Java File I/O

[anirbanghosh]

I have the following file ...

INPUT.TXT

5
0 0
0 1
0.5 0.5
1 0
1 1

I want to read the numbers...

import java.io.*;


class ConvexHull
{
	public static void main(String args[]) throws IOException
	{
	    DataInputStream dataIn;
		
	    try 
	    {
	    	dataIn = new DataInputStream(new FileInputStream("INPUT.TXT"));
	    }

	    catch(FileNotFoundException exc) 
	    {
	    	System.out.println("File Not Found");
	    	return;
	    }

	    BufferedReader inputFileReader = new BufferedReader(new InputStreamReader(dataIn));
	    
	    String line;
	    
	    line = inputFileReader.readLine();
	    System.out.println(line);
	    
		while (  (line = inputFileReader.readLine()) != null ) 
		{
				line = inputFileReader.readLine();
				
				System.out.println(line);
		}
	    
	    dataIn.close();
	    
	    System.out.println("\nProgram terminated successfully!!");

	}
}

I am getting the following output. Please help me out!

5
0 1
1 0
null

Program terminated successfully!!

[goldest]

             line = inputFileReader.readLine();
	     System.out.println(line);

	     while (  (line = inputFileReader.readLine()) != null ) {
				line = inputFileReader.readLine();
			        System.out.println(line);
	     }

This is where you are messing up the things. You are reading the file contents, twice here in while loop, but printing them only once. This is resulting into skipping the alternate lines of the text file.

Even you are not supposed to read the text file and print the contents before the while loop.

Can you now figure out, what needs to be removed in your code?

Goldest

[JavaHater]

you can use the Scanner to read your file as well. here's an example

        Scanner sc = new Scanner( new File("file") );
        String line ;
        while( sc.hasNext() ){
            line = sc.nextLine();
            System.out.println(line);
        }
        sc.close()

[anirbanghosh]

Thanks a lot!