サンプル

public class ClassA implements Cloneable {
public final Object clone throws CloneNotSupportedException () {
//...
}
public final void clone(){
//...
}
}


解決策
clone メソッドは 1 つでなければなりません

public class ClassA implements Cloneable {
public final Object clone throws CloneNotSupportedException () {
//...
}
}