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Runtime error app Android

I try my app on acer Z120 smartphone (vers. Android 4.1.1) and I have this runtime error:
09-09 12:03:24.827: W/dalvikvm(6414): threadid=11: thread exiting with uncaught exception (group=0x419af908)
09-09 12:03:24.830: E/AndroidRuntime(6414): FATAL EXCEPTION: Thread-546
09-09 12:03:24.830: E/AndroidRuntime(6414): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
09-09 12:03:24.830: E/AndroidRuntime(6414): at android.os.Handler.<init>(Handler.java:121)
09-09 12:03:24.830: E/AndroidRuntime(6414): at android.app.Dialog.<init>(Dialog.java:107)
09-09 12:03:24.830: E/AndroidRuntime(6414): at android.app.AlertDialog.<init>(AlertDialog.java:114)
09-09 12:03:24.830: E/AndroidRuntime(6414): at android.app.AlertDialog$Builder.create(AlertDialog.java:913)
09-09 12:03:24.830: E/AndroidRuntime(6414): at android.app.AlertDialog$Builder.show(AlertDialog.java:931)
09-09 12:03:24.830: E/AndroidRuntime(6414): at aqua.example.aquasalt.MainActivity.setAlertMsg(MainActivity.java:753)
09-09 12:03:24.830: E/AndroidRuntime(6414): at aqua.example.aquasalt.MainActivity$ConnectedThread.run(MainActivity.java:250)
09-09 12:03:24.931: W/MMUMapper(6414): fail to register MVA, unsupported format(0x5)
App works well on my smartphone (Samsung Galaxy S Advance).
Can I do?

You are attempting to show a dialog in a background thread. Only the main UI thread may show dialogs and touch the UI otherwise.
To post a Runnable to the main UI thread handler, you can use runOnUiThread() in an activity.

This is my code:
public void connect() {
// address is public variable
BluetoothDevice device = myBluetoothAdapter.getRemoteDevice(address);
try {
btSocket = createBluetoothSocket(device);
} catch (IOException e1) {
}
myBluetoothAdapter.cancelDiscovery();
// Establish the connection. This will block until it connects.
try {
btSocket.connect();
connesso = true;
} catch (IOException e) { //here I have exception
try {
btSocket.close();
connesso = false;
} catch (IOException e2) {}
}
if(connesso){
mConnectedThread = new ConnectedThread(btSocket);
mConnectedThread.start();
}
}
private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException {
BluetoothSocket socket = null;
if (Build.VERSION.SDK_INT >= 10) {
try {
socket = device.createInsecureRfcommSocketToServiceRecord(MY_UUID);
Method m = device.getClass().getMethod("createInsecureRfcommSocket", new Class[] {int.class});
socket = (BluetoothSocket) m.invoke(device, Integer.valueOf(1));
} catch (Exception e) {
System.out.println(e);
}
}
return socket;
}

Can't create handler inside thread that has not called Looper.prepare() android [duplicate]

This question already has answers here:
Can't create handler inside thread that has not called Looper.prepare()
(30 answers)
Closed 9 years ago.
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)

try this:
if (serverMessage != null && mMessageListener != null)
{
// call the method messageReceived from MyActivity class
mMessageListener.messageReceived(serverMessage);
new Handler(Looper.getMainLooper()).post(new Runnable() {
#Override
public void run() {
MessageHandler handler = new MessageHandler(serverMessage);
handler.runCommand();
}
});
}

According to the error information,you create handler inside a non-ui thread, you have declared mMyLooper,why not use it?
so my advice is that add this code:
mMyLooper = Looper.getMainLooper();
Looper.prepare();
before while (mRun).

