单词统计

package text;
import java.io.*;
import java.util.*;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Scanner;
import java.util.Set;

public class abc {
    public static void main(String[] args) throws FileNotFoundException
    {        File file=new File("D://input.txt");        
    if(!file.exists())        {            System.out.println("文件不存在");            
    return;        }    
    Scanner scanner=new Scanner(file);        //单词和数量映射表        
    HashMap<String, Integer > hashMap=new HashMap<String,Integer>();        
    System.out.println("文章-----------------------------------");        
    while(scanner.hasNextLine())        
    {            
        String line=scanner.nextLine();            
    System.out.println(line);        
    //w+ : 匹配所有的单词            
    //W+ : 匹配所有非单词            
    String[] lineWords=line.split("\W+");
    //用非单词符来做分割，分割出来的就是一个个单词                        
    Set<String> wordSet=hashMap.keySet();            
    for(int i=0;i<lineWords.length;i++){                //如果已经有这个单词了，            
        if(wordSet.contains(lineWords[i]))            
        {Integer number=hashMap.get(lineWords[i]);            
        number++;                
        hashMap.put(lineWords[i], number);                }        
        else                 {                    hashMap.put(lineWords[i], 1);    
        }        
        }        
    }    
    System.out.println("统计单词：------------------------------");    
    Iterator<String> iterator=hashMap.keySet().iterator();        
while(iterator.hasNext())        {            String word=iterator.next();                
//System.out.printf("单词： "+word+"出现次数："+hashMap.get(word));            
System.out.printf("单词:%-12s 出现次数:%d
",word,hashMap.get(word));        }                    
System.out.println("程序结束--------------------------------");
}
}