//Server code:
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import java.util.Vector;
public class ClientServerMsg {
static final int LISTENING_PORT = 1025;
public static void main(String[] args) throws Exception {
ServerSocket listener;
listener = new ServerSocket(LISTENING_PORT);
System.out.println("Port: " + LISTENING_PORT);
while (true) {
Socket connection = listener.accept();
new ConnectionHandler(connection);
}
}
static class ConnectionHandler extends Thread {
int MAX = 10;
Vector msgsList = new Vector();
Socket connection;
PrintWriter out;
//out = System.out;
private OutputStream outputstream;
ConnectionHandler(Socket conn) throws IOException {
connection = conn;
outputstream = conn.getOutputStream();
out = new PrintWriter(outputstream, true);
start();
}
/*
ConnectionHandler(Socket conn) {
connection = conn;
start();
}
*/
void sendPOSTMESSAGE(String msg) throws Exception {
try {
if (msgsList.size() < MAX) {
msgsList.addElement(msg);
out.println("OK");
out.flush();
} else {
out.println("ERROR");
out.flush();
}
} catch (Exception ex) {
out.println("ERROR");
out.flush();
}
if (out.checkError())
throw new Exception("Error while receiving the message");
}
void sendREADMESSAGE() throws Exception {
if (msgsList.size() == 0) {
out.println("ERROR");
out.flush();
} else if (msgsList.size() > 0)
{
for (int i = 0; i < msgsList.size(); i++) {
if (((String) msgsList.elementAt(i)).startsWith("URGENT:")) {
out.write((String) msgsList.elementAt(i));
msgsList.remove(i);
} else {
out.write((String) msgsList.elementAt(0));
msgsList.remove(0);
}
}
} else {
if (out.checkError())
throw new Exception("Error");
}
}
void sendREMOVEMESSAGE(String remvmsg) throws Exception {
for (int i = 0; i < msgsList.size(); i++) {
if (((String) msgsList.elementAt(i)).equals(remvmsg)) {
msgsList.remove(i);
out.println("OK");
out.flush();
} else {
out.println("ERROR");
out.flush();
}
}
}
void sendQUIT() throws Exception {
out.close();
connection.close();
}
public void run() {
String command = "";
try {
InputStream instream = null;
try {
instream = connection.getInputStream();
} catch (IOException e) {
e.printStackTrace();
}
Scanner in = new Scanner(instream);
try {
outputstream = connection.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
}
//command = in.nextLine();
if (in.hasNextLine()) {
command = in.nextLine();
}
if (command.startsWith("POSTMESSAGE")) {
try {
sendPOSTMESSAGE(command);
} catch (Exception e) {
e.printStackTrace();
}
} else if (command.equals("READMESSAGE")) {
try {
sendREADMESSAGE();
} catch (Exception e) {
e.printStackTrace();
}
} else if (command.startsWith("REMOVEMESSAGE")) {
try {
sendREMOVEMESSAGE(command);
} catch (Exception e) {
e.printStackTrace();
}
} else if (command.equals("QUIT")) {
try {
sendQUIT();
} catch (Exception e) {
e.printStackTrace();
}
} else {
out.println("UNKNOWN COMMAND");
out.flush();
}
} finally {
try {
connection.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
//Client code:
import java.io.*;
import java.net.*;
public class Client {
public static void main(String argv[]) throws Exception
{
String sentence;
String modifiedSentence;
String hostname;
int portNumber;
String portString;
BufferedReader inFromUser =
new BufferedReader(new InputStreamReader(System.in));
System.out.println("What host would you like to connect to?");
hostname = inFromUser.readLine();
System.out.println("What port would you like to connect to?");
portString = inFromUser.readLine();
portNumber = Integer.parseInt(portString);
System.out.println("Connecting to port "+ portNumber+ " of "+ hostname +"....\n");
Socket clientSocket = new Socket(hostname, portNumber);
DataOutputStream outToServer =
new DataOutputStream(clientSocket.getOutputStream());
BufferedReader inFromServer =
new BufferedReader(new
InputStreamReader(clientSocket.getInputStream()));
System.out.println("Connection establised");
sentence = inFromUser.readLine();
while (sentence != null)
{
/* send the sentence to the server */
outToServer.writeBytes(sentence + '\n');
/* read response from the server */
modifiedSentence = inFromServer.readLine();
outToServer.flush();
}
clientSocket.close();
}
}
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