[java] 'Must Override a Superclass Method' Errors after importing a project into Eclipse

Anytime I have to re-import my projects into Eclipse (if I reinstalled Eclipse, or changed the location of the projects), almost all of my overridden methods are not formatted correctly, causing the error:

The method must override a superclass method

It may be noteworthy to mention this is with Android projects for whatever reason, the method argument values are not always populated, so I have to manually populate them myself. For instance:

list.setOnCreateContextMenuListener(new OnCreateContextMenuListener() {

    //These arguments have their correct names
    public void onCreateContextMenu(ContextMenu menu, View v, 
                                    ContextMenuInfo menuInfo) {                 
    }

});

will be initially populated like this:

list.setOnCreateContextMenuListener(new OnCreateContextMenuListener() {

    //This methods arguments were not automatically provided    
    public void onCreateContextMenu(ContextMenu arg1, View arg2,
                                    ContextMenuInfo arg3) {
    }

});

The odd thing is, if I remove my code, and have Eclipse automatically recreate the method, it uses the same argument names I already had, so I don't really know where the problem is, other then it auto-formatting the method for me.

This becomes quite a pain having to manually recreate ALL my overridden methods by hand. If anyone can explain why this happens or how to fix it. I would be very happy.

Maybe it is due to the way I am formatting the methods, which are inside an argument of another method?

With Eclipse Galileo you go to Eclipse -> Preferences menu item, then select Java and Compiler in the dialog.

Now it still may show compiler compliance level at 1.6, yet you still see this problem. So now select the link "Configure Project Specific Settings..." and in there you'll see the project is set to 1.5, now change this to 1.6. You'll need to do this for all affected projects.

This byzantine menu / dialog interface is typical of Eclipse's poor UI design.

In my case this problem happened when I imported a Maven project into Eclipse. To solve this, I added the following in pom.xml:

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

Then in the context menu of the project, go to "Maven -> Update Project ...", and press OK.

That's it. Hope this helps.

If nothing of the above helps, make sure you have a proper "Execution environment" selected, and not an "Alternate JRE".

To be found under:

Project -> Build Path -> Libraries

Select the JRE System Library and click Edit....

If "Alternate JRE ..." is selected, change it to a fitting "Execution Environment" like JavaSE-1.8 (jre1.8.0_60). No idea why, but this will solve it.

It's 2020 -

Project>Right Click>Java Compiler>Compiler Compliance Level> Change this to 1.8 [or latest level]

The answer by Paul worked for me partially. I still had one error then. So, in addition to that, I also had to go to Properties-> Project Facets and there set the Java version from 1.5 to 1.6.

Maybe that helps.

This happens when your maven project uses different Compiler Compliance level and Eclipse IDE uses different Compiler Compliance level. In order to fix this we need to change the Compiler Compliance level of Maven project to the level IDE uses.

1) To See Java Compiler Compliance level uses in Eclipse IDE

*) Window -> Preferences -> Compiler -> Compiler Compliance level : 1.8 (or 1.7, 1.6 ,, ect)

2) To Change Java Compiler Compliance level of Maven project

*) Go to "Project" -> "Properties" -> Select "Java Compiler" -> Change the Compiler Compliance level : 1.8 (or 1.7, 1.6 ,, ect)

In my case, none the solutions above works. I have to checkout my source code to another folder. From eclipse select File > Switch workSpaces > Other... and then import code to the new workspaces. it works after that.

Fixing must override a super class method error is not difficult, You just need to change Java source version to 1.6 because from Java 1.6 @Override annotation can be used along with interface method. In order to change source version to 1.6 follow below steps :

1. Select Project , Right click , Properties
2. Select Java Compiler and check the check box "Enable project specific settings"
3. Now make Compiler compliance level to 1.6
4. Apply changes

In case this happens to anyone else who tried both alphazero and Paul's method and still didn't work.

For me, eclipse somehow 'cached' the compile errors even after doing a Project > Clean...

I had to uncheck Project > Build Automatically, then do a Project > Clean, and then build again.

Also, when in doubt, try restarting Eclipse. This can fix a lot of awkward, unexplainable errors.

To resolve this issue, Go to your Project properties -> Java compiler -> Select compiler compliance level to 1.6-> Apply.

This is my second time encounter this problem. first time according the alphazero's recommendation it worked. but in the second time I set to 1.6 it don't work it just like 'CACHE' this error after clean and rebuild.

Try to switch off 'Build Automatically' as Rollin_s said -> error still here!

So I removed the problem project (already set to 1.6) from Package Explorer and import it again -> it start a rebuild and no error this time

Hope this help someone

Guys in my case none of the solutions above worked.

I had to delete the files within the Project workspace:

• .project
• .classpath

And the folder:

• .settings

Then I copied the ones from a similar project that was working before. This managed to fix my broken project.

Of course do not use this method before trying the previous alternatives!.