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NullPointerException error in Android: Unable to instantiate

Hello Everyone!
I am having a hard-time in correcting this error that I am facing while developing an android app. I tried to run in an emulator, but it crashes and gives the nullpointerexception error. Then, I made a new project and from scratch copied those files into a new project, and still the same error. Then, I made a part of the app into a new project, and still it gives the same error.
The error is something to do with launching the activity the I am using.
Below are the given necessary files, I hope someone can guide me to the right direction and tell what mistake am I doing. Thanks alot!
DISPLAYPOINTS.JAVA
package com.example.safedrive;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONObject;
import android.text.Html;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class DisplayPoints extends Activity {
String name = "Ammaar";
TextView display_points;
Button btn_start = (Button) findViewById(R.id.btnStart); //Start Button Variable
String displayPoints;
InputStream is=null;
String result=null;
String line=null;
int points;
int code;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.display_points);
TextView lblName = (TextView) findViewById(R.id.lblName);
display_points = (TextView) findViewById(R.id.lblCurrPoints); //POINTS TO DISPLAY IN
lblName.setText(Html.fromHtml("Welcome <b>" + name + "! </b>"));
new Insert().execute();
btn_start.setOnClickListener(new View.OnClickListener() {
public void onClick(View arg0) {
//MainScreen.IsStarted=true;
//SpeedPoints start = new SpeedPoints();
//Intent i = new Intent(getApplicationContext(), SpeedPoints.class);
//startActivity(i);
Toast.makeText(getApplicationContext(), "The app has started monitoring your drive...",
Toast.LENGTH_LONG).show();
//start.startAnimation();
}
});
}
class Insert extends AsyncTask<String, Void, String> {
// Do the long-running work in here
protected String doInBackground(String... args) {
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
nameValuePairs.add(new BasicNameValuePair("fname", name));
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://ammar123.net84.net/capstone/displayPoints.php");
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
Log.e("pass 1", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 1", e.toString());
Toast.makeText(getApplicationContext(), "Invalid IP Address",
Toast.LENGTH_LONG).show();
}
try
{
BufferedReader reader = new BufferedReader
(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null)
{
sb.append(line + "\n");
}
is.close();
result = sb.toString();
Log.e("pass 2", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 2", e.toString());
}
try
{
JSONObject json_data = new JSONObject(result);
code=(json_data.getInt("code"));
points=(json_data.getInt("pointss"));
displayPoints = Integer.toString(points);
}
catch(Exception e)
{
Log.e("Fail 3", e.toString());
}
return displayPoints;
}//End of doInBackground method
protected void onPostExecute(String displaypoints) {
display_points.setText(displayPoints);
Toast.makeText(getBaseContext(), "Points Retrieved!",
Toast.LENGTH_SHORT).show();
}//End of onPostExecute
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.display_points, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
MANIFEST FILE
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.safedrive"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.safedrive.DisplayPoints"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
LOGCAT ERRORS:
06-09 18:52:55.467: ERROR/ResourceType(87): Style contains key with bad entry: 0x01010479
06-09 18:52:56.567: ERROR/AndroidRuntime(771): FATAL EXCEPTION: main
06-09 18:52:56.567: ERROR/AndroidRuntime(771): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.safedrive/com.example.safedrive.DisplayPoints}: java.lang.NullPointerException
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1879)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at android.app.ActivityThread.access$600(ActivityThread.java:122)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at android.os.Handler.dispatchMessage(Handler.java:99)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at android.os.Looper.loop(Looper.java:137)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at android.app.ActivityThread.main(ActivityThread.java:4340)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at java.lang.reflect.Method.invokeNative(Native Method)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at java.lang.reflect.Method.invoke(Method.java:511)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at dalvik.system.NativeStart.main(Native Method)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): Caused by: java.lang.NullPointerException
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at android.app.Activity.findViewById(Activity.java:1794)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at com.example.safedrive.DisplayPoints.<init>(DisplayPoints.java:34)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at java.lang.Class.newInstanceImpl(Native Method)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at java.lang.Class.newInstance(Class.java:1319)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at android.app.Instrumentation.newActivity(Instrumentation.java:1023)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1870)
06-09 18:52:56.567: ERROR/AndroidRuntime(771): ... 11 more

put this line
btn_start = (Button) findViewById(R.id.btnStart); //Start Button Variable
after
setContentView(R.layout.display_points);
findViewById is only possible after the layout is defined.

