🖥️TCP Server

Class Features

• Support for TLS and non-TLS client connections

• Support for client authentication with Java key file (JKS)

• Read/write methods for byte[], char[], String and line input

• The optional TLS client authentication allows the server application to handle authenticated and non-authenticated clients separately (similar to authenticated and non-authenticated HTTP sessions). Use method getAuthenticatedClient() to check for a valid name.

Test TLS connections macOS/Linux: openssl s_client -connect hostname:port

Test non-TLS connections macOS/Linux: nc hostname port Windows: telnet hostname port

Example Start Echo Server

// Start echo server on port 8080
try (KServerSocket server = New KServerSocket(8080, KSocketServerThreadSample.class)) {
   KLog.abort(!server.isActive(), "Unable to start server: " + server.getLastError());

   // Let client connect (e.g. "nc localhost 8080" or "telnet localhost 8080")
   K.waitMinutes(5);
}

Example Echo Server Server Thread

public class KSocketServerThreadSample extends KSocketServerThread {

   public KSocketServerThreadSample(Socket argSocket) {
      super(argSocket);
   }

   public void run() {
      KLog.info("Upper-Case-Echo-Server started");
      
      String newLine    = K.getLineSeparator();
      String clientData = null;
      
      write((!isSecuredConnection() ? "Non-" : "") + "TLS Upper-Case-Echo-Server ready" + newLine);
      
      while ((clientData = readLine()) != null) {
         write(clientData.toUpperCase() + newLine);
      }
      close();
      
      KLog.info("Upper-Case-Echo-Server terminated");
   }
}

Architecture Overview