Java实现词频统计(Wordcount)-Map或Hashtable的value排序

叁歲伎倆 2022-07-16 07:57 12阅读 0赞

我们在文本操作时，经常需要用到词频统计，并对统计后的词频进行排序，然后输出。  
以下是我写的一个供大家参考：

package com.qian;
    
    import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.io.OutputStreamWriter;
    import java.util.ArrayList;
    import java.util.Collections;
    import java.util.Comparator;
    import java.util.Hashtable;
    import java.util.List;
    import java.util.Map;
    import java.util.Map.Entry;
    /* * author:合肥工业大学 管院学院 钱洋 * email：1563178220@qq.com */
    public class WordCount { 
        public static void main(String args []) throws IOException {
            Hashtable<String, Integer>  wordCount = new Hashtable<String, Integer>();
            BufferedReader reader = new BufferedReader( new InputStreamReader( new FileInputStream( new File("E:\\钱洋个人\\预测数据\\文本合并\\user_content_combine")),"utf-8"));
            BufferedWriter Writer = new BufferedWriter( new OutputStreamWriter( new FileOutputStream( new File("E:\\钱洋个人\\预测数据\\wordcount\\user_content_count.txt")),"utf-8"));
            String s=null;
            int c=0;
            while ((s=reader.readLine())!=null) {
                String arry[] =s.split(" ");
                for (int i = 0; i < arry.length; i++) {
                    if (!wordCount.containsKey(arry[i])) {
                        wordCount.put(arry[i], Integer.valueOf(1));
                    } else {
                        wordCount.put(arry[i], Integer.valueOf(wordCount.get(arry[i]).intValue() + 1));
                    }
                }
            }
            for (java.util.Map.Entry<String, Integer> j : wordCount.entrySet()) {
                String key = j.getKey();
                int value = j.getValue();
                Writer.append(key+" "+value+"\r\n");
            }
            //if the number of the word is 1,output the word and the number
    
            //将map.entrySet()转换成list 
            List<Map.Entry<String, Integer>> list = new ArrayList<Map.Entry<String, Integer>>(wordCount.entrySet());  
            Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {  
                //降序排序 
                public int compare(Entry<String, Integer> o1, Entry<String, Integer> o2) {  
                    //return o1.getValue().compareTo(o2.getValue()); 
                    return o2.getValue().compareTo(o1.getValue());  
                }  
            });  
    
            for (Map.Entry<String, Integer> mapping : list) {  
                System.out.println(mapping.getKey() + ":" + mapping.getValue());  
            }  
    
        }
    
    }