removing a value from a list<String> in java throws java.lang.UnsupportedOperationException

Question

I want to remove specific elements from my List. I don't want to do this while iterating through the list. I want to specify the value which has to be deleted. In javadocs I found the function List.remove(Object 0) This is my code :

         String str="1,2,3,4,5,6,7,8,9,10";
         String[] stra=str.split(",");
         List<String> a=Arrays.asList(stra);
         a.remove("2");
         a.remove("3");

But I get an Exception : java.lang.UnsupportedOperationException

Answer 1

The problem is that Arrays.asList() returns a list that doesn't support insertion/removal (it's simply a view onto stra).

To fix, change:

List<String> a = Arrays.asList(stra);

to:

List<String> a = new ArrayList<String>(Arrays.asList(stra));

This makes a copy of the list, allowing you to modify it.

Answer 2

http://docs.oracle.com/javase/6/docs/api/java/util/Arrays.html#asList%28T...%29

See this. Arrays.asList returns a fixed list. Which is an immutable one. By its definition you cant modify that object once it creates.Thats why it is throwing unsupported exception.