Develop Reference

Export data to google sheet with android studio : "Unfortunately, My application has stopped"

i'm trying to apply a tutorial on youtube about posting some data on a google sheet :
https://www.youtube.com/watch?v=GyuJ2GtpZd0
It's really well explained and I did everything same than the guy did, but I don't understand why my app stops...
I manage to build it without any problem (I didn't change the layout, I just added the class "HttpRequest").
I don't have any knowledge in java, I just copied the tutorial, here is the code :
package com.example.test;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import java.net.URLEncoder;
public class MainActivity extends Activity {
final String myTag = "DocsUpload";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.i(myTag, "OnCreate()");
Thread t = new Thread(new Runnable() {
#Override
public void run() {
postData();
}
});
t.start();
}
public void postData() {
String fullUrl = "https://docs.google.com/forms/d/e/1FAIpQLSeADSNYrRj2c8ctLn5Q0M7taM6ayYnykFbp3oZI_xorAt6gKg/formResponse";
HttpRequest mReq = new HttpRequest();
String col1 = "Hello";
String data = "entry.1529019979=" + URLEncoder.encode(col1);
String response = mReq.sendPost(fullUrl, data);
Log.i(myTag, response);
}
}
And here are the errors displayed :
10-28 18:23:35.254 10736-10736/? E/libprocessgroup: failed to make and chown /acct/uid_10057: Read-only file system
10-28 18:23:35.353 10736-10752/? E/Your App Name Here: HttpUtils: java.lang.SecurityException: Permission denied (missing INTERNET permission?)
10-28 18:23:35.354 10736-10752/? E/AndroidRuntime: FATAL EXCEPTION: Thread-602
Process: com.example.test, PID: 10736
java.lang.NullPointerException: println needs a message
at android.util.Log.println_native(Native Method)
at android.util.Log.i(Log.java:160)
at com.example.test.MainActivity.postData(MainActivity.java:40)
at com.example.test.MainActivity$1.run(MainActivity.java:23)
at java.lang.Thread.run(Thread.java:818)
10-28 18:23:35.694 10736-10753/? E/eglCodecCommon: glUtilsParamSize: unknow param 0x00008cdf
10-28 18:23:35.695 10736-10753/? E/eglCodecCommon: glUtilsParamSize: unknow param 0x00008824
Please, could anyone help me ? I don't understand anything in this report...
Thank you so much!

You have to add INTERNET permission in your AndroidManifest.xml file
<uses-permission android:name="android.permission.INTERNET" />

Bluetooth Android app keeps crashing on startup [duplicate]

