升级到Java7后生成失败,缺少Tools.jar和错误的类版本
我最近在MacBookPro上升级到了Java7。我下载了JDK(不是JRE) 但是,当尝试运行构建时,一个maven编译器插件失败,声称我安装了JRE:升级到Java7后生成失败,缺少Tools.jar和错误的类版本,java,Java,我最近在MacBookPro上升级到了Java7。我下载了JDK(不是JRE) 但是,当尝试运行构建时,一个maven编译器插件失败,声称我安装了JRE: » mvn install [ERROR] execute error org.apache.maven.plugin.MojoExecutionException: You need to run build with JDK or have tools.jar on the classpath. If this occures duri
» mvn install
[ERROR] execute error
org.apache.maven.plugin.MojoExecutionException: You need to run build with JDK
or have tools.jar on the classpath.
If this occures during eclipse build make sure you run eclipse under JDK as well
at com.mysema.maven.apt.AbstractProcessorMojo.execute(AbstractProcessorMojo.java:263)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
我很困惑,因为我显然安装了JDK。我的MAVEN_选项
不要做任何有趣的事:
» echo $MAVEN_OPTS
-Xmx512m
尝试调试时,我检查了有问题的插件的名称,它正在执行以下操作:
try {
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
if (compiler == null) {
throw new MojoExecutionException("You need to run build with JDK or have tools.jar on the classpath."
+ "If this occures during eclipse build make sure you run eclipse under JDK as well");
}
drwxrwxr-x 10 root wheel 340 5 Feb 08:10 jre
-rw-rw-r-- 1 root wheel 123324 5 Feb 08:10 THIRDPARTYLICENSEREADME-JAVAFX.txt
drwxrwxr-x 5 root wheel 170 5 Feb 08:10 man
drwxrwxr-x 9 root wheel 306 2 Mar 02:10 db
-rw-rw-r-- 1 root wheel 3339 2 Mar 02:10 COPYRIGHT
drwxrwxr-x 9 root wheel 306 2 Mar 02:10 include
-rw-rw-r-- 1 root wheel 19997030 2 Mar 02:10 src.zip
-rw-rw-r-- 1 root wheel 447 2 Mar 02:10 release
-rw-rw-r-- 1 root wheel 172252 2 Mar 02:10 THIRDPARTYLICENSEREADME.txt
-rw-rw-r-- 1 root wheel 114 2 Mar 02:10 README.html
-rw-rw-r-- 1 root wheel 40 2 Mar 02:10 LICENSE
drwxrwxr-x 5 root wheel 170 2 Mar 02:10 ..
drwxrwxr-x 15 root wheel 510 2 Mar 02:13 .
drwxrwxr-x 13 root wheel 442 2 Mar 02:13 lib
drwxrwxr-x 43 root wheel 1462 2 Mar 02:13 bin
这似乎是无害的,所以我怀疑我的命令行env有问题,并编写了一个简单的测试:
// Main.java
import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;
public class Main {
public static void main(String[] args) {
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
if (compiler == null)
{
System.out.print("Compiler is null");
} else {
System.out.print("Compiler is not null");
}
}
}
» javac Main.java
Main.java:1: cannot access javax.tools.JavaCompiler
bad class file: /Library/Java/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents/Home/jre/lib/rt.jar(javax/tools/JavaCompiler.class)
class file has wrong version 51.0, should be 49.0
Please remove or make sure it appears in the correct subdirectory of the classpath.
import javax.tools.JavaCompiler;
^
1 error
如果我正确理解了这个错误,它建议使用一个针对Java5rt.jar运行的Java7编译器
我不知道这里发生了什么
我显然安装了Java7 JDK,但不明白:
- 为什么maven插件为编译器返回null
- 为什么会出现类版本错误
更新
答案是一个混乱的JRE/JDK安装。我同意这似乎是可能的,但在追查罪犯的下落时遇到了困难
其他一些信息:
» which javac
/usr/bin/javac
ls -ltra /usr/bin/javac
/usr/bin/javac -> /System/Library/Frameworks/JavaVM.framework/Versions/Current/Commands/javac
cd /System/Library/Frameworks/JavaVM.framework/Versions
ls -ltra
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.6.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.6 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.5.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.5 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.4.2 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.4 -> CurrentJDK
drwxr-xr-x 8 root wheel 272 18 Feb 08:39 A
drwxr-xr-x 11 root wheel 374 18 Feb 08:39 ..
