package com.example.test;

 import java.util.ArrayList;

 import java.util.Arrays;

 import java.util.HashMap;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Map;

 import java.util.Set;

 public class ConvertorTest {

     /**

      * @param args

      */

     public static void main(String[] args) {

         testList2Array();

         testArray2List();

         testSet2List();

         testList2Set();

         testSet2Array();

         testArray2Set();

         testMap2Set();

         testMap2List();

     }

     private static void testMap2List() {

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

         map.put("A", "ABC");

         map.put("K", "KK");

         map.put("L", "LV");  

         // 将Map Key 转化为List

         List<String> mapKeyList = new ArrayList<String>(map.keySet());

         System.out.println("mapKeyList:"+mapKeyList);

         // 将Map Key 转化为List

         List<String> mapValuesList = new ArrayList<String>(map.values());

         System.out.println("mapValuesList:"+mapValuesList);

     }

     private static void testMap2Set() {

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

         map.put("A", "ABC");

         map.put("K", "KK");

         map.put("L", "LV");  

         // 将Map 的键转化为Set

         Set<String> mapKeySet = map.keySet();

         System.out.println("mapKeySet:"+mapKeySet);

         // 将Map 的值转化为Set

         Set<String> mapValuesSet = new HashSet<String>(map.values());

         System.out.println("mapValuesSet:"+mapValuesSet);

     }

     private static void testArray2Set() {

         String[] arr = {"AA","BB","DD","CC","BB"};  

         //数组-->Set

         Set<String> set = new HashSet<String>(Arrays.asList(arr));

         System.out.println(set);

     }

     private static void testSet2Array() {

         Set<String> set = new HashSet<String>();

         set.add("AA");

         set.add("BB");

         set.add("CC");

         String[] arr = new String[set.size()];

         //Set-->数组

         set.toArray(arr);

         System.out.println(Arrays.toString(arr));

     }

     private static void testList2Set() {

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

         list.add("ABC");

         list.add("EFG");

         list.add("LMN");

         list.add("LMN");

         //List-->Set

         Set<String> listSet = new HashSet<String>(list);

         System.out.println(listSet);

     }

     private static void testSet2List() {

         Set<String> set = new HashSet<String>();

         set.add("AA");

         set.add("BB");

         set.add("CC");

         //Set --> List

         List<String> setList = new ArrayList<String>(set);

         System.out.println(setList);

     }

     private static void testList2Array() {

         //List-->数组

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

         list.add("AA");

         list.add("BB");

         list.add("CC");

         Object[] objects = list.toArray();//返回Object数组

         System.out.println("objects:"+Arrays.toString(objects));  

         String[] arr = new String[list.size()];

         list.toArray(arr);//将转化后的数组放入已经创建好的对象中

         System.out.println("strings1:"+Arrays.toString(arr));

     }

     private static void testArray2List() {

         //数组-->List

         String[] ss = {"JJ","KK"};

         List<String> list1 = Arrays.asList(ss);

         List<String> list2 = Arrays.asList("AAA","BBB");

         System.out.println(list1);

         System.out.println(list2);

     }

 }