code: package com.egreksystems.mailuber;
  
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  import android.support.v7.widget.AppCompatSpinner;
  import android.view.View;
  import android.widget.ArrayAdapter;
  import android.widget.Button;
  import android.widget.Toast;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.net.Socket;
  
  public class OrderRobot extends AppCompatActivity {
  
      String SERVER_IP;
      int SERVER_PORT;
      AppCompatSpinner fromSpinner;
      AppCompatSpinner toSpinner;
      Thread Thread1 = null;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_order_robot);
          Bundle extras = getIntent().getExtras();
  
          if (extras != null){
              SERVER_IP = extras.getString("IP");
              SERVER_PORT = extras.getInt("PORT");
              Thread1 = new Thread(new Thread1());
              Thread1.start();
          }
  
           fromSpinner = findViewById(R.id.from);
           toSpinner = findViewById(R.id.to);
  
          ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
                  R.array.post_points, android.R.layout.simple_spinner_item);
  
          adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
  
          fromSpinner.setAdapter(adapter);
          toSpinner.setAdapter(adapter);
  
          Button send = findViewById(R.id.order);
  
  
          send.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View v) {
                  String message = "" + fromSpinner.getSelectedItem() + "," + toSpinner.getSelectedItem();
                  if (!message.isEmpty()) {
                      new Thread(new Thread3(message)).start();
                  }
              }
          });
  
  
  
      }
  
      private PrintWriter output;
      private BufferedReader input;
      class Thread1 implements Runnable {
          public void run() {
              Socket socket;
              try {
                  socket = new Socket(SERVER_IP, SERVER_PORT);
                  output = new PrintWriter(socket.getOutputStream());
                  input = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                  runOnUiThread(new Runnable() {
                      @Override
                      public void run() {
                          Toast.makeText(getApplicationContext(), "Connected", Toast.LENGTH_LONG).show();
                      }
                  });
  
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
      }
  
      class Thread3 implements Runnable {
          private String message;
          Thread3(String message) {
              this.message = message;
          }
          @Override
          public void run() {
              output.write(message);
              output.flush();
              runOnUiThread(new Runnable() {
                  @Override
                  public void run() {
                      Toast.makeText(getApplicationContext(), "Sent", Toast.LENGTH_LONG).show();
                  }
              });
          }
      }
  }
  