CODEWITHSUNDEEP
java
h-rai
h-rai

Reputation: 3984

Reading file's content and writing to console

I have a program which reads contents from a file and prints it on the screen. But program prints every other line i.e., skips every other line. package InputOutput;

import java.io.*;

public class CharacterFileReaderAndFileWriter{

    private BufferedReader br = null;

    private PrintWriter pw = new PrintWriter(System.out, true);


    /* Read from file and print to console */
    public void readFromFile() throws IOException{

        try{
            br = new BufferedReader(new FileReader("E:\\Programming\\Class files\\practice\\src\\InputOutput\\test.txt"));
        }
        catch(FileNotFoundException ex){
            ex.printStackTrace();
        }

        String s = null;
        do{
            s = br.readLine();
            pw.println(s);
        }
        while((s = br.readLine())!=null);

        br.close();
    }

    /* Main method */
    public static void main(String[] args) throws IOException{

        CharacterFileReaderAndFileWriter cfr = new CharacterFileReaderAndFileWriter();

        cfr.readFromFile();
    }

}

Upvotes: 1

Views: 2318

Answers (7)

ProPrajapat
ProPrajapat

Reputation: 11

you are using br.readLine() two times. 

String s = null;
    do{
        s = br.readLine();  //here it read first line 
        pw.println(s);      //here it prints first line    
    }
    while((s = br.readLine())!=null); //here s read second line
                                      //note that it is not printing that line

String s = null;
    do{
        s = br.readLine();  //this time it read third line
        pw.println(s);      //now it prints third line
    }
    while((s = br.readLine())!=null);   // this time it reads fourth line

So, this process will go on and your program will print lines one after another

Upvotes: 0

Nikhar
Nikhar

Reputation: 1074

Why are you doing s=br.readline() twice.. you can have it like this.

String s = null;
 while((s = br.readLine())!=null)
{
   pw.println(s);
}

readline()reads a line everytime you call it, and goes to next one. so when you call it twice, obviously you are skipping a line. use this code, and it will work.

Upvotes: 6

Paul Vargas
Paul Vargas

Reputation: 42060

Change by:

  for(String s; (s = br.readLine()) != null;) {
        pw.println(s);
  }

Upvotes: 0

Shaikh Farooque
Shaikh Farooque

Reputation: 2640

You need to modify your do-while loop if you want to go with do-while then kindly code it as follows.

String s = null;
do{        
    pw.println(s);
}
while((s = br.readLine())!=null);

br.close();

Upvotes: 0

Sergey Kalinichenko
Sergey Kalinichenko

Reputation: 727137

Reverse your do/while loop to avoid calling readline twice and discarding every other result:

String s = null;
while((s = br.readLine())!=null) {
    pw.println(s);
}

Upvotes: 1

Pau Kiat Wee
Pau Kiat Wee

Reputation: 9505

You loop is wrong:

String s = null;
do{
    s = br.readLine();
    pw.println(s);
}
while((s = br.readLine())!=null);

Should be:

String s = null;
while((s = br.readLine())!=null) {
    pw.println(s);
};

Upvotes: 1

lynks
lynks

Reputation: 5689

remove the first line of your do loop. you are calling readLine() twice.

ie:

String s = null;
while((s = br.readLine())!=null) {
    pw.println(s);
}

Upvotes: 0

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