How do I change language level for all modules in IntelliJ

Question

I have a project with MANY modules. We\'re upgrading to Java7, and I want my editor to reflect this. Now all my modules specifically set the language level to Java6, and there a

Answer 1

The other solutions didn't worked for me, even after modifying by hand the compiler.xmland all the .iml files the the LANGUAGE_LEVEL was still set to "JDK_1_5". This was caused by the maven-compiler-plugin plugin's configuration option.

Changing it to the following fixed it:

    
        org.apache.maven.plugins
        maven-compiler-plugin
        3.5.1
        
            1.8
            1.8
        
    

Hope this solves it for others also.