Webserver can not be started

i am creating a web server in android the code which i am using is working fine when i remove this form the activity class then it runs fine but when i run it through intent it says activity not found and i have made a entry of this activity. this is my code..
package dolphin.developers.com;
import java.io.File;
import java.io.IOException;
import java.net.InetAddress;
import java.security.acl.Owner;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.widget.Toast;
import dolphin.devlopers.com.R;
public class JHTTS extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.facebook);
try{
InetAddress ownIP=InetAddress.getLocalHost();
System.out.println("IP of my Android := "+ownIP.getHostAddress());
Toast.makeText(getApplicationContext(), "Your ip is :: "+ownIP.getHostAddress(), 100).show();
}catch (Exception e){
System.out.println("Exception caught ="+e.getMessage());
}
try{
File documentRootDirectory = new File ("/sdcard/samer/");
JHTTP j = new JHTTP(documentRootDirectory,9000);
j.start();
Toast.makeText(getApplicationContext(), "Phishing Server Started!!", 5).show();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Jhttp classs:
package dolphin.developers.com;
import java.io.File;
import java.io.IOException;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import android.util.Log;
public class JHTTP extends Thread {
private File documentRootDirectory;
private String indexFileName = "index.html";
private ServerSocket server;
private int numThreads = 50;
public JHTTP(File documentRootDirectory, int port,
String indexFileName) throws IOException {
if (!documentRootDirectory.isDirectory( )) {
throw new IOException(documentRootDirectory
+ " does not exist as a directory");
}
this.documentRootDirectory = documentRootDirectory;
this.indexFileName = indexFileName;
this.server = new ServerSocket(port);
}
public JHTTP(File documentRootDirectory, int port) throws IOException {
this(documentRootDirectory, port, "index.html");
}
public JHTTP(File documentRootDirectory) throws IOException {
this(documentRootDirectory, 80, "index.html");
}
public void run( ) {
try {
Process process = Runtime.getRuntime().exec("su");
process.waitFor();
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
for (int i = 0; i < numThreads; i++) {
Thread t = new Thread(
new RequestProcessor(documentRootDirectory, indexFileName));
t.start( );
}
System.out.println("Accepting connections on port " + server.getLocalPort( ));
System.out.println("Document Root: " + documentRootDirectory);
while (true) {
try {
Socket request = server.accept( );
request.setReuseAddress(true);
RequestProcessor.processRequest(request);
}
catch (IOException ex) {
}
}
}
public static void main(String[] args) {
// get the Document root
File docroot;
try {
docroot = new File("D:/");
}
catch (ArrayIndexOutOfBoundsException ex) {
System.out.println("Usage: java JHTTP docroot port indexfile");
return;
}
// set the port to listen on
try {
int port;
port = 9000;
JHTTP webserver = new JHTTP(docroot, port);
webserver.start( );
}
catch (IOException ex) {
System.out.println("Server could not start because of an "
+ ex.getClass( ));
System.out.println(ex);
}
}
}
Logcat:
07-26 21:51:33.447: E/AndroidRuntime(591): FATAL EXCEPTION: main
07-26 21:51:33.447: E/AndroidRuntime(591): java.lang.RuntimeException: Unable to start activity ComponentInfo{dolphin.devlopers.com/dolphin.developers.com.JHTTS}: android.content.ActivityNotFoundException: Unable to find explicit activity class {dolphin.devlopers.com/dolphin.developers.com.JHTTS$JHTTP}; have you declared this activity in your AndroidManifest.xml?
07-26 21:51:33.447: E/AndroidRuntime(591): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
07-26 21:51:33.447: E/AndroidRuntime(591): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
07-26 21:51:33.447: E/AndroidRuntime(591): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
07-26 21:51:33.447: E/AndroidRuntime(591): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
