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SMTP client for Gmail on java using sockets authentication issue

I found a socket SMTP client example slightly modified for it to connect to gmail using SSLsockets, but now I don't know how to authorise account, that I am sending from. (I don't use JAVAMAIL, because this is homework)
public class SMTP {
public static void main(String args[]) throws IOException,
UnknownHostException {
String msgFile = "file.txt";
String from = "from#gmail.com";
String to = "to#gmail.com";
String mailHost = "smtp.gmail.com";
SMTP mail = new SMTP(mailHost);
if (mail != null) {
if (mail.send(new FileReader(msgFile), from, to)) {
System.out.println("Mail sent.");
} else {
System.out.println("Connect to SMTP server failed!");
}
}
System.out.println("Done.");
}
static class SMTP {
private final static int SMTP_PORT = 25;
InetAddress mailHost;
InetAddress localhost;
BufferedReader in;
PrintWriter out;
public SMTP(String host) throws UnknownHostException {
mailHost = InetAddress.getByName(host);
localhost = InetAddress.getLocalHost();
System.out.println("mailhost = " + mailHost);
System.out.println("localhost= " + localhost);
System.out.println("SMTP constructor done\n");
}
public boolean send(FileReader msgFileReader, String from, String to)
throws IOException {
SSLSocket smtpPipe;
InputStream inn;
OutputStream outt;
BufferedReader msg;
msg = new BufferedReader(msgFileReader);
smtpPipe = (SSLSocket) ((SSLSocketFactory) SSLSocketFactory.getDefault()).createSocket(InetAddress.getByName("smtp.gmail.com"), 465);
if (smtpPipe == null) {
return false;
}
inn = smtpPipe.getInputStream();
outt = smtpPipe.getOutputStream();
in = new BufferedReader(new InputStreamReader(inn));
out = new PrintWriter(new OutputStreamWriter(outt), true);
if (inn == null || outt == null) {
System.out.println("Failed to open streams to socket.");
return false;
}
String initialID = in.readLine();
System.out.println(initialID);
System.out.println("HELO " + localhost.getHostName());
out.println("HELO " + localhost.getHostName());
String welcome = in.readLine();
System.out.println(welcome);
System.out.println("MAIL From:<" + from + ">");
out.println("MAIL From:<" + from + ">");
String senderOK = in.readLine();
System.out.println(senderOK);
System.out.println("RCPT TO:<" + to + ">");
out.println("RCPT TO:<" + to + ">");
String recipientOK = in.readLine();
System.out.println(recipientOK);
System.out.println("DATA");
out.println("DATA");
String line;
while ((line = msg.readLine()) != null) {
out.println(line);
}
System.out.println(".");
out.println(".");
String acceptedOK = in.readLine();
System.out.println(acceptedOK);
System.out.println("QUIT");
out.println("QUIT");
return true;
}
}
}

Rewrote the code. This works fine.
public class TotalTemp
{
private static DataOutputStream dos;
public static void main(String[] args) throws Exception
{
int delay = 1000;
String user = "xxxxx#gmail.com";
String pass = "xxxxxxxx11";
String username = Base64.encodeBase64String(user.getBytes(StandardCharsets.UTF_8));
String password = Base64.encodeBase64String(pass.getBytes(StandardCharsets.UTF_8));
SSLSocket sock = (SSLSocket)((SSLSocketFactory)SSLSocketFactory.getDefault()).createSocket("smtp.gmail.com", 465);
// Socket sock = new Socket("smtp.gmail.com", 587);
final BufferedReader br = new BufferedReader(new InputStreamReader(sock.getInputStream()));
(new Thread(new Runnable()
{
public void run()
{
try
{
String line;
while((line = br.readLine()) != null)
System.out.println("SERVER: "+line);
}
catch (IOException e)
{
e.printStackTrace();
}
}
})).start();
dos = new DataOutputStream(sock.getOutputStream());
send("EHLO smtp.gmail.com\r\n");
Thread.sleep(delay);
send("AUTH LOGIN\r\n");
Thread.sleep(delay);
send(username + "\r\n");
Thread.sleep(delay);
send(password + "\r\n");
Thread.sleep(delay);
send("MAIL FROM:<XXXXXXXX#gmail.com>\r\n");
//send("\r\n");
Thread.sleep(delay);
send("RCPT TO:<YYYYYYYY#gmail.com>\r\n");
Thread.sleep(delay);
send("DATA\r\n");
Thread.sleep(delay);
send("Subject: Email test\r\n");
Thread.sleep(delay);
send("Test 1 2 3\r\n");
Thread.sleep(delay);
send(".\r\n");
Thread.sleep(delay);
send("QUIT\r\n");
}
private static void send(String s) throws Exception
{
dos.writeBytes(s);
System.out.println("CLIENT: "+s);
}
}

