Java IO help please. program doesnt end

[peshal]

Hello, i am learning the java IO class currently. i was able to create and also append content to the file. then i was trying to open the file and display the content of the file in the console. i was able to do that too . however the program keep on displaying the content of the first line and never stops until i force stop. It would be really great if someone can correct my code. Here is the code.


import java.util.Scanner;
import java.io.*;
public class filereader {

/**
* @param args
*/
public static void main(String[] args) throws IOException
{
// TODO Auto-generated method stub
FileWriter fw = new FileWriter("c:/java/new.txt", true);
PrintWriter append = new PrintWriter(fw);
Scanner in = new Scanner(System.in);
System.out.println("Enter Your name..");
String name = in.nextLine();
append.println(name);
fw.close();
in.close();
FileReader fr = new FileReader("c:/java/new.txt");
BufferedReader br = new BufferedReader(fr);
String data = br.readLine();
while (data != null) {
System.out.println(data);
}
br.close();

}

}

[JosAH]

while (data  != null) {
	System.out.println(data);	
}

This loop prints the same data over and over again; after printing you should read a next line.

kind regards,

Jos

[Fubarable]

You've got an interesting while loop:

String data = br.readLine();
while (data != null) {
   System.out.println(data);	
}

If you logically walk through your code, you should be thinking, where does data change inside of the while loop? If data doesn't change, how will the loop ever end?

After noticing this, your fix should be trivial, and I'll leave it to you to implement.

[peshal]

Thanks a lot both of you. That really helped and i fixed my code.
this is how i fixed.

while (data != null) {
System.out.println(data);
data = br.readLine();
}

[JosAH]

Well done; here's a more idiomatic way of writng the same:

while ((data= br.readLine()) != null) {
   System.out.println(data);
}

kind regards,

Jos

[DarrylBurke]

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[FussyCashew]

Your issue is in the while loop. That loop will continue to run until data is null. Which it will never be.