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Thread Pooled Concurrent Server (JAVA)

This is my 2nd ever Post I'm pretty new to Programming.
I'm working on making my Socket Server Concurrent (Multithreaded) on the Server side. I understand I have to use Threaded Pools after my Socket accepts but I'm just very confused what to do. currently the requests are slower then it was when it was only iterative because its not working correctly.
//MultiClient Class
import java.util.*;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.net.*;
import java.io.*;
public class MultiServer {
public static void main(String[] args) throws IOException {
Scanner scnr = new Scanner(System.in);
System.out.println("What port should the server be using?");
int portNumber = scnr.nextInt();
while ((portNumber < 1025) ||(portNumber > 4998)) {
System.out.println("Please enter a Port Number between '1025' and '4998'.");
portNumber = scnr.nextInt();
}
try (ServerSocket serverSock = new ServerSocket(portNumber)){
System.out.println("Server listening on port " + portNumber);
while(true) {
Socket sock = serverSock.accept();
MultiServerHandler msh = new MultiServerHandler(sock);
ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newFixedThreadPool(10);
executor.execute(msh);
}
} catch (IOException ex) {
System.out.println("Server exception: " + ex.getMessage());
ex.printStackTrace();
}
}
}
//MultiClientHandler Class
import java.io.*;
import java.net.*;
public class MultiServerHandler extends Thread{
private Socket sock;
public MultiServerHandler(Socket sock) {
this.sock = sock;
}
public void run() {
try {
System.out.println("New client connected");
InputStream input = sock.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(input));
OutputStream output = sock.getOutputStream();
PrintWriter writer = new PrintWriter(output, true);
String command;
command = reader.readLine();
Process process = Runtime.getRuntime().exec(command);
BufferedReader read = new BufferedReader(new InputStreamReader(process.getInputStream()));
String result;
while((result = read.readLine()) != null) {
writer.println(result);
}
sock.close();
}
catch (IOException e) {
e.printStackTrace();
}
}
}
So far I just know I have to implement it after the socket accepts but I'm not too sure yet.

TCP Client/Server program getting stuck when

I have been working on creating a program where communication can be exchanged between a server and a client using to program files in java. However, when I try to send messages from server to client. I have been working on a project where I am trying to send a message from a server to a client. However, when I put in my message, from the server, the client seems to get stuck on sentence = inFromServer.readLine(); in the client portion of my code and I'm not sure why. I ran the debugger on this, and it seems that "sentence" takes in the value that was inputted from the client, so im not sure why it get stuck. Does anyone have an idea what the problem may be?
Here's my code for reference-
Server Code:
package com.company;
import java.io.*;
import java.net.*;
import java.util.Scanner;
import java.util.concurrent.*;
import java.io.IOException;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
class threading implements Runnable {
private int portnumbers;
Socket clientsocket;
ServerSocket connectorsocket;
public threading(Socket clientsocket)
{
this.clientsocket = clientsocket;
}
public void run(){
try {
Serverstuff(this.clientsocket);
}
catch(Exception ex)
{
System.out.print("I found exception" + ex);
}
}
public void Serverstuff(Socket socketlol)
{
// File h = null;
int width = 1536;
int height = 2048;
BufferedImage image = null;
File f = null;
while(true) {
try {
String sentence1;
//Wait on welcoming socket for client
BufferedReader inFromClient = new BufferedReader(new InputStreamReader(socketlol.getInputStream()));
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
DataOutputStream outToClient = new DataOutputStream(socketlol.getOutputStream());//create input stream, attached to socket
System.out.println("Flag1");
sentence1 = inFromUser.readLine();
System.out.println("Flag2");
System.out.println("Flag3");
outToClient.writeBytes(sentence1);
}
catch(Exception ex)
{
System.out.print("I found exception" + ex);
}
}
}
}
public class server{
public static void main(String argv[]) throws Exception {
String clientSentence;
String capitalizedSentence;
int portnumber;
Scanner scanney = new Scanner(System.in);
System.out.println("Enter the number of clients");
String arg1 = scanney.next();
int arg2 = Integer.parseInt(arg1);
int[] socketarray = new int[arg2];
for(int i = 0; i < arg2; i++) {
System.out.println("enter the port number");
String portnumberstr = scanney.next();
portnumber = Integer.parseInt(portnumberstr);
socketarray[i] = portnumber;
}
//ServerSocket welcomeSocket = new ServerSocket(5000);
int g = 0;
int whatever;
//ServerSocket welcomeSocket2 = new ServerSocket(5001);
while (true) {
if(g < arg2) {
System.out.println("Flagwhile1");
whatever = socketarray[g];
ServerSocket welcomeSocket = new ServerSocket(whatever);
System.out.println("Flagwhile2");
Socket clientsock = welcomeSocket.accept();
threading newthread = new threading(clientsock);
System.out.println("Flagwhile3");
new Thread(newthread).start();
g = g + 1;
}
}
}
}
Client Code:
package com.company;
import java.io.*;
import java.net.*;
import java.util.Scanner;
import java.util.concurrent.*;
import java.io.IOException;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
public class client2{
public static void main(String argv[]) throws Exception {
try {
String sentence;
String modifiedSentence;
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in)); //Create input stream
Socket clientSocket = new Socket("127.0.0.2", 5001); //Create client socket connect to server
DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream()); //Create output stream, attached to socket
System.out.println("Flag19");
BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream())); //Create input stream attached to socket
System.out.println("Flag20");
sentence = inFromUser.readLine();
outToServer.writeBytes(sentence + '\n'); //send line to server
System.out.println("Flag21");
sentence = inFromServer.readLine();
System.out.println("Flag22");
System.out.println(sentence);
int test = 5;
clientSocket.close();
}
catch(IOException e){
System.out.println("Error: " + e);
}
}
}

