java中list里面存放map，根据map中的某一个字段进行排序

java中list里面存放map，根据map中的某一个字段进行排序

例如：

package com;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 Com {/** * @param args */@SuppressWarnings({ "rawtypes", "unchecked" })public static void main(String[] args) {// TODO Auto-generated method stubList<Map<String, Object>> list = new ArrayList<Map<String, Object>>();Map<String, Object> map1 = new HashMap<String, Object>();map1.put("id", "1");map1.put("name", "p");Map<String, Object> map2 = new HashMap<String, Object>();map2.put("id", "2");map2.put("name", "h");Map<String, Object> map3 = new HashMap<String, Object>();map3.put("id", "3");map3.put("name", "f");list.add(map1);list.add(map3);list.add(map2);//排序前for (Map<String, Object> map : list) {System.out.println(map.get("id"));}Collections.sort(list, new Comparator<Map<String, Object>>(){   public int compare(Map<String, Object> o1, Map<String, Object> o2) {    String name1 =(String)o1.get("id");//name1是从你list里面拿出来的一个    String name2= (String)o2.get("id"); //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("id"));}}}

运行结果是：

1

3

2

-------------------

1

2

3