使用stringtokenizer来计算单词问题

Question

I have some trouble getting my program to run as it should. It's about done except for this part i have been working on for a week now and cant get it. The program should count the number of times each word occurs.

With an input of :

This is my file, yes my file My file.. ? ! , : ; / \ |" ^ * + = _( ) { } [ ] < >

the output should look like this:

    file *3
    is *1
    my *3
    this *1
    yes *1

here is my code

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Collections;

public class cleanup3 {

public cleanup3() {}

public static void main(String[] args) {   
  try{
     ArrayList myArraylist = new ArrayList();
     System.out.println("Please Enter file");

     InputStreamReader istream = new InputStreamReader(System.in) ;

     BufferedReader bufRead = new BufferedReader(istream) ;
     String fileName = bufRead.readLine();

     BufferedReader file = new BufferedReader(new FileReader(fileName));

     String s = null;
     while((s = file.readLine()) != null) {                      
         String updated2 = s.replaceAll("[\\.\\,\\?\\!\\:\\;\\/\\|\\\\\\^\\*\\+\\=\\_\\(\\)\\{\\}\\[\\]\\<\\>\"]+"," ");  

         //note to self: missing Single quotes (only if the LAST character of a token)
         StringTokenizer st = new StringTokenizer(updated2.toLowerCase());
         while (st.hasMoreTokens()) {
              String nextToken = st.nextToken();

              String myKeyValue = (String)myMap.get(nextToken);
              if(myKeyValue == null){
                  myMap.put(nextToken, "1");
              }
              else{
                  int mycount = Integer.parseInt(myKeyValue) + 1;
                  myMap.put(nextToken, String.valueOf(mycount));
              }
              System.out.println(nextToken);                           
           }   
        }
            System.out.println( updated2.toLowerCase());
            myArraylist.add(updated2.toLowerCase());                     
    }           
    Collections.sort(myArraylist);
    String outPutFileName =  fileName + "sorted.txt";         
    PrintStream ps = new PrintStream( outPutFileName );
    ps.print(myArraylist.toString());
    ps.flush();
    ps.close();        
  }
  catch (Exception e){
      System.out.println(e.toString());
  }
 }

Answer 1

Your code is way too complicated - you only need a few lines of code.

Here's the elegant way to do it:

Map<String, Integer> map = new TreeMap<String, Integer>();
for (String word : input.toLowerCase().replaceAll("[^a-z ]", "").trim().split(" +"))
    map.put(word, map.containsKey(word) ? map.get(word) + 1 : 1);
for (Map.Entry<String, Integer> entry : map.entrySet())
    System.out.println(entry.getKey() + " *" + entry.getValue());

The input:

• is folded to lowercase, which takes care of the case issues
• has all non-letters/spaces removed, which takes care of cleaning the input
• is trimmed, which gets the input ready for splitting
• is split on 1-n spaces
• is added to a map which accumulates the totals, employing a ternary to handle initialising the word total

The map entries are then iterated to output the totals.

Using a TreeMap takes care of ordering alphabetically for free.

Answer 2

Try BufferedReader and Regex, like so:

    Map<String, Integer> map = new HashMap<String, Integer>();
    String line;
    try (BufferedReader r = new BufferedReader(new FileReader(myFile))) {
            Pattern pattern = Pattern.compile("[a-zA-Z]+");
            while ((line = r.readLine())!=null) {
                Matcher matcher = pattern.matcher(line);
                while (matcher.find()) {
                    String word = matcher.group();
                    map.put(word, map.get(word) == null ? 1 : map.get(word)+1);
                }
            }
    }
    System.out.println(map.toString());