This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 5 years ago.
I tried to build an app that lets you send data over bluetooth to an
arduino. But I got stuck while creating the socket. The app keeps
crashing on startup, but I don't know why.
package de.lutherschule.bled.bluetoothled;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.icu.util.Output;
import android.support.annotation.WorkerThread;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Set;
import java.util.UUID;
public class MainActivity extends AppCompatActivity {
BluetoothAdapter bAdapter;
BluetoothDevice device;
Boolean found;
BluetoothSocket btSocket;
OutputStream outputStream;
InputStream inputStream;
public static final String DEVICE_ADRESS = "";
private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
private static final String TAG = "MainActvity";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bAdapter = BluetoothAdapter.getDefaultAdapter();
found = false;
btSocket = null;
Log.v(TAG, "Funst");
if (bAdapter == null) {
Toast.makeText(getApplicationContext(),"Funst net",Toast.LENGTH_SHORT).show();
}
if(!bAdapter.isEnabled()) {
Intent enableAdapter = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableAdapter, 0);
}
Set<BluetoothDevice> bondedDevices = bAdapter.getBondedDevices();
if(bondedDevices.isEmpty()) {
Toast.makeText(getApplicationContext(),"Muss gepaired werden",Toast.LENGTH_SHORT).show();
} else {
for (BluetoothDevice iter : bondedDevices) {
if(iter.getAddress().equals(DEVICE_ADRESS)) { // oder iter.getName() wenn Name bekannt muessen dann aendern
device=iter;
found=true;
break;
}
}
}
When I delete the section under this quote. The app starts just fine.
try{
btSocket = device.createInsecureRfcommSocketToServiceRecord(MY_UUID);
}catch(IOException ioe){
Log.v(TAG, "socket nit erstellt");
}
}
#Override
public void onResume() {
super.onResume();
Intent intent = getIntent();
device = bAdapter.getRemoteDevice(DEVICE_ADRESS);
try {
btSocket = device.createInsecureRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) {
Toast.makeText(getBaseContext(), "Socket nit erstellt", Toast.LENGTH_LONG).show();
}
try {
btSocket.connect();
} catch (IOException e) {
try {
btSocket.close();
} catch (IOException e2) {
}
}
}
#Override
public void onPause() {
super.onPause();
try {
btSocket.close();
} catch (IOException e2) {
}
}
}
I'd appreciate any help. By the way sorry for my formatting... I'm a newbie in creating posts.
Android Monitor:
08-27 17:56:51.857 3071-3071/? E/libprocessgroup: failed to make and chown /acct/uid_10058: Read-only file system
08-27 17:56:51.857 3071-3071/? W/Zygote: createProcessGroup failed, kernel missing CONFIG_CGROUP_CPUACCT?
08-27 17:56:51.857 3071-3071/? I/art: Not late-enabling -Xcheck:jni (already on)
08-27 17:56:52.086 3071-3071/de.lutherschule.bled.bluetoothled I/InstantRun: Starting Instant Run Server for de.lutherschule.bled.bluetoothled
08-27 17:56:52.288 3071-3071/de.lutherschule.bled.bluetoothled W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
[ 08-27 17:56:52.386 1162: 2146 D/ ]
HostConnection::get() New Host Connection established 0xb68aea60, tid 2146
08-27 17:56:52.429 3071-3079/de.lutherschule.bled.bluetoothled W/art: Suspending all threads took: 17.085ms
08-27 17:56:52.442 3071-3071/de.lutherschule.bled.bluetoothled E/BluetoothAdapter: Bluetooth binder is null
08-27 17:56:52.442 3071-3071/de.lutherschule.bled.bluetoothled V/MainActvity: Funst
08-27 17:56:52.452 3071-3071/de.lutherschule.bled.bluetoothled D/AndroidRuntime: Shutting down VM
--------- beginning of crash
08-27 17:56:52.453 3071-3071/de.lutherschule.bled.bluetoothled E/AndroidRuntime: FATAL EXCEPTION: main
Process: de.lutherschule.bled.bluetoothled, PID: 3071
java.lang.RuntimeException: Unable to start activity ComponentInfo{de.lutherschule.bled.bluetoothled/de.lutherschule.bled.bluetoothled.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.bluetooth.BluetoothAdapter.isEnabled()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.bluetooth.BluetoothAdapter.isEnabled()' on a null object reference
at de.lutherschule.bled.bluetoothled.MainActivity.onCreate(MainActivity.java:59)
at android.app.Activity.performCreate(Activity.java:5990)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) 
at android.app.ActivityThread.access$800(ActivityThread.java:151) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5254) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 

Try to use
BluetoothDevice device = mAdapter.getRemoteDevice(address);
btsocket = device.createRfcommSocketToServiceRecord(MY_UUID);
socket.connect();
Here is my code.
try {
socket = connect_device.createRfcommSocketToServiceRecord(MY_UUID);
socket.connect();
h.sendEmptyMessage(0);
} catch (IOException e) {
// TODO Auto-generated catch block
h.sendEmptyMessage(1);
e.printStackTrace();
try {
socket.close();
} catch (IOException e2) {
}
}

"Unfortunately, My LibGDX game has stopped" shows up on genymotion emulator

the game on libgdx installs in the emulator but is then the error shows up. The game works on my real nexus 4 device but not the emulator. is there any way to fix this? the code is below and the log cat is below the code.
package com.Redwanur.AndroidGame;
import java.io.IOException;
import com.Redwanur.Screens.MainMenu;
import com.Redwanur.Screens.PlayScreen;
import com.badlogic.gdx.Game;
public class AndroidGame extends Game {
Game game;
public void create() {
game = this;
setScreen(new MainMenu(game));
}
public void dispose() {
try {
Score score = PlayScreen.getScore();
score.saveScore(score.getHighscore());
System.out.print("saving end");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public void render() {
super.render();
}
#Override
public void resize(int width, int height) {
}
#Override
public void pause() {
}
#Override
public void resume() {
}
}
12-31 18:37:36.482: D/dalvikvm(1204): Trying to load lib /data/app-lib/com.Redwanur.AndroidGame-2/libgdx.so 0xa5095408
12-31 18:37:37.238: A/libc(1204): Fatal signal 11 (SIGSEGV) at 0x000000b4 (code=1), thread 1204 (nur.AndroidGame)
12-31 18:37:41.342: D/dalvikvm(1225): Trying to load lib /data/app-lib/com.Redwanur.AndroidGame-2/libgdx.so 0xa5096298
12-31 18:37:41.522: A/libc(1225): Fatal signal 11 (SIGSEGV) at 0x000000b4 (code=1), thread 1225 (nur.AndroidGame)
12-31 18:46:18.978: D/dalvikvm(1272): Trying to load lib /data/app-lib/com.Redwanur.AndroidGame-2/libgdx.so 0xa5097128
12-31 18:46:19.786: A/libc(1272): Fatal signal 11 (SIGSEGV) at 0x000000b4 (code=1), thread 1272 (nur.AndroidGame)

