Thread: Analyzing Input Files, Code Runs Forever

So, my assignment is to write a program that takes a file as an input and give some statistics on the file. Right now, I'm just trying to find the average number of words per sentence.

I extended the Echo class,

import java.util.Scanner;
  import java.io.*;
 
  public class Echo{
    String fileName; // external file name
    Scanner scan; // Scanner object for reading from external file
 
    public Echo(String f) throws IOException
    {
     fileName = f;
     scan = new Scanner(new FileReader(fileName));
   }
 
   public void readLines(){ // reads lines, hands each to processLine
     while(scan.hasNext()){
       processLine(scan.nextLine());
     }
     scan.close();
   }
 
   public void processLine(String line){ // does the real processing work
     System.out.println(line);
   }
}

With my class WorldMap,

 import java.io.*;
import java.util.*;
 
public class WorldMap extends Echo{
  int numWords = 0; int numSentence = 0;
 
  public WorldMap(String f) throws IOException{
    super(f);
  }
 
  public double getAvg(){
    return ((double)numWords/numSentence);
  }
 
  public void processLine(String line){
    try{
    StringTokenizer sentence = new StringTokenizer(line, ".?,"); // Breaks line by punctuation, into sentences
    StringTokenizer words = new StringTokenizer(line, " "); // Breaks line by spaces, into words
    while (words.hasMoreTokens()){
      numWords++;
    }
    while (sentence.hasMoreTokens()){
      numSentence++;
    }
}
    catch (Exception e){
      System.out.println("Invaid line: Line " + line);
    }
}
}

& Here is my main, driver class

import java.util.*;
import java.io.*;
 
public class WorldMapDriver{
  public static void main(String[] args) throws IOException{
    try{
      Scanner scan = new Scanner(System.in);
      System.out.println("Enter the name of a text file");
      String file = scan.next();
      WorldMap world = new WorldMap(file);
      world.readLines();
      world.getAvg();
    }
    catch (FileNotFoundException e){
      System.out.println("File not found");
    }
  }
}

I don't know much about reading input files, but I can't see why this program won't work. When I enter the location of a file, nothing happens... the client just sort of freezes like its still thinking.

The code compiles fine, with no errors or warnings.

Any help is greatly appreciated!

Originally Posted by Norm

Try debugging the code by adding some println() statements to print out messages as the executes. Be sure to put one inside any loops that could be long running. The print out will show you where the code is executing. If you also print the values of the variables the code uses, that will help you understand what the program is doing.

Ah, good idea. The problem I found is that it doesn't stop counting the number of words, or it is taking too long.
Is

StringTokenizer words = new StringTokenizer(line, " ");

The write code to use here to break a line into words? I think it might just be breaking into individual characters which is taking too long.

Originally Posted by Norm

Have you located a loop that is going forever?


Probably not a problem. Try testing with a short file.

Yes, this loop is running forever:

while (words.hasMoreTokens()){
      numWords++;
      System.out.println("Word Count: " + numWords);
    }

I also tried using

StringTokenizer words = new StringTokenizer(line, "\\W");

instead of

(line, " ");

But the same thing happens

Originally Posted by Norm

Where is the code reading any tokens from the StringTokenizer? It asks if there is one, but never gets it so there is always one ready to be read.

Ahh, I see. So now I just need to make use of

words.nextToken()

somehow... Is there a way I can do this without having the nextToken printed every time?

--- Update ---

Ah, nevermind. That was a silly question, I just have to write words.nextToken() in there. Thanks again Norm!