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import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/** * ClassName: Sort
* @Description: list集合按元素的某一属性排序
* @author ljw
* @date 2018年5月24日
*/
public class Sort {
public static void main(String[] args) {
List<Map<String, Integer>> list = new ArrayList<>();
for (int i = 0; i < 10; i++) {
Map<String, Integer> map = new HashMap<>();
Integer random = (int)(Math.random() * 100);
map.put("random", random);
list.add(map);
}
//排序前
System.out.println("排序前：" + list);
Collections.sort(list, new Comparator<Map<String, Integer>>() {
public int compare(Map<String, Integer> m1, Map<String, Integer> m2) {
//降序
//return m2.get("random").compareTo(m1.get("random"));
//升序
return m1.get("random").compareTo(m2.get("random"));
}
});
//排序后
System.out.println("排序后：" + list);
}
} |
排序前：[{random=79}, {random=44}, {random=38}, {random=65}, {random=43}, {random=83}, {random=90}, {random=87}, {random=83}, {random=13}]
排序后：[{random=13}, {random=38}, {random=43}, {random=44}, {random=65}, {random=79}, {random=83}, {random=83}, {random=87}, {random=90}]