Question

I’m a novice android app developer. I wrote an application which fetches Bible Readings from online. I wrote the separate Java class for fetching the reading and I tested it and it’s working fine. But when I tried to use that in my Android App, my app crashed and stops working. I’ve understood from the logs that it’s throwing a null pointer exception, but I don’t how to fix that. I’ve also checked the internet and I can’t find an exact solution for this. I’m attaching the logs and file related to my application below. Could anyone go through my code and throw some light on fixing the error. I appreciate your time on my behalf and many thanks in advance.

10-25 09:49:23.243: E/AndroidRuntime(620): FATAL EXCEPTION: main
10-25 09:49:23.243: E/AndroidRuntime(620): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mgocsm/com.mgocsm.EveningKymthaPrayers}: java.lang.NullPointerException: println needs a message
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.app.ActivityThread.access$600(ActivityThread.java:130)
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.os.Handler.dispatchMessage(Handler.java:99)
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.os.Looper.loop(Looper.java:137)
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.app.ActivityThread.main(ActivityThread.java:4745)
10-25 09:49:23.243: E/AndroidRuntime(620):  at java.lang.reflect.Method.invokeNative(Native Method)
10-25 09:49:23.243: E/AndroidRuntime(620):  at java.lang.reflect.Method.invoke(Method.java:511)
10-25 09:49:23.243: E/AndroidRuntime(620):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
10-25 09:49:23.243: E/AndroidRuntime(620):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-25 09:49:23.243: E/AndroidRuntime(620):  at dalvik.system.NativeStart.main(Native Method)
10-25 09:49:23.243: E/AndroidRuntime(620): Caused by: java.lang.NullPointerException: println needs a message
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.util.Log.println_native(Native Method)
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.util.Log.d(Log.java:138)
10-25 09:49:23.243: E/AndroidRuntime(620):  at com.mgocsm.BibleReader.getVerses(BibleReader.java:44)
10-25 09:49:23.243: E/AndroidRuntime(620):  at com.mgocsm.EveningKymthaPrayers.onCreate(EveningKymthaPrayers.java:25)
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.app.Activity.performCreate(Activity.java:5008)
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
10-25 09:49:23.243: E/AndroidRuntime(620):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
10-25 09:49:23.243: E/AndroidRuntime(620):  ... 11 more

EveningKymthaPrayers.java (Activitiy from where I call the Java class to fetch readings)
=========================

.

public class EveningKymthaPrayers extends Activity {
    AssetManager am;
    FileReader f;
    TextView kymtha_prayer;
    BibleReader bible;
    //ReadingList rl = new ReadingList();
    @Override   
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.evening_kymtha);        
        am = getAssets();
        f = new FileReader(am,"kymtha.txt");               
        kymtha_prayer = (TextView) findViewById(R.id.show_kymtha);    
        kymtha_prayer.setMovementMethod(new ScrollingMovementMethod());
        bible = new BibleReader("John 3:16-17");
        kymtha_prayer.setText(bible.getVerses());        
        //kymtha_prayer.setText(f.readFile());
        //kymtha_prayer.setText(setText);                          
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

BibleReader.java (Java class for fetching Bible verses)

public class BibleReader {
    public static final String  URL="http://labs.bible.org/api/?passage=";
    String verse;   
    String logName = "BibleReader";
    String line;
    StringBuilder recText;
    private static final int BUFFER_SIZE = 1024 * 10;    
    private final byte[] dataBuffer = new byte[BUFFER_SIZE];

    public BibleReader(String verse) {
        // TODO Auto-generated constructor stub
        this.verse = verse; 
        this.verse = this.verse.toString().replaceAll(" ", "%20");      
    }

    public String getVerses() 
    {
        String body = null;
        try{        
            URL url = new URL(URL+this.verse);
            URLConnection con = url.openConnection();
            InputStream in = con.getInputStream();
            String encoding = con.getContentEncoding();
            encoding = encoding == null ? "UTF-8" : encoding;
            ByteArrayOutputStream baos = new ByteArrayOutputStream();   
            int len = 0;
            while ((len = in.read(dataBuffer)) != -1) {
                baos.write(dataBuffer, 0, len);
            }   
            body = new String(baos.toByteArray(), encoding);
            Log.d(logName, "Fetched Verse"+body);
        }
        catch(Exception e){
            Log.d(logName, e.getMessage());
        }               
        return body.toString();     
    }

}

AndroidMainfest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.mgocsm"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".DailyPrayers" android:label="@string/app_name"></activity>        
        <activity android:name=".EveningPrayers" android:label="@string/app_name"></activity>
        <activity android:name=".EveningKymthaPrayers" android:label="@string/app_name"></activity> 
    </application>  
</manifest>

MainActivity.java

public class MainActivity extends Activity {


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    public void onClick(View v){
        switch(v.getId()){
        case R.id.daily_prayers:
            startActivity(new Intent(getApplicationContext(),DailyPrayers.class));
            break;
        }

    }

}

DailyPrayers.java

public class DailyPrayers extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.daily_prayers);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    public void onClick(View v){
        switch(v.getId()){
        case R.id.home:
            startActivity(new Intent(getApplicationContext(),MainActivity.class));
            break;
        case R.id.evening_prayers:
            startActivity(new Intent(getApplicationContext(),EveningPrayers.class));
            break;
        }
    }
}

EveningPrayers.java

public class EveningPrayers extends Activity {

    @Override   
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.evening_prayers);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    public void onClick(View v){
        switch(v.getId()){
        case R.id.kymtha_evening:
            startActivity(new Intent(getApplicationContext(),EveningKymthaPrayers.class));          
            break;
        case R.id.sleeba_evening:
            break;
        }
    }

}

Answer 1

What i have noticed in your code:

• bible.getVerses() is returning null
• It seems INTERNET permission is not included in AndroidManifest.xml file

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

• Don’t make a web call on Main thread. Instead you can use AsyncTask or AsyncTaskLoader
• Instead of using:

this.verse = this.verse.toString().replaceAll(" ", "%20");

You must use:

String webURL = URLEncoder.encode("your web url", "utf-8");