Java tutorial
/* From http://java.sun.com/docs/books/tutorial/index.html */
/*
* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;
public class EchoClient {
public static void main(String[] args) throws IOException {
Socket echoSocket = null;
PrintWriter out = null;
BufferedReader in = null;
try {
echoSocket = new Socket("taranis", 7);
out = new PrintWriter(echoSocket.getOutputStream(), true);
in = new BufferedReader(new InputStreamReader(
echoSocket.getInputStream()));
} catch (UnknownHostException e) {
System.err.println("Don't know about host: taranis.");
System.exit(1);
} catch (IOException e) {
System.err.println("Couldn't get I/O for "
+ "the connection to: taranis.");
System.exit(1);
}
BufferedReader stdIn = new BufferedReader(
new InputStreamReader(System.in));
String userInput;
while ((userInput = stdIn.readLine()) != null) {
out.println(userInput);
System.out.println("echo: " + in.readLine());
}
out.close();
in.close();
stdIn.close();
echoSocket.close();
}
}
////////////////////////////////////////////////////////////
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class KnockKnockServer {
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = null;
try {
serverSocket = new ServerSocket(4444);
} catch (IOException e) {
System.err.println("Could not listen on port: 4444.");
System.exit(1);
}
Socket clientSocket = null;
try {
clientSocket = serverSocket.accept();
} catch (IOException e) {
System.err.println("Accept failed.");
System.exit(1);
}
PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
BufferedReader in = new BufferedReader(new InputStreamReader(
clientSocket.getInputStream()));
String inputLine, outputLine;
KnockKnockProtocol kkp = new KnockKnockProtocol();
outputLine = kkp.processInput(null);
out.println(outputLine);
while ((inputLine = in.readLine()) != null) {
outputLine = kkp.processInput(inputLine);
out.println(outputLine);
if (outputLine.equals("Bye."))
break;
}
out.close();
in.close();
clientSocket.close();
serverSocket.close();
}
}
class KnockKnockProtocol {
private static final int WAITING = 0;
private static final int SENTKNOCKKNOCK = 1;
private static final int SENTCLUE = 2;
private static final int ANOTHER = 3;
private static final int NUMJOKES = 5;
private int state = WAITING;
private int currentJoke = 0;
private String[] clues = { "Turnip", "Little Old Lady", "Atch", "Who", "Who" };
private String[] answers = { "Turnip the heat, it's cold in here!", "I didn't know you could yodel!",
"Bless you!", "Is there an owl in here?", "Is there an echo in here?" };
public String processInput(String theInput) {
String theOutput = null;
if (state == WAITING) {
theOutput = "Knock! Knock!";
state = SENTKNOCKKNOCK;
} else if (state == SENTKNOCKKNOCK) {
if (theInput.equalsIgnoreCase("Who's there?")) {
theOutput = clues[currentJoke];
state = SENTCLUE;
} else {
theOutput = "You're supposed to say \"Who's there?\"! " + "Try again. Knock! Knock!";
}
} else if (state == SENTCLUE) {
if (theInput.equalsIgnoreCase(clues[currentJoke] + " who?")) {
theOutput = answers[currentJoke] + " Want another? (y/n)";
state = ANOTHER;
} else {
theOutput = "You're supposed to say \"" + clues[currentJoke] + " who?\""
+ "! Try again. Knock! Knock!";
state = SENTKNOCKKNOCK;
}
} else if (state == ANOTHER) {
if (theInput.equalsIgnoreCase("y")) {
theOutput = "Knock! Knock!";
if (currentJoke == (NUMJOKES - 1))
currentJoke = 0;
else
currentJoke++;
state = SENTKNOCKKNOCK;
} else {
theOutput = "Bye.";
state = WAITING;
}
}
return theOutput;
}
}
////////////////////////////////////////////////////////////
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class KKMultiServer {
public static void main(String[] args) throws IOException {
ServerSocket serverSocket = null;
boolean listening = true;
try {
serverSocket = new ServerSocket(4444);
} catch (IOException e) {
System.err.println("Could not listen on port: 4444.");
System.exit(-1);
}
while (listening)
new KKMultiServerThread(serverSocket.accept()).start();
serverSocket.close();
}
}
class KKMultiServerThread extends Thread {
private Socket socket = null;
public KKMultiServerThread(Socket socket) {
super("KKMultiServerThread");
this.socket = socket;
}
public void run() {
try {
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String inputLine, outputLine;
KnockKnockProtocol kkp = new KnockKnockProtocol();
outputLine = kkp.processInput(null);
out.println(outputLine);
while ((inputLine = in.readLine()) != null) {
outputLine = kkp.processInput(inputLine);
out.println(outputLine);
if (outputLine.equals("Bye"))
break;
}
out.close();
in.close();
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
class KnockKnockProtocol {
private static final int WAITING = 0;
private static final int SENTKNOCKKNOCK = 1;
private static final int SENTCLUE = 2;
private static final int ANOTHER = 3;
private static final int NUMJOKES = 5;
private int state = WAITING;
private int currentJoke = 0;
private String[] clues = { "Turnip", "Little Old Lady", "Atch", "Who", "Who" };
private String[] answers = { "Turnip the heat, it's cold in here!", "I didn't know you could yodel!",
"Bless you!", "Is there an owl in here?", "Is there an echo in here?" };
public String processInput(String theInput) {
String theOutput = null;
if (state == WAITING) {
theOutput = "Knock! Knock!";
state = SENTKNOCKKNOCK;
} else if (state == SENTKNOCKKNOCK) {
if (theInput.equalsIgnoreCase("Who's there?")) {
theOutput = clues[currentJoke];
state = SENTCLUE;
} else {
theOutput = "You're supposed to say \"Who's there?\"! " + "Try again. Knock! Knock!";
}
} else if (state == SENTCLUE) {
if (theInput.equalsIgnoreCase(clues[currentJoke] + " who?")) {
theOutput = answers[currentJoke] + " Want another? (y/n)";
state = ANOTHER;
} else {
theOutput = "You're supposed to say \"" + clues[currentJoke] + " who?\""
+ "! Try again. Knock! Knock!";
state = SENTKNOCKKNOCK;
}
} else if (state == ANOTHER) {
if (theInput.equalsIgnoreCase("y")) {
theOutput = "Knock! Knock!";
if (currentJoke == (NUMJOKES - 1))
currentJoke = 0;
else
currentJoke++;
state = SENTKNOCKKNOCK;
} else {
theOutput = "Bye.";
state = WAITING;
}
}
return theOutput;
}
}
////////////////////////////////////////////////////////////
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;
public class KnockKnockClient {
public static void main(String[] args) throws IOException {
Socket kkSocket = null;
PrintWriter out = null;
BufferedReader in = null;
try {
kkSocket = new Socket("taranis", 4444);
out = new PrintWriter(kkSocket.getOutputStream(), true);
in = new BufferedReader(new InputStreamReader(kkSocket.getInputStream()));
} catch (UnknownHostException e) {
System.err.println("Don't know about host: taranis.");
System.exit(1);
} catch (IOException e) {
System.err.println("Couldn't get I/O for the connection to: taranis.");
System.exit(1);
}
BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
String fromServer;
String fromUser;
while ((fromServer = in.readLine()) != null) {
System.out.println("Server: " + fromServer);
if (fromServer.equals("Bye."))
break;
fromUser = stdIn.readLine();
if (fromUser != null) {
System.out.println("Client: " + fromUser);
out.println(fromUser);
}
}
out.close();
in.close();
stdIn.close();
kkSocket.close();
}
}