blocks|key|1433057|text|当你说你已经“清楚地设置”JAVA_HOME为"C:\Program+Files\Java\jdk1.6.0_14“时-这是你从命令行运行"set”时看到的吗？我相信如果根本没有设置一个值，Ant会猜测JAVA_HOME的值……有没有可能你设置的是JAVAHOME而不是JAVA_HOME？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1433058|如果不是这样，我建议您编辑ant.bat批处理文件(不管它叫什么--我记不清它是不是很复杂了)，以便在开始时和其他有趣的地方打印出JAVA_HOME。|offset|length|style|CODE|1433059|entityMap^0|0|D|7|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

When you say you have "clearly set" JAVA_HOME to "C:\Program Files\Java\jdk1.6.0_14" - is that what you see when you run "set" from the command line? I believe Ant will guess at a value for JAVA_HOME if one isn't set at all... is it possible that you've set JAVAHOME instead of JAVA_HOME?

If it's nothing like that, I suggest you edit the <code>ant.bat</code> batch file (and whatever it calls - I can't remember whether it's convoluted or not offhand) to print out JAVA_HOME at the start and at various other interesting places.

blocks|key|1433306|text|当我尝试使用以下命令运行Ant+build时，我遇到了同样的问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1433307|java+-cp+ant.jar:ant-launcher.jar+org.apache.tools.ant.Main|code-block|syntax|javascript|1433308|该命令的输出为：|1433309|BUILD+FAILED
XXX/build.xml:8:+Unable+to+find+a+javac+compiler;
com.sun.tools.javac.Main+is+not+on+the+classpath.
Perhaps+JAVA_HOME+does+not+point+to+the+JDK.
It+is+currently+set+to+"/usr/lib/jvm/java-6-openjdk/jre"|1433310|看起来java可执行文件选择"/usr/lib/jvm/java-6-openjdk/jre“作为JAVA_HOME，而不是选择安装JDK的"/usr/lib/jvm/java-6-openjdk”。|1433311|我通过在<javac>任务中设置fork="yes"解决了这个问题。|offset|length|style|CODE|1433312|看一下：http://ant.apache.org/manual/Tasks/javac.html|1433313|entityMap|0|LINK|mutability|MUTABLE|url|http://ant.apache.org/manual/Tasks/javac.html^0|0|0|0|0|0|4|7|G|A|0|4|19|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|14|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|15|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|16|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|17|8|@$O|18|P|19|Q|R]|$O|1A|P|1B|Q|R]]|9|@]|A|$]]|$1|S|3|T|5|6|7|1C|8|@]|9|@$O|1D|P|1E|1|1F]]|A|$]]|$1|U|3|-4|5|6|7|1G|8|@]|9|@]|A|$]]]|V|$W|$5|X|Y|Z|A|$10|11]]]]

I encountered the same problem when I try to run Ant build using the following command:

<pre><code>java -cp ant.jar:ant-launcher.jar org.apache.tools.ant.Main
</code></pre>

The output of the command is:

<pre><code>BUILD FAILED
XXX/build.xml:8: Unable to find a javac compiler;
com.sun.tools.javac.Main is not on the classpath.
Perhaps JAVA_HOME does not point to the JDK.
It is currently set to "/usr/lib/jvm/java-6-openjdk/jre"
</code></pre>

It seems the java executable is picking "/usr/lib/jvm/java-6-openjdk/jre" as JAVA_HOME, as opposed to "/usr/lib/jvm/java-6-openjdk" where JDK is installed.

I resolved this issue by setting <code>fork="yes"</code> in my <code>&lt;javac&gt;</code> task.

Take a look at: <a href="http://ant.apache.org/manual/Tasks/javac.html" rel="noreferrer">http://ant.apache.org/manual/Tasks/javac.html</a>

blocks|key|1218343|text|也有可能是你的JAVA_HOME设置中包含了/bin，而Ant正在将/bin添加到其中--从而找不到任何可执行文件。我就遇到过这种情况:}|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1218344|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

It's also possible that you have included /bin in your JAVA_HOME setting, and Ant is adding /bin to it - thereby not finding any exe's. It's happened to me :}

blocks|key|1218442|text|为了解决这个问题，在window->preferences->ant->+runtime中添加tools.jar文件。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1218443|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

To solve this problem add tools.jar file in window->preferences->ant-> runtime .

