去除List中重复数据

/**
 * 去除List中重复数据
 * @author wjcom
 * @Date 2010-12-22
 * @version [版本号]
 * @see [相关类/方法]
 * @since [产品/模块版本]
 */
public class test
{

	/**
	 * @param args
	 */
	public static void main(String[] args)
	{
		Long[] initData = {1l, 10l,15l,1l,15l};
		
		//方法一
		List<Object> list1 = deleteRepeatIds1(initData);
		

		for (int i = 0; i < list1.size(); i++)
		{
			System.out.println(list1.get(i));
		}
		
		System.out.println("==================");
		
		//方法二
		List list2 = deleteRepeatIds2(initData);
		for (int j=0;j<list2.size();j++)
		{
			System.out.println(list2.get(j));
		}
		
		System.out.println("==================");
		
		//方法三：最简洁的方法
		List list3 = deleteRepeatIds3(initData);
		for (int k=0;k<list3.size();k++)
		{
			System.out.println(list3.get(k));
		}
	}
	
	/**
	 * 方法一
	 * @param ids
	 * @return
	 */
	private static List<Object> deleteRepeatIds1(Long[] ids)
	{
		List<Long> list = new ArrayList<Long>();
		
		for (int j = 0; j < ids.length; j++)
		{
			list.add(ids[j]);
		}

		Set<Object> set = new HashSet<Object>();
		List<Object> newList = new ArrayList<Object>();
		for (Iterator iter = list.iterator(); iter.hasNext();)
		{
			Object element = iter.next();
			if (set.add(element))
				newList.add(element);
		}
		list.clear();

		return newList;
	}
	
	/**
	 * 方法二
	 * @param ids
	 * @return
	 */
	private static List deleteRepeatIds2(Long[] ids)
	{
		List<Long> list = new ArrayList<Long>();
		 
		for (int j = 0; j < ids.length; j++)
		{
			boolean bl1 = true;
			boolean bl2 = false;
			
			if (list.size()>0)
			{
				for (int i = 0;i<list.size();i++)
				{
					if (list.get(i).equals(ids[j]))
					{
						bl2 = true;
					}
				}
				bl1 = false;
			}
			
			if (bl1 || (!bl1 && !bl2))
			{
				list.add(ids[j]);
			}
		}

		return list;
	}
	
	/**
	 * 方法三
	 * 最简洁的方法
	 * @param ids
	 * @return
	 */
	private static List deleteRepeatIds3(Long[] ids)
	{
		List<Long> list = new ArrayList<Long>();
		
		for (int j = 0; j < ids.length; j++)
		{
			if (!list.contains(ids[j]))
			{
				list.add(ids[j]);	
			}
		}
		return list;
	}

	
}