lrwxr-xr-x 1 root wheel 1 14 Jun 11:14 Current -> A
lrwxr-xr-x 1 root wheel 58 14 Jun 11:15 CurrentJDK -> /Library/Java/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents
drwxr-xr-x 11 root wheel 374 14 Jun 11:15 .
因此,正在运行的javac就是安装在A/Commands
中的javac。我不确定这是否正确。在我的windows时代,这似乎是错误的,但我对Mac如何处理Java安装的问题还不够熟悉
我的$JAVA_HOME
指向/Library/JAVA/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents/HOME
,它具有以下内容:
try {
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
if (compiler == null) {
throw new MojoExecutionException("You need to run build with JDK or have tools.jar on the classpath."
+ "If this occures during eclipse build make sure you run eclipse under JDK as well");
}
drwxrwxr-x 10 root wheel 340 5 Feb 08:10 jre
-rw-rw-r-- 1 root wheel 123324 5 Feb 08:10 THIRDPARTYLICENSEREADME-JAVAFX.txt
drwxrwxr-x 5 root wheel 170 5 Feb 08:10 man
drwxrwxr-x 9 root wheel 306 2 Mar 02:10 db
-rw-rw-r-- 1 root wheel 3339 2 Mar 02:10 COPYRIGHT
drwxrwxr-x 9 root wheel 306 2 Mar 02:10 include
-rw-rw-r-- 1 root wheel 19997030 2 Mar 02:10 src.zip
-rw-rw-r-- 1 root wheel 447 2 Mar 02:10 release
-rw-rw-r-- 1 root wheel 172252 2 Mar 02:10 THIRDPARTYLICENSEREADME.txt
-rw-rw-r-- 1 root wheel 114 2 Mar 02:10 README.html
-rw-rw-r-- 1 root wheel 40 2 Mar 02:10 LICENSE
drwxrwxr-x 5 root wheel 170 2 Mar 02:10 ..
drwxrwxr-x 15 root wheel 510 2 Mar 02:13 .
drwxrwxr-x 13 root wheel 442 2 Mar 02:13 lib
drwxrwxr-x 43 root wheel 1462 2 Mar 02:13 bin
忘了Maven吧
JDK/bin
目录在哪个目录中?那是JAVA\u HOME
我怀疑您设置的环境变量不正确
而/bin
应该拥有JDK工具的所有可执行文件:javac、java、jar、javap等等
如果不是这样,那么你没有JDK,你有JRE
我有一台Windows电脑。下面是我安装JDK的地方:
C:\Program Files\Java\jdk1.7.0_17
这里是JAVA_主页:
JAVA_HOME=C:/Program Files/Java/jdk1.7.0_02
很可能javac是从JRE而不是JDK运行的。jar仅在JDK中可用。使用which
which javac
将正确的Java7版本拖动到Java首选项的顶部(Launchapad/Others)。这应该指向JDK7。我在/Library/Java/Extensions
中找到了一个tools.jar
我不确定这是否是标准的
但是,将tools.jar
从JDK7$JAVA_HOME/lib
复制到/Library/JAVA/Extensions
解决了我的所有问题
我还应该指出,在我最初的问题中,我已将JavaCurrentSDK
更新为指向JDK7
:
CurrentJDK -> /Library/Java/JavaVirtualMachines/jdk1.7.0_17.jdk/Contents
正如所指出的,这是一个坏主意
我将其更新为1.6。尽管这似乎有悖常理,但它是让事情正常运转所必需的
带有1.7
JDK的/System/Library/Frameworks/JavaVM.framework/Versions的当前列表如下所示:
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.6.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.6 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.5.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.5 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.4.2 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.4 -> CurrentJDK
drwxr-xr-x 8 root wheel 272 18 Feb 08:39 A
drwxr-xr-x 11 root wheel 374 18 Feb 08:39 ..