blocks|key|1218370|text|在eclipse中，将installed+JRE设置为JDK+-在项目中(项目属性->+Java+Build+Path->+Libraries)，或在preferences+(Java->Installed+JRE)中设置全局默认值。eclispe设置比系统变量更强。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1218371|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

In eclipse set the installed JRE setting to the JDK - in the project (project properties -> Java Build Path-> Libraries), or global default in preferences (Java->Installed JREs). The eclispe setting is stronger than the system variable.

blocks|key|1218242|text|我希望您了解系统和用户环境变量。用户模式比系统模式更受欢迎。如果您在系统变量中设置了JAVA_HOME，并且在用户变量中有与之对应的条目，那么您将只获得后者。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1218243|右键单击“我的电脑”，转到“属性”，选择“高级”选项卡，然后单击“环境变量”以查看用户和系统环境变量的列表。|1218244|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

I hope you are aware about System and User environmental variables. The user ones are preferred over system. If you have set your JAVA_HOME in system variables and if there is an entry for the same in user variables, then you will get the latter one only. 

Right click on My computer, Go to properties, Select Advanced tab and click on Environmental variables to see the list of user and system environment variables.

blocks|key|1218411|text|分号把我弄糊涂了:我把JAVA_HOME设置为"C:\jdk1.6.0_26;“而不是"C:\jdk1.6.0_26”。在遵循Jon+Skeet的建议检查ant.bat文件后，我删除了尾随的分号。这是该文件的一部分：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1218412|if+"%25JAVA_HOME%25"+==+""+goto+noJavaHome
if+not+exist+"%25JAVA_HOME%25\bin\java.exe"+goto+noJavaHome|code-block|syntax|javascript|1218413|因此，分号没有被修剪掉，导致无法找到文件，因此缺省为"C:\Java\jre6“或类似的内容。|1218414|令人困惑的部分是，HowtoBuild页面声明使用分号，但这似乎打破了它。|1218415|entityMap|0|LINK|mutability|MUTABLE|url|http://code.google.com/p/codeswarm/wiki/HowtoBuild^0|B|9|25|7|0|0|0|9|A|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]|$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|11|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|12|8|@]|D|@]|E|$]]|$1|M|3|N|5|6|7|13|8|@]|D|@$9|14|A|15|1|16]]|E|$]]|$1|O|3|-4|5|6|7|17|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

The semicolon was throwing me off: I had <code>JAVA_HOME</code> set to "C:\jdk1.6.0_26;" instead of "C:\jdk1.6.0_26". I removed the trailing semicolon after following Jon Skeet's suggestion to examine the <code>ant.bat</code> file. This is part of that file:

<pre><code>if "%JAVA_HOME%" == "" goto noJavaHome
if not exist "%JAVA_HOME%\bin\java.exe" goto noJavaHome
</code></pre>

So the semi-colon wasn't being trimmed off the end, causing this to fail to find the file, therefore defaulting to "C:\Java\jre6" or something like that.

The confusing part is that the <a href="http://code.google.com/p/codeswarm/wiki/HowtoBuild" rel="nofollow">HowtoBuild</a> page states to use the semi-colon, but that seems to break it.

blocks|key|1218297|text|如果您设置了JAVA_HOME，但其中有一个拼写错误，您还会看到对jre6路径的虚假引用。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1218298|entityMap^0|6|9|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

If you have <code>JAVA_HOME</code> set but there's a typo in it, you will also see the bogus reference to a jre6 path.

blocks|key|1433382|text|我也面临着同样的问题，将javac标记中的executable属性设置为javac.exe的位置，为我解决了这个问题。这就解决了问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1433383|<javac+srcdir="${srcDir}"+destdir="${buildDir}"+fork="true"+executable="C:\Program+Files\Java\jdk1.7.0_03\bin\javac"/>|code-block|syntax|javascript|1433384|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I was facing the same problem, making the executable property in the javac tag to be set to the location of javac.exe resolved the problem for me.
This resolved the problem

<pre><code>&lt;javac srcdir="${srcDir}" destdir="${buildDir}" fork="true" executable="C:\Program Files\Java\jdk1.7.0_03\bin\javac"/&gt;
</code></pre>

blocks|key|1218740|text|实际上，我在superuser.com上找到了这个答案，但我必须将tools.jar从我的JDK目录复制到JRE目录。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1218741|我能想到的是Sun在最新的Java运行时(Java7Update11)中引入了这个错误，或者是Ant中读取当前sense...only位置的错误(显然，JRE比JDK更新，这也是愚蠢的，Sun...they应该在每次更新JRE时释放JDK+)。|1218742|我的JAVA_HOME设置正确。我通过执行"set+JAVA_HOME“来确认。它指向我的JDK目录并且拼写正确。然而，Ant声称它找不到javac，但是认为JAVA_HOME在我的JRE目录中。|1218743|在最新的Sun+JRE7更新(10和11)之前，我的系统运行良好。Ant版本为1.8.4|1218744|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

Actually found this answer on superuser.com, but I had to copy tools.jar from my JDK\lib directory to the JRE\lib directory.

