Unable to instantiate main activity

[shawn peter]

I write a android app to download PDf file from link.below is main activity

package com.android.pdf;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;

import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import com.itextpdf.text.Document;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.pdf.PdfWriter;

import android.support.v7.app.ActionBarActivity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends ActionBarActivity {

	
	public void onCreate(Bundle savedInstanceState) {
	    super.onCreate(savedInstanceState);
	    //Run the code in a different thread than the UI thread
	   
	    //tryDownloadingPDF("http://dsapn.asiaone.com/temp/moduletest/20140718/1.pdf");
	    
	    Thread thread = new Thread() {
	        @Override
	        public void run() {
	            tryDownloadingPDF("http://dsapn.asiaone.com/temp/moduletest/20140718/1.pdf");
	        }
	    };
	    thread.start();
	   
	}
	 
	public void tryDownloadingPDF(String url){
	    String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
	    File folder = new File(extStorageDirectory, "pdf");
	    folder.mkdir();
	 
	    //Download the file
	    downloadFile(url);
	     
	    //Show the downloaded file
	    showPdf();
	}
	 
	 
	public void downloadFile(String fileURL) {
	    HttpClient httpclient = new DefaultHttpClient();
	   // HttpPost httppost = new HttpPost(getResources().getString(R.string.login_page));
	    try {
	        // Add your data*
	    	/*
	        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
	        nameValuePairs.add(new BasicNameValuePair("userName", "theUserName"));
	        nameValuePairs.add(new BasicNameValuePair("password", "thePassword"));
	        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
	 
	        //Login to the sites login page
	        HttpResponse response = httpclient.execute(httppost);
	 */
	        HttpGet hGet = new HttpGet(fileURL);
	         
	        //Now hit the site for the file
	        HttpResponse response = httpclient.execute(hGet);
	 
	        InputStream is = response.getEntity().getContent();
	        FileOutputStream fos = new FileOutputStream(new File(Environment.getExternalStorageDirectory(), "/pdf/temp.pdf"));
	        encriptFile(fos);
	        int read = 0;
	        byte[] buffer = new byte[32768];
	        while((read = is.read(buffer)) > 0){
	            fos.write(buffer, 0, read);
	        }
	 
	        fos.close();
	        is.close();
	 
	    } catch (ClientProtocolException e) {
	    } catch (IOException e) {
	    }
	}
	 
	public void showPdf(){
	    File file = new File(Environment.getExternalStorageDirectory()+"/pdf/temp.pdf");
	    
	    Intent intent = new Intent();
	    intent.setAction(Intent.ACTION_VIEW);
	    Uri uri = Uri.fromFile(file);
	    intent.setDataAndType(uri, "application/pdf");
	    startActivity(intent);
	}
	
	public void encriptFile(FileOutputStream f){
		
		try {
			//OutputStream file = new FileOutputStream(new File("D:\\Test.pdf"));
			//OutputStream file = new FileOutputStream(f);

			Document document = new Document();
			PdfWriter writer = PdfWriter.getInstance(document, f);

			writer.setEncryption("hello".getBytes(), "hello123".getBytes(),
					PdfWriter.ALLOW_PRINTING, PdfWriter.ENCRYPTION_AES_128);

			document.open();
			document.add(new Paragraph("Hello World, iText"));
			document.add(new Paragraph(new Date().toString()));

			document.close();
			//file.close();

		} catch (Exception e) {

			e.printStackTrace();
		}
		
	}
	
	
}

when i run this below is the error i a getting

09-16 10:49:06.791: W/dalvikvm(6723): Unable to resolve superclass of Lcom/android/pdf/MainActivity; (7)
09-16 10:49:06.791: W/dalvikvm(6723): Link of class 'Lcom/android/pdf/MainActivity;' failed
09-16 10:49:06.791: D/AndroidRuntime(6723): Shutting down VM
09-16 10:49:06.791: W/dalvikvm(6723): threadid=1: thread exiting with uncaught exception (group=0x2aac8578)
09-16 10:49:06.791: E/AndroidRuntime(6723): FATAL EXCEPTION: main
09-16 10:49:06.791: E/AndroidRuntime(6723): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.android.pdf/com.android.pdf.MainActivity}: java.lang.ClassNotFoundException: com.android.pdf.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.android.pdf-1.apk]
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1581)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1675)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at android.app.ActivityThread.access$1500(ActivityThread.java:121)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:943)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at android.os.Handler.dispatchMessage(Handler.java:99)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at android.os.Looper.loop(Looper.java:130)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at android.app.ActivityThread.main(ActivityThread.java:3701)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at java.lang.reflect.Method.invokeNative(Native Method)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at java.lang.reflect.Method.invoke(Method.java:507)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:624)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at dalvik.system.NativeStart.main(Native Method)
09-16 10:49:06.791: E/AndroidRuntime(6723): Caused by: java.lang.ClassNotFoundException: com.android.pdf.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.android.pdf-1.apk]
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1573)
09-16 10:49:06.791: E/AndroidRuntime(6723): 	... 11 more

[Maneesh Godbole]

A good developer always pays close attention to the information which the stack trace provides.