lrwxr-xr-x 1 root wheel 1 14 Jun 11:35 Current -> A
lrwxr-xr-x 1 root wheel 59 14 Jun 12:31 CurrentJDK -> /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents
drwxr-xr-x 11 root wheel 374 14 Jun 12:31 .
export JAVA_HOME=/Library/Java/Home
在MacOS X上设置JAVA_主页的正确方法是使用:
[user@ip ~]$ export JAVA_HOME=$(/usr/libexec/java_home -v1.7)
[user@ip ~]$ echo $JAVA_HOME
/Library/Java/JavaVirtualMachines/jdk1.7.0_25.jdk/Contents/Home
如果执行此操作后,$java_HOME/lib不包含tools.jar,则java安装将中断
提示:我在~/.bash_配置文件中指定了这两个别名:
alias java6="export JAVA_HOME=$(/usr/libexec/java_home -v1.6)"
alias java7="export JAVA_HOME=$(/usr/libexec/java_home -v1.7)"
将JAR放在/Library/Java/Extensions中相当于将它们放在全局类路径中,这很少是一个好主意。我遇到了类似的问题,并在另一个线程中找到了答案:
我将JAVA_HOME设置如下:
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.6.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.6 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.5.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.5 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.4.2 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 18 Feb 08:36 1.4 -> CurrentJDK
drwxr-xr-x 8 root wheel 272 18 Feb 08:39 A
drwxr-xr-x 11 root wheel 374 18 Feb 08:39 ..
lrwxr-xr-x 1 root wheel 1 14 Jun 11:35 Current -> A
lrwxr-xr-x 1 root wheel 59 14 Jun 12:31 CurrentJDK -> /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents
drwxr-xr-x 11 root wheel 374 14 Jun 12:31 .
export JAVA_HOME=/Library/Java/Home
如果您发现/Library/Java/Extensions
中的tools.jar
不是来自正确版本的JDK,那么请将其移到一边,这样那里就没有tools.jar,而$Java_HOME/lib
中有一个tools.jar(如前面的响应中所设置的)
乙二醇
我在maven项目上遇到以下错误:未能在项目cobertura maven plugin上执行目标:无法解析项目org.codehaus.mojo:cobertura maven plugin:maven plugin:2.6:无法在指定路径上找到工件com.sun:tools:jar:0/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/。/lib/tools.jar->[帮助1]
org.apache.maven.lifecycle.LifecycleExecutionException:未能对项目cobertura maven插件执行目标:无法解析项目org.codehaus.mojo:cobertura maven插件:maven插件:2.6:无法在指定路径上找到工件com.sun:tools:jar:0/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/。/lib/tools.jar
我通过在/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents下创建一个libdir并向其中添加tools.jar来修复它
在此特定实例中,tools.jar的完整路径为:/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/lib/tools.jar此环境中不提供编译器。也许您运行的是JRE而不是JDK
eclipse中出现上述错误的Maven build failure(Maven build failure in eclipse中的Maven build failure)是通过取消安装旧版本的java来修复的。是的,我想可能是$java\u HOME
和哪个javac
之间存在不一致。谢谢,我已经更新以回答您的问题。当前的JDK(根据JAVA\u HOME
的定义,它包含/bin
目录。但是,哪个javac
是从某个看起来像wierd mac的路径运行的,我真的不明白。顺便说一句:我无意中否决了它,而不是向上投票,因为它为我修正了它!如果你介意,编辑你的答案,它将允许我向上投票:)如果你想回到基本的Java安装,这是可行的。如果你想使用不同版本的Java,这对你没有任何好处。