java.net.SocketException Error. What am I doing wrong?

I created a SOA service with Socket Adapter on JDeveloper and I need to run/test it using Java. So I created a server class and a client class but I am getting an error
I did some research on how to create this service and test it and I came across some helpful material online but yet I'm getting an error and I dont know how to fix it. I am very new to making socket servers and stuff.
here is my server class
package client;
import java.net.ServerSocket;
import java.net.Socket;
public class Class1 {
try {
ServerSocket socket = new ServerSocket(12110);
Socket s=socket.accept();
System.out.println("Connected!");
} catch (Exception e) {
e.printStackTrace();
}
}
}
and here is my client class
package client;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.Socket;
public class Client{
public static void main(String[] args) {
try {
Socket socket = new Socket("localhost", 12110);
OutputStream os = socket.getOutputStream();
os.write("FirstName,LastName\nWaslley,Souza\nJohn,Snow".getBytes());
os.flush();
socket.shutdownOutput();
BufferedReader soc_in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String response = soc_in.readLine();
System.out.println("Response: " + response);
socket.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
here is the error I get:
java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(SocketInputStream.java:210)
at java.net.SocketInputStream.read(SocketInputStream.java:141)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:161)
at java.io.BufferedReader.readLine(BufferedReader.java:324)
at java.io.BufferedReader.readLine(BufferedReader.java:389)
at client.Client.main(Client.java:23)

This happens because your server code exits after accepting a socket connection. Consequently, the JVM of this server will exit and (among others) close all socket connections it holds. This results in a SocketException on the client side.
To fix this, you should prevent the server's JVM from exiting, for instance by nesting the accept() call in a while loop:
public class Server {
public static void main(String[] args) {
try {
ServerSocket socket = new ServerSocket(12110);
while (true) {
Socket s = socket.accept();
System.out.println("Connected! to " + s);
}
} catch (final Exception e) {
e.printStackTrace();
}
}
}