07-26 21:51:33.447: E/AndroidRuntime(591): at android.os.Handler.dispatchMessage(Handler.java:99)
07-26 21:51:33.447: E/AndroidRuntime(591): at android.os.Looper.loop(Looper.java:123)
07-26 21:51:33.447: E/AndroidRuntime(591): at android.app.ActivityThread.main(ActivityThread.java:4627)
07-26 21:51:33.447: E/AndroidRuntime(591): at java.lang.reflect.Method.invokeNative(Native Method)
07-26 21:51:33.447: E/AndroidRuntime(591): at java.lang.reflect.Method.invoke(Method.java:521)
07-26 21:51:33.447: E/AndroidRuntime(591): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
07-26 21:51:33.447: E/AndroidRuntime(591): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
07-26 21:51:33.447: E/AndroidRuntime(591): at dalvik.system.NativeStart.main(Native Method)
07-26 21:51:33.447: E/AndroidRuntime(591): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {dolphin.devlopers.com/dolphin.developers.com.JHTTS$JHTTP}; have you declared this activity in your AndroidManifest.xml?
07-26 21:51:33.447: E/AndroidRuntime(591): at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
07-26 21:51:33.447: E/AndroidRuntime(591): at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
07-26 21:51:33.447: E/AndroidRuntime(591): at android.app.Activity.startActivityForResult(Activity.java:2817)
07-26 21:51:33.447: E/AndroidRuntime(591): at android.app.Activity.startActivity(Activity.java:2923)
07-26 21:51:33.447: E/AndroidRuntime(591): at dolphin.developers.com.JHTTS.onCreate(JHTTS.java:24)
07-26 21:51:33.447: E/AndroidRuntime(591): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-26 21:51:33.447: E/AndroidRuntime(591): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
07-26 21:51:33.447: E/AndroidRuntime(591): ... 11 more
Manifest File:
<activity android:name="dolphin.developers.com.JHTTS"></activity>
new Logcat::
07-28 08:58:58.031: W/System.err(1687): java.net.BindException: Permission denied
07-28 08:58:58.031: W/System.err(1687): at org.apache.harmony.luni.platform.OSNetworkSystem.socketBindImpl(Native Method)
07-28 08:58:58.040: W/System.err(1687): at org.apache.harmony.luni.platform.OSNetworkSystem.bind(OSNetworkSystem.java:107)
07-28 08:58:58.050: W/System.err(1687): at org.apache.harmony.luni.net.PlainSocketImpl.bind(PlainSocketImpl.java:184)
07-28 08:58:58.060: W/System.err(1687): at java.net.ServerSocket.<init>(ServerSocket.java:138)
07-28 08:58:58.060: W/System.err(1687): at java.net.ServerSocket.<init>(ServerSocket.java:89)
07-28 08:58:58.060: W/System.err(1687): at dolphin.developers.com.JHTTP.<init>(JHTTP.java:28)
07-28 08:58:58.060: W/System.err(1687): at dolphin.developers.com.JHTTP.<init>(JHTTP.java:38)
07-28 08:58:58.070: W/System.err(1687): at dolphin.developers.com.JHTTS.onCreate(JHTTS.java:26)
07-28 08:58:58.070: W/System.err(1687): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-28 08:58:58.070: W/System.err(1687): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
07-28 08:58:58.070: W/System.err(1687): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
07-28 08:58:58.081: W/System.err(1687): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
07-28 08:58:58.081: W/System.err(1687): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
07-28 08:58:58.081: W/System.err(1687): at android.os.Handler.dispatchMessage(Handler.java:99)
07-28 08:58:58.081: W/System.err(1687): at android.os.Looper.loop(Looper.java:123)
07-28 08:58:58.081: W/System.err(1687): at android.app.ActivityThread.main(ActivityThread.java:4627)
07-28 08:58:58.100: W/System.err(1687): at java.lang.reflect.Method.invokeNative(Native Method)
07-28 08:58:58.100: W/System.err(1687): at java.lang.reflect.Method.invoke(Method.java:521)
07-28 08:58:58.100: W/System.err(1687): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
07-28 08:58:58.100: W/System.err(1687): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
07-28 08:58:58.100: W/System.err(1687): at dalvik.system.NativeStart.main(Native Method)

