Maven in Eclipse complains that "Unable to locate the Javac Compiler" whenever POM changed_问答_开发者

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

Build errors for myapp; org开发者_如何学Go.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.

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.

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

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

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".

This worked for me too :

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

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.

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.

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.

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.

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.

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.

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.