First, Make sure you have turned on 'Allow Less Secure Apps' from your Gmail.
We can improve the code by ignoring the Multi-threading part by just reading the output from server. As we know from the RFC that server sends 9 lines after getting the first 'EHLO' request. So, we are just reading 9 lines with bufferedReader. Then for the next few commands, it returns only one line. So, the simplified code without multithreading will be like this :
import java.nio.charset.StandardCharsets;
import javax.net.ssl.*;
import java.io.*;
import java.util.Base64;
public class SMTP_Simplified_v2 {
// Credentials
public static String user = "xxxxxxx#gmail.com";
public static String pass = "xxxxxxxxxx";
private static DataOutputStream dataOutputStream;
public static BufferedReader br = null;
public static void main(String[] args) throws Exception {
int delay = 1000;
String username = Base64.getEncoder().encodeToString(user.getBytes(StandardCharsets.UTF_8));
String password = Base64.getEncoder().encodeToString(pass.getBytes(StandardCharsets.UTF_8));
SSLSocketFactory sslSocketFactory = (SSLSocketFactory) SSLSocketFactory.getDefault();
SSLSocket sslSocket = (SSLSocket) sslSocketFactory.createSocket("smtp.gmail.com", 465);
br = new BufferedReader(new InputStreamReader(sslSocket.getInputStream()));
dataOutputStream = new DataOutputStream(sslSocket.getOutputStream());
send("EHLO smtp.gmail.com\r\n",9);
send("AUTH LOGIN\r\n",1);
send(username+"\r\n",1);
send(password+"\r\n",1);
send("MAIL FROM:<xxxxxxxx#gmail.com>\r\n",1);
send("RCPT TO:<xxxxx#gmail.com>\r\n",1);
send("DATA\r\n",1);
send("Subject: Email test\r\n",0);
send("Email Body\r\n",0);
send(".\r\n",0);
send("QUIT\r\n",1);
}
private static void send(String s, int no_of_response_line) throws Exception
{
dataOutputStream.writeBytes(s);
System.out.println("CLIENT: "+s);
Thread.sleep(1000);
// Just reading the number of lines the server will respond.
for (int i = 0; i < no_of_response_line; i++) {
System.out.println("SERVER : " +br.readLine());
}
}
}

