转载自：http://blog.csdn.net/top_code/article/details/10552827

代码：

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
     
       map = new HashMap
      
       ();          map.put("A", "ABC");          map.put("K", "KK");          map.put("L", "LV");                  // 将Map Key 转化为List            List
       
         mapKeyList = new ArrayList
        
         (map.keySet());          System.out.println("mapKeyList:"+mapKeyList);                // 将Map Key 转化为List            List
         
           mapValuesList = new ArrayList
          
           (map.values()); System.out.println("mapValuesList:"+mapValuesList); } private static void testMap2Set() { Map
           
             map = new HashMap
            
             (); map.put("A", "ABC"); map.put("K", "KK"); map.put("L", "LV"); // 将Map 的键转化为Set Set
             
               mapKeySet = map.keySet(); System.out.println("mapKeySet:"+mapKeySet); // 将Map 的值转化为Set Set
              
                mapValuesSet = new HashSet
               
                (map.values()); System.out.println("mapValuesSet:"+mapValuesSet); } private static void testArray2Set() { String[] arr = {"AA","BB","DD","CC","BB"}; //数组-->Set Set
                
                  set = new HashSet
                 
                  (Arrays.asList(arr)); System.out.println(set); } private static void testSet2Array() { Set
                  
                    set = new HashSet
                   
                    (); 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
                    
                      list = new ArrayList
                     
                      (); list.add("ABC"); list.add("EFG"); list.add("LMN"); list.add("LMN"); //List-->Set Set
                      
                        listSet = new HashSet
                       
                        (list); System.out.println(listSet); } private static void testSet2List() { Set
                        
                          set = new HashSet
                         
                          (); set.add("AA"); set.add("BB"); set.add("CC"); //Set --> List List
                          
                            setList = new ArrayList
                           
                            (set); System.out.println(setList); } private static void testList2Array() { //List-->数组 List
                            
                              list = new ArrayList
                             
                              (); 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
                              
                                list1 = Arrays.asList(ss); List
                               
                                 list2 = Arrays.asList("AAA","BBB"); System.out.println(list1); System.out.println(list2); }}
                               
                              
                             
                            
                           
                          
                         
                        
                       
                      
                     
                    
                   
                  
                 
                
               
              
             
            
           
          
         
        
       
      
     

完毕。