tcp server raw implementation

src/main/java/org/lumijiez/Main.java

@@ -1,17 +1,28 @@
 package org.lumijiez;
 
-//TIP To <b>Run</b> code, press <shortcut actionId="Run"/> or
-// click the <icon src="AllIcons.Actions.Execute"/> icon in the gutter.
+import org.lumijiez.core.TcpServer;
+
 public class Main {
     public static void main(String[] args) {
-        //TIP Press <shortcut actionId="ShowIntentionActions"/> with your caret at the highlighted text
-        // to see how IntelliJ IDEA suggests fixing it.
-        System.out.printf("Hello and welcome!");
+        TcpServer server = new TcpServer(8080, (message, clientSocket) -> {
+            System.out.println("Processing message from " + clientSocket.getInetAddress() + ": " + message);
 
-        for (int i = 1; i <= 5; i++) {
-            //TIP Press <shortcut actionId="Debug"/> to start debugging your code. We have set one <icon src="AllIcons.Debugger.Db_set_breakpoint"/> breakpoint
-            // for you, but you can always add more by pressing <shortcut actionId="ToggleLineBreakpoint"/>.
-            System.out.println("i = " + i);
+            if (message.equalsIgnoreCase("hello")) {
+                return "Hello, client!";
+            } else if (message.equalsIgnoreCase("bye")) {
+                return "Goodbye!";
+            } else {
+                return "Unknown command.";
+            }
+        });
+
+        new Thread(server::start).start();
+
+        try {
+            Thread.sleep(60000);
+            server.stop();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
         }
     }
 }

src/main/java/org/lumijiez/core/TcpClientHandler.java

@@ -0,0 +1,45 @@
+package org.lumijiez.core;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.net.Socket;
+
+public class TcpClientHandler implements Runnable {
+    private final Socket clientSocket;
+    private final TcpServerCallback callback;
+
+    public TcpClientHandler(Socket clientSocket, TcpServerCallback callback) {
+        this.clientSocket = clientSocket;
+        this.callback = callback;
+    }
+
+    @Override
+    public void run() {
+        try (BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
+             OutputStream out = clientSocket.getOutputStream()) {
+
+            String receivedMessage;
+            while ((receivedMessage = in.readLine()) != null) {
+                System.out.println("Received from client: " + receivedMessage);
+
+                String response = callback.onClientMessage(receivedMessage, clientSocket);
+
+                if (response != null) {
+                    out.write((response + "\n").getBytes());
+                    out.flush();
+                }
+            }
+
+        } catch (IOException e) {
+            System.out.println("Error handling client: " + e.getMessage());
+        } finally {
+            try {
+                clientSocket.close();
+                System.out.println("Client disconnected: " + clientSocket.getInetAddress());
+            } catch (IOException e) {
+                System.out.println("Error closing client socket: " + e.getMessage());
+            }
+        }
+    }
+}

src/main/java/org/lumijiez/core/TcpServer.java

@@ -0,0 +1,65 @@
+package org.lumijiez.core;
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+public class TcpServer {
+    private final int port;
+    private boolean running;
+    private ServerSocket serverSocket;
+    private final ExecutorService threadPool;
+    private final TcpServerCallback callback;
+
+    public TcpServer(int port, TcpServerCallback callback) {
+        this.port = port;
+        this.callback = callback;
+        this.running = false;
+        this.threadPool = Executors.newCachedThreadPool();
+    }
+
+    public void start() {
+        try {
+            serverSocket = new ServerSocket(port);
+            running = true;
+            System.out.println("Server started on port " + port);
+
+            while (running) {
+                try {
+                    Socket clientSocket = serverSocket.accept();
+                    System.out.println("New client connected: " + clientSocket.getInetAddress());
+
+                    TcpClientHandler clientHandler = new TcpClientHandler(clientSocket, callback);
+                    threadPool.submit(clientHandler);
+                } catch (IOException e) {
+                    if (running) {
+                        System.out.println("Error accepting client connection: " + e.getMessage());
+                    }
+                }
+            }
+        } catch (IOException e) {
+            System.out.println("Error starting server: " + e.getMessage());
+        } finally {
+            stop();
+        }
+    }
+
+    public void stop() {
+        running = false;
+        if (serverSocket != null) {
+            try {
+                serverSocket.close();
+                System.out.println("Server stopped.");
+            } catch (IOException e) {
+                System.out.println("Error stopping server: " + e.getMessage());
+            }
+        }
+        threadPool.shutdownNow();
+    }
+
+    public boolean isRunning() {
+        return running;
+    }
+}
+

src/main/java/org/lumijiez/core/TcpServerCallback.java

@@ -0,0 +1,7 @@
+package org.lumijiez.core;
+
+import java.net.Socket;
+
+public interface TcpServerCallback {
+    String onClientMessage(String message, Socket clientSocket);
+}