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POAndroid application unable to start activity
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  1. POAndroid application unable to start activity
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    copied!<p>Hello I am programming an android application that has a database that allows the user to search through it for specific events. Currently I am running into an issue with the activity getting started. I am testing this application on my Droid Bionic device and I am using eclipse SDK 4.2 to program. How do I get my activity started? I am new to android and everything I've learned up to this point has been through me teaching myself and other tutorials online. Any help would be greatly appreciated.</p> <p>Main Activity where the db is created:</p> <pre><code>package com.example.database; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.util.Log; import android.widget.EditText; public class MainActivity { EditText dEdit; public static final String KEY_ROWID = "_id"; public static final String KEY_BUSINESS = "business"; public static final String KEY_ADDRESS = "address"; public static final String KEY_PHONE = "phone"; public static final String KEY_HOURS = "hours"; public static final String KEY_WEB = "website"; public static final String KEY_TYPE = "type"; private static final String TAG = "MainActivity"; private static final String DATABASE_NAME = "LocalDB"; private static final String DATABASE_TABLE = "Business"; private static final int DATABASE_VERSION = 1; private static final String DATABASE_CREATE = "create table Business (_id integer primary key autoincrement, " + "business text not null, address text not null, phone text not null,hours text not null,website text not null,type text not null" + ")"; private final Context context; private DatabaseHelper DBHelper; private SQLiteDatabase mDB; public MainActivity(Context ctx) { this.context = ctx; DBHelper = new DatabaseHelper(context); } private class DatabaseHelper extends SQLiteOpenHelper { DatabaseHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); } @Override public void onCreate(SQLiteDatabase db) { try{ mDB=db; mDB.execSQL(DATABASE_CREATE); } catch(SQLException e){ e.printStackTrace(); } } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { try{ mDB=db; Log.w(TAG, "Upgrading database from version " + oldVersion + " to " + newVersion + ", which will destroy all old data"); mDB.execSQL("DROP TABLE IF EXISTS Business"); onCreate(mDB); }catch (SQLException e){ e.printStackTrace(); } } } //---opens the database--- public MainActivity open() throws SQLException { mDB = DBHelper.getWritableDatabase(); return this; } //---closes the database--- public void close() { DBHelper.close(); } //---insert a title into the database--- public long insertTitle(String business, String address, String phone, String hours, String website, String type) { ContentValues initialValues = new ContentValues(); initialValues.put(KEY_BUSINESS, business); initialValues.put(KEY_ADDRESS, address); initialValues.put(KEY_PHONE, phone); initialValues.put(KEY_HOURS, hours); initialValues.put(KEY_WEB, hours); initialValues.put(KEY_TYPE, type); return mDB.insert(DATABASE_TABLE, null, initialValues); } //---deletes a particular title--- public boolean deleteTitle(long rowId) { return mDB.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) &gt; 0; } //---retrieves all the titles--- public Cursor getAllTitles() { return mDB.query(DATABASE_TABLE, new String[] { KEY_ROWID, KEY_BUSINESS, KEY_ADDRESS, KEY_PHONE, KEY_HOURS, KEY_WEB, KEY_TYPE}, null, null, null, null, null); } //---retrieves a particular title--- public Cursor getTitle(long rowId) throws SQLException { Cursor mCursor = mDB.query(true, DATABASE_TABLE, new String[] { KEY_ROWID, KEY_BUSINESS, KEY_ADDRESS, KEY_PHONE, KEY_HOURS, KEY_WEB, KEY_TYPE }, KEY_ROWID + "=" + rowId, null, null, null, null, null); if (mCursor != null) { mCursor.moveToFirst(); } return mCursor; } //---updates a title--- public boolean updateTitle(long rowId, String business, String address, String phone, String hours, String website, String type) { ContentValues args = new ContentValues(); args.put(KEY_BUSINESS, business); args.put(KEY_ADDRESS, address); args.put(KEY_PHONE, phone); args.put(KEY_HOURS,hours); args.put(KEY_WEB,website); args.put(KEY_TYPE, type); return mDB.