The idea is when the TCP server receives a String message, if it is equal to "::turnOnBluetoothOn::". Will simply turn on the bluetooth on the device. By using the runCommand Method of the MessageHandler class. The problem is that I am getting the error Can't create handler inside thread that has not called Looper.prepare()
Here is my code:
import android.os.Looper;
import android.util.Log;
import java.io.*;
import java.net.InetAddress;
import java.net.Socket;
public class TCPClient
{
private String serverMessage;
// <<<<<<< .mine
public static final String SERVERIP = "xx.xxx.xx.xx"; // your computer IP
public static final int SERVERPORT = 4444;
private OnMessageReceived mMessageListener = null;
private boolean mRun = false;
PrintWriter out;
BufferedReader in;
// Test for Thread
private volatile Looper mMyLooper;
/**
* Constructor of the class. OnMessagedReceived listens for the messages
* received from server
*/
public TCPClient(OnMessageReceived listener)
{
mMessageListener = listener;
}
/**
* Sends the message entered by client to the server
*
* @param message
* text entered by client
*/
public void sendMessage(String message)
{
if (out != null && !out.checkError())
{
out.println(message);
out.flush();
}
}
public void stopClient()
{
mRun = false;
}
public void run()
{
mRun = true;
try
{
// here you must put your computer's IP address.
InetAddress serverAddr = InetAddress.getByName(SERVERIP);
Log.e("TCP Client", "C: Connecting...");
// create a socket to make the connection with the server
Socket socket = new Socket(serverAddr, SERVERPORT);
try
{
// send the message to the server
out = new PrintWriter(new BufferedWriter(
new OutputStreamWriter(socket.getOutputStream())), true);
Log.e("TCP Client", "C: Sent.");
Log.e("TCP Client", "C: Done.");
// receive the message which the server sends back
in = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
// in this while the client listens for the messages sent by the
// server
while (mRun)
{
serverMessage = in.readLine();
if (serverMessage != null && mMessageListener != null)
{
// call the method messageReceived from MyActivity class
mMessageListener.messageReceived(serverMessage);
System.out.println(serverMessage);
MessageHandler handler = new MessageHandler(serverMessage);
handler.runCommand();
}
serverMessage = null;
}
Log.e("RESPONSE FROM SERVER", "S: Received Message: '"
+ serverMessage + "'");
} catch (Exception e)
{
Log.e("TCP", "S: Error", e);
}
finally
{
// the socket must be closed. It is not possible to reconnect to
// this socket
// after it is closed, which means a new socket instance has to
// be created.
socket.close();
}
} catch (Exception e)
{
Log.e("TCP", "C: Error", e);
}
}
// Declare the interface. The method messageReceived(String message) will
// must be implemented in the MyActivity
// class at on asynckTask doInBackground
public interface OnMessageReceived
{
public void messageReceived(String message);
}
}
//AND THIS IS THE HANDLER CLASS
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.content.Intent;
public class MessageHandler extends Activity
{
private static final int REQUEST_ENABLE_BT = 0;
private static final int REQUEST_DISCOVERABLE_BT = 0;
final BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
private String Instruction;
MessageHandler(String Command)
{
Instruction = Command;
}
public void runCommand()
{
if (Instruction.equals("::turnBluetoothOn::"))
{
if (!mBluetoothAdapter.isEnabled())
{
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}
return;
}
}
}
Update: Here is the LogCat:
03-01 18:16:09.486: I/System.out(4752): ::turnBluetoothOn::
03-01 18:16:09.526: D/AndroidRuntime(4752): Shutting down VM
03-01 18:16:09.526: W/dalvikvm(4752): threadid=1: thread exiting with uncaught exception (group=0x4193a700)
03-01 18:16:09.546: E/AndroidRuntime(4752): FATAL EXCEPTION: main
03-01 18:16:09.546: E/AndroidRuntime(4752): java.lang.NullPointerException
03-01 18:16:09.546: E/AndroidRuntime(4752): at com.example.myactivity.MessageHandler.runCommand(MessageHandler.java:22)
03-01 18:16:09.546: E/AndroidRuntime(4752): at com.example.myactivity.TCPClient$1.run(TCPClient.java:108)
03-01 18:16:09.546: E/AndroidRuntime(4752): at android.os.Handler.handleCallback(Handler.java:730)
03-01 18:16:09.546: E/AndroidRuntime(4752): at android.os.Handler.dispatchMessage(Handler.java:92)
03-01 18:16:09.546: E/AndroidRuntime(4752): at android.os.Looper.loop(Looper.java:137)
03-01 18:16:09.546: E/AndroidRuntime(4752): at android.app.ActivityThread.main(ActivityThread.java:5103)
03-01 18:16:09.546: E/AndroidRuntime(4752): at java.lang.reflect.Method.invokeNative(Native Method)
03-01 18:16:09.546: E/AndroidRuntime(4752): at java.lang.reflect.Method.invoke(Method.java:525)
03-01 18:16:09.546: E/AndroidRuntime(4752): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
03-01 18:16:09.546: E/AndroidRuntime(4752): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
03-01 18:16:09.546: E/AndroidRuntime(4752): at dalvik.system.NativeStart.main(Native Method)
