Getting Error running javac.exe compiler message,

问题:

When I run my Ant build in Eclipse, I'm getting the following error message and the Ant build fails.

Error Message: Error running javac.exe compiler

Line where the build stops:

<javac destdir="${classes.home}" debug="on" fork="true" memoryinitialsize="512M" memorymaximumsize="1G">
        <classpath refid="classpath"/>
        <src path="${source.home}"/>
</javac>

Has anyone faced a similar problem before? or does anybody know what's wrong here?

System Information: Eclipse Helio, JDK 1.5

回答1:

I had the same problem and the issue was, in eclipse java.home was referring to JRE instead of JDK. I changed it and the build was successful. You can do the following to change it to JDK:

Preferences > Java > Installed JRE's > Add... For 'JRE Type' select 'Standard VM' > Next > Directory: select your JDK directory (instead of JRE) (in my case: C:\Program Files\Java\jdk1.6.0_16 ), press OK.

Now, you are back at 'Installed JRE's', select the JDK here also.

The below post helped in finding the solution. JAVA_HOME points to the wrong place

回答2:

If the accepted answer above doesn't solve the problem for you (as it didn't for me), after updating the java.home to JDK instead of JRE as suggested in the accepted answer above, Go to Run -> External Tools -> External Tools Configuration -> select your build.xml on the left menu -> select JRE tab -> select the JDK(from the dropdown) for Separate JRE radio button option -> Click Run.

This should fix the problem.

回答3:

I had the same problem and removed the attribute fork from javac and problem was gone.

回答4:

Maybe the javac problem is because "javac.exe" is not in your System PATH, please edit your system path and add your JDK's /bin directory to it to correct this problem.

Open a shell or command prompt and try typing: javac to check if the system path is set correctly.

回答5:

Configuring eclipse to point to JDK instead of JRE did not work for me. With further investigation, I solved this problem by stopping the build process from forking. In your build.xml, remove the attribute fork from <javac> tag.

回答6:

I faced the same problem, and here is my advice, maybe it will help someone.
In fact, message Error running javac.exe compiler means that something went wrong. The question is, what exactly. When Ant runs javac task with fork="true" flag, it doesn't print any error details. In my case, it didn't print them even after I added verbose="true", as suggested here. Solution was to add -verbose flag to Ant command line:

ant -verbose

After this, Ant starts printing full error messages, so you are able to fix a problem.

回答7:

I solved this by checking my Environment Variables in my Windows 7. I found that JAVA_HOME is pointing to C:\ Program Files (x86)\Java\jdk1.6.0_31 when it supposed be C:\ Program Files\Java\jdk1.6.0_31. If you want to know how read this

回答8:

If you are running ant in eclipse click run as --> Ant second option and choose JDK path and run the build again.

回答9:

Try changing memorymaximumsize="1G" to memorymaximumsize="512M".

回答10:

Try to free some main memory. Close memory-hungry programs, and stop memory-hungry processes if you can.

回答11:

I've tried everything but nothing worked for me till I've set (fork='no' or fork='false' in your case) and worked for me perfectly

回答12:

I removed fork="true" and I got past that piece of code. What might be interesting to those of you who have this problem is that now, at that line, I get the output:

'Since fork is false, ignoring memoryMaximumSize setting.'

So it may be an issue with memoryMaximumSize if you need to keep your fork="true" setting, as suggested above.

回答13:

I fixed the problem like this:

My Java home folder had the wrong path. It should have been C:\Program Files (x86)\Java\jdk1.5.0_15 but instead it was C:\Program Files (x86)\Java\jdk1.5.0_15\bin.

回答14:

We hit the same issue on a windows build machine whereas locally (on a unix machine) everything worked out. Fork = true didnt helped either, it resulted in a Process fork failed exception also only on the build server

Research

After some research, we had a clue that the classpath might be too long. We recreated the exact folder structure locally on a windows machine and we hit the same issue and we saw that the classpath was way too long (we used -v and -d for details how long it was) and this was the cause of the error.

Solution

The solution was to create a jar, which contains only the manifest with all the libraries, see this answer for more details

回答15:

The accepted answer didn't work for me. But right-clicking in Ant and setting the Java Runtime Environment (JRE) to the Jave Development Kit (JDK) worked for me.

Abhi Rampal's answer is the step by step the same way I solved the problem on my eclipse.

Go to Run -> External Tools -> External Tools Configuration -> select your build.xml on the left menu -> select JRE tab -> select the JDK(from the dropdown) for Separate JRE radio button option -> Click Run.

回答16:

For me it was backup libs inside WEB-INF/lib directory. I had multiple lib directory inside the main lib. And the classpath was including them all causing the javac command to become too long.

I removed those directories and it worked for me.