1.On the Eclipse IDE, just go into the Window > Preferences > Java > Installed JREs > and just try to check your installed JREs. You should have some entry with your JDK there.
2.Select your Execution Env and click OK
3.Then just Right-Click on the Project -> Maven -> Update Project
You can change your Maven JRE as follows. You need to Go to Run -> Run Configurations, selecting your Maven Build I was running (from my left panel). Then just click a JRE tab and select a option Workspace default JRE
1.Set your JAVA_HOME environment variable to a JDK root folder it is required if you run command line or the maven (mvn).
2.From a project properties in a section Java Compiler select a required JDK it is required if you run it directly from a eclipse