package com.abc.test;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.Comparator;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Scanner;

import java.util.Set;

import java.util.SortedMap;

import java.util.TreeMap;

import java.util.Map.Entry;

/**

 * 可能会遇到这样的情况，我可能要对Map<key,value>的集合进行排序，而这种排序又分为两种情况，你可能按key值排序；

 * 另外你也可能会遇到按value值进行排序的情况。

 * 大家都知道，默认的情况下，TreeMap：是按key升序,进行排序的；LinkedHashMap：是按加入顺序进行排序的

 * ；HashMap：内部数值的顺序并不是以存放的先后顺序为主

 * ，而是以hash值的顺序为主，其次才是存放的先后顺序。在这里我们只讨论如何实现HashMap的排序。

 *

 */

@SuppressWarnings("unchecked")

public class MapSortTest {

	public static void main(String[] args) {

		//初始化map

		Map<String, Integer> map=getMapInstance();

		printMap(map);

		//选择操作

		Scanner input=new Scanner(System.in);

		int num=input.nextInt();

		switch (num) {

			case 0:

				System.exit(0);

				break;

			case 1:

				Map<String, Integer> sortMaps = sortMapByKey(map);

				printMap(sortMaps);

				break;

			case 2:

				sortMapByValue(map);

				break;

			case 3:

				mapSortByKey(map);

				break;

			case 4:

				mapSortByValue(map);

				break;

			default:

				System.out.println("error input!");

				break;

		}

	}

	public static Map sortMapByKey(Map map) {

		Map<Object, Object> mapVK = new TreeMap<Object, Object>(

				new Comparator<Object>() {

					public int compare(Object obj1, Object obj2) {

						String v1 = (String) obj1;

						String v2 = (String) obj2;

						int s = v2.compareTo(v1);

						return s;

					}

				});

		Set col = map.keySet();

		Iterator iter = col.iterator();

		while (iter.hasNext()) {

			String key = (String) iter.next();

			Integer value = (Integer) map.get(key);

			mapVK.put(key, value);

		}

		return mapVK;

	}

	public static void sortMapByValue(Map maps) {

		List<Map.Entry<String, Integer>> info = new ArrayList<Map.Entry<String, Integer>>(maps.entrySet());

		Collections.sort(info, new Comparator<Map.Entry<String, Integer>>() {

			public int compare(Map.Entry<String, Integer> obj1,Map.Entry<String, Integer> obj2) {

				return obj2.getValue() - obj1.getValue();

			}

		});

		for (int j = 0; j < info.size(); j++) {

			System.out.println(info.get(j).getKey() + "------->"+ info.get(j).getValue());

		}

	}

	// ====================================================================================

	private static SortedMap<String, Integer> mapSortByKey(Map<String, Integer> unsort_map) {

		TreeMap<String, Integer> result = new TreeMap<String, Integer>();

		Object[] unsort_key = unsort_map.keySet().toArray();

		Arrays.sort(unsort_key);

		for (int i = 0; i < unsort_key.length; i++) {

			result.put(unsort_key[i].toString(), unsort_map.get(unsort_key[i]));

		}

		return result.tailMap(result.firstKey());

	}

	public static void mapSortByValue(Map map) {

		List arrayList = new ArrayList(map.entrySet());

		Collections.sort(arrayList,new Comparator(){

			@Override

			public int compare(Object o1, Object o2) {

				Map.Entry obj1 = (Map.Entry)o1;

				Map.Entry obj2 = (Map.Entry)o2;

				return obj1.getValue().toString().compareTo(obj2.getValue().toString());

			}

		});

		for(Iterator it = arrayList.iterator();it.hasNext();){

			Map.Entry entry = (Map.Entry)it.next();

			System.out.println(entry.getKey()+":"+entry.getValue());

		}

	}

	public static void abc(Map map){

		TreeMap treemap = new TreeMap(map);

	}

	public static void abcd() {

		Map<String, Integer> keyfreqs = new HashMap<String, Integer>();

		ArrayList<Entry<String, Integer>> list = new ArrayList<Entry<String, Integer>>(keyfreqs.entrySet());

		Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {

			public int compare(Map.Entry<String, Integer> o1,Map.Entry<String, Integer> o2) {

				return (o2.getValue() - o1.getValue());

			}

		});

		for (Entry<String, Integer> e : list) {

			System.out.println(e.getKey() + "::::" + e.getValue());

		}

	}

	public static Map getMapInstance(){

		Map<String, Integer> map = new HashMap<String, Integer>();

		map.put("apple",40);

		map.put("boy",30);

		map.put("cat",20);

		map.put("dog",10);

		return map;

	}

	public static void printMap(Map map){

		Iterator i = map.entrySet().iterator();

		while (i.hasNext()) {

			Map.Entry<String, Integer> entry = (Map.Entry<String, Integer>) i.next();

			System.out.println(entry.getKey() + ":"+ entry.getValue());

		}

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

	}

}