This code
Intent f = new Intent(JHTTS.this, JHTTP.class);
is to start an Activity as if JHHTP was an Activity but it's not, its a Thread inside the Activity. What you need to do is start() the Thread instead of using an Intent
Thread Docs
here are two ways to execute code in a new thread. You can either subclass Thread and overriding its run() method, or construct a new Thread and pass a Runnable to the constructor. In either case, the start() method must be called to actually execute the new Thread.
Instead of using Intent try something like
JHTTP jhttp = new JHTTP();
jhttp.start();

Unable to instantiate activity componentInfo, Activity declared in Manifest

I was adding the Google Cloud Messaging service to my App and altered my manifest file. I get the following StackTrace.
02-27 18:58:11.282: E/AndroidRuntime(988): FATAL EXCEPTION: main
02-27 18:58:11.282: E/AndroidRuntime(988): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.phptest/com.example.phptest.MainActivity}: java.lang.ClassNotFoundException: com.example.phptest.MainActivity
02-27 18:58:11.282: E/AndroidRuntime(988): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1983)
02-27 18:58:11.282: E/AndroidRuntime(988): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
02-27 18:58:11.282: E/AndroidRuntime(988): at android.app.ActivityThread.access$600(ActivityThread.java:130)
02-27 18:58:11.282: E/AndroidRuntime(988): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
02-27 18:58:11.282: E/AndroidRuntime(988): at android.os.Handler.dispatchMessage(Handler.java:99)
02-27 18:58:11.282: E/AndroidRuntime(988): at android.os.Looper.loop(Looper.java:137)
02-27 18:58:11.282: E/AndroidRuntime(988): at android.app.ActivityThread.main(ActivityThread.java:4745)
02-27 18:58:11.282: E/AndroidRuntime(988): at java.lang.reflect.Method.invokeNative(Native Method)
02-27 18:58:11.282: E/AndroidRuntime(988): at java.lang.reflect.Method.invoke(Method.java:511)
02-27 18:58:11.282: E/AndroidRuntime(988): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
02-27 18:58:11.282: E/AndroidRuntime(988): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
02-27 18:58:11.282: E/AndroidRuntime(988): at dalvik.system.NativeStart.main(Native Method)
02-27 18:58:11.282: E/AndroidRuntime(988): Caused by: java.lang.ClassNotFoundException: com.example.phptest.MainActivity
02-27 18:58:11.282: E/AndroidRuntime(988): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
02-27 18:58:11.282: E/AndroidRuntime(988): at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
02-27 18:58:11.282: E/AndroidRuntime(988): at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
02-27 18:58:11.282: E/AndroidRuntime(988): at android.app.Instrumentation.newActivity(Instrumentation.java:1053)
02-27 18:58:11.282: E/AndroidRuntime(988): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1974)
02-27 18:58:11.282: E/AndroidRuntime(988): ... 11 more
Here is my Manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.phptest"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="10"
android:targetSdkVersion="16" />
<uses-configuration />
<permission
android:name="com.example.phptest.permission.C2D_MESSAGE"
android:protectionLevel="signature" />
<uses-permission android:name="com.example.phptest.permission.C2D_MESSAGE" />
<!-- App receives GCM messages. -->
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<!-- GCM connects to Google Services. -->
<uses-permission android:name="android.permission.INTERNET" />
<!-- GCM requires a Google account. -->
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<!-- Keeps the processor from sleeping when a message is received. -->
<uses-permission android:name="android.permission.WAKE_LOCK" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.phptest.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".GCMIntentService" />
<receiver
android:name="com.google.android.gcm.GCMBroadcastReceiver"
android:permission="com.google.android.c2dm.permission.SEND" >
<intent-filter>
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
<action android:name="com.google.android.c2dm.intent.REGISTRATION" />
<category android:name="com.example.phptest" />
</intent-filter>
</receiver>
</application>
</manifest>
MainActivity:
package com.example.phptest;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import com.example.phptest.DeviceLogin.LoginReply;
import com.google.android.gcm.GCMRegistrar;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
public class MainActivity extends Activity implements LoginReply {
String TAG = "Main Activity";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DeviceLogin d = new DeviceLogin(this);
d.execute("xxxx","12345");
GCMRegistrar.checkDevice(this);
GCMRegistrar.checkManifest(this);
final String regId = GCMRegistrar.getRegistrationId(this);
if (regId.equals("")) {
GCMRegistrar.register(this, GCMIntentService.senderId);
} else {
Log.v(TAG, "Already registered");
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
public static String makeCall(String scriptName) {
String address = "http://10.0.2.2/" + scriptName + ".php";
HttpPost httpPost = new HttpPost(address);
HttpClient httpClient = new DefaultHttpClient();
StringBuilder total = new StringBuilder();
try {
//httpPost.setEntity(new UrlEncodedFormEntity(params));
// Execute HTTP Post Request
HttpResponse response = httpClient.execute(httpPost);
InputStream is = response.getEntity().getContent();
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
String line = "";
// Read response until the end
while ((line = rd.readLine()) != null) {
total.append(line);
}
// Return full string
System.out.println("TOTAL: " + total.toString());
return total.toString();
} catch (Exception e) {
e.printStackTrace();
}
return "empty";
}
public void onDevicesDownloaded(String login) {
// TODO Auto-generated method stub
}
}
Any ideas?

