Array to Collection: Optimized code

Question

Is there a better way of achieving this?

public static List<String> toList(String[] array) {      List<String> list = new ArrayList(array.length);      for(int i=0; i<array.length; i++)         list.add(array[i]);      return list; } 

NOTE: Arrays.asList(a) Returns a fixed-size list backed by the specified array. (Changes to the returned list "write through" to the array.). I don't want that behavior. I assume that MY function above bypasses that (or am I wrong?)

So, here we have the alternative method:

public static List<String> toList(String[] array) {      List<String> list = new ArrayList(array.length);      list.addAll(Arrays.asList(array));      return list; } 

Just looking at it, I don't believe it's FASTER than the first method.

Answer 1

What do you mean by better way:

more readable:

List<String> list = new ArrayList<String>(Arrays.asList(array)); 

less memory consumption, and maybe faster (but definitely not thread safe):

public static List<String> toList(String[] array) {     if (array==null) {        return new ArrayList(0);     } else {        int size = array.length;        List<String> list = new ArrayList(size);        for(int i = 0; i < size; i++) {           list.add(array[i]);        }        return list;     } } 

Btw: here is a bug in your first example:

array.length will raise a null pointer exception if array is null, so the check if (array!=null) must be done first.

Answer 2

Arrays.asList(array);     

Example:

 List<String> stooges = Arrays.asList("Larry", "Moe", "Curly"); 

See Arrays.asList class documentation.