BufferReader inside try clause : cannot find symbol

Question

I'm trying to write a class that handles reading files. In order to read the file word by word, I used the following code which I found on the internet. Netbeans seems to disagree and says that it cannot find the symbole br inside the while loop.

public class Reader {
  public String file2string() {
    String line;
    try (InputStream fis = new FileInputStream("smth")) {
      InputStreamReader isr = new InputStreamReader(fis, Charset.forName("UTF-8"));
      BufferedReader br = new BufferedReader(isr);
    } catch (IOException ex) {
      Logger.getLogger(Reader.class.getName()).log(Level.SEVERE, null, ex);
    }
    {
      while ((line = br.readLine()) != null) {
        String[] words = line.split(" ");
        // Now you have a String array containing each word in the current line
      }
    }
    return line;
  }
}

Please indent your code properly if you are asking people to try and read it. — khelwood, Aug 11 '16 at 13:54
your `while loop` is outside the `try-catch` so the variable `br` is out of the scope yet — SomeJavaGuy, Aug 11 '16 at 13:55

khelwood · Answer 1 · 2016-08-11T14:02:44.980

You have a {} block after your try statement

{
    InputStreamReader isr = new InputStreamReader(fis, Charset.forName("UTF-8"));
    BufferedReader br = new BufferedReader(isr);
}

And then you have another {} block.

{
    while ((line = br.readLine()) != null) {
        String[] words = line.split(" ");
        // Now you have a String array containing each word in the current line
    }
}

Variables declared in the first block are not visible in the second block.

Combine the two blocks:

public String file2string() {
    String line;
    try (InputStream fis = new FileInputStream("smth")) {
        InputStreamReader isr = new InputStreamReader(fis, Charset.forName("UTF-8"));
        BufferedReader br = new BufferedReader(isr);
        while ((line = br.readLine()) != null) {
            String[] words = line.split(" ");           
        }
        return line;
    } catch (IOException ex) {
        Logger.getLogger(Reader.class.getName()).log(Level.SEVERE, null, ex);
    }
    // you need to decide what you want to return here if you got an exception.
}

You seem to be splitting each line and ignoring the result, and then returning the last line of the file. I don't know why you're doing that, or what you were actually trying to do; but this is how to fix the compile error.

How do i resolve the problem ? i can't declare the buffeedreader before declarinf the inputstreamreader — Majd, Aug 11 '16 at 13:58
Basically, put the code that uses `br` >>inside<< the `try` block. — Stephen C, Aug 11 '16 at 14:00

score 1 · Answer 2 · answered Aug 11 '16 at 13:57

1

The variable "br" is declared in the try{} block, so that's its scope. It won't be visible outside of that block. Try putting the while loop inside the try block.

answered Aug 11 '16 at 13:57

Graeme Cole

276
1
4

Nikolas Charalambidis · Accepted Answer · 2016-08-11T14:02:14.860

Your loop is out the try so the variable br is unknown in the context. Put your while-loop inside the try structure like here:

public String file2string() {
    String line = null;
    try (InputStream fis = new FileInputStream("smth")) {
        InputStreamReader isr = new InputStreamReader(fis, Charset.forName("UTF-8"));
        BufferedReader br = new BufferedReader(isr);

        while ((line = br.readLine()) != null) {
            String[] words = line.split(" ");
            // Now you have a String array containing each word in the current line
        }
    } catch (IOException ex) {
        Logger.getLogger(Reader.class.getName()).log(Level.SEVERE, null, ex);
    }  
    return line;
}

BufferReader inside try clause : cannot find symbol

3 Answers3