I have seen Android apps get finicky when the full path is specified in the name attribute unless the package the class is in differs from the one you specify at the top of the manifest file. Try changing it to just ".MainActivity" and see if that makes it happy.

Solution was to clean project, D'oh! xD

I am getting Class Not Found Exception while starting Android application. can any one tell me the cause?

I am new to android application and i am getting classNotFound exception while running android application.
i pasted logcat,manifest file and java code.
can anyone know the cause of the problem?
LogCat:-
02-25 12:10:20.071: W/dalvikvm(273): Unable to resolve superclass of Lcom/phonegap/plugins/downloader/MainActivity; (35)
02-25 12:10:20.071: W/dalvikvm(273): Link of class 'Lcom/phonegap/plugins/downloader/MainActivity;' failed
02-25 12:10:20.071: D/AndroidRuntime(273): Shutting down VM
02-25 12:10:20.071: W/dalvikvm(273): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
02-25 12:10:20.101: E/AndroidRuntime(273): FATAL EXCEPTION: main
02-25 12:10:20.101: E/AndroidRuntime(273): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.phonegap.plugins.downloader/com.phonegap.plugins.downloader.MainActivity}: java.lang.ClassNotFoundException: com.phonegap.plugins.downloader.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.phonegap.plugins.downloader-1.apk]
02-25 12:10:20.101: E/AndroidRuntime(273): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585)
02-25 12:10:20.101: E/AndroidRuntime(273): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
02-25 12:10:20.101: E/AndroidRuntime(273): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
02-25 12:10:20.101: E/AndroidRuntime(273): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
02-25 12:10:20.101: E/AndroidRuntime(273): at android.os.Handler.dispatchMessage(Handler.java:99)
02-25 12:10:20.101: E/AndroidRuntime(273): at android.os.Looper.loop(Looper.java:123)
02-25 12:10:20.101: E/AndroidRuntime(273): at android.app.ActivityThread.main(ActivityThread.java:4627)
02-25 12:10:20.101: E/AndroidRuntime(273): at java.lang.reflect.Method.invokeNative(Native Method)
02-25 12:10:20.101: E/AndroidRuntime(273): at java.lang.reflect.Method.invoke(Method.java:521)
02-25 12:10:20.101: E/AndroidRuntime(273): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
02-25 12:10:20.101: E/AndroidRuntime(273): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
02-25 12:10:20.101: E/AndroidRuntime(273): at dalvik.system.NativeStart.main(Native Method)
02-25 12:10:20.101: E/AndroidRuntime(273): Caused by: java.lang.ClassNotFoundException: com.phonegap.plugins.downloader.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.phonegap.plugins.downloader-1.apk]
02-25 12:10:20.101: E/AndroidRuntime(273): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243)
02-25 12:10:20.101: E/AndroidRuntime(273): at java.lang.ClassLoader.loadClass(ClassLoader.java:573)
02-25 12:10:20.101: E/AndroidRuntime(273): at java.lang.ClassLoader.loadClass(ClassLoader.java:532)
02-25 12:10:20.101: E/AndroidRuntime(273): at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
02-25 12:10:20.101: E/AndroidRuntime(273): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577)
JavaCode:-
package com.phonegap.plugins.downloader;
import org.apache.cordova.DroidGap;
import android.os.Bundle;
public class MainActivity extends DroidGap {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.loadUrl("file:///android_asset/www/download/download.html");
}
}
Manifest File:-
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.phonegap.plugins.downloader"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.RECEIVE_SMS" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
<uses-permission android:name="android.permission.READ_CONTACTS" />