Server Code:
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class Class1 {
//static ServerSocket variable
private static ServerSocket server;
//socket server port on which it will listen
private static int port = 12110;
public static void main(String args[]) throws IOException, ClassNotFoundException {
//create the socket server object
server = new ServerSocket(port);
//keep listens indefinitely until receives 'exit' call or program terminates
while (true) {
System.out.println("Waiting for the client request");
//creating socket and waiting for client connection
Socket socket = server.accept();
//read from socket to ObjectInputStream object
ObjectInputStream ois = new ObjectInputStream(socket.getInputStream());
//convert ObjectInputStream object to String
String message = (String) ois.readObject();
System.out.println("Message Received: " + message);
//create ObjectOutputStream object
ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
//write object to Socket
oos.writeObject("Hi Client " + message);
//close resources
ois.close();
oos.close();
socket.close();
//terminate the server if client sends exit request
if (message.equalsIgnoreCase("exit")) {
break;
}
}
System.out.println("Shutting down Socket server!!");
//close the ServerSocket object
server.close();
}
}
Client Code:
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
public class Client {
public static void main(String[] args) throws UnknownHostException, IOException, ClassNotFoundException, InterruptedException {
//get the localhost IP address, if server is running on some other IP, you need to use that
InetAddress host = InetAddress.getLocalHost();
Socket socket = null;
ObjectOutputStream oos = null;
ObjectInputStream ois = null;
//establish socket connection to server
socket = new Socket(host.getHostName(), 12110);
//write to socket using ObjectOutputStream
oos = new ObjectOutputStream(socket.getOutputStream());
System.out.println("Sending request to Socket Server");
oos.writeObject("SEND SOME DATA");
//read the server response message
ois = new ObjectInputStream(socket.getInputStream());
String message = (String) ois.readObject();
System.out.println("Message: " + message);
//close resources
ois.close();
oos.close();
Thread.sleep(100);
}
}
do in this way.

yo #Mike sorry was not clear last time dig in this is the full server code
import java.net.ServerSocket;
import java.net.Socket;
import java.io.*;
public class Serv1 {
public static void main(String[] args) {
new Serv1().start();
}
public void start(){
String input = "";
try(ServerSocket socket = new ServerSocket(12110)) {
System.out.println("Connected!");
while (true) {
try(Socket server = socket.accept()){
BufferedReader in = new BufferedReader(new InputStreamReader(server.getInputStream(), "UTF-8"));
PrintStream echo = new PrintStream(server.getOutputStream());
while ((input = in.readLine()) != null && !input.equals(".")) {
System.out.println(input);
echo.println("Echoed: " + input);
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}

This should do it
String input= "";
Socket server=socket.accept();
BufferedReader in = new BufferedReader(new InputStreamReader(server.getInputStream(), "UTF-8"));
PrintStream echo = new PrintStream(server.getOutputStream());
while((input = in.readLine()) != null && !input.equals(".")) {
System.out.println(input);
echo.println("echo: "+input);
}

Java socket connection receiving and sending String and Object

I've created a client, a server and an object called CcyData. When the client connects to the server I would like the server the send a "Welcome message" like "Hello, you are client# " + clientNumber. as a String and then send an object CcyData. I've managed to get the sending of the CcyData object to work but when I try to read in the "Welcome message" with
input = new BufferedReader(new InputStreamReader(socket.getInputStream()));
System.out.println("Welcome message from server: "+ input.readLine());
the client stops working, nothing happens. No error message. Below is my code. How can I solve this?
Server.
package net.something;
import java.io.IOException;
import java.net.ServerSocket;
public class SocketServer {
private ServerSocket serverSocket = null;
private int clientNumber = 0;
public SocketServer() {
}
public void listenSocket () {
int clientNumber = 0;
try{
serverSocket = new ServerSocket(9090);
System.out.println("Server started on port 9090");
} catch(IOException e) {
e.printStackTrace();
}
while (true) {
ClientSocket clientSocket;
try{
clientSocket = new ClientSocket(serverSocket.accept(), serverSocket, clientNumber++);
Thread thread = new Thread(clientSocket);
thread.start();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Class ClientSocket
package net.something;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class ClientSocket implements Runnable {
private Socket clientSocket;
private ServerSocket serverSocket;
private int clientNumber;
public ClientSocket(Socket clientSocket, ServerSocket serverSocket, int clientNumber) {
this.clientSocket = clientSocket;
this.serverSocket = serverSocket;
this.clientNumber = clientNumber;
System.out.println("New connection with client# " + clientNumber + " at " + clientSocket);
}
public void run() {
PrintWriter out;
ObjectOutputStream outObjectStream;
try {
out = new PrintWriter(clientSocket.getOutputStream());
out.println("Hello, you are client# " + clientNumber);
outObjectStream = new ObjectOutputStream(clientSocket.getOutputStream());
CcyData ccyData = new CcyData("EUR", 9.56);
System.out.println("CcyData: " + ccyData.getCcy() + " " + ccyData.getFxRate());
outObjectStream.writeObject(ccyData);
} catch (IOException e) {
e.printStackTrace();
}
}
public void finalize() {
try{
serverSocket.close();
System.out.println("Server socket closed");
} catch (IOException e) {
e.printStackTrace();
}
}
}
Client
package net.something;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.net.Socket;
public class SocketClient {
private Socket socket = null;
private BufferedReader input;
private ObjectInputStream inObjectStream = null;
public SocketClient() {
}
public void connectToServer() {
try{
socket = new Socket("127.0.0.1", 9090);
input = new BufferedReader(new InputStreamReader(socket.getInputStream()));
System.out.println("Welcome message from server: "+ input.readLine());
inObjectStream = new ObjectInputStream(socket.getInputStream());
CcyData ccyData = (CcyData) inObjectStream.readObject();
System.out.println(ccyData.getCcy() + " " + ccyData.getFxRate());
} catch (IOException | ClassNotFoundException e) {
e.printStackTrace();
}
}
}