Multithreading with client server program

I am trying to implement multi threading with a client/server program I have been working on. I need to allow multiple clients to connect to the server at the same time. I currently have 4 classes: a Client, a Server, a Protocol and a Worker to handle the threads. The following code is what I have for those classes:
SocketServer Class:
public class SocketServer {
public static void main(String[] args) throws IOException {
int portNumber = 9987;
try (
ServerSocket serverSocket = new ServerSocket(portNumber);
Socket clientSocket = serverSocket.accept();
PrintWriter out =
new PrintWriter(clientSocket.getOutputStream(), true);
BufferedReader in = new BufferedReader(
new InputStreamReader(clientSocket.getInputStream()));
) {
Thread thread = new Thread(new ClientWorker(clientSocket));
thread.start(); //start thread
String inputLine, outputLine;
// Initiate conversation with client
Protocol prot = new Protocol();
outputLine = prot.processInput(null);
out.println(outputLine);
while ((inputLine = in.readLine()) != null) {
outputLine = prot.processInput(inputLine);
out.println(outputLine);
if (outputLine.equals("quit"))
break;
}
} catch (IOException e) {
System.out.println("Exception caught when trying to listen on port "
+ portNumber + " or listening for a connection");
System.out.println(e.getMessage());
}
}
}
SocketClient Class:
public class SocketClient {
public static void main(String[] args) throws IOException
{
String hostName = "localhost";
int portNumber = 9987;
try (
Socket socket = new Socket(hostName, portNumber);
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
BufferedReader in = new BufferedReader(
new InputStreamReader(socket.getInputStream()));
) {
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("quit"))
break;
fromUser = stdIn.readLine();
if (fromUser != null) {
System.out.println("Client: " + fromUser);
out.println(fromUser);
}
}
} catch (UnknownHostException e) {
System.err.println("Don't know about host " + hostName);
System.exit(1);
} catch (IOException e) {
System.err.println("Couldn't get I/O for the connection to " +
hostName);
System.exit(1);
}
}
}
Protocol Class:
public class Protocol {
private static final int waiting = 0;
private static final int sentPrompt = 1;
private int status = waiting;
public String processInput(String theInput) {
String theOutput = null;
if (status == waiting) {
theOutput = "Please enter what you would like to retrieve: 'customer' or 'product' ";
status = sentPrompt;
}
else if ( status == sentPrompt ) {
if ( theInput.equalsIgnoreCase("product")) {
File f = new File("product.txt");
Scanner sc = null;
try {
sc = new Scanner(f);
} catch (FileNotFoundException ex) {
Logger.getLogger(Protocol.class.getName()).log(Level.SEVERE, null, ex);
}
while ( sc.hasNextLine() ) {
String line = sc.nextLine();
theOutput = "The current product entries are : " + line;
}
return theOutput;
}
else if ( theInput.equalsIgnoreCase("customer")) {
File f = new File("customer.txt");
Scanner sc = null;
try {
sc = new Scanner(f);
} catch (FileNotFoundException ex) {
Logger.getLogger(Protocol.class.getName()).log(Level.SEVERE, null, ex);
}
while ( sc.hasNextLine() ) {
String line = sc.nextLine();
theOutput = "The current customer entries are : " + line;
}
return theOutput;
}
else if ( theInput.equalsIgnoreCase("quit")) {
return "quit";
}
else {
return "quit";
}
}
return theOutput;
}
}
The ClientWorker Class:
public class ClientWorker implements Runnable {
private final Socket client;
public ClientWorker( Socket client ) {
this.client = client;
}
#Override
public void run() {
String line;
BufferedReader in = null;
PrintWriter out = null;
try {
System.out.println("Thread started with name:"+Thread.currentThread().getName());
in = new BufferedReader(new InputStreamReader(client.getInputStream()));
out = new PrintWriter(client.getOutputStream(), true);
} catch (IOException e) {
System.out.println("in or out failed");
System.exit(-1);
}
while (true) {
try {
System.out.println("Thread running with name:"+Thread.currentThread().getName());
line = in.readLine();
//Send data back to client
out.println(line);
//Append data to text area
} catch (IOException e) {
System.out.println("Read failed");
System.exit(-1);
}
}
}
}
When I run the server and client, everything works fine as expected. Then when I try to run another client, it just hangs there and does not prompt the client to give a response. Any insight into what I am missing is greatly appreciated!

Your server code should address implement below functionalities.
Keep accepting socket from ServerSocket in a while loop
Create new thread after accept() call by passing client socket i.e Socket
Do IO processing in client socket thread e.g ClientWorker in your case.
Have a look at this article
Your code should be
ServerSocket serverSocket = new ServerSocket(portNumber);
while(true){
try{
Socket clientSocket = serverSocket.accept();
Thread thread = new ClientWorker(clientSocket);
thread.start(); //start thread
}catch(Exception err){
err.printStackTrace();
}
}

How many times does serverSocket.accept() get called?
Once.
That's how many clients it will handle.
Subsequent clients trying to contact will not have anybody listening to receive them.
To handle more clients, you need to call serverSocket.accept() in a loop.

