计算一个字符串中每个词的数量并降序输出

Posted 2020-11-22 程序猿养成中

结果：

 

代码：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


public class demo {

    public static void main(String[] args) throws IOException {
        String S = "马佳；刘胜；马佳；刘胜；慧；慧；刘胜；";
        String str[] = S.split("；");
        
        System.out.println(str.length);
        
        Map <String, Integer> map = new HashMap<String, Integer>();
        
        for (String s1 : str) {
            
            if (!map.containsKey(s1))  
                map.put(s1, 1);  
            else  
                map.put(s1, (map.get(s1)+1));  
        }

      
        List<Map.Entry<String, Integer>> list = new ArrayList<Map.Entry<String, Integer>>(map.entrySet());

        Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {
            
            public int compare(Map.Entry<String, Integer> mapping2, Map.Entry<String, Integer> mapping1) 
            {
                return mapping1.getValue().compareTo(mapping2.getValue());
            }
        });
     
        Map.Entry<String, Integer> mapping = null;
        for (int i = 0 ;i<list.size() ;i++) {
            mapping = list.get(i);
            if (i<10)
            System.out.println(mapping.getKey() + "=" + mapping.getValue());
        }
    }
}