JAVA中對list map根據map某個key值進行排序
阿新 • • 發佈:2019-01-07
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是從你list裡面拿出來的一個
Integer name2 = Integer.valueOf(o2.get("cj").toString()) ; //name1是從你list裡面拿出來的第二個name
return name1.compareTo(name2);
}
});
//排序後
System.out.println("-------------------");
for (Map<String, Object> map : list) {
System.out.println(map.get("cj"));
}
}
}