Fatal error compiling: tools.jar not found - maven-compiler-plugin

Question

Issue: The following problem occurs when I compile my project w/ maven (note: I'm working on windows):

Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.5.1:compile (default-compile) on project XYZ: Fatal error compiling: tools.jar not found: C:\java\jdk1.8.0_40..\lib\tools.jar -> [Help 1]

Error occurs from both command line and eclipse (Eclipse STS) - mvn clean; mvn install

Notes:

• System env variable, JAVA_HOME, was set to C:\java\jdk1.8.0_40
• C:\java\jdk1.8.0_40\lib\tools.jar is there
• Tried clearing local maven repo (.m2) - error still occurred
• configured maven compiler plugin to point to C:/java/jdk1.7.0_75/bin/javac.exe executable with source=target=1.7 - same error
• Tried installing java 1.7.0_75 in eclipse and using that (but maven is still used for the compile -- right-click on project, run as, maven install): same error (even with maven compiler's plugin configuration's executable set to C:/java/jdk1.7.0_75/bin/javac.exe)

Answer 1

Issue resolved: Setting System env variable, JAVA_HOME, to Java JDK 1.7 fixed the problem.

I tried jdk1.7.0_45 and jdk1.7.0_75 - they both worked.

Notes:

• I thought setting the compiler executable for the compiler plugin in pom.xml would mean that the executable was used in all cases;
  apparently it's not - the JAVA_HOME variable overrode it in this
  case.
• Some other folks had issues b/c their JAVA_HOME was set to a JRE instead of a JDK. My JAVA_HOME for Java 1.8 was set to JDK 1.8, but I still received the same error.

Answer 2

I also faced similar issue when building the project in eclipse ( sts version) I figured out the issue was because I had jre installed in 2 locations and I jre configured in the eclipse was pointing to the pure jre folder. So just check that your jre is pointing to the jre folder inside the jdk not any other jre as the tools.jar is in jdk/lib

Answer 3

Even after configuring Eclipse to use a JDK from Window -> Preferences -> Java -> Installed JRES, you may still get errors when you try to perform a Maven build.

In this case make sure that the JRE tab in Maven Build is configured correctly.

Go to Run -> Run Configurations, open the Maven Build category and do one of the following:

1. Make sure that the Workspace default JRE is selected and it points to a JDK.
2. In the Alternate JRE menu, select a configured JDK.