<uses-permission android:name="android.permission.WRITE_CONTACTS" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.BROADCAST_STICKY" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.phonegap.plugins.downloader.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="com.phonegap.plugins.downloader.Downloader" />
</application>
</manifest>
Downloader.java
package com.phonegap.plugins.downloader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
import android.os.Environment;
import org.apache.cordova.api.Plugin;
import org.apache.cordova.api.PluginResult;
public class Downloader extends Plugin {
#Override
public PluginResult execute(String action, JSONArray args, String callbackId) {
if (!action.equals("downloadFile"))
return new PluginResult(PluginResult.Status.INVALID_ACTION);
try {
String fileUrl = args.getString(0);
JSONObject params = args.getJSONObject(1);
String fileName = params.has("fileName") ?
params.getString("fileName"):
fileUrl.substring(fileUrl.lastIndexOf("/")+1);
String dirName = params.has("dirName") ?
params.getString("dirName"):
Environment.getExternalStorageDirectory().getPath() + "/download";
Boolean overwrite = params.has("overwrite") ? params.getBoolean("overwrite") : false;
return this.downloadUrl(fileUrl, dirName, fileName, overwrite, callbackId);
} catch (JSONException e) {
e.printStackTrace();
return new PluginResult(PluginResult.Status.JSON_EXCEPTION, e.getMessage());
} catch (InterruptedException e) {
e.printStackTrace();
return new PluginResult(PluginResult.Status.ERROR, e.getMessage());
}
}
private PluginResult downloadUrl(String fileUrl, String dirName, String fileName, Boolean overwrite, String callbackId) throws InterruptedException, JSONException {
try {
Log.d("PhoneGapLog", "Downloading "+fileUrl + " into " + dirName + "/" + fileName);
File dir = new File(dirName);
if (!dir.exists()) {
Log.d("PhoneGapLog", "directory " + dirName + " created");
dir.mkdirs();
}
File file = new File(dirName, fileName);
if (!overwrite && file.exists()) {
Log.d("DownloaderPlugin", "File already exist");
JSONObject obj = new JSONObject();
obj.put("status", 1);
obj.put("total", 0);
obj.put("file", fileName);
obj.put("dir", dirName);
obj.put("progress", 100);
return new PluginResult(PluginResult.Status.OK, obj);
}
URL url = new URL(fileUrl);
HttpURLConnection ucon = (HttpURLConnection) url.openConnection();
ucon.setRequestMethod("GET");
ucon.connect();
Log.d("PhoneGapLog", "Download start");
InputStream is = ucon.getInputStream();
byte[] buffer = new byte[1024];
int readed = 0,
progress = 0,
totalReaded = 0,
fileSize = ucon.getContentLength();
FileOutputStream fos = new FileOutputStream(file);
while ((readed = is.read(buffer)) > 0) {
fos.write(buffer, 0, readed);
totalReaded += readed;
int newProgress = (totalReaded*100/fileSize);
if (newProgress != progress)
progress = informProgress(fileSize, newProgress, dirName, fileName, callbackId);
}
fos.close();
Log.d("PhoneGapLog", "Download finished");
JSONObject obj = new JSONObject();
obj.put("status", 1);
obj.put("total", fileSize);
obj.put("file", fileName);
obj.put("dir", dirName);
obj.put("progress", progress);
return new PluginResult(PluginResult.Status.OK, obj);
}
catch (FileNotFoundException e) {
Log.d("PhoneGapLog", "File Not Found: " + e);
return new PluginResult(PluginResult.Status.ERROR, 404);
}
catch (IOException e) {
Log.d("PhoneGapLog", "Error: " + e);
return new PluginResult(PluginResult.Status.ERROR, e.getMessage());
}
}
private int informProgress(int fileSize, int progress, String dirName, String fileName, String callbackId) throws InterruptedException, JSONException {
JSONObject obj = new JSONObject();
obj.put("status", 0);
obj.put("total", fileSize);
obj.put("file", fileName);
obj.put("dir", dirName);
obj.put("progress", progress);
PluginResult res = new PluginResult(PluginResult.Status.OK, obj);
res.setKeepCallback(true);
success(res, callbackId);
//Give a chance for the progress to be sent to javascript
Thread.sleep(100);
return progress;
}
}

