Java中list里面存放map，根据map中的某一个字段进行排序

╰半夏微凉° 2023-02-26 10:27 5阅读 0赞

package com.example.demo;
    
    import java.util.ArrayList;
    
    import java.util.Collections;
    import java.util.Comparator;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    
    /**
     * 
     * <p>
     * Description:
     * </p>
     * 
     * @author xuyangwei
     * 
     * @date 2020年7月15日
     * 
     */
    public class SortListMap {
    	/**
    	 * @param args
    	 */
    	public static void main(String[] args) {
    		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", "jack");
    		Map<String, Object> map2 = new HashMap<String, Object>();
    		map2.put("id", "2");
    		map2.put("name", "tom");
    		Map<String, Object> map3 = new HashMap<String, Object>();
    		map3.put("id", "3");
    		map3.put("name", "marry");
    		list.add(map1);
    		list.add(map3);
    		list.add(map2);
    		// 排序前
    		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 id1 = (String) o1.get("id");
    				String id2 = (String) o2.get("id"); 
    				return id1.compareTo(id2);
    			}
    
    		});
    		// 排序后
    		System.out.println("-------------------");
    		for (Map<String, Object> map : list) {
    			System.out.println(map.get("id"));
    		}
    
    	}
    
    }