PipedWriter is a character stream class in the java.io package used to write characters to a pipe. This pipe can be connected to a PipedReader which reads the characters written by PipedWriter. This mechanism facilitates inter-thread communication where one thread writes data, and another reads it.
Commonly Used Constructors and Methods
Simple Program Using PipedWriter
Mahesh and LotusJavaPrince want to simulate a simple chat system using threads. Mahesh acts as a sender writing messages to a PipedWriter. LotusJavaPrince acts as a receiver reading the messages via a connected PipedReader. The communication should be thread-safe and continuous until Mahesh sends a termination message "exit".
import java.io.*;
class ChatSender implements Runnable {
private PipedWriter writer;
public ChatSender(PipedWriter writer) {
this.writer = writer;
}
@Override
public void run() {
String[] messages = {
"Hello LotusJavaPrince!",
"How are you today?",
"Did you check the latest update?",
"Let's meet tomorrow.",
"exit" // Signal to end chat
};
try (PrintWriter pw = new PrintWriter(writer)) {
for (String msg : messages) {
pw.println(msg);
pw.flush();
Thread.sleep(500); // Simulate delay between messages
}
} catch (IOException | InterruptedException e) {
System.out.println("Sender error: " + e.getMessage());
}
}
}
class ChatReceiver implements Runnable {
private PipedReader reader;
public ChatReceiver(PipedReader reader) {
this.reader = reader;
}
@Override
public void run() {
try (BufferedReader br = new BufferedReader(reader)) {
String msg;
while ((msg = br.readLine()) != null) {
if ("exit".equalsIgnoreCase(msg.trim())) {
System.out.println("Chat ended by sender.");
break;
}
System.out.println("LotusJavaPrince received: " + msg);
}
} catch (IOException e) {
System.out.println("Receiver error: " + e.getMessage());
}
}
}
public class ChatApplicationCaseStudy {
public static void main(String[] args) throws IOException {
PipedWriter writer = new PipedWriter();
PipedReader reader = new PipedReader(writer);
Thread senderThread = new Thread(new ChatSender(writer));
Thread receiverThread = new Thread(new ChatReceiver(reader));
receiverThread.start();
senderThread.start();
}
}Output
LotusJavaPrince received: Hello LotusJavaPrince!
LotusJavaPrince received: How are you today?
LotusJavaPrince received: Did you check the latest update?
LotusJavaPrince received: Let's meet tomorrow.
Chat ended by sender.PipedWriter provides a way for one thread to send character data to another thread through a connected PipedReader.It supports thread communication via character streams and must be connected to a PipedReader.Always ensure proper closing of the streams to avoid resource leaks.