EchoServer.java EchoServer.java Below is the syntax highlighted version of EchoServer.java from §8.4 Operating Systems. /******************************************************************************
* Compilation: javac EchoServer.java
* Execution: java EchoServer port
* Dependencies: In.java Out.java
*
* Runs an echo server which listents for connections on port 4444,
* and echoes back whatever is sent to it.
*
*
* % java EchoServer 4444
*
*
* Limitations
* -----------
* The server is not multi-threaded, so at most one client can connect
* at a time.
*
******************************************************************************/
import java.net.Socket;
import java.net.ServerSocket;
public class EchoServer {
public static void main(String[] args) throws Exception {
// create socket
int port = 4444;
ServerSocket serverSocket = new ServerSocket(port);
System.err.println("Started server on port " + port);
// repeatedly wait for connections, and process
while (true) {
// a "blocking" call which waits until a connection is requested
Socket clientSocket = serverSocket.accept();
System.err.println("Accepted connection from client");
// open up IO streams
In in = new In (clientSocket);
Out out = new Out(clientSocket);
// waits for data and reads it in until connection dies
// readLine() blocks until the server receives a new line from client
String s;
while ((s = in.readLine()) != null) {
out.println(s);
}
// close IO streams, then socket
System.err.println("Closing connection with client");
out.close();
in.close();
clientSocket.close();
}
}
}
Copyright © 2000–2017, Robert Sedgewick and Kevin Wayne. Last updated: Fri Oct 20 14:12:12 EDT 2017.