Makes ZERO sense...only thing I can think of is Sun introduced this bug in the latest Java runtime (Java 7 Update 11) or a bug in Ant in how it reads the current JDK location (the JRE is more updated than the JDK obviously which is also stupid of Sun...they should release the JDK each time they update the JRE).

My JAVA_HOME was set correctly. I confirmed by doing "set JAVA_HOME". It pointed to my JDK directory and was spelled correctly. However, Ant was claiming it couldn't find javac, but thought JAVA_HOME was in my JRE directory.

My system worked fine before the latest Sun JRE7 updates (10 and 11). Ant is version 1.8.4

blocks|key|1218497|text|在环境变量中将JAVA_HOME设置为D:\Program+Files\IBM\SDP\jdk，不要给出任何引号或分号。它适用于me.Please，试试这个解决方案吧。实际上，在ant.bat中，它会检查合适的JAVA_HOME，如果ant.bat找不到它，那么JAVA_HOME会指向默认的JRE。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1218498|entityMap^0|J|S|2X|9|3N|9|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|O|8|@]|D|@]|E|$]]]|G|$]]

Set JAVA_HOME in the environment variables as <code>D:\Program Files\IBM\SDP\jdk</code>
Do not give any quotes or semicolon. It's works for me.Please try the solution.
Actually in ant.bat it checks for appropriate <code>JAVA_HOME</code> in case if ant.bat not able to find it then it's <code>JAVA_HOME</code> points the default JRE.

blocks|key|1218561|text|我也有同样的问题。我的JAVA_HOME指出的JDK包没有任何tools.jar请确保你的JDK+instal.lation有tools.jar|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1218562|(很明显，消息错误令人困惑)|1218563|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

I had the same problem. My JDK package pointed by JAVA_HOME didn't have any tools.jar
Be sure that your JDK instal.lation has tools.jar 

(clearly the message error is confusing)

blocks|key|1433615|text|当我和Jenkins一起构建我的项目时，我遇到了这个问题。首先，它找不到ant.bat，这是通过将ant.bat的路径添加到系统环境变量path来修复的。然后ant找不到jdk目录。通过右键单击my+computer+>+properties+>+advanced+>+environment+variables并创建一个名为JAVA_HOME的新环境变量并为其赋值C:\Program+Files\Java\jdk1.7.0_21，修复了此问题。不要在用户变量中创建此环境变量。仅在系统变量下创建。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1433616|在这两种情况下，我都必须重新启动系统。|1433617|entityMap^0|10|7|2P|1N|4J|9|53|X|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|I|$]]

I faced this problem when building my project with Jenkins. First, it could not find <code>ant.bat</code>, which was fixed by adding the path to ant.bat to the system environment variable path. Then ant could not find the jdk directory. This was fixed by right-clicking on <code>my computer &gt; properties &gt; advanced &gt; environment variables</code> and creating a new environment variable called <code>JAVA_HOME</code> and assigning it a value of <code>C:\Program Files\Java\jdk1.7.0_21</code>. Don't create this environment variable in User Variables. Create it under System Variables only. 
In both cases, I had to restart the system.

blocks|key|1433668|text|这是一个常见的问题。我不能在我的系统中设置任何特定的Java+home，因为我有两个不同版本的Java+(Java+6和Java+7)用于不同的环境。为了解决这个问题，我在打开build.xml文件时在运行配置中包含了JDK路径。这样，两个不同的构建文件使用两个不同的Java版本进行构建。我认为这个问题可能有更好的解决方案，但至少上面的方法避免了设置JAVA_HOME变量。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1433669|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

It is common to get this issue. I cannot set any specific Java home in my system as I have 2 different version of Java (Java 6 and Java 7) for different environment.
To resolve the issue, I included the JDK path in the run configuration when opening the build.xml file. 
This way, 2 different build files use 2 different Java version for build. 
I think there might be a better solution to this problem but at least the above approach avoid setting the JAVA_HOME variable.

