Question

I am trying to get a Scanner to read the input of a text file, have that input put into a String, have a StringTokenizer of that String, and then have a String[] with each element of that array being a token of that StringTokenizer. The purpose of this is to get a String[] of the inputted text from the text file such that each element of the array is a word in the text file. However, the code I have so far generates a NoSuchElementFound Exception.

    Scanner f = new Scanner(  "input.txt" ); // Yes, I have the file path here, I changed it though. 

    PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("output.txt" );
    String temp = "";
    String cString = "";

    while( ( cString = f.nextLine() ) != null ) { // Line where exception occurs

        temp += cString;
    }
    StringTokenizer everythingTokens = new StringTokenizer( temp );
    String[] everything = new String[ everythingTokens.countTokens() ];

    for( int i = 0; i < everything.length; i++ ) {
        everything[ i ] = everythingTokens.nextToken();
    }

    out.println( everything[ 0 ] );

Here is the error message

Exception in thread "main" java.util.NoSuchElementException: No line found
at java.util.Scanner.nextLine(Scanner.java:1585)
at gift1.main(gift1.java:21)
Java Result: 1

The input for this in the text file is

Hey,
How are you?

Why is this happening and how can I fix it?

Answer 1

That’s not how you use a Scanner. You’d instead do:

while (scanner.hasNextLine()) {
   String line = scanner.nextLine();
   // work with your line here
}

Please have a look at the Scanner API and you’ll see that it doesn’t return null if it runs out of lines. Instead it throws a …. NoSuchElementException. I think that you’re confusing its use with that of a BufferedReader, and they’re really two completely distinct species.