Multi-Threading Server/Client Chat

So this is my first post here, I am currently trying to make a Java client/server chat application using socket programming.
I currently have the server waiting for a client to connect and then passing the client's messages back to the client. So far I have tried different methods to make the server continuously listen to new clients and connect them allowing them to post and view messages with each other.
Can you point me in the right direction and how I should implement this?
SERVER
class TCPServer {
private ServerSocket serverSocket;
private int port;
String newLine = System.getProperty("line.separator");
public TCPServer(int port) {
this.port = port;
}
public void begin() throws IOException {
System.out.println("Starting the server at port: " + port);
serverSocket = new ServerSocket(port);
System.out.println("Waiting for clients... " + newLine);
try {
Socket connectionSocket = serverSocket.accept();
DataOutputStream hello =
new DataOutputStream(connectionSocket.getOutputStream());
hello.writeUTF("You have successfully connected!" + newLine + "please type your username");
//A client has connected to this server. Get client's username
String username = getUserName(connectionSocket);
System.out.println(username + " has connected" + newLine);
//Start chat method
startChat(connectionSocket, username);
} catch (Exception e) {
}
}
public String getUserName(Socket connectionSocket) throws IOException {
String clientUserName;
// ArrayList clients = new ArrayList();
BufferedReader userNameClient =
new BufferedReader(new InputStreamReader(
connectionSocket.getInputStream()));
clientUserName = userNameClient.readLine();
//clients.add(clientUserName);
DataOutputStream greetingFromServer =
new DataOutputStream(connectionSocket.getOutputStream());
//writeUTF Caused incorrect key codes to appear at beginning of String
greetingFromServer.writeBytes("Welcome " + clientUserName + ", please type your message" + newLine);
return clientUserName;
}
public void startChat(Socket connectionSocket, String username) throws IOException {
String clientSentence;
String clientMessageOut;
while (true) {
//Socket connectionSocket = welcomeSocket.accept();
BufferedReader inFromClient =
new BufferedReader(new InputStreamReader(
connectionSocket.getInputStream()));
DataOutputStream outToClient =
new DataOutputStream(connectionSocket.getOutputStream());
//Loops to check if client message is not empty
while ((clientSentence = inFromClient.readLine()) != null) {
outToClient.writeBytes(username + ": " + clientSentence + newLine);
if (clientSentence.equals("close")) {
System.out.println(username + " has left the server");
}
}
}
}
public static void main(String[] args) throws Exception {
int port = 6788;
TCPServer welcomeSocket = new TCPServer(port);
welcomeSocket.begin();
}
}
CLIENT
class TCPClient {
public static void main(String[] args) throws Exception {
String sentence;
String modifiedSentence;
boolean keepConnection = true;
int port = 6788;
Scanner inFromUser = new Scanner(System.in);
Socket clientSocket = new Socket("localhost", 6788);
//System.out.println("You are connented to server"+ '\n'+"Please enter your username: ");
String newLine = System.getProperty("line.separator");
//Recieve greeting message
InputStream messageFromServer = clientSocket.getInputStream();
DataInputStream in =
new DataInputStream(messageFromServer);
System.out.println("FROM SERVER: " + in.readUTF());
DataOutputStream outToServer =
new DataOutputStream(clientSocket.getOutputStream());
BufferedReader inFromServer =
new BufferedReader(new InputStreamReader(
clientSocket.getInputStream()));
while ((sentence = inFromUser.nextLine()) != null) {
outToServer.writeBytes(sentence + '\n');
modifiedSentence = inFromServer.readLine();
System.out.println("sentence = " + sentence);
System.out.println(modifiedSentence);
if (sentence.equals("close")) {
System.out.println("You have left the server");
outToServer.writeBytes("close" + newLine);
break;
}
}
clientSocket.close();
}
}

You can use a while(true){} or while((socket = serverSocket.accept()) != null) for the server to loop indefinitely.

To make the server able to connect to multiple clients, you can create a loop where you accept new connections:
while (true) {
try {
Socket connectionSocket = serverSocket.accept();
...
}
...
}
To keep it responsive, you can work with each client in a new thread or maintain a thread pool and submit a task to it for each new connection.

Here is an example (taken from ServerSocketEx) of how you could do it. ServerSocketEx extends ServerSocket, but this is just for ease of use; all of the code following super.accept is relevent to your question.
As others have suggested, you should call accept() in a loop, surrounded by a try { } catch (IOException ...); so that you can shut down if you choose to close the ServerSocket
public Socket accept() throws IOException {
Socket s = super.accept();
if (getSocketRunnerFactory() != null) {
SocketRunner runner = getSocketRunnerFactory().createSocketRunner(s);
if (executor != null) {
Future f =
executor.submit(runner);
if (futures != null) futures.add(f);
}
else {
Thread t = new Thread(runner);
t.start();
}
}
return s;
}

