Maven in Eclipse complains that “Unable to locate the Javac Compiler” whenever POM changed

问题

I got error message every time I changed my pom.xml in eclipse.

Build errors for myapp; org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.0.2:compile (default-compile) on project web: Compilation failure
Unable to locate the Javac Compiler in:
  C:\Program Files (x86)\Java\jre6\..\lib\tools.jar
Please ensure you are using JDK 1.4 or above and
not a JRE (the com.sun.tools.javac.Main class is required).
In most cases you can change the location of your Java
installation by setting the JAVA_HOME environment variable

I have set JAVA_HOME environment variable. It is:JAVA_HOME=D:\Java\jdk1.6.0_23

Thanks.

回答1:

This is the step I did to solve that problem (Eclipse 3.7 Indigo):

Window -> Preferences -> Java -> installed JREs -> I have a JRE from the JDK location, my location looks like C:\Program Files\Java\jdk1.6.0_26

Window -> Preferences -> Java -> installed JREs -> Execution Environments -> Select JavaSE-1.6 and select a compatible JDK which should be the one set in the previous step.

回答2:

None of the above worked for me but when I followed the following steps, the problem went away.

• Go to Window -> Preferences -> Java -> installed JREs
• Select the JRE you are using (Should be the one inside jdk. Ex: C:\Program Files\Java\jdk1.6.0_25\jre)
• Press Edit -> Add External JARs...
• Browse to Java\jdk1.6.0_25\lib and select tools.jar and Press Enter
• Press Finish and OK

回答3:

Window -> Preferences -> Java -> installed JREs -> Execution Enviroments -> click the checkbox on the right side

回答4:

I had this same issue which I just figured out. The Runtime JRE was specified correctly in EVERY other part of eclipse.

I use an eclipse Run Configuration...

The Run Configuration is YET ANOTHER place where the java runtime JRE is specified. If you are using a maven Run Configuration, open that up, click the JRE tab and select the proper (JDK) "Runtime JRE".

回答5:

This worked for me too :

1. Go to Window -> Preferences -> Java -> installed JREs
2. Select the JRE you are using (Should be the one inside jdk. Ex: C:\Program Files\Java\jdk1.6.0_25\jre)
3. Press Edit -> Add External JARs...
4. Browse to Java\jdk1.6.0_25\lib and select tools.jar and Press Enter
5. Press Finish and OK

回答6:

Adding the following two lines at the very beginning of your eclipse.ini file should tell maven where to find JDK:

-vm
C:\Program Files\Java\jdk1.6.0_23\bin\javaw.exe

or whatever path you installed JDK into.

回答7:

If you are encountering this problem when trying to run maven from eclipse, then you may want to refer to this discussion, which also outlines the solution.

回答8:

I had a similar issue; what you should try is performing a mvn install from the POM directory itself, any Maven install you do next in Eclipse itself will work as well afterwards.

回答9:

I had a similiar issue it got resolved by specifying attributes of the maven-compiler-plugin as below:

<plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
<!-- Need to provide the below properties as the current maven-compiler-plugin version is 2.0.2 and defaults to JDK 1.3 for compiling -->
                <source>1.5</source>
                <target>1.5</target>
            </configuration>
        </plugin>

I had to explicitly specify the source and target attribute. it seems there compilation also depends on the version maven-compiler-plugin and its default JDK setting. Mine was 2.0.2 and its default was JDK 1.3 i gather.

回答10:

1.Go to Window -> Preferences -> Java -> installed JREs 2.Select the JRE you are using (Should be the one inside jdk. Ex: C:\Program Files\Java\jdk1.6.0_25\jre) 3.Press Edit -> Add External JARs... 4.Browse to Java\jdk1.6.0_25\lib and select tools.jar and Press Enter 5.Press Finish and OK..

This worked for me.

回答11:

It looks like your JAVA_HOME is not set properly. Can you echo JAVA_HOME from your terminal & see where it is pointing to? From the above error log it looks like its pointing to program files folder.

回答12:

Window -> Preferences -> Java -> installed JREs, add jdk6 to point to your jdk(C:\Program Files\Java\jdk1.6.0_25), delete default jre6. it works.

来源：https://stackoverflow.com/questions/5163021/maven-in-eclipse-complains-that-unable-to-locate-the-javac-compiler-whenever-p