Reading an input file in java

Question

My input file:

/home/gcj/finals

I want to have each character after / My approach:

StringTokenizer sr = new StringTokenizer(br.readLine());
      String s = sr.nextToken("/");
                 while(s != null){
                     System.out.println(s);
                     s = sr.nextToken("/");
                 }

Output:

gcj
finals
Exception in thread "main" java.util.NoSuchElementException
    at java.util.StringTokenizer.nextToken(Unknown Source)
    at java.util.StringTokenizer.nextToken(Unknown Source)
    at jobs.TestClass.main(TestClass.java:118)

Please Help me out. OR if there any better method.

Do you mean "each character" or "each string"? Each character would be 'h', 'g', 'f' — Stewart, Oct 03 '14 at 15:45

score 1 · Answer 1 · answered Oct 03 '14 at 15:46

1

Instead of while (s != null), use hasMoreTokens().

answered Oct 03 '14 at 15:46

reservoirman

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phtrivier · Answer 2 · 2014-10-03T15:49:08.607

As the StringTokenizer docs explains, you must use the hasMoreTokens method to loop instead of comparing next() to null.

 StringTokenizer st = new StringTokenizer(...);
 while (st.hasMoreTokens()) {
     System.out.println(st.nextToken());
 }

And again, as the docs explains, split is a better option to split a String in general.

Finally, since you're trying to read a file line by line, you should check out libraries like Apache Commons, they have what you're looking for in FileUtils.lineIterator.

score 0 · Answer 3 · answered Oct 03 '14 at 15:44

0

for (String s : "/home/gcj/finals".split("/")) {
   System.out.println(s);
}

answered Oct 03 '14 at 15:44

NPE

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You should add some explanation of why this is an answer. – Whymarrh Oct 03 '14 at 16:11

score 0 · Answer 4 · edited May 23 '17 at 12:21

0

If you want to read a file, you can take the classes IO, In and Out from here. Then you can simply invoke IO.in.readFile(String filename).

Hope it helps.

Clemencio Morales Lucas.

edited May 23 '17 at 12:21

Community

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answered Oct 03 '14 at 15:45

Clemencio Morales Lucas

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Reading an input file in java

4 Answers4