public class main {

	public static void main(String[] args) {

		List<String> list = new ArrayList<>();

		list.add("李菊福");

		list.add("狗娃");

		list.add("尼古拉斯赵四");

		list.add("尼古拉斯赵四");

		list.add("尼古拉斯赵四");

		list.add("刘能");

		list.add("刘能");

		list.add("阿里郎");

		System.out.println("排序前");

		for (String string : list) {

			System.out.println(string);

		}
                //排序

		HashSet h = new HashSet(list);

		list.clear();

		list.addAll(h);

		System.out.println("排序后");

		for (String string : list) {

			System.out.println(string);

		}

	}

}

-----去重前----

李菊福

狗娃

尼古拉斯赵四

尼古拉斯赵四

尼古拉斯赵四

刘能

刘能

阿里郎

-------去重后--------

狗娃

李菊福

阿里郎

尼古拉斯赵四

刘能

	 public static void main(String[] args) {

	        List<Map<String,String>> list = new ArrayList();

	        Map<String,String> map1 = new HashMap<String, String>();

	        Map<String,String> map2 = new HashMap<String, String>();

	        Map<String,String> map3 = new HashMap<String, String>();

	        Map<String,String> map4 = new HashMap<String, String>();

	        Map<String,String> map5 = new HashMap<String, String>();

	        Map<String,String> map6 = new HashMap<String, String>();

	        Map<String,String> map7 = new HashMap<String, String>();

	        map1.put("custName","shoes");

	        map1.put("productId","1");

	        map2.put("custName","shoes");

	        map2.put("productId","2");

	        map3.put("custName","hat");

	        map3.put("productId","3");

	        map4.put("custName","hat");

	        map4.put("productId","3");

	        map5.put("custName","shoes");

	        map5.put("productId","2");

	        map6.put("custName","clothes");

	        map6.put("productId","2");

	        map7.put("custName","clothesSample");

	        map7.put("productId","2");

	        list.add(map1);

	        list.add(map2);

	        list.add(map3);

	        list.add(map4);

	        list.add(map5);

	        list.add(map6);

	        list.add(map7);	       

	        System.out.println("去重前");

	        for (Map<String,String> map : list) {

	            System.out.println(map.get("custName")+ " : " +map.get("productId"));

	        }

	        //去重

	        HashSet h = new HashSet(list);

	        list.clear();

	        list.addAll(h);

	        System.out.println("-----");

	        System.out.println("去重后");

	        for (Map<String,String> map : list) {

	            System.out.println(map.get("custName")+ " : " +map.get("productId"));

	        }

	    }　

去重前

shoes : 1

shoes : 2

hat : 3

hat : 3

shoes : 2

clothes : 2

clothesSample : 2

-----

去重后

clothes : 2

shoes : 2

clothesSample : 2

shoes : 1

hat : 3