--想把list类型里面位置2和位置3的数据进行调换
public class Dmeo3 {
public static void main(String[] args) {
Dmeo3 d=new Dmeo3();
List<Map<String, Object>> list=new ArrayList<>();
Map<String, Object>map=new HashMap<String, Object>();
Map<String, Object>map2=new HashMap<String, Object>();
Map<String, Object>map3=new HashMap<String, Object>();
map.put("1", 1);
map.put("2", 2);
map2.put("3", 3);
map2.put("4", 4);
map3.put("5", 5);
map3.put("6", 6);
list.add(map);
list.add(map2);
list.add(map3);
list.get(0).put("aa", 1);
list.get(0).put("bb", 2);
list.get(1).put("gg", 5);
list.get(1).put("hh", 6);
list.get(2).put("jj", 77);
list.get(2).put("kk", 88);
for (Map<String, Object> map4 : list) {
System.out.println(map4);
}
d.changePosition(list,list.size()-1,list.size()-2);
System.out.println("================");
for (Map<String, Object> map7 : list) {
System.out.println(map7);
}
}
--工具方法
public void changePosition( List<Map<String, Object>> list,int rootIndex,int targetIndex){
Map<String, Object> rootMap = list.get(rootIndex);
Map<String, Object> targeMap = list.get(targetIndex);
list.set(rootIndex, targeMap);
list.set(targetIndex, rootMap);
}
}
改变list类型的数据值使用list.set()方法