Application crashes while starting the new thread

I have a thread class when I start the thread and create the instance of thread class in the main class my app get crash. My main activity code for creating the thread is:
broadcast broadcastobject=new broadcast(messages);
broadcastobject.start();
My thread class is :
public class broadcast extends Thread {
private DatagramSocket socket;
String str;
private static final int TIMEOUT_MS = 10;
WifiManager mWifi;
EditText et;
DatagramPacket packet;
Button bt;
private static final int SERVERPORT = 11111;
private static final String SERVER_IP = "192.168.1.255";
public broadcast(String to) {
// TODO Auto-generated constructor stub
str = to;
}
/*
private InetAddress getBroadcastAddress() throws IOException {
DhcpInfo dhcp = mWifi.getDhcpInfo();
if (dhcp == null) {
//Log.d(TAG, "Could not get dhcp info");
return null;
}
int broadcast = (dhcp.ipAddress & dhcp.netmask) | ~dhcp.netmask;
byte[] quads = new byte[4];
for (int k = 0; k < 4; k++)
quads[k] = (byte) ((broadcast >> k * 8) & 0xFF);
return InetAddress.getByAddress(quads);
}
*/
#Override
public void run() {
try {
socket = new DatagramSocket(SERVERPORT);
socket.setBroadcast(true);
} catch (SocketException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// socket.setSoTimeout(TIMEOUT_MS);
InetAddress serverAddr = null;
try {
serverAddr = InetAddress.getByName(SERVER_IP);
} catch (UnknownHostException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
packet = new DatagramPacket(str.getBytes(), str.length(),serverAddr,SERVERPORT);
try {
socket.send(packet);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
My log cat error is:
09-01 08:23:47.949: D/gralloc_goldfish(1720): Emulator without GPU emulation detected.
09-01 08:24:01.941: W/System.err(1720): java.net.SocketException: socket failed: EACCES (Permission denied)
09-01 08:24:01.941: W/System.err(1720): at libcore.io.IoBridge.socket(IoBridge.java:573)
09-01 08:24:01.979: W/System.err(1720): at java.net.PlainDatagramSocketImpl.create(PlainDatagramSocketImpl.java:91)
09-01 08:24:01.979: W/System.err(1720): at java.net.DatagramSocket.createSocket(DatagramSocket.java:131)
09-01 08:24:01.979: W/System.err(1720): at java.net.DatagramSocket.<init>(DatagramSocket.java:78)
09-01 08:24:01.989: W/System.err(1720): at soft.b.peopleassist.broadcast.run(broadcast.java:65)
09-01 08:24:01.989: W/System.err(1720): Caused by: libcore.io.ErrnoException: socket failed: EACCES (Permission denied)
09-01 08:24:01.999: W/System.err(1720): at libcore.io.Posix.socket(Native Method)
09-01 08:24:01.999: W/System.err(1720): at libcore.io.BlockGuardOs.socket(BlockGuardOs.java:169)
09-01 08:24:01.999: W/System.err(1720): at libcore.io.IoBridge.socket(IoBridge.java:558)
09-01 08:24:02.009: W/System.err(1720): ... 4 more
09-01 08:24:02.149: W/dalvikvm(1720): threadid=11: thread exiting with uncaught exception (group=0x409961f8)
09-01 08:24:02.149: E/AndroidRuntime(1720): FATAL EXCEPTION: Thread-114
09-01 08:24:02.149: E/AndroidRuntime(1720): java.lang.NullPointerException
09-01 08:24:02.149: E/AndroidRuntime(1720): at soft.b.peopleassist.broadcast.run(broadcast.java:92)
09-01 08:24:03.329: W/IInputConnectionWrapper(1720): showStatusIcon on inactive InputConnection

The thread is not the issue, the real issue is the EACCES (Permission denied), add this permission to your manifest file
<uses-permission android:name="android.permission.INTERNET"></uses-permission>

my application crashes when i start new thread [duplicate]

