clark clark - 5 months ago 23
Java Question

name clash when implementing Comparable

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

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;
    }
}
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