${frmwk.compile.compilerVersion}</compilerVersion>
</configuration>
</plugin>
<!-- - - - - - - - - - - - - - - - - -
SOURCES JAVA
- - - - - - - - - - - - - - - - - -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-source-plugin</artifactId>
<executions>
<execution>
<id>attach-sources</id>
<goals>
<goal>jar</goal>
</goals>
</execution>
</executions>
</plugin>
<!-- =================================
PREPARER LIVRAISON AMELY
================================= -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<executions>
<!-- - - - - - - - - - - - - - - - - -
target: copy-jars-to-delivery-dir
- - - - - - - - - - - - - - - - - -->
<execution>
<id>copy-jars-to-delivery-dir</id>
<phase>install</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<target name="Jar" description="Livrer la librairie">
<!-- S'assurer de l'existence du dossier de livraison -->
<mkdir dir="${frmwk.project.delivery.dir}" />
<!-- Copier les jar -->
<copy todir="${frmwk.project.delivery.dir}" overwrite="true" >
<fileset dir="${frmwk.web.directory.build}">
<filename name="*.jar"/>
</fileset>
</copy>
</target>
</configuration>
</execution>
<!-- - - - - - - - - - - - - - - - - -
target: copy-javadoc-to-delivery-dir
- - - - - - - - - - - - - - - - - -->
<execution>
<id>copy-javadoc-to-delivery-dir</id>
<phase>install</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<target name="Javadoc" description="Livrer la documentation en ligne (api)">
<!-- S'assurer de l'existence du dossier dedestination -->
<mkdir dir="${frmwk.project.delivery.dir}/Javadoc/${project.artifactId}" />
<!-- Copier le dossier -->
<copy todir="${frmwk.project.delivery.dir}/Javadoc/${project.artifactId}" overwrite="true" >
<fileset dir="${frmwk.web.directory.build}/apidocs">
<filename name="**/*"/>
</fileset>
</copy>
<!-- Copier le template de dossier Amely -->
<filter token="projectVersion" value="${project.version}"/>
<filter token="projectName" value="${project.artifactId}"/>
<copy file="${frmwk.web.directory.templates}/amely/Javadoc/project.name/folder.amely"
tofile="${frmwk.project.delivery.dir}/Javadoc/${project.artifactId}/folder.amely"
filtering="true"/>
</target>
</configuration>
</execution>
<!-- - - - - - - - - - - - - - - - - -
target: zip-sources-non-public
- - - - - - - - - - - - - - - - - -->
<execution>
<id>zip-sources-non-public</id>
<phase>package</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<target name="SourcesNonPublic" description="Livrer les sources (non public)">
<mkdir dir="${frmwk.project.delivery.dir}/SourcesNonPublic" />
<!-- Zipper l'intégralité du projet -->
<zip destfile="${frmwk.project.delivery.dir}/SourcesNonPublic/${project.artifactId}_${project.version}.srcnonpublic.zip">
<fileset dir="${basedir}">
<include name=".settings/**/*"/>
<include name="commun/**/*"/>
<include name="fwk/**/*"/>
<include name="WEB-INF/**/*"/>
<include name=".*"/>
<exclude name="build/"/>
<exclude name="*.log"/>
</fileset>
</zip>
</target>
</configuration>
</execution>
<!-- - - - - - - - - - - - - - - - - -
target: fwkweb-jsp-zip
- - - - - - - - - - - - - - - - - -->
<execution>
<id>fwkweb-jsp-zip</id>
<phase>package</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<target name="jsp-build-zip">
<delete dir="${frmwk.project.delivery.dir}/${frmwk.resources.jsp}.zip" failonerror="false" />
<zip zipfile="${frmwk.project.delivery.dir}/${frmwk.resources.jsp}.zip">
<zipfileset dir="${basedir}" prefix="src/main/webapp">
<include name="fwk/**/*"/>
</zipfileset>
<zipfileset dir="${basedir}/WEB-INF/ressources" prefix="src/main/resources">
<include name="*.properties"/>
</zipfileset>
</zip>
</target>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>build-helper-maven-plugin</artifactId>
<executions>
<!-- =================================
target: FRMWK-${project.version}.zip
================================= -->
<execution>
<id>attach-artifacts</id>
<phase>package</phase>
<goals>
<goal>attach-artifact</goal>
</goals>
<configuration>
<artifacts>
<artifact>
<file>${frmwk.project.delivery.dir}/${frmwk.resources.jsp}.zip</file>
<type>zip</type>
<classifier>jsp</classifier>
</artifact>
</artifacts>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<profiles>
<!--
- - - - - - - - - - - - - - - - - - -
Profile: FRMWK
- - - - - - - - - - - - - - - - - - - -
-->
<profile>
<id>FRMWK</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
<properties>
<!-- Paramètre de build des modules FRMWK -->
<frmwk.compile.executable>${JAVA_1_6_HOME}/bin/${JAVAC_EXE}</frmwk.compile.executable>
<frmwk.javadoc.executable>${JAVA_1_6_HOME}/bin/${JAVADOC_EXE}</frmwk.javadoc.executable>
<!-- Options de compilation -->
<frmwk.compile.source>1.6</frmwk.compile.source>
<frmwk.compile.target>${frmwk.compile.source}</frmwk.compile.target>
<frmwk.compile.verbose>true</frmwk.compile.verbose>
<frmwk.compile.debug>true</frmwk.compile.debug>
<frmwk.compile.deprecation>true</frmwk.compile.deprecation>
<frmwk.compile.optimize>true</frmwk.compile.optimize>
<frmwk.compile.fork>true</frmwk.compile.fork>
<frmwk.compile.compilerVersion>${frmwk.compile.source}</frmwk.compile.compilerVersion>
<frmwk.project.delivery.dir>${FRMWK_DELIVRY_HOME}/V${project.version}</frmwk.project.delivery.dir>
</properties>
</profile>
</profiles>
</project>
答案 0 :(得分：2)
错误消息，例如
线程中的异常＆＃34; main＆＃34; java.lang.UnsupportedClassVersionError：org / apache / maven / cli / MavenCli：不支持的major.minor版本51.0
将始终指示使用JDK 7编译的代码正由不兼容的JRE版本执行（最可能是6或更低版本）。
在您的特定用例（项目需要 JDK6）中，您必须确保使用的最大Maven版本是3.2.5（当前最新的官方JDK6兼容Maven版本）。
如果您的系统托管不同版本的Maven，您必须强制使用该版本。
而且，根据Maven的推出方式，您可以通过以下方式强制使用Maven版本：