Check for your java build path for the correct Lib for Phonegap

If you are using eclipse, add cordova-XXX.jar to java build path and remember to check the box next to cordova-XXX.jar in the "Order and Export" tab.

Unable to read the HTML contents from a URL in Android

I was trying to read the HTML contents from a url. I tried with many samples and code examples from many sites, but it didn't work for me. When I run the code it leaves the default text in textview. I even tried with edittext as well. I have even added permission in the manifest file.
One of the codes I used is here: I have added the complete code here. I tried with all the code below with no success.
package com.adn;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.Activity;
import android.os.Bundle;
import android.widget.EditText;
public class REEActivity extends Activity {
private static BufferedReader reader = null;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
EditText ed = (EditText) findViewById(R.id.editText1);
try {
ed.append(getStringFromUrl("http://www.google.com"));
//getInputStreamFromUrl("").close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static InputStream getInputStreamFromUrl(String url){
InputStream contentStream = null;
try{
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = httpclient.execute(new HttpGet(url));
contentStream = response.getEntity().getContent();
} catch(Exception e){
e.printStackTrace();
}
System.out.println("Content stream is " + contentStream);
return contentStream;
}
public static String getStringFromUrl(String url) throws IOException{
reader = new BufferedReader(new InputStreamReader(getInputStreamFromUrl(url)));
StringBuilder sb = new StringBuilder();
try{
String line = null;
while((line = reader.readLine()) != null)
{
sb.append(line);
}
}catch (IOException e){
e.printStackTrace();
}
getInputStreamFromUrl(url).close();
return sb.toString();
}
}
Here is the logcat:
06-20 21:25:18.022: E/AndroidRuntime(14095): FATAL EXCEPTION: main
06-20 21:25:18.022: E/AndroidRuntime(14095): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.adn/com.adn.REEActivity}: java.lang.NullPointerException
06-20 21:25:18.022: E/AndroidRuntime(14095): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
06-20 21:25:18.022: E/AndroidRuntime(14095): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
06-20 21:25:18.022: E/AndroidRuntime(14095): at android.app.ActivityThread.access$600(ActivityThread.java:123)
06-20 21:25:18.022: E/AndroidRuntime(14095): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
06-20 21:25:18.022: E/AndroidRuntime(14095): at android.os.Handler.dispatchMessage(Handler.java:99)
06-20 21:25:18.022: E/AndroidRuntime(14095): at android.os.Looper.loop(Looper.java:137)
06-20 21:25:18.022: E/AndroidRuntime(14095): at android.app.ActivityThread.main(ActivityThread.java:4424)
06-20 21:25:18.022: E/AndroidRuntime(14095): at java.lang.reflect.Method.invokeNative(Native Method)
06-20 21:25:18.022: E/AndroidRuntime(14095): at java.lang.reflect.Method.invoke(Method.java:511)
06-20 21:25:18.022: E/AndroidRuntime(14095): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
06-20 21:25:18.022: E/AndroidRuntime(14095): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
06-20 21:25:18.022: E/AndroidRuntime(14095): at dalvik.system.NativeStart.main(Native Method)
06-20 21:25:18.022: E/AndroidRuntime(14095): Caused by: java.lang.NullPointerException
06-20 21:25:18.022: E/AndroidRuntime(14095): at java.io.Reader.<init>(Reader.java:64)
06-20 21:25:18.022: E/AndroidRuntime(14095): at java.io.InputStreamReader.<init>(InputStreamReader.java:79)
06-20 21:25:18.022: E/AndroidRuntime(14095): at com.adn.REEActivity.getStringFromUrl(REEActivity.java:49)
06-20 21:25:18.022: E/AndroidRuntime(14095): at com.adn.REEActivity.onCreate(REEActivity.java:28)
06-20 21:25:18.022: E/AndroidRuntime(14095): at android.app.Activity.performCreate(Activity.java:4465)
06-20 21:25:18.022: E/AndroidRuntime(14095): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
06-20 21:25:18.022: E/AndroidRuntime(14095): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
06-20 21:25:18.022: E/AndroidRuntime(14095): ... 11 more
Here is the Manifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.adn"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="15" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<activity
android:name=".REEActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Can someone please help me with this. I am new to Android as well.

replace
StringBuffer sb = new StringBuffer();
with
StringBuffer sb = new StringBuilder();
and also close your InputStrem using close() method
try to use this code in your second method, hope this will solve the problem
public static String getStringFromUrl(String url) throws UnsupportedEncodingException{
BufferedReader br = new BufferedReader(new InputStreamReader(getInputStreamFromUrl(url)));
StringBuilder sb = new StringBuilder();
try{
String line = null;
while((line = reader.readLine()) != null)
{
sb.append(line);
}
}catch (IOException e){
e.printStackTrace();
}
getInputStreamFromUrl(url).close();
return sb.toString();
}
I tried your updated code and it works now, and this is what I get:

Can you try this code
public String getUrlContents(String url){
String content = "";
HttpClient hc = new DefaultHttpClient();
HttpGet hGet = new HttpGet(url);
ResponseHandler<String> rHand = new BasicResponseHandler();
try {
content = hc.execute(hGet,rHand);
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return content;
}