kwic--Java统计单词个数并按照顺序输出

Z时代
2024-01-10
分类：综合

java

是一个统计文件中单词个数，并按照个数从大到小输出的。输入文件名OK 了

单词是按照首字母排序的，，，里面用到映射等，，，注意重写比较函数，因为我们是要按值排序，而不是一般的按照键排序，，，，我们要输出的由多到少的个数，，，有个数是重复的

由于我们要按照个数多少排序，所以记得重写比较函数，为啥不能让数字做键，因为键不能重复，所以这里单词是键，OK 。

1 str.split("\\s+");这里记录分隔符

2 正则表达式,
\\d表示 0-9 的数字,
\\s表示空格,回车,换行等空白符,
\\w表示单词字符(数字字母下划线)
+号表示一个或多个的意思

代码：

  1 package calnum;
  2 
  3 import java.io.BufferedReader;
  4 import java.io.FileNotFoundException;
  5 import java.io.FileReader;
  6 import java.io.IOException;
  7 import java.nio.Buffer;
  8 import java.nio.ShortBuffer;
  9 import java.util.ArrayList;
 10 import java.util.Collections;
 11 import java.util.Comparator;
 12 import java.util.HashMap;
 13 import java.util.Iterator;
 14 import java.util.List;
 15 import java.util.Map;
 16 import java.util.Map.Entry;
 17 import java.util.Scanner;
 18 import java.util.TreeMap;
 19 
 20 import javax.swing.Spring;
 21 import javax.swing.text.html.parser.Entity;
 22 
 23 public class calwordnum{
 24 
 25     public String readfile() throws IOException {
 26         String all = null;
 27         // System.out.print("##########################");
 28         Scanner cin = new Scanner(System.in);
 29         System.out.print("plz input file name:");
 30         String filename = cin.next();
 31         FileReader read = new FileReader(filename);
 32         BufferedReader re = new BufferedReader(read);
 33         StringBuffer strbuf = new StringBuffer();
 34 
 35         String ss;
 36         while ((ss = re.readLine()) != null) {
 37             strbuf.append(ss);
 38         //读全文
 39         }
 40 
 41         return strbuf.toString();
 42 
 43     }
 44 
 45     //
 46     public String[] input(String str) {
 47         String[] arr = str.split("\\s+");
 48 
 49         return arr;
 50     }
 51 
 52     public void putmap(List<String> ls) {
 53         String temp, theword = null;
 54         int flage = 0;
 55         theword = ls.get(0);
 56         Map<String, Integer> map = new HashMap<String, Integer>();
 57         Iterator it = ls.iterator();
 58         while (it.hasNext()) {
 59             // System.out.println("sss"+it.next().toString());
 60             temp = it.next().toString();
 61 
 62             if (temp.equals(theword)) {
 63                 flage++;
 64                 continue;
 65             } else {
 66                 map.put(theword, flage);
 67                 flage = 1;
 68                 theword = temp;
 69 
 70             }
 71         }
 72 
 73         map.put(theword, flage);
 74         //重写比较方法，treemap按值排序。用两个map 比较函数需要参数
 75         ValueComparator bvc =  new ValueComparator(map);  
 76        Map<String,Integer> map2 = new TreeMap<String,Integer>(bvc);  
 77        map2.putAll(map);
 78         Iterator mapit = map2.entrySet().iterator();
 79         while (mapit.hasNext()) {
 80             Entry tr = (Entry) mapit.next();
 81             
 82             String num = (String) tr.getKey();
 83             int sa = (Integer) tr.getValue();
 84             System.out.println("this word:"+num + " has:" + sa + "个");
 85         }
 86 
 87     }
 88 
 89     // /
 90     public static void main(String[] args) throws IOException {
 91         // TODO Auto-generated method stub
 92         List<String> ls = new ArrayList<String>();
 93 
 94         calwordnum ca = new calwordnum();
 95 
 96         String allword = ca.readfile();
 97         String[] arr = ca.input(allword);
 98         for (int i = 0; i < arr.length; i++) {
 99 
100             ls.add(arr[i].toLowerCase());
101         }
102 
103         Collections.sort(ls);
104         display(ls);
105         ca.putmap(ls);
106 
107     }
108 
109     @Override
110     public boolean equals(Object obj) {
111         // TODO Auto-generated method stub
112         return super.equals(obj);
113     }
114 
115     private static void display(List<String> ls) {
116         // TODO Auto-generated method stub
117 
118         for (String s : ls)
119             System.out.println(s);
120     }    
121     
122 }
123 //
124 class ValueComparator implements Comparator<String> {  
125       
126     Map<String, Integer> base;  
127     public ValueComparator(Map<String, Integer> base) {  
128         this.base = base;  
129     }  
130   
131         
132     public int compare(String a, String b) {  
133         if (base.get(a) >=base.get(b)) {  
134             return -1;  //注意   不要返回0 会删除重复
135         } 
136         
137         else {  
138             return 1;  
139         } 
140     }  
141 }