socket draft

package pgdp.test;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ConnectException;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Arrays;

public class PinguinTest {

  @BeforeEach
  public static void main(String[] args) {
    try {
      Socket socket = new Socket("127.0.0.1", 25565);
      DataInputStream input = new DataInputStream(System.in);
      DataOutputStream out = new DataOutputStream(socket.getOutputStream());
      // string to read message from input
      args[0] = input.readLine();

      if (args[0].equals("Was ergibt die folgende Summe?")) {
        input = new DataInputStream(System.in);
        out = new DataOutputStream(socket.getOutputStream());
        args[0] = input.readLine();
        if (args[0].matches("<int>( + <int>)*")) {
          long sum = Arrays.stream(args[0].split("\\\\d+")).mapToLong(Long::parseLong).sum();
          System.out.println(sum);
        } else {
          System.err.println("Das ist keine Summe!");
        }
      } else if (args[0].equals("Zähle die Fische in")) {
        input = new DataInputStream(System.in);
        out = new DataOutputStream(socket.getOutputStream());
        args[0] = input.toString();
        if (args[0].length() == 0) {
          System.err.println(0);
        }
        // ...
      }
      PinguinTest.main(new String[1]);
      if (!args[0].equals("Was ergibt die folgende Summe?") || !args[0].equals("Zähle die Fische in")) {
        System.err.println("Tut mir leid, das habe ich nicht verstanden.");
      }
      input = new DataInputStream(System.in);
      out = new DataOutputStream(socket.getOutputStream());
      args[0] = input.toString();
      if (args[0].contains("Bye") || args[0].contains("Goodbye") || args[0].contains("Servus")
        || args[0].contains("Bis dann")) {
        System.out.println(args[0]);
      }
      input.close();
      out.close();
      socket.close();
    } catch (UnknownHostException e) {
      System.err.println("Unknown host, try again!");
    } catch (NumberFormatException e) {
      System.err.println("Port invalid, try again!");
    } catch (ConnectException e) {
      System.err.println("Connection refused, try again!");
    } catch (IOException e) {
      System.err.println("I/O error, try again!");
    }
  }

  @Test
  public void Test01() {

  }

}