无法按升序排序顺序列表 [英] Unable to sort the the list by ascending order

问题描述

 地图＆LT;字符串，字符串＆GT;图;
清单＆LT;地图＆LT;字符串，字符串＆GT;＆GT;名单=新的ArrayList＆LT;地图＆LT;字符串，字符串＆GT;＆GT;（）;
/////的OnCreate .............
功能1（）{
地图=新TreeMap的＆LT;字符串，字符串＆GT;（）;
map.put（ID，ID）;
map.put（入账金额，金额）;list.add（地图）;的System.out.println（名单）;
}
 

id的输入值= 1,3,5,57,80

有关量的输入值= 100,500,200,10,10000

无法按升序排序多少的顺序列表。它仍然显示了它被插入的顺序。

我该如何解决这个问题？我AP preciate任何帮助。先谢谢了。

预计产量：量的升序：

  AMT = 10 ID = 4
AMT = 100的id = 1
AMT = 200的id = 3
AMT = 500 ID = 2
AMT = 10000 ID = 5
 

解决方案

假设这是你输入

 地图＆LT;字符串，字符串＆GT;图;
  清单＆LT;地图＆LT;字符串，字符串＆GT;＆GT;名单=新的ArrayList＆LT;地图＆LT;字符串，字符串＆GT;＆GT;（）;
  地图=新TreeMap的＆LT;字符串，字符串＆GT;（）;
  map.put（ID，1）;
  map.put（量，100）;
  list.add（地图）;
  地图=新TreeMap的＆LT;字符串，字符串＆GT;（）;
  map.put（ID，2）;
  map.put（量，500）;
  list.add（地图）;
  地图=新TreeMap的＆LT;字符串，字符串＆GT;（）;
  map.put（ID，3）;
  map.put（量，200）;
  list.add（地图）;
  地图=新TreeMap的＆LT;字符串，字符串＆GT;（）;
  map.put（ID，4）;
  map.put（量，10）;
  list.add（地图）;
  地图=新TreeMap的＆LT;字符串，字符串＆GT;（）;
  map.put（ID，5）;
  map.put（额，10000）;
  list.add（地图）;
 

下面是您的排序code

  Col​​lections.sort（名单，新的比较＆LT;地图＆LT;字符串，字符串＆GT;＆GT;（）{        @覆盖
        公众诠释比较（地图＆LT;字符串，字符串＆GT; 01，地图＆LT;字符串，字符串＆GT; O2）{
            字符串值1 = o1.get（额）;
            字符串值2 = o2.get（额）;
            返回的Integer.parseInt（值）-Integer.parseInt（值2）;
        }
    }）;    对于（地图＆LT;字符串，字符串＆GT; MAP1：名单）{
        字符串ID = map1.get（ID）;
        串金额= map1.get（额）;
        的System.out.println（金额=量+ +，+的id =+ ID）;
    }
 

输出

 额= 10，ID = 4
量= 100，ID = 1
量= 200，ID = 3
量= 500，ID = 2
量= 10000，ID = 5
 

更新

替换返回的Integer.parseInt（值）-Integer.parseInt（值2）; 通过以下code。如果值是小数

 返回Double.valueOf（值）.compareTo（Double.valueOf（值2））;
 

Map<String, String> map ;
List<Map<String, String>> list = new ArrayList<Map<String, String>>();


/////OnCreate.............


function1(){
map = new TreeMap<String, String>();
map.put("id", "id");
map.put("amont", "amount");

list.add(map);

System.out.println(list);
}

input values for id=1,3,5,57,80

input values for amount=100,500,200,10,10000

Unable to sort the list by ascending order of amount. It still shows in the order it was inserted.

How do I fix this? I appreciate any help. Thanks in advance.

Expected output: Ascending order of amount:

amt=10 id=4  
amt=100 id=1  
amt=200 id=3  
amt=500 id=2  
amt=10000 id=5  

解决方案

Assuming this is your input

  Map<String, String> map ;
  List<Map<String, String>> list = new ArrayList<Map<String, String>>();
  map = new TreeMap<String, String>();
  map.put("id","1");
  map.put("amount","100");
  list.add(map);
  map = new TreeMap<String, String>();
  map.put("id","2");
  map.put("amount","500");  
  list.add(map);
  map = new TreeMap<String, String>();
  map.put("id","3");
  map.put("amount","200");
  list.add(map);
  map = new TreeMap<String, String>();
  map.put("id","4");
  map.put("amount","10");
  list.add(map);
  map = new TreeMap<String, String>();
  map.put("id","5");
  map.put("amount","10000");
  list.add(map);

Here is your sorting code

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

        @Override
        public int compare(Map<String, String> o1, Map<String, String> o2) {
            String value1 =  o1.get("amount");
            String value2 =  o2.get("amount");
            return Integer.parseInt(value1)-Integer.parseInt(value2);
        }
    });

    for (Map<String, String> map1 : list) {
        String id = map1.get("id");
        String amount = map1.get("amount");
        System.out.println("amount= "+amount + " , " +"id = "+id);
    }

Output

amount= 10 , id = 4
amount= 100 , id = 1
amount= 200 , id = 3
amount= 500 , id = 2
amount= 10000 , id = 5

update

Replace return Integer.parseInt(value1)-Integer.parseInt(value2); with the following code if the values are decimal.

return Double.valueOf(value1).compareTo(Double.valueOf(value2));

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