Collections.copy method for lists ? how it works

[Tanu Gulati]

I have a code below where i tried to copy an arrayList to listusing Collections.copy method.
I am getting IndexOutofBoundsException since the size of destination list is not equal to the source list.

my question.. is there any Java API help through which i can copy an entire list of any size to a new list(the destination list can be of any size and may be empty).

public static void main(String[] args) {

List arrayList = new ArrayList();
arrayList.add(34);
arrayList.add("test");
arrayList.add(56);
arrayList.add("89");


List list=new ArrayList(20); 
                 // i have declared the max size here for list
list.add("tanu"); 
          //list has size 1 but arrayList has size 4 so Exception generated
Collections.copy(list,arrayList);
}

[rakesh sugirtharaj]

I think this would work

  
                List<String> x = new ArrayList<String>();
x.add("1");
String[] y = new String[x.size()];

List<String> z = new ArrayList<String>(Arrays.asList(y));

Collections.copy(z, x);
System.out.println(z.get(0));  

[Tanu Gulati]

hey rakesh ..thanks it works ..thanks a lot

[Ilja Preuss]

Even simpler:

List list=new ArrayList(arrayList);