Java中对list map根据map某个key值进行排序的方法

package test;import java.util.ArrayList;import java.util.Collections;import java.util.Comparator;import java.util.HashMap;import java.util.List;import java.util.Map;public class java_ListMapSort {  public static void main(String[] args) {    // TODO Auto-generated method stub     List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();    Map<String, Object> map1 = new HashMap<String, Object>();    map1.put("name", "p");    map1.put("cj", "5");    Map<String, Object> map2 = new HashMap<String, Object>();    map2.put("name", "h");    map2.put("cj", "12");    Map<String, Object> map3 = new HashMap<String, Object>();    map3.put("name", "f");    map3.put("cj", "31");    list.add(map1);    list.add(map3);    list.add(map2);    //排序前     for (Map<String, Object> map : list) {      System.out.println(map.get("cj"));    }    Collections.sort(list, new Comparator<Map<String, Object>>() {      public int compare(Map<String, Object> o1, Map<String, Object> o2) {        Integer name1 = Integer.valueOf(o1.get("cj").toString()) ;//name1是从你list里面拿出来的一个         Integer name2 = Integer.valueOf(o2.get("cj").toString()) ; //name1是从你list里面拿出来的第二个name        return name1.compareTo(name2);      }    });    //排序后     System.out.println("-------------------");    for (Map<String, Object> map : list) {      System.out.println(map.get("cj"));    }  }}