50 lines
1.4 KiB
Java
50 lines
1.4 KiB
Java
// network/ChatterServer.java
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// {ValidateByHand}
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// A server that echoes datagrams
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import java.net.*;
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import java.io.*;
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import onjava.*;
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public class ChatterServer {
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static final int INPORT = 1711;
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private byte[] buf = new byte[1000];
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private DatagramPacket dp =
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new DatagramPacket(buf, buf.length);
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// Can listen & send on the same socket:
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private DatagramSocket socket;
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public ChatterServer() {
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try {
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socket = new DatagramSocket(INPORT);
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System.out.println("Server started");
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while(true) {
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// Block until a datagram appears:
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socket.receive(dp);
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String rcvd = Dgram.toString(dp) +
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", from address: " + dp.getAddress() +
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", port: " + dp.getPort();
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System.out.println(rcvd);
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String echoString =
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"Echoed: " + rcvd;
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// Extract the address and port from the
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// received datagram to find out where to
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// send it back:
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DatagramPacket echo =
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Dgram.toDatagram(echoString,
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dp.getAddress(), dp.getPort());
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socket.send(echo);
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}
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} catch(SocketException e) {
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System.err.println("Can't open socket");
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System.exit(1);
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} catch(IOException e) {
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System.out.println("Communication error");
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throw new RuntimeException(e);
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}
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}
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public static void main(String[] args) {
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new TimedAbort(5); // Terminate after 5 seconds
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new ChatterServer();
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}
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}
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