[shawn peter]

09-16 10:49:06.791: W/dalvikvm(6723): Link of class 'Lcom/android/pdf/MainActivity;' failed
i don't know how it comes to Lcom.android.pdf. It should be com.android.pdf.

below is my manifest file,Manesh please advice.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.android.pdf"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="10"
        android:targetSdkVersion="15" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".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>
    </application>

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

</manifest>

[Ulf Dittmer]

sam liya wrote:09-16 10:49:06.791: W/dalvikvm(6723): Link of class 'Lcom/android/pdf/MainActivity;' failed

That's not the first error message in the stack trace - the root cause is something else.

[shawn peter]

why it gives me ClassNotFoundException.I have already declared it on the manifest file.?

[Maneesh Godbole]

sam liya wrote:why it gives me ClassNotFoundException.I have already declared it on the manifest file.?

Ulf Dittmer wrote:

sam liya wrote:09-16 10:49:06.791: W/dalvikvm(6723): Link of class 'Lcom/android/pdf/MainActivity;' failed

That's not the first error message in the stack trace - the root cause is something else.

Maneesh Godbole wrote:A good developer always pays close attention to the information which the stack trace provides.

[shawn peter]

why it unable to find MainActivity?

Caused by: java.lang.ClassNotFoundException: com.android.pdf.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.android.pdf-1.apk] 

[Maneesh Godbole]

Did you notice this line

09-16 10:49:06.791: W/dalvikvm(6723): Unable to resolve superclass of Lcom/android/pdf/MainActivity; (7)  

Do you know what it means? Are you curious what it means? Did you google it?
Please ShowSomeEffort instead of just dumping your stack trace and waiting for someone to tell you what you are doing wrong

[shawn peter]

i serached internet manesh.BUt those answers did not worked for me.

[Maneesh Godbole]

Which answers did you find on the net that did not work for you?

[shawn peter]

1)Right Click on your Project then

Goto Build Path-> Configure Build Path -> Order and Export

when you are there you should check the Android Private Libraries and then click OK.

if you still face the problem delete all the files inside your bin folder and rebuilt you project.

Hope this solves your issue

2)
Configure Build Path.
Choose Order and Export Tab,
Select all the listed path or JAR file.
And Try it!

[Maneesh Godbole]

Instead of searching for Unable to resolve superclass of Activity try Unable to resolve superclass of ActionBarActivity

[shawn peter]

I done below thing .but not worked for me

I think it is the same problem at the Build Path-> Configure Build Path -> Order and Export, the "android-support-v4.jar" needs to be checked.

[Maneesh Godbole]

You can add an ActionBar to your activity when running on API level 7 or higher by extending this class for your activity and setting the activity theme to Theme.AppCompat or a similar theme.

https://developer.android.com/reference/android/support/v7/app/ActionBarActivity.html

http://stackoverflow.com/questions/17897247/actionbaractivity-catch-an-error-on-phone

Hint: Theme

[shawn peter]

I added the theme to my manifest file as below.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.android.pdf"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="10"
        android:targetSdkVersion="15" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
         >
        <activity
            android:name=".MainActivity"
           android:theme="@style/Theme.AppCompat.Light"
            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>

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

</manifest>

Still i am getting below error.

09-17 06:27:23.827: E/AndroidRuntime(1957): FATAL EXCEPTION: main
09-17 06:27:23.827: E/AndroidRuntime(1957): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.android.pdf/com.android.pdf.MainActivity}: java.lang.ClassNotFoundException: com.android.pdf.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.android.pdf-1.apk]
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1581)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1675)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at android.app.ActivityThread.access$1500(ActivityThread.java:121)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:943)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at android.os.Handler.dispatchMessage(Handler.java:99)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at android.os.Looper.loop(Looper.java:130)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at android.app.ActivityThread.main(ActivityThread.java:3701)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at java.lang.reflect.Method.invokeNative(Native Method)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at java.lang.reflect.Method.invoke(Method.java:507)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:624)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at dalvik.system.NativeStart.main(Native Method)
09-17 06:27:23.827: E/AndroidRuntime(1957): Caused by: java.lang.ClassNotFoundException: com.android.pdf.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.android.pdf-1.apk]
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1573)
09-17 06:27:23.827: E/AndroidRuntime(1957): 	... 11 more