NullPointerException in setPreviewDisplay(holder)

Pretty new on this android stuff and gets a NullPointException that I can't seem to figure out. I am trying to implement an onResume() method in my CameraActivity and have moved almost all of the orginal code in onCreate() to onResume() and then call onResume() in onCreate(). The activity worked fine when the code was in onCreate(), but when placed in onResume() the exception arsises. What is causing it?
package com.example.tensioncamapp_project;
import java.io.IOException;
import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
/** A basic Camera preview class */
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private static final String TAG = "PreviewAactivity";
private SurfaceHolder mHolder;
private Camera mCamera;
public CameraPreview(Context context, Camera camera) {
super(context);
this.mCamera = camera;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
this.mHolder = getHolder();
this.mHolder.addCallback(this);
}
/**Displays the picture on the camera */
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {
this.mCamera.setPreviewDisplay(holder);
this.mCamera.startPreview();
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
this.mCamera.release();
this.mCamera = null;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
//add things here
}
}
and my CameraActivityClass
package com.example.tensioncamapp_project;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.Date;
import java.text.SimpleDateFormat;
import android.content.Intent;
import android.app.Activity;
import android.graphics.Bitmap;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.ImageButton;
import android.widget.ImageView;
public class CameraActivity extends Activity {
private ImageButton captureButton;
private Camera mCamera;
private CameraPreview mPreview;
private PictureCallback mPicture;
private ImageView imageView;
private static final int STD_DELAY = 400;
private static final int MEDIA_TYPE_IMAGE = 1;
protected static final String TAG = "CameraActivity";
/**Starts up the camera */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_camera);
onResume();
}
/**Connects the capture button on the view to a listener
* and redirects the client to a preview of the captures image*/
private void addListenerOnButton() {
this.captureButton = (ImageButton) findViewById(R.id.button_capture_symbol);
this.captureButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View capturebutton) {
mCamera.takePicture(null, null, mPicture);
delay();
Intent viewPic = new Intent(CameraActivity.this, ViewPicActivity.class);
startActivity(viewPic);
}
});
}
/** A safe way to get an instance of the Camera object. Code collected from elsewhere */
public static Camera getCameraInstance(){
Camera c = null;
try {
// attempt to get a Camera instance
c = Camera.open();
//getting current parameters
Camera.Parameters params = c.getParameters();
//setting new parameters with flash
params.setFlashMode(Parameters.FLASH_MODE_TORCH);
c.setParameters(params);
}
catch (Exception e){
// camera is not available (in use or does not exist)
}
// returns null if camera is unavailable
return c;
}
/**Generates a delay needed for application to save new pictures */
private void delay(){
try {
//Makes the program inactive for a specific amout of time
Thread.sleep(STD_DELAY);
} catch (Exception e) {
e.getStackTrace();
}
}
/**Method for releasing the camera immediately on pause event*/
#Override
protected void onPause() {
super.onPause();
//Shuts down the preview shown on the screen
mCamera.stopPreview();
//Calls an internal help method to restore the camera
releaseCamera();
}
/**Help method to release the camera */
private void releaseCamera(){
//Checks if there is a camera object active
if (this.mCamera != null){
//Releases the camera
this.mCamera.release();
//Restore the camera object to its initial state
this.mCamera = null;
}
}
/**Activates the camera and makes it appear on the screen */
protected void onResume() {
// TODO Auto-generated method stub
// deleting image from external storage
FileHandler.deleteFromExternalStorage();
// Create an instance of Camera.
this.mCamera = getCameraInstance();
// Create our Preview view and set it as the content of our activity.
this.mPreview = new CameraPreview(this, this.mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(this.mPreview);
//add the capture button
addListenerOnButton();
// In order to receive data in JPEG format
this.mPicture = new PictureCallback() {
/**Creates a file when a image is taken, if the file doesn't already exists*/
#Override
public void onPictureTaken(byte[] data, Camera mCamera) {
File pictureFile = FileHandler.getOutputMediaFile(MEDIA_TYPE_IMAGE);
if (pictureFile == null){
Log.d(TAG, "Error creating media file, check storage permissions");
return;
}
try {
//Writes the image to the disc
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
Log.d(TAG, "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d(TAG, "Error accessing file: " + e.getMessage());
}
}
};
super.onResume();
}
}
Log cat:
05-21 14:32:05.424: D/OpenGLRenderer(1030): Enabling debug mode 0
05-21 14:32:10.986: E/CameraActivity(1030): camera not availableFail to connect to camera service
05-21 14:32:11.033: I/Choreographer(1030): Skipped 66 frames! The application may be doing too much work on its main thread.
05-21 14:32:11.203: W/EGL_emulation(1030): eglSurfaceAttrib not implemented
05-21 14:32:13.013: D/AndroidRuntime(1030): Shutting down VM
05-21 14:32:13.013: W/dalvikvm(1030): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
05-21 14:32:13.083: E/AndroidRuntime(1030): FATAL EXCEPTION: main
05-21 14:32:13.083: E/AndroidRuntime(1030): java.lang.NullPointerException
05-21 14:32:13.083: E/AndroidRuntime(1030): at com.example.tensioncamapp_project.CameraPreview.surfaceCreated(CameraPreview.java:33)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.view.SurfaceView.updateWindow(SurfaceView.java:569)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.view.SurfaceView.access$000(SurfaceView.java:86)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:174)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:680)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1842)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.view.Choreographer.doCallbacks(Choreographer.java:562)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.view.Choreographer.doFrame(Choreographer.java:532)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.os.Handler.handleCallback(Handler.java:725)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.os.Handler.dispatchMessage(Handler.java:92)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.os.Looper.loop(Looper.java:137)
05-21 14:32:13.083: E/AndroidRuntime(1030): at android.app.ActivityThread.main(ActivityThread.java:5041)
05-21 14:32:13.083: E/AndroidRuntime(1030): at java.lang.reflect.Method.invokeNative(Native Method)
05-21 14:32:13.083: E/AndroidRuntime(1030): at java.lang.reflect.Method.invoke(Method.java:511)
05-21 14:32:13.083: E/AndroidRuntime(1030): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-21 14:32:13.083: E/AndroidRuntime(1030): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-21 14:32:13.083: E/AndroidRuntime(1030): at dalvik.system.NativeStart.main(Native Method)

