1、普通的int或者double类型

public class ListMapSort {
    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("name", "张三");
        map1.put("age", "18");
        Map<String, Object> map2 = new HashMap<String, Object>();
        map2.put("name", "李四");
        map2.put("age", "20");
        Map<String, Object> map3 = new HashMap<String, Object>();
        map3.put("name", "王五");
        map3.put("age", "5");
        list.add(map1);
        list.add(map3);
        list.add(map2);
        //排序前 
        for (Map<String, Object> map : list) {
            System.out.println(map.get("age"));
        }
        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()) ;
                Integer name2 = Integer.valueOf(o2.get("cj").toString()) ; 
                return name1.compareTo(name2);
            }
        });
        //排序后 
        System.out.println("-------------------");
        System.out.println("-------------------");
        System.out.println("-------------------");
        for (Map<String, Object> map : list) {
            System.out.println(map.get("age"));
        }
    }
}

！注：如果age的value是double类型的，在compare要使用double类型接收。

2、中文字符串首字母排序

public static void main(String[] args) {    
        // TODO Auto-generated method stub    
        Comparator<Object> com=Collator.getInstance(java.util.Locale.CHINA);    
        String[] newArray={"三眼塘","沅江","益阳","回龙村","长沙","宁乡","星沙","安沙","深圳","北京"};    
        List<String> list = Arrays.asList(newArray);  
        Collections.sort(list, com);   
        for(String i:list){    
            System.out.print(i+"  ");    
        }  
    }