Java, Sockets, BufferedReader and StringBuilder

Yestarday I wrote a post about Java and Sockets, and today I'm still here because I'm having an issue with BufferedReaders.
I searched some questions here in StackOverflow and I understand the problem, but I can't fix it
My "application" has got two parts: a server and a client, and the scope of the application is to execute MS-DOS commands on the machine where the server is running (the commands are sent by the client).
Now the code (I will post the total code because it's easier to understand, I will put a comment in non-working part of the code) Server:
import java.net.*;
import java.io.*;
public class TCPCmdServer {
public int port;
public ServerSocket server;
public final String version = "Beta 1.0";
TCPCmdServer(int port) {
this.port = port;
if (!createServer())
System.out.println("Cannot start the server");
else {
System.out.println("**********************************************");
System.out.println("Command executer, server version: " + version);
System.out.println("Server running on port " + port);
System.out.println("Code by luc99a alias L99");
System.out.println("**********************************************");
}
}
public boolean createServer() {
try {
server = new ServerSocket(port);
} catch (IOException e) {
e.printStackTrace();
return false;
}
return true;
}
public static void main(String[] args) {
TCPCmdServer tcp = new TCPCmdServer(5000);
while (true) {
Socket socket = null;
BufferedReader in = null;
BufferedWriter out = null;
try {
socket = tcp.server.accept();
System.out.println("A client has connected");
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
out = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
out.write("Welcome on the server... type the commands you like, type END to close the connection\n");
out.flush();
} catch (IOException exc) {
exc.printStackTrace();
}
if (socket != null && in != null && out != null) {
try {
String cmd = null;
while (!(cmd = in.readLine()).equals("END")) {
System.out.println("Recieved: " + cmd);
Process p = Runtime.getRuntime().exec(cmd);
BufferedReader pRead = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
StringBuilder builder = new StringBuilder();
while ((line = pRead.readLine()) != null) {
builder = builder.append(line + "\n");
}
out.write(builder.toString() + "\n");
//here is sent "EnD"
out.write("EnD \n");
out.flush();
System.out.println(builder.toString());
pRead.close();
}
} catch (IOException ex) {
ex.printStackTrace();
} finally {
System.out.println("Closing connection...");
try {
socket.close();
in.close();
out.close();
} catch (IOException excp) {
excp.printStackTrace();
}
}
}
}
}
}
And now the code for the client part
import java.net.*;
import java.io.*;
public class TCPCmdClient {
public Socket socket;
public int port;
public String ip;
public final String version = "Beta 1.0";
TCPCmdClient(String ip, int port) {
this.ip = ip;
this.port = port;
if (!createSocket())
System.out.println("Cannot connect to the server. IP: " + ip + " PORT: " + port);
else {
System.out.println("**********************************************");
System.out.println("Command executer, client version: " + version);
System.out.println("Connected to " + ip + ":" + port);
System.out.println("Code by luc99a alias L99");
System.out.println("**********************************************");
}
}
public boolean createSocket() {
try {
socket = new Socket(ip, port);
} catch (IOException e) {
return false;
}
return true;
}
public static void main(String[] args) {
TCPCmdClient client = new TCPCmdClient("127.0.0.1", 5000);
try {
BufferedReader sysRead = new BufferedReader(new InputStreamReader(System.in));
BufferedReader in = new BufferedReader(new InputStreamReader(client.socket.getInputStream()));
BufferedWriter out = new BufferedWriter(new OutputStreamWriter(client.socket.getOutputStream()));
String response = in.readLine();
System.out.println("Server: " + response);
boolean flag = true;
while (flag) {
System.out.println("Type a command... type END to close the connection");
String cmd = sysRead.readLine();
out.write(cmd + "\n");
out.flush();
if (cmd.equals("END")) {
client.socket.close();
sysRead.close();
in.close();
out.close();
flag = false;
} else {
//The loop doesn't finish because the reader
//listens for a new line
//so I used the string "EnD", sent by the server to
//stop the loop, anyway it doesn't seem to work
//I put a comment in the server where "EnD" is sent
String output;
while (((output = in.readLine()) != null)) {
if (output.equals("EnD")) {
break;
} else {
System.out.println(output);
}
}
System.out.println(" *************************************** ");
}
}
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
The problem is that the BufferedReader waits for a new line forever in the while loop (I wrote a comment in the code). I tryed to stop it using a "special string", but it doesn't seem to work.
I can't change the while in
String output;
while (((output = in.readLine()) != null) && output.length > 0)
{
//code here...
}
because in the output of the MS-DOS command (think on "ipconfig") are also present empty lines.
How could I correct it?
Thank you for your help!