The solution was to call the getCameraInstancemethod() in onResume() in an if-statement
protected void onResume() {
// TODO Auto-generated method stub
// deleting image from external storage
FileHandler.deleteFromExternalStorage();
// Create an instance of Camera.
if (this.mCamera == null){
this.mCamera = getCameraInstance();}

I think your problem is here
this.mPreview = new CameraPreview(this, this.mCamera);
this.mCamera seems to be null, it's not be set a new instance of the class, this needs to be done in the getCameraInstance() method.

getCameraInstance() returns null if an exception was thrown.
This cause the NPE as this.mCamera is null.
You should check if an exception was thrown in getCameraInstance and handle it correctly. The most basic thing is to log it and try to understand the reason.

Android application unable to run on emulator

I'm quite new to android development, I'm trying to develop a server-client application where the server is a simple java application that reads some text from a file and sends it using output stream. the client is an android application that reads this stream when clicking a button and displays it on a text view.
I'm using eclipse with ADK, and testing on an emulator here's how both codes look like:
Server:
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;
public class Server {
/**
* #param args
* #throws IOException
* #throws UnknownHostException
*/
public static void main(String[] args) throws UnknownHostException, IOException
{
System.out.println("***********Starting ***********");
ServerSocket servsock = new ServerSocket(12344);
System.out.println("Waiting...");
Socket sock = servsock.accept();
while (true)
{
System.out.println("Accepted connection : " + sock);
File myFile = new File ("source.txt");
while (true){
byte [] mybytearray = new byte [(int)myFile.length()];
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(mybytearray,0,mybytearray.length);
OutputStream os = sock.getOutputStream();
System.out.println("Sending...");
os.write(mybytearray,0,mybytearray.length);
os.flush();
}
}
}
}
Client:
-MainActivity
package com.example.streamerclient;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity implements OnClickListener {
Button ConnectBtn ;
#Override
public void onResume() {
super.onResume();
//setContentView(R.layout.activity_main);
System.out.println(" on resume ");
ConnectBtn = (Button)findViewById(R.id.ConnectButton);
ConnectBtn.setOnClickListener(this);
}
#Override
public void onPause() {
super.onPause();
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Connecting c = new Connecting();
}
}
-Connecting class
package com.example.streamerclient;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
import android.app.Activity;
import android.widget.TextView;
public class Connecting extends Activity implements Runnable
{
private Socket sock;
private BufferedReader r;
private BufferedWriter out;
TextView Data;
public Connecting ()
{
Data = (TextView) findViewById(R.id.DataTextView);
Thread th = new Thread(this);
th.start();
}
#Override
public void run() {
try
{
System.out.println("trying to initiated ");
Data.setText("trying to initiated ");
sock = new Socket("10.0.2.2",12344);
System.out.println(" socket initiated ");
Data.setText(" socket initiated ");
r = new BufferedReader(new InputStreamReader(sock.getInputStream()));
Data.setText(" buffer reader initiated ");
System.out.println(" buffer reader initiated ");
out = new BufferedWriter(new OutputStreamWriter(sock.getOutputStream()));
Data.setText(" buffer writer initiated ");
System.out.println(" buffer writer initiated ");
final String data = r.readLine();
Data.setText(" Data read is: \n"+data);