finalize is only called when the JVM garbage collector decides that there are no more references to your thread and disposes it. Thus, you cannot ensure that finalize will be called when your thread has reached the end of its run() method. Try closing the socket in the run method instead!

TCP socket communication failed after the first trial

I have received error message after the client side successful received one message from server side. The error message is: Exception in thread "main" java.net.SocketException: Software caused connection abort: recv failed
It seems in client class, line = inFromserver.readLine(); would not receive any message from server, making it become "null". But I dont know why. Could somebody please help me?
Server class
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
public class ConcurrentServer {
public static void main(String args[]) throws IOException
{
int portNumber = 20020;
ServerSocket serverSocket = new ServerSocket(portNumber);
while ( true ) {
new ServerConnection(serverSocket.accept()).start();
}
}
}
class ServerConnection extends Thread
{
Socket clientSocket;
PrintWriter outToClient;
ServerConnection (Socket clientSocket) throws SocketException
{
this.clientSocket = clientSocket;
setPriority(NORM_PRIORITY - 1);
}
public void run()
{
BufferedReader inFromClient;
try{
inFromClient = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
OutputStream outToClient = clientSocket.getOutputStream();
PrintWriter printOutPut = new PrintWriter(new OutputStreamWriter(outToClient),true);
String request= inFromClient.readLine();
if(request !=null)
{
if(!request.equalsIgnoreCase("finished"))
{
printOutPut.write("Receving data");
}
else
{
printOutPut.write("file received");
}
}
}catch (IOException e) {
System.out.println(e.getMessage());
e.printStackTrace();
}
try
{
clientSocket.close();
}catch (IOException e) {
System.out.println(e.getMessage());
e.printStackTrace();
}
}
}
client class
import java.io.*;
import java.net.*;
import java.util.concurrent.TimeUnit;
public class client{
public static void main(String[] args) throws Exception{
final int PORT=20020;
String serverHostname = new String("127.0.0.1");
Socket socket;
PrintWriter outToServer;
BufferedReader inFromServer;
BufferedReader inFromUser;
byte[] dataToTransfer;
String line;
int counter=0;
int i=0;
socket = new Socket(serverHostname, PORT);
outToServer = new PrintWriter(socket.getOutputStream(),true);
inFromServer = new BufferedReader(new InputStreamReader(socket.getInputStream()));
inFromUser = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Simulation of file transferring");
System.out.println("Enter the file size you want to transfer (Max Size 50MB)");
int userInput = Integer.parseInt(inFromUser.readLine());
System.out.println("Transferring start");
boolean connection = true;
while(connection)
{
//set transfer rate at 1MB/s
dataToTransfer = new byte[1000000];
Thread.sleep(1000);
if(i<userInput)
{
outToServer.println(dataToTransfer);
counter++;
System.out.println(counter + "MB file has been transferred");
}
else
{
outToServer.println("Finished");
}
line = inFromServer.readLine();
System.out.println(line);
if(!line.equalsIgnoreCase("file received"))
{
}
else
{
System.out.println("Transfer completed");
break;
}
i++;
}
outToServer.close();
inFromServer.close();
inFromUser.close();
socket.close();
}
}

You are sending byte array from client to server and reading string on server side.
Insert somthing in your byte array and then Convert your byte array into String
String str = new String(dataToTransfer,int offset, 1000000);
then write:
outToServer.println(str);