The map is stored in the list in java, and it is sorted according to a field in the map
E.g:
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 stub
List<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);
//before sorting
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 is the one taken from your list
String name2= (String)o2.get("id"); //name1 is the second name taken from your list
return name1.compareTo(name2);
}
});
// after sorting
System.out.println("-------------------");
for (Map<String, Object> map : list) {
System.out.println(map.get("id"));
}
}
}
The result of running is:
1
3
2
-------------------1
2
3