List差集

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

/**
 * List工具类
 * <p>
 *   提供处理List对象的各种方法实现。
 * </p>
 * 
 * @author harbey
 * @version 1.0
 * @since 2009-07-30
 */
public class ListUtil {

	/**
	 * List对象差集
	 * <p>
	 *   使用深复制，不会影响List参数对象。
	 * </p>
	 * @param decList 被减数List对象
	 * @param subList 减数List对象
	 * @return 结果List
	 * @throws IllegalArgumentException
	 */
	public static List<String> plusArrayList(List<String> decList,List<String> subList) throws IllegalArgumentException{

		   if(decList==null || subList==null){
			   throw new IllegalArgumentException();
		   }

			List<String> tempDecList = new ArrayList<String>(new ArrayList(Arrays.asList(new Object[decList.size()])));
			List<String> tempSubList = new ArrayList<String>(new ArrayList(Arrays.asList(new Object[subList.size()])));

			Collections.copy(tempDecList, decList);
			Collections.copy(tempSubList, decList);

			tempDecList.removeAll(tempSubList);

		    return tempDecList;
	   }

}

如果
List<String> tempDecList = new ArrayList<String>(decList.size());
则会报java.lang.IndexOutOfBoundsException错误！
原因：
ArrayList iss=new ArrayList(ist.size());does not ensure size, but set the initialize of the internal array.