CODEWITHSUNDEEP
javasystemoutputstream
felipeek
felipeek

Reputation: 1213

Why write() method of OutputStream class doesn't work in the console?

I'm starting to learn Java and I didn't understand why this code doesn't work:

import java.io.*;

public class Principal
{
    public static void main (String args[]) throws IOException
    {
        OutputStream outConsole = System.out;

        outConsole.write(101);
    }
}

System.out is an PrintStream object, PrintStream is a subclass of OutputStream. OutputStream is an abstract class and write() is an abstract method of it. So I guess PrintStream must have the write method implemented, why this code doesn't work, then?

Upvotes: 1

Views: 1299

Answers (2)

nos
nos

Reputation: 229088

System.out is a PrintSteam, which is line buffered. Flush it

outConsole.flush();

Upvotes: 1

Sotirios Delimanolis
Sotirios Delimanolis

Reputation: 279950

PrintStream#write(int) doesn't automatically flush the stream under all conditions. The javadoc states

Writes the specified byte to this stream. If the byte is a newline and automatic flushing is enabled then the flush method will be invoked.

In any other case, you need to do so explicitly

outConsole.flush();

Upvotes: 4

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