Explain what are the difference between Comparable And Comparator Interface in java?

The difference is quite obvious . Comparable is interface that is implemented by a class of object that have to be sorted.

For example:

class SortObject implements Comparable{
 public int compareTo(Object obj){

 }
}

and for sorting an array of SortObjects

Arrays.sort(sortObjectsArray); //this is enough

Comparator is mainly used to override a method compare. But it is more generic and can be used to sort any "collection" (of appropriate type) class 

CompClass implements Comparator{  public int compare(Object obj1,Object obj2){
    //make a cast of obj1 and obj2 for comparison.
   // return compare result.
 }
}

Usage will be like:

Arrays.sort(sortArray,new CompClass());

If you are not careful in using the Comparator it can result in ClassCastException at runtime.

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