Using BufferedReader.readLine() in a while loop properly

billg118 picture billg118 · Nov 15, 2012 · Viewed 149.7k times · Source

So I'm having an issue reading a text file into my program. Here is the code:

     try{
        InputStream fis=new FileInputStream(targetsFile);
        BufferedReader br=new BufferedReader(new InputStreamReader(fis));

        //while(br.readLine()!=null){
        for(int i=0;i<100;i++){
            String[] words=br.readLine().split(" ");
            int targetX=Integer.parseInt(words[0]);
            int targetY=Integer.parseInt(words[1]);
            int targetW=Integer.parseInt(words[2]);
            int targetH=Integer.parseInt(words[3]);
            int targetHits=Integer.parseInt(words[4]);
            Target a=new Target(targetX, targetY, targetW, targetH, targetHits);
            targets.add(a);
        }
        br.close();
    }
    catch(Exception e){
        System.err.println("Error: Target File Cannot Be Read");
    }

The file I am reading from is 100 lines of arguments. If I use a for loop it works perfectly. If I use the while statement (the one commented out above the for loop) it stops at 50. There is a possibility that a user can run the program with a file that has any number of lines, so my current for loop implementation won't work.

Why does the line while(br.readLine()!=null) stop at 50? I checked the text file and there is nothing that would hang it up.

I don't get any errors from the try-catch when I use the while loop so I am stumped. Anyone have any ideas?

Answer

ramin picture ramin · Feb 11, 2014

also very comprehensive...

try{
    InputStream fis=new FileInputStream(targetsFile);
    BufferedReader br=new BufferedReader(new InputStreamReader(fis));

    for (String line = br.readLine(); line != null; line = br.readLine()) {
       System.out.println(line);
    }

    br.close();
}
catch(Exception e){
    System.err.println("Error: Target File Cannot Be Read");
}