name clash when implementing Comparable

Question

I'm no Java expert but I can usually figure out the errors I encounter when working with it. This particular one however has me scratching my head.

I have the following class (with unnecessary fluff removed for ease of reading this post)

package miui.content.res;

import android.app.ActivityManagerNative;
import android.app.IActivityManager;
import android.content.res.Configuration;
import android.os.Parcel;
import android.os.RemoteException;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

public class ExtraConfiguration
    implements Comparable<ExtraConfiguration>
{
    public int themeChanged;

    public int compareTo(ExtraConfiguration that)
    {
        return this.themeChanged - that.themeChanged;
    }
}

To me, this seems pretty straight forward but upon compilation I get the following error:

out/target/common/obj/JAVA_LIBRARIES/android_stubs_current_intermediates/src/miui/content/res/ExtraConfiguration.java:2: 
name clash: 
    compareTo(java.lang.Object) in miui.content.res.ExtraConfiguration and 
    compareTo(T) in java.lang.Comparable<miui.content.res.ExtraConfiguration> 
    have the same erasure, yet neither overrides the other

I did some brushing up on the concept of erasure, and the compareTo() method I show in the code snippet is the only one in the ExtraConfiguration class. At this point I am not sure what the issue is.

This particular class is from an Android framework for a ROM known as MIUI which I am trying to duplicate from some decompiled source. In the meantime I have simply removed the 'implements Comparable

Thanks in advance.

Answer 1

You should be able to do this to get around it, but I can't explain why you are getting the error:

public class ExtraConfiguration
    implements Comparable<Object>
{
    public int themeChanged;

    public int compareTo(Object that)
    {
        if (!(that instanceof ExtraConfiguration)) {
            throw new ClassCastException();
        } else {
            return compareTo((ExtraConfiguration) that);
        }
    }

    public int compareTo(ExtraConfiguration that)
    {
        return this.themeChanged - that.themeChanged;
    }
}

Answer 2

Try adding an @Override to the compareTo signature.