list中放map的几种方式

package Test;

import java.util.*;

public class Test {
public static void main(String[] args) {

//第一种：直接加入
List<Map<String,Object>> list1 = new ArrayList<Map<String,Object>>();
Map<String,Object> m1 =new HashMap<String,Object>();
m1.put("age", "55");
m1.put("name", "66");
list1.add(m1);
System.out.println(list1);
//[{name=66, age=55}]

//第二种：直接插入，但是key永远只对应一个value
List<Map<String,Object>> list2 = new ArrayList<Map<String,Object>>();
Map<String,Object> m =new HashMap<String,Object>();
m.put("age", "55");
m.put("name", "66");
list2.add(m);
for(Map<String,Object> m2:list2){
m2.put("key", "123");
}
System.out.println(list2);
//[{name=66, age=55, key=123}]

//第三种:能插入多个值，就是一个key能对应多个value
List<Map<String,Object>> list3 = new ArrayList<Map<String,Object>>();
Map<String,Object> m3 =new HashMap<String,Object>();
m3.put("age", "55");
m3.put("name", "66");
for(int i =0;i<2;i++){
Map<String,Object> mm =new HashMap<String,Object>();
mm.putAll(m3);
mm.put("key1", i);
list3.add(mm);
}
System.out.println(list3);
//[{name=66, key1=0, age=55}, {name=66, key1=1, age=55}]

}

}