System.out.println(" Data read is: \n"+data);
}
catch (IOException ioe) { }
}
public void OnPause()
{
System.out.println(" paused");
try {
if (sock != null) {
sock.getOutputStream().close();
sock.getInputStream().close();
sock.close();
System.out.println(" everything is closed ");
}
} catch (IOException e) {}
}
}
I know I know, there are some parts of the code that are not used .. my next task is to have this application send commands to the server ... so I'm still experimenting.
when running the application on the emulator it stops before even displaying any of the GUI components. Any idea why ? Here's what the log file says
03-17 08:16:30.886: W/Trace(846): Unexpected value from nativeGetEnabledTags: 0
03-17 08:16:30.886: W/Trace(846): Unexpected value from nativeGetEnabledTags: 0
03-17 08:16:30.886: W/Trace(846): Unexpected value from nativeGetEnabledTags: 0
03-17 08:16:31.016: W/Trace(846): Unexpected value from nativeGetEnabledTags: 0
03-17 08:16:31.016: W/Trace(846): Unexpected value from nativeGetEnabledTags: 0
03-17 08:16:31.126: I/System.out(846): on resume
03-17 08:16:31.447: D/AndroidRuntime(846): Shutting down VM
03-17 08:16:31.447: W/dalvikvm(846): threadid=1: thread exiting with uncaught exception (group=0x40a70930)
03-17 08:16:31.457: E/AndroidRuntime(846): FATAL EXCEPTION: main
03-17 08:16:31.457: E/AndroidRuntime(846): java.lang.RuntimeException: Unable to resume activity {com.example.streamerclient/com.example.streamerclient.MainActivity}: java.lang.NullPointerException
03-17 08:16:31.457: E/AndroidRuntime(846): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2742)
03-17 08:16:31.457: E/AndroidRuntime(846): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2771)
03-17 08:16:31.457: E/AndroidRuntime(846): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2235)
03-17 08:16:31.457: E/AndroidRuntime(846): at android.app.ActivityThread.access$600(ActivityThread.java:141)
03-17 08:16:31.457: E/AndroidRuntime(846): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
03-17 08:16:31.457: E/AndroidRuntime(846): at android.os.Handler.dispatchMessage(Handler.java:99)
03-17 08:16:31.457: E/AndroidRuntime(846): at android.os.Looper.loop(Looper.java:137)
03-17 08:16:31.457: E/AndroidRuntime(846): at android.app.ActivityThread.main(ActivityThread.java:5039)
03-17 08:16:31.457: E/AndroidRuntime(846): at java.lang.reflect.Method.invokeNative(Native Method)
03-17 08:16:31.457: E/AndroidRuntime(846): at java.lang.reflect.Method.invoke(Method.java:511)
03-17 08:16:31.457: E/AndroidRuntime(846): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
03-17 08:16:31.457: E/AndroidRuntime(846): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
03-17 08:16:31.457: E/AndroidRuntime(846): at dalvik.system.NativeStart.main(Native Method)
03-17 08:16:31.457: E/AndroidRuntime(846): Caused by: java.lang.NullPointerException
03-17 08:16:31.457: E/AndroidRuntime(846): at com.example.streamerclient.MainActivity.onResume(MainActivity.java:20)
03-17 08:16:31.457: E/AndroidRuntime(846): at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1185)
03-17 08:16:31.457: E/AndroidRuntime(846): at android.app.Activity.performResume(Activity.java:5182)
03-17 08:16:31.457: E/AndroidRuntime(846): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2732)
03-17 08:16:31.457: E/AndroidRuntime(846): ... 12 more
thanks!

Try moving the contents of your entire onResume() to an onCreate() method. Always do the UI setup in onCreate(). Read this: Activity Lifecycle Management.
And take any further queries to stackoverflow :)
Cheers!

You are getting a NullPointerException on line 20 in MainActivity, check that line.
I think this question is better suited for stackoverflow