Java Scanner cannot find word

Question

I am sorry if there is something very simple I am missing.

I have the following code:

import java.util.Scanner;
import java.io.File;
import java.util.regex.Pattern;
public class UnJumble
{
    String[] ws;
    int ind=0;
    public static void main(String args[]) throws Exception
    {
        System.out.println("Enter a jumbled word");
        String w = new Scanner(System.in).next();

        UnJumble uj = new UnJumble();
        uj.ws = new String[uj.fact(w.length())];
        uj.makeWords("",w);

        int c=1;
        Scanner sc = new Scanner(new File("dict.txt"));
        for(int i=0; i<uj.ws.length; i++)
        {
              Pattern pat = Pattern.compile(uj.ws[i].toUpperCase());
              if(sc.hasNext(pat))
                    System.out.println(c+++" : \'"+uj.ws[i]+"\'");
        }

        System.out.println("Search Completed.");
        if(c==1) System.out.println("No word found.");
    }

    public void makeWords(String p,String s)
    {
        if(s.length()==0)
              ws[ind++] = p;
        else
              for(int i=0; i<s.length(); i++)
                    makeWords(p+s.charAt(i),s.substring(0,i)+s.substring(i+1));
    }

    public int fact(int n)
    {
        if(n==0) return 1;
        else return n*fact(n-1);
    }
}

The dict.txt file is the SOWPODS dictionary, which is the official Scrabble dictionary..

I want to take in a jumbled word, and rearrange it to check if it is present in the dictionary. If it is, then print it out.

When I try tra as input, the output says No word Found. . But the output should have the words tar , art and rat .

Please tell me where I am making a mistake. I apologize if I have made a very simple mistake, because this is the first time I am working with Pattern .

Answer 1

This is from the JavaDoc of Scanner.hasNext(Pattern pattern) (with my highlighting)

Returns true if the next complete token matches the specified pattern.

As your Scanner was initialized with file dict.txt , it is positioned on first word .

And the first complete token in dict.txt does not match any of your scambled words, so no match is found.

Note: This assumes you have one word per line

I'd think you may want to change your code to find your scrambled text somewhere in the dictionary file (with start-of-line before and end-of-line after) resulting in a pattern "(^|\\\\W)"+uj.ws[i].toUpperCase()+"(\\\\W|$)" and something like

 String dictstring = your dictionary as one string;

 Matcher m = p.matcher(dictstring);
 if(m.find()) {
  ...

I recommend IOUtils.toString() for reading your file like this:

String dictstring = "";
try(InputStream is = new FileInputStream("dict.txt")) {
  dictstring = IOUtils.toString(is);
}

Here's a small example code to get familiar with pattern and matcher:

    String dictString= "ONE\r\nTWO\r\nTHREE";
    Pattern p = Pattern.compile("(^|\\W)TWO(\\W|$)");
    Matcher m = p.matcher(dictString);
    if(m.find()) {
        System.out.println("MATCH: " + m.group());
    }