Maven uses JRE7 instead of JDK?

Question

Eclipse Juno Release Window / Preferences / Java / Installed Jres shows two installed Jres. jdk1.7.0_07 and jre7.

I get the following error when trying to clean and process-classes with maven:

Failed to execute goal org.apache.maven.plugins:maven-compiler- 
plugin:2.4:compile (default-compile) on project reputation: Fatal 
error compiling: tools.jar not found: C:\Program 
Files\Java\jre7\..\lib\tools.jar

I added tools.jar as external jar already, out of desperation, but it didn't help. Why is maven trying to use the other JRE?

EDIT:

Compiler plugin excerpt from pom.xml

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>2.4</version>
    <configuration>
        <source>1.6</source>
        <target>1.6</target>
    </configuration>
</plugin>

Answer 1

You need to set your JAVA_HOME environment variable to the JDK directory.

EDIT:

In your installed JREs preferences window in Eclipse remove the JRE and select the JDK. Also make sure that your project is set to use that JRE library (Right-click on the "JRE System Library" under your maven project structure in the explorer and set it as the "Execution Environment")

Answer 2

You should verify that the Maven "run configurations..." is connected to the correct JRE. If the project JRE is correct but the run configuration JRE is incorrect you will get this error. To fix, go Under Maven Build, choose the JRE tab.