blocks|key|1433685|text|仅供参考，我使用的是Windows7，为了使新的JAVA_HOME设置生效，我不得不重启Windows7。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1433686|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

FYI, I am using Windows 7 and had to restart Windows in order for the new JAVA_HOME setting to take effect.

blocks|key|1218926|text|也有同样的问题；|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1218927|c:\jb\src\build.xml:191:+Unable+to+find+a+javac+compiler;
com.sun.tools.javac.Main+is+not+on+the+classpath.
Perhaps+JAVA_HOME+does+not+point+to+the+JDK.
It+is+currently+set+to+"C:\Program+Files\Java\jre7"

Total+time:+0+seconds

c:\jb\src>echo+%25JAVA_HOME%25
c:\Program+Files\Java\jdk1.7.0_13|code-block|syntax|javascript|1218928|解决方案：|1218929|path+=+c:\ant\bin\;%25PATH%25
path+=+c:\Program+Files\Java\jdk1.7.0_17\bin;%25PATH%25
set+"JAVA_HOME=c:\Program+Files\Java\jdk1.7.0_13"|1218930|我猜只有jdk路径指令就可以做到这一点，但我懒得弄清楚上面的解决方案是万无一失的。:-)|1218931|也使用Windows7|1218932|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

had the same problem;

<pre><code>c:\jb\src\build.xml:191: Unable to find a javac compiler;
com.sun.tools.javac.Main is not on the classpath.
Perhaps JAVA_HOME does not point to the JDK.
It is currently set to "C:\Program Files\Java\jre7"

Total time: 0 seconds

c:\jb\src&gt;echo %JAVA_HOME%
c:\Program Files\Java\jdk1.7.0_13
</code></pre>

solution:

<pre><code>path = c:\ant\bin\;%PATH%
path = c:\Program Files\Java\jdk1.7.0_17\bin;%PATH%
set "JAVA_HOME=c:\Program Files\Java\jdk1.7.0_13"
</code></pre>

I guess the jdk path instruction alone would do it but I'm to lazy to figure it out above solution is bullet proof. :-)

Also using Windows7

blocks|key|1433790|text|解决这个问题的快速方法是|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1433791|将C:\Program+Files\Java\jdk1.6.0_14\lib\tools.jar复制到C:\Program+Files\Java\jre6\lib\|1433792|出现此异常是因为JAVA_HOME被设置为C:\Program+Files\javaJRE6，而Ant无法在其中找到tools.jar。|1433793|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|I|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|G|$]]

Quick work around for the same is

Copy C:\Program Files\Java\jdk1.6.0_14\lib\tools.jar to C:\Program Files\Java\jre6\lib\

This exception is coming because JAVA_HOME is being set as C:\Program Files\Java\jre6 and Ant is not able to find tools.jar in it.

blocks|key|1433860|text|如果需要使用内置的eclipse+jdk在eclipse中运行ant，请在build.xml中添加以下行|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1433861|<property+name="build.compiler"+value="org.eclipse.jdt.core.JDTCompilerAdapter"/>|code-block|syntax|javascript|1433862|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

If need to run ant in eclipse with inbuilt eclipse jdk add the below line in build.xml

<pre><code>&lt;property name="build.compiler" value="org.eclipse.jdt.core.JDTCompilerAdapter"/&gt;
</code></pre>

I get the error: 

C:\dev\ws\springapp\build.xml:81: Unable to find a javac compiler;
com.sun.tools.javac.Main is not on the classpath.
Perhaps JAVA_HOME does not point to the JDK.
It is currently set to "C:\Program Files\Java\jre6"

But I have clearly set my JAVA_HOME to be C:\Program Files\Java\jdk1.6.0_14

Where is ANT getting this value?

Why does ANT tell me that JAVA_HOME is wrong when it is not?

编译器

Java

我得到了错误：C:\dev\ws\springapp\build.xml:81:找不到com.sun.tools.javac.Main编译器；javac不在类路径上。也许JAVA_HOME并没有指向JDK。它当前设置为"C:\Program Files\Java\jre6“但是我已经明确地将我的程序设置为C：\ JAVA_HOME Files\Java\jdk1.6.0_14ANT是从哪里获得这个

问为什么ANT告诉我JAVA_HOME是错的，而事实并非如此？
EN

回答 18

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问为什么ANT告诉我JAVA_HOME是错的，而事实并非如此？EN

回答 18

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问为什么ANT告诉我JAVA_HOME是错的，而事实并非如此？
EN