This question already has an answer here:
Application crashes while starting the new thread
(1 answer)
Closed 9 years ago.
I have a class where I have implemented runnable and I start the thread in one of the function of this class, and I call this function from the main activity,I create the object of this class and call the method of thread class.My main activity code from where I call this class method is:
broadcast broadcastobject.threadfunc(messages);
My class where I create threads is:
public class broadcast {
private DatagramSocket socket;
String str;
private static final int TIMEOUT_MS = 10;
WifiManager mWifi;
EditText et;
DatagramPacket packet;
Button bt;
private static final int SERVERPORT = 11111;
private static final String SERVER_IP = "192.168.1.255";
public void threadfunc(String message){
str=message;
new Thread(new ClientThread()).start();
}
/*
private InetAddress getBroadcastAddress() throws IOException {
DhcpInfo dhcp = mWifi.getDhcpInfo();
if (dhcp == null) {
//Log.d(TAG, "Could not get dhcp info");
return null;
}
int broadcast = (dhcp.ipAddress & dhcp.netmask) | ~dhcp.netmask;
byte[] quads = new byte[4];
for (int k = 0; k < 4; k++)
quads[k] = (byte) ((broadcast >> k * 8) & 0xFF);
return InetAddress.getByAddress(quads);
}
*/
class ClientThread implements Runnable {
#Override
public void run() {
try {
socket = new DatagramSocket(SERVERPORT);
socket.setBroadcast(true);
// socket.setSoTimeout(TIMEOUT_MS);
} catch (SocketException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
InetAddress serverAddr = null;
try {
serverAddr = InetAddress.getByName(SERVER_IP);
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
packet = new DatagramPacket(str.getBytes(), str.length(),serverAddr,SERVERPORT);
try {
socket.send(packet);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
My log cat is:
08-31 21:55:56.277: D/gralloc_goldfish(1669): Emulator without GPU emulation detected.
08-31 21:56:02.467: D/AndroidRuntime(1669): Shutting down VM
08-31 21:56:02.467: W/dalvikvm(1669): threadid=1: thread exiting with uncaught exception (group=0x409961f8)
08-31 21:56:02.517: E/AndroidRuntime(1669): FATAL EXCEPTION: main
08-31 21:56:02.517: E/AndroidRuntime(1669): java.lang.NullPointerException
08-31 21:56:02.517: E/AndroidRuntime(1669): at soft.b.peopleassist.Send$1.onClick(Send.java:113)
08-31 21:56:02.517: E/AndroidRuntime(1669): at android.view.View.performClick(View.java:3480)
08-31 21:56:02.517: E/AndroidRuntime(1669): at android.view.View$PerformClick.run(View.java:13983)
08-31 21:56:02.517: E/AndroidRuntime(1669): at android.os.Handler.handleCallback(Handler.java:605)
08-31 21:56:02.517: E/AndroidRuntime(1669): at android.os.Handler.dispatchMessage(Handler.java:92)
08-31 21:56:02.517: E/AndroidRuntime(1669): at android.os.Looper.loop(Looper.java:137)
08-31 21:56:02.517: E/AndroidRuntime(1669): at android.app.ActivityThread.main(ActivityThread.java:4340)
08-31 21:56:02.517: E/AndroidRuntime(1669): at java.lang.reflect.Method.invokeNative(Native Method)
08-31 21:56:02.517: E/AndroidRuntime(1669): at java.lang.reflect.Method.invoke(Method.java:511)
08-31 21:56:02.517: E/AndroidRuntime(1669): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
08-31 21:56:02.517: E/AndroidRuntime(1669): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
08-31 21:56:02.517: E/AndroidRuntime(1669): at dalvik.system.NativeStart.main(Native Method)

This simply means that the emulator you are using does not have GPU emulation enabled. In Android SDK Tools R15 you can enable GPU emulation.You need to create a new emulator virtual device and set GPU emulation to true in Hardware properties.

