public static <V> boolean isEmpty(ArrayList<V> sourceList) {
 return (sourceList == null || sourceList.size() == 0);
}

/**
 * 打乱ArrayList
 * 
 * */
public static <V> ArrayList<V> randomList(ArrayList<V> sourceList){
 if (isEmpty(sourceList)) {
  return sourceList;
 }

 ArrayList<V> randomList = new ArrayList<V>( sourceList.size( ) );
 do{
  int randomIndex = Math.abs( new Random( ).nextInt( sourceList.size() ) );
  randomList.add( sourceList.remove( randomIndex ) );
 }while( sourceList.size( ) > 0 );

 return randomList;
}