ArrayList 源码

 1 private void grow( int minCapacity) {
 2         // overflow-conscious code
 3         int oldCapacity = elementData .length ;
 4         int newCapacity = oldCapacity + (oldCapacity >> 1);//按1.5倍增长
 5         if (newCapacity - minCapacity < 0)
 6             newCapacity = minCapacity ;
 7         if (newCapacity - MAX_ARRAY_SIZE > 0)
 8             newCapacity = hugeCapacity( minCapacity );
 9         // minCapacity is usually close to size, so this is a win:
10         elementData = Arrays.copyOf( elementData , newCapacity );
11     }
12  
13     private static int hugeCapacity( int minCapacity) {
14         if (minCapacity < 0) // overflow
15             throw new OutOfMemoryError();
16         return (minCapacity > MAX_ARRAY_SIZE) ?
17             Integer. MAX_VALUE :
18             MAX_ARRAY_SIZE ;
19     }