java - Eclipse 中的 Ant 脚本使用了不正确的 Java 版本

Question

我正在开发一个需要使用 Java 1.5 的旧项目，但是当我运行构建脚本时，出现错误：

java.lang.UnsupportedClassVersionError: Bad version number in .class file

我相信这个错误是指正在使用的较新版本的 Java，即使我只想使用 Java 1.5。我已经更改了下Windows->Preferences->Java->Installed JREs和下的设置Run As->External Tool Configuration->JRE，使两者都指向Java 1.5. 在下Run As->External Tool Configuration->Environment，我添加了变量JAVA_HOME并JRE_HOME指向旧版本的 Java。将此行添加到构建脚本时：

<echo message="ant.java.version: ${ant.java.version}"/>

Eclipse 返回此值：

[echo] ant.java.version: 1.5

但上述错误仍然存在。我能够构建项目的唯一方法是更改我的环境变量JAVA_HOME和JRE_HOME环境变量以指向旧版本的 Java。Eclipse 中是否有任何其他设置可以在不更改系统环境变量的情况下更改以构建项目？（即 Ant 使用 Java 1.5 构建项目，但系统变量仍指向 Java 1.7）。

代码build.xml：

<project name="osd-bits" basedir="." default="deploy">

<!-- Project settings -->

<!-- TODO -->
<!-- This needs to be set individually by each developer to the correct Tomcat path -->
<property name="tomcat.path" value="C:\Tomcat 6\apache-tomcat-6.0.35" />

<property name="project.title" value="OSD BITS"/>
<property name="project.name" value="osd-bits"/>
<property name="project.version" value="2.0"/>
<property name="project.deploypath" value="${tomcat.path}\\webapps"/>
<property name="project.workdir" value="${tomcat.path}\\work\Catalina\localhost"/>

<!-- Test Server Settings -->   
<property name="project.deploypathtest" value="T:\Program Files\jakarta-tomcat-5.0.28\webapps"/>    
<property name="project.workdirtest" value="T:\Program Files\jakarta-tomcat-5.0.28\work\Catalina\localhost"/>


<!-- Staging Server Settings -->    
<property name="project.deploypathstage" value="S:\Program Files\jakarta-tomcat-5.0.28\webapps"/>   
<property name="project.workdirstage" value="S:\Program Files\jakarta-tomcat-5.0.28\work\Catalina\localhost"/>

<!-- Production Server Settings -->
<property name="project.deploypathprod" value="P:\Program Files\jakarta-tomcat-5.0.28\webapps"/>    
<property name="project.workdirprod" value="P:\Program Files\jakarta-tomcat-5.0.28\work\Catalina\localhost"/>   

<!-- Path settings -->  
<property name="path.binary" value="${basedir}/../../baja2/bin"/>        
<property name="path.webroot" value="${basedir}/webroot"/>   
<property name="path.conf" value="${basedir}/conf"/>
<property name="path.src" value="${basedir}/src"/>
<property name="path.build" value="${basedir}/bin"/>
<property name="path.cmdlib" value="${basedir}/cmd/lib"/>    
<property name="path.buildlib" value="${tomcat.path}\\lib"/>
<property name="path.webinf" value="${path.webroot}/WEB-INF"/>
<property name="path.lib" value="${path.webinf}/lib"/>
<property name="path.classes" value="${path.webinf}/classes"/>
<property name="path.classpath" value="${path.lib}/baja.jar;
                                       ${path.lib}/struts.jar;
                                       ${path.buildlib}/fop.jar;
                                       ${basedir}/lib/servlet.jar;
                                       ${path.buildlib}/velocity-dep-1.4.jar;
                                       ${basedir}/lib/jxl.jar;
                                       ${path.lib}/display.jar;
                                       ${path.buildlib}/commons-validator.jar;
                                       ${path.buildlib}/commons-beanutils.jar;
                                       ${path.lib}/quartz-1.6.3.jar"/>

<!-- Check timestamp on files -->
<target name="timecheck">
    <tstamp/>
</target>

<!-- Remove classes for clean build -->
<target name="clean" description="Prepare for clean build">
  <delete dir="${path.build}/com"/>
  <delete file="${path.lib}/${project.name}.jar"/>
  <delete file="${path.lib}/${project.name}-config.jar"/>
</target>


<!-- jar up config files -->
<target name="config">
    <jar jarfile="${path.lib}/${project.name}-config.jar" basedir="${path.conf}"/>
</target>

<!-- Full build of java and config files-->
<target name="build" depends="timecheck,clean,config">
    <echo message="ant.java.version: ${ant.java.version}" />
    <javac srcdir="${path.src}" destdir="${path.build}" classpath="${path.classpath}" debug="true" target="1.5" includeantruntime="false"/>
    <jar jarfile="${path.lib}/${project.name}.jar" basedir="${path.build}"/>
</target>

<!-- Builds everything in src directory and deploys .war to deployment directory -->       
<target name="deploy" depends="build" description="Deploys project to deployment directory">
    <delete file="${project.deploypath}\${project.name}.war"/>
    <delete dir="${project.deploypath}\${project.name}"/>
    <delete dir="${project.workdir}\${project.name}"/>
    <copy todir="${project.deploypath}\${project.name}">
        <fileset dir="${path.webroot}"/>
    </copy>
</target>