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) &gt; 0; } } </code></pre> <p>Data added to the DB:</p> <pre><code>package com.example.database; import android.app.Activity; import android.os.Bundle; public class DBActivity extends Activity { //MainActivity eventsData; //EditText output; @Override public void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); MainActivity db= new MainActivity(this); //output = (EditText) findViewById(R.id.textView1); //type.setOnClickListener( // new OnClickListener(){ // public void onClick(View view){ // Log.v("Entry",dEdit.getText().toString()); // } /// }); //try{String destPath="/data/data" +getPackageName()+ "/databases/BloomBusiness"; // File f = new File(destPath); // if(!f.exists()){ // CopyDB(getBaseContext().getAssets().open("db"), new FileOutputStream(destPath)); // } // // //}catch(FileNotFoundException e){ // e.printStackTrace(); //}catch(IOException e){ // e.printStackTrace(); //} db.open(); //inserting all data long id; id =db.insertTitle("BloomingFoods","419 E. Kirkwood Ave. Bloomington, IN", "812-336-5300", "M-Sat:8AM-9PM Sun:9AM-8PM","http://www.bloomingfoods.coop","Grocery"); id=db.insertTitle("BloomingFoods","316 W. 6th Street Bloomington, IN", "812-333-5300", "M-Sat:7AM-10PM Sun:9AM-9PM","http://www.bloomingfoods.coop","Grocery"); id=db.insertTitle("BloomingFoods","3220 E. 3rd Street Bloomington, IN", "812-336-5300", "M-Sun:8AM-10PM","http://www.bloomingfoods.coop","Grocery"); id=db.insertTitle("The Uptown Cafe","102 E. Kirkwood Ave. Bloomington, IN", "812-339-0900", "M-Sat:8AM-9PM Sun:9AM-8PM", "http://www.the-uptown.com/","Cajun-Creole"); id=db.insertTitle("Crazy Horse","214 W. Kirkwood Ave. Bloomington, IN", "812-336-8877", "M-Sat:11AM-2AM Sun:Noon-Midnight", "http://www.crazyhorseindiana.com/","Restaurant &amp; Live Music"); id=db.insertTitle("FARMbloomington","108 E. Kirkwood Ave. Bloomington, IN", "812-323-0002", "Tue.-Thurs.:8AM-10PM F:8AM-1AM Sat: 10AM-3AM Sun: 10AM-10PM","http://www.farm-bloomington.com","Grocery"); id=db.insertTitle("Laughing Planet","322 E. Kirkwood Ave. Bloomington, IN", "812-323-2233", "M-Sun:11AM-9PM","http://www.facebook.com/laughingplanetbtown","Burritos &amp; Salads"); id=db.insertTitle("Soma Coffeehouse","322 E. Kirkwood Bloomington, IN", "812-331-2770", "M-Sat:7AM-11PM Sun:8AM-11PM","http://www.iheartsoma.com","Coffee House"); id=db.insertTitle("Upland Brewing Company","350 W. 11th St. Bloomington, IN", "812-336-2337", "M-Thurs:11AM-Midnight F-Sat:11AM-1AM Sun: Noon-Midnight","http://www.uplandbeer.com","Brewery &amp; Restaraunt"); id=db.insertTitle("Nick's English Hut","423 E. Kirkwood Bloomington, IN", "812-332-4040", "M-Sat:11AM-2AM Sun: Noon-Midnight","http://www.nicksenglishhut.com","Bar &amp; Restaraunt"); id=db.insertTitle("The Village Deli","409 E. Kirkwood Ave. Bloomington, IN", "812-336-2303", "M-F:7AM-8PM Sat-Sun 8AM-8PM","http://www.villagedeli.biz","Breakfast,Lunch,Dinner"); id=db.insertTitle("Rachael's Cafe","300 E. 3rd St. Bloomington, IN", "812-330-1882", "M-F:8AM-9PM Sat-Sun 9AM-9PM","http://www.rachaelscafe.com","Coffee House &amp; Live Music"); id=db.insertTitle("Happy Pig","1604 W. 7th St. Bloomington, IN", "None", "W:Sample Gates Noon-3PM Thurs:Sample Gates Noon-3PM F:Atlas Bar 11:30PM-3:30AM Sat:Courthouse Square 11:30PM-3:30AM","http://www.happypigbloomington.com","BBQ Streetfood"); id=db.insertTitle("Lennie's Restaurant and Brewpub","1795 E. 10th St. Bloomington, IN", "812-323-2112", "Sun-Th:11AM-11PM F-Sat 11AM-Midnight","http://www.lenniesgourmetpizza.com","Bar &amp; Restaurant"); id=db.insertTitle("Pizza X","1791 E. 10th St. Bloomington, IN", "812-339-7737", "Sun-Tues:11AM-2AM Wed-Thur: 11AM-3AM F-Sat:11AM-4AM","http://www.pizzaxbloomington.com","Pizza"); id=db.insertTitle("Pizza X","1610 W. 3rd St. Bloomington, IN", "812-332-2522", "Sun-Wed:4PM-Midnight Thur: 4PM-3AM F-Sat:4PM-4AM","http://www.pizzaxbloomington.com","Pizza"); id=db.insertTitle("Pizza X","877 S. College Mall Rd. Bloomington, IN", "812-355-5000", "Sun-Wed:4PM-Midnight Thur: 4PM-3AM F-Sat:4PM-4AM","http://www.pizzaxbloomington.com","Pizza"); } </code></pre> <p>Searching the DB:</p> <pre><code>package com.example.database; import android.app.Activity; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; public class DBUse extends Activity { EditText dEdit; SQLiteDatabase data; public static final String KEY_ROWID = "_id"; public static final String KEY_BUSINESS = "business"; public static final String KEY_ADDRESS = "address"; public static final String KEY_PHONE = "phone"; public static final String KEY_HOURS = "hours"; public static final String KEY_WEB = "website"; public static final String KEY_TYPE = "type"; @Override public void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); MainActivity datab = new MainActivity(this); Button buttonName =(Button)findViewById(R.id.buttonName); buttonName.setOnClickListener(startName); Button buttonType =(Button)findViewById(R.id.buttonType); buttonType.setOnClickListener(startType); dEdit =(EditText)findViewById(R.id.textView1); datab.open(); Cursor c = datab.getAllTitles(); if((c!