your client Sends "EnD " (with a whitespace at the end) and you are comparing to "EnD" without a whitespace. So the two strings are not equal. try to send it without the white space:
out.write("EnD\n");

Space is missing. In TCPCmdClient.java change
if (output.equals("EnD")) {
to
if (output.equals("EnD ")) {

java.net.SocketException: Connection Reset

I'm trying to write a socket program where a string is sent to the server, reversed and the reversed string is sent back to the client.
Here's my server code:
import java.io.*;
import java.net.*;
class ClientSystem
{
public static void main(String[] args)
{
String hostname = "127.0.0.1";
int port = 1234;
Socket clientsocket = null;
DataOutputStream output =null;
BufferedReader input = null;
try
{
clientsocket = new Socket(hostname,port);
output = new DataOutputStream(clientsocket.getOutputStream());
input = new BufferedReader(new InputStreamReader(clientsocket.getInputStream()));
}
catch(Exception e)
{
System.out.println("Error occured"+e);
}
try
{
while(true)
{
System.out.println("Enter input string ('exit' to terminate connection): ");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String inputstring = br.readLine();
output.writeBytes(inputstring+"\n");
//int n = Integer.parseInt(inputstring);
if(inputstring.equals("exit"))
break;
String response = input.readLine();
System.out.println("Reversed string is: "+response);
}
output.close();
input.close();
clientsocket.close();
}
catch(Exception e)
{
System.out.println("Error occured."+e);
}
/*finally
{
output.close();
input.close();
clientsocket.close();
}*/
}
}
Here's my server code:
import java.io.*;
import java.net.*;
public class ServerSystem
{
ServerSocket server = null;
Socket clientsocket = null;
int numOfConnections = 0, port;
public ServerSystem(int port)
{
this.port = port;
}
public static void main(String[] args)
{
int port = 1234;
ServerSystem ss = new ServerSystem(port);
ss.startServer();
}
public void startServer()
{
try
{
server = new ServerSocket(port);
}
catch(Exception e)
{
System.out.println("Error occured."+e);
}
System.out.println("Server has started. Ready to accept connections.");
while(true)
{
try
{
clientsocket = server.accept();
numOfConnections++;
ServerConnection sc = new ServerConnection(clientsocket, numOfConnections, this);
new Thread(sc).start();
}
catch(Exception e)
{
System.out.println("Error occured."+e);
}
}
}
public void stopServer()
{
System.out.println("Terminating connection");
System.exit(0);
}
}
class ServerConnection extends Thread
{
BufferedReader br;
PrintStream ps;
Socket clientsocket;
int id;
ServerSystem ss;
public ServerConnection(Socket clientsocket, int numOfConnections, ServerSystem ss)
{
this.clientsocket = clientsocket;
id = numOfConnections;
this.ss = ss;
System.out.println("Connection "+id+" established with "+clientsocket);
try
{
br = new BufferedReader(new InputStreamReader(clientsocket.getInputStream()));
ps = new PrintStream(clientsocket.getOutputStream());
}
catch(Exception e)
{
System.out.println("Error occured."+e);
}
}
public void run()
{
String line;
try
{
boolean stopserver = false;
while(true)
{
line = br.readLine();
System.out.println("Received string: "+line+" from connection "+id);
long threadID = Thread.currentThread().getId();
System.out.println("Thread ID: "+threadID+" is doing the current task.");
if(line.equals("exit"))
{
stopserver = true;
break;
}
else
{
int len = line.length();
String reversedstring = "";
for (int i=len-1; i>=0; i--)
reversedstring = reversedstring + line.charAt(i);
ps.println(""+reversedstring);
}
}
System.out.println("Connection "+id+" is closed.");
br.close();
ps.close();
clientsocket.close();
if(stopserver)
ss.stopServer();
}
catch(Exception e)
{
System.out.println("Error occured."+e);
}
}
}
I'm trying to open two clients. When I type "exit" in one of the clients (say client1), the server itself is terminating. But I don't want the server to close but just the connection to client1 to close. When I next type a string in client2, I get "java.net.SocketException: Connection Reset" .
How do I get rid of the exception and the connection at server be still open for client2?

It's your code:
while(true){
...
if(line.equals("exit"))
{
stopserver = true;
break;
}
...
}
...
if(stopserver)
ss.stopServer();