<!-- Builds everything in src directory and deploys to test server deployment directory -->       
<target name="deploytotest" depends="build" description="Deploys project to test deployment directory">
    <delete file="${project.deploypathtest}\${project.name}.war"/>
    <delete dir="${project.deploypathtest}\${project.name}"/>
    <delete dir="${project.workdirtest}\${project.name}"/>
    <copy todir="${project.deploypathtest}\${project.name}">
        <fileset dir="${path.webroot}"/>
    </copy>
</target>

<!-- Builds everything in src directory and deploys to staging server deployment directory -->       
<target name="deploytostage" depends="build" description="Deploys project to stage deployment directory">
    <delete file="${project.deploypathstage}\${project.name}.war"/>
    <delete dir="${project.deploypathstage}\${project.name}"/>
    <delete dir="${project.workdirstage}\${project.name}"/>
    <copy todir="${project.deploypathstage}\${project.name}">
        <fileset dir="${path.webroot}"/>
    </copy>
</target>

<!-- Builds everything in src directory and deploys to production server deployment directory -->       
<target name="deploytoprod" depends="build" description="Deploys project to production deployment directory">
    <delete file="${project.deploypathprod}\${project.name}.war"/>
    <delete dir="${project.deploypathprod}\${project.name}"/>
    <delete dir="${project.workdirprod}\${project.name}"/>
    <copy todir="${project.deploypathprod}\${project.name}">
        <fileset dir="${path.webroot}"/>
    </copy>
</target>

<target name="movejsps" description="Moves all JSP files without doing a complete rebuild">
    <copy todir="${project.deploypath}\${project.name}\jsp" preservelastmodified="false" >
        <fileset dir="${path.webroot}/jsp" />
    </copy> 
</target>

<target name="movejs" description="Moves all JS files without doing a complete rebuild">
    <copy todir="${project.deploypath}\${project.name}\js" preservelastmodified="false" >
        <fileset dir="${path.webroot}/js" />
    </copy> 
</target>

<target name="movecss" description="Moves all CSS files without doing a complete rebuild">
    <copy todir="${project.deploypath}\${project.name}\css" preservelastmodified="false" >
        <fileset dir="${path.webroot}/css" />
    </copy> 
</target>

<target name="movetemplates" description="Moves all Report Template files without doing a complete rebuild">
    <copy todir="${project.deploypath}\${project.name}\templates" preservelastmodified="false" >
        <fileset dir="${path.webroot}/templates" />
    </copy> 
</target>


<target name="copyjar" description="Moves latests baja.jar into demos webinf lib">
    <copy file="${path.binary}/baja.jar" todir="${path.lib}" preservelastmodified="true" />     
</target>

<!-- Builds the command line distribution -->       
<target name="deploycmd" depends="build" description="Deploys project to test deployment directory">
    <delete file="${path.cmdlib}\${project.name}.jar"/>
    <delete file="${path.cmdlib}\${project.name}-config.jar"/>
    <copy file="${path.lib}/${project.name}.jar" todir="${path.cmdlib}" preservelastmodified="true" />  
    <copy file="${path.lib}/${project.name}-config.jar" todir="${path.cmdlib}" preservelastmodified="true" />   
</target>

score 2 · Accepted Answer

可能有多种原因：

您使用为 java 1.6 编译的库
在 ant 脚本中，您可以指定要编译到的 java 版本。它可能是与 ant 本身运行的版本不同的版本。
在eclipse设置里面，可以选择一个ant安装。ant 安装可能是为 java 1.6 编译的（不太可能）。您可以添加（？）/选择另一个 ant 安装
如果 ant 不编译您的源代码但使用类文件，则 eclipse 自动编译已经生成，您需要更改项目的 java 编译器版本和项目设置中的项目 JRE（显然有 ;-)

score 0 · Accepted Answer

如果你不使用eclipse。然后，您可以直接在文件上更改 ant java 属性，如此处所述。为我工作。

http://pissedoff-techie.blogspot.in/2014/09/ant-picks-up-incorrect-java-version.html

score 0 · Accepted Answer

带着所有的罐子去图书馆。如果您可以运行 bash 脚本，请执行以下操作：

#!/bin/bash
for jarfile in `ls *.jar`
do
    directory=${jarfile%.jar}
    if [ -d $directory ]
    then
        rm -r $directory
    fi  

    mkdir $directory
    cd $directory
    jar xf ../$jarfile
    cd ..
    for classfile in `find ./ -name *.class`
    do
        file $classfile | grep -v "version 46" | grep -v "version 47" | grep -v "version 48" | grep -v "version 49"
    done
done

这应该吐出任何不是版本 46 (Java 1.2)、版本 47 (Java 1.3)、48 (Java 1.4) 或 49 (Java 1.5) 的类。石英罐有一个 45.3 的类，即 Java 1.1。也许这是个问题？如果不是（谷歌搜索建议 JVM 1.5 可以运行 1.1 类），那么也排除“45.3”：

file $classfile | grep -v "version 45.3" | grep -v "version 46" | grep -v "version 47" | grep -v "version 48" | grep -v "version 49"

java - Eclipse 中的 Ant 脚本使用了不正确的 Java 版本

3 回答 3

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