=null) &amp;&amp; c.moveToFirst()) { do{DisplayTitle(c); }while (c.moveToNext()); } datab.open(); Cursor b = datab.getAllTitles(); if ((b!=null) &amp;&amp; b.moveToFirst()) DisplayTitle(b); else Toast.makeText(this,"No business found",Toast.LENGTH_LONG).show(); data.close(); data.close(); } //displays the data public void DisplayTitle(Cursor c) { Toast.makeText(this, "Name: " + c.getString(1)+"\n"+ "Address:" + c.getString(2)+"\n"+ "Phone:" + c.getString(3)+"\n"+ "Hours:" + c.getString(4)+"\n"+ "Website"+ c.getShort(5)+ "Type" + c.getShort(6), Toast.LENGTH_LONG).show(); } //Informs the user what is being searched private OnClickListener startName=new OnClickListener(){ public void onClick (View v) { Cursor cur=data.rawQuery("SELECT business,address,phone,hours,website,type FROM Business where name like %"+dEdit.getText().toString()+"%", null); String result=""; int iRow=cur.getColumnIndex(KEY_ROWID); int iName=cur.getColumnIndex(KEY_BUSINESS); int iAddress=cur.getColumnIndex(KEY_ADDRESS); int iPhone=cur.getColumnIndex(KEY_PHONE); int iHours=cur.getColumnIndex(KEY_HOURS); int iWebsite=cur.getColumnIndex(KEY_WEB); int iType=cur.getColumnIndex(KEY_TYPE); Toast.makeText(DBUse.this, "Searching by Name", Toast.LENGTH_LONG).show(); // log.d("result",DBUse.getString(0)); for(cur.moveToFirst(); !cur.isAfterLast(); cur.moveToNext()){ result=result +cur.getString(iRow) + " " +cur.getString(iName) + " " +cur.getString(iAddress) + " " +cur.getString(iPhone) + " " +cur.getString(iHours) + " " +cur.getString(iWebsite) + " " +cur.getString(iType) + " " + "\n"; }; return; } }; //Informs the user what is being searched private OnClickListener startType=new OnClickListener(){ public void onClick (View v){ Cursor cur=data.rawQuery("SELECT business,address,phone,hours,website,type FROM Business where type like %"+dEdit.getText().toString()+"%", null); String result=""; int iRow=cur.getColumnIndex(KEY_ROWID); int iName=cur.getColumnIndex(KEY_BUSINESS); int iAddress=cur.getColumnIndex(KEY_ADDRESS); int iPhone=cur.getColumnIndex(KEY_PHONE); int iHours=cur.getColumnIndex(KEY_HOURS); int iWebsite=cur.getColumnIndex(KEY_WEB); int iType=cur.getColumnIndex(KEY_TYPE); Toast.makeText(DBUse.this, "Searching by Name", Toast.LENGTH_LONG).show(); // log.d("result",DBUse.getString(0)); for(cur.moveToFirst(); !cur.isAfterLast(); cur.moveToNext()){ result=result +cur.getString(iRow) + " " +cur.getString(iName) + " " +cur.getString(iAddress) + " " +cur.getString(iPhone) + " " +cur.getString(iHours) + " " +cur.getString(iWebsite) + " " +cur.getString(iType) + " " + "\n"; }; return; }; }; } </code></pre> <p>The Manifest:</p> <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt; &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.database" android:versionCode="1" android:versionName="1.0" &gt; &lt;uses-sdk android:minSdkVersion="8" android:targetSdkVersion="17" /&gt; &lt;uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/&gt; &lt;application android:allowBackup="true" android:debuggable="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" &gt; &lt;activity android:name="com.example.database.DBUse" android:label="@string/app_name" &gt; &lt;intent-filter&gt; &lt;action android:name="android.intent.action.MAIN" /&gt; &lt;category android:name="android.intent.category.LAUNCHER" /&gt; &lt;/intent-filter&gt; &lt;/activity&gt; &lt;/application&gt; &lt;/manifest&gt; </code></pre> <p>Finally the LogCat:</p> <pre><code>04-28 17:27:15.055: E/Trace(721): error opening trace file: No such file or directory (2) 04-28 17:27:16.124: D/dalvikvm(721): GC_FOR_ALLOC freed 47K, 2% free 10842K/11011K, paused 44ms, total 48ms 04-28 17:27:16.134: I/dalvikvm-heap(721): Grow heap (frag case) to 11.204MB for 614416-byte allocation 04-28 17:27:16.274: D/dalvikvm(721): GC_CONCURRENT freed 1K, 2% free 11441K/11655K