(Android™) Socket Send/Receive 16-bit Integers

Demonstrates sending and receiving 16-bit integers over a socket connection using either big-endian or little-endian byte ordering.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkSocket sock = new CkSocket();

    // --------------------------------------------------------------------
    // This example uses the public TCP echo service at https://tcpbin.com/
    // --------------------------------------------------------------------

    boolean useTls = false;
    int port = 4242;
    int maxWaitMs = 5000;
    boolean success = sock.Connect("tcpbin.com",port,useTls,maxWaitMs);
    if (success == false) {
        Log.i(TAG, sock.lastErrorText());
        return;
        }

    // Wait a max of 2 seconds for a response..
    sock.put_MaxReadIdleMs(2000);

    // Send a 16-bit integer using big-endian byte ordering (also called network byte order)
    // 12022 decimal = 2EF6 hex
    int value = 12022;
    boolean bigEndian = true;
    sock.SendInt16(value,bigEndian);
    // Send it again, because we'll read it two different ways..
    sock.SendInt16(value,bigEndian);

    // The tcpbin.com echo server only echoes after receiving an LF (linefeed char)
    sock.SendByte(10);

    // Let's see hex values of the 2 bytes sent in network byte order (big-endian)
    // (The echo server sends back exactly the bytes received.)
    String hexStr = sock.receiveNBytesENC(2,"hex");

    // In the big-ending byte order, the byte order is most significant byte to least significant,
    // therefore we should see the bytes in the order 0x2E 0xF6.
    Log.i(TAG, "Expecting big-endian 2EF6");
    Log.i(TAG, hexStr);

    // Let's read directly to an integer..
    success = sock.ReceiveInt16(bigEndian,true);
    Log.i(TAG, "Expecting 12022");
    Log.i(TAG, "Received: " + String.valueOf(sock.get_ReceivedInt()));

    // Consume the LF that gets echoed back..
    sock.ReceiveByte(true);

    // --------------------------------------------------------------------
    // Let's do the same thing, but with little-endian byte ordering.

    Log.i(TAG, "----");

    // 12022 decimal = 2EF6 hex, but little-endian byte ordering will send the bytes in the order 0xF6 0x2E
    value = 12022;
    bigEndian = false;
    sock.SendInt16(value,bigEndian);
    sock.SendInt16(value,bigEndian);
    sock.SendByte(10);

    hexStr = sock.receiveNBytesENC(2,"hex");

    Log.i(TAG, "Expecting little-endian F62E");
    Log.i(TAG, hexStr);

    success = sock.ReceiveInt16(bigEndian,true);
    Log.i(TAG, "Expecting 12022");
    Log.i(TAG, "Received: " + String.valueOf(sock.get_ReceivedInt()));

    // Consume the LF that gets echoed back..
    sock.ReceiveByte(true);

    sock.Close(1000);

    // Output:

    // Expecting big-endian 2EF6
    // 2EF6
    // Expecting 12022
    // Received: 12022
    // ----
    // Expecting little-endian F62E
    // F62E
    // Expecting 12022
    // Received: 12022

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}