Somebody please explain the error

I am new to android programming.I have been trying to establish connection between two emulators.While my server emulator is up and running,client has a problem.Here is the code and logcat error description.Please tell me the error in this.
public class SocketClient extends Activity
{
private Button bt;
private TextView tv;
private Socket socket;
private String serverIpAddress = "192.168.0.5";
private static final int REDIRECTED_SERVERPORT = 5000;
public void connect()
{
try
{
InetAddress serverAddr = InetAddress.getByName(serverIpAddress);
tv.setText((CharSequence) serverAddr);
socket = new Socket(serverAddr, REDIRECTED_SERVERPORT);
}
catch (UnknownHostException e1)
{
e1.printStackTrace();
System.out.println("Here");
}
catch (IOException e1)
{
e1.printStackTrace();
System.out.println("Here too");
}
}
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
bt = (Button) findViewById(R.id.myButton);
tv = (TextView) findViewById(R.id.myTextView);
connect();
bt.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
try
{
EditText et = (EditText) findViewById(R.id.EditText01);
String str = et.getText().toString();
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
out.println(str);
Log.d("Client", "Client sent message");
}
catch (UnknownHostException e)
{
tv.setText("Error1");
e.printStackTrace();
}
catch (IOException e)
{
tv.setText("Error2");
e.printStackTrace();
}
catch (Exception e)
{
tv.setText("Error3");
e.printStackTrace();
}
}
}
);
}
}
The logcat error is
01-31 04:42:51.170: W/dalvikvm(529): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
01-31 04:42:51.187: E/AndroidRuntime(529): FATAL EXCEPTION: main
01-31 04:42:51.187: E/AndroidRuntime(529): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.app.ServerClient/com.app.ServerClient.SocketClient}: java.lang.ClassCastException: java.net.Inet4Address cannot be cast to java.lang.CharSequence
01-31 04:42:51.187: E/AndroidRuntime(529): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
01-31 04:42:51.187: E/AndroidRuntime(529): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
01-31 04:42:51.187: E/AndroidRuntime(529): at android.app.ActivityThread.access$600(ActivityThread.java:123)
01-31 04:42:51.187: E/AndroidRuntime(529): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
01-31 04:42:51.187: E/AndroidRuntime(529): at android.os.Handler.dispatchMessage(Handler.java:99)
01-31 04:42:51.187: E/AndroidRuntime(529): at android.os.Looper.loop(Looper.java:137)
01-31 04:42:51.187: E/AndroidRuntime(529): at android.app.ActivityThread.main(ActivityThread.java:4424)
01-31 04:42:51.187: E/AndroidRuntime(529): at java.lang.reflect.Method.invokeNative(Native Method)
01-31 04:42:51.187: E/AndroidRuntime(529): at java.lang.reflect.Method.invoke(Method.java:511)
01-31 04:42:51.187: E/AndroidRuntime(529): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
01-31 04:42:51.187: E/AndroidRuntime(529): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
01-31 04:42:51.187: E/AndroidRuntime(529): at dalvik.system.NativeStart.main(Native Method)
01-31 04:42:51.187: E/AndroidRuntime(529): Caused by: java.lang.ClassCastException: java.net.Inet4Address cannot be cast to java.lang.CharSequence
01-31 04:42:51.187: E/AndroidRuntime(529): at com.app.ServerClient.SocketClient.connect(SocketClient.java:25)
01-31 04:42:51.187: E/AndroidRuntime(529): at com.app.ServerClient.SocketClient.onCreate(SocketClient.java:48)
01-31 04:42:51.187: E/AndroidRuntime(529): at android.app.Activity.performCreate(Activity.java:4465)
01-31 04:42:51.187: E/AndroidRuntime(529): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
01-31 04:42:51.187: E/AndroidRuntime(529): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
01-31 04:42:51.187: E/AndroidRuntime(529): ... 11 more
Thanks in advance.
Thank You David and Jitendra.
I corrected the error and I get a nullPointerException in one part of the code.What did I do wrong?
public void onClick(View v)
{
try // The error is in this block
{
EditText et = (EditText) findViewById(R.id.EditText01);
String str = et.getText().toString();
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
out.println(str);
Log.d("Client", "Client sent message");
}
catch (UnknownHostException e)
{
tv.setText("Error1");
e.printStackTrace();
}
catch (IOException e)
{
tv.setText("Error2");
e.printStackTrace();
}
catch (Exception f) // I get the error here. java.lang.NullPointerException
{
tv.setText("Error3");
tv.setText(f.toString());
f.printStackTrace();
}
}

Your error is on this line:
tv.setText((CharSequence) serverAddr);
serverAddr is of type InetAddress, and you're trying to cast it to a CharSequence which cannot be done. Perhaps you meant:
tv.setText(serverIpAddress);

Exception is in following line:
tv.setText((CharSequence) serverAddr);
and it is because you are trying to cast serverAddr into CharSequence.
If you really want to print serverAddr use
tv.setText((CharSequence) serverAddr.toString());