在Windows 10上为Maven设置JAVA_HOME

Question

I recently upgraded to Windows 10. I'm trying to create a new maven project in eclipse, but it doesn't seem to be picking up my JAVA_HOME setting.

Here is the JDK installation directory:

And here is my JAVA_HOME environment variable setting:

If I run mvn -version in a command prompt, maven does seem to get the correct value for JAVA_HOME:

I then try to create a new maven project in eclipse, using a barebones pom.xml:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>StaticVoidGames</groupId>
    <artifactId>DatabaseTest</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>DatabaseTest</name>
</project>

But the project's JRE is 1.5 for some reason:

For what it's worth, my eclipse workspace default JRE is the same as my JAVA_HOME setting.

I've tried manually changing the build path to use the correct jdk, but it simply reverts. I've tried cleaning the project, doing a maven update, restarting eclipse, restarting my computer, and creating a new project. Maven still chooses Java 1.5, which isn't even installed on my machine.

All of my googling says that maven should pick up the JAVA_HOME setting to figure out which Java to use, but that doesn't seem to be the case here. Is there another setting that I'm missing somewhere?

Answer 1

As per screenshoot, Maven is correctly picking up your JAVA_HOME, however what you see in Eclipse is not the version of Java installed (1.5) but the version Maven will use by default to compile .
In your case, Maven will use JDK 1.8 and compile settings source and target to 1.5 (version by default).

To set Maven to the same level as the Java version installed, you need to configure the Maven Compiler Plugin. Once done that and after an Eclipse update (right click on the project, Maven, Update Project), Eclipse will update its view accordingly.

You can add to your POM the following Maven Compiler Plugin configuration :

<project>
  [...]
  <build>
    [...]
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.3</version>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
    </plugins>
    [...]
  </build>
  [...]
</project>

Alternatively, you can use well-known Maven properties to achieve the same by only settings:

<properties>
   <maven.compiler.source>1.8</maven.compiler.source>
   <maven.compiler.target>1.8</maven.compiler.target>
</properties>