Java Map 按Key排序实例代码

Java Map 按Key排序

有时候我们业务上需要对map里面的值按照key的大小来进行排序的时候我们就可以利用如下方法来进行排序了，

package test;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Comparator;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Set;

import java.util.TreeSet;

public class Demo {

private HashMap<Integer, Object> map =new HashMap<Integer, Object>();

private Set<Integer> keySet = map.keySet();

public Object get(Integer key) {

return map.get(key);

}

public void put(Integer key, Object value) {

map.put(key, value);

}

@SuppressWarnings("unchecked")

public void sort() {

List<Integer> list =new ArrayList<Integer>(map.keySet());

Collections.sort(list, new Comparator<Object>(){

public int compare(Object a, Object b) {

return a.toString().toLowerCase().compareTo(b.toString().toLowerCase());

}

});

this.keySet = new TreeSet<Integer>(list);

}

public Set<Integer> keySet() {

return this.key

}

public static void main(String [] args){

Demo map= new Demo();

map.put(11, "加");

map.put(12, "关");

map.put(13, "注");

map.put(10, "添");

map.put(1, "小");

map.put(8, "记");

map.put(9, "得");

map.put(7, "客");

map.put(5, "的");

map.put(6, "博");

map.put(4, "豆");

map.put(3, "糖");

map.put(2, "小");

System.out.println("排序前");

for (Iterator it =map.keySet().iterator();it.hasNext();){

Integer key= (Integer)it.next();

System.out.println( "key[ " + key + "], value[ " + map.get(key) + "] ");

}

//

System.out.println("排序后");

System.out.println( "\\n ");

map.sort();

for (Iterator it=map.keySet().iterator();it.hasNext();) {

Integer key=(Integer)it.next();

System.out.println( "key[ " + key + "], value[ " + map.get(key) + "] ");

}

运行效果如下

Java Map 按Key排序实例代码

相关文章

快网idc优惠网

相关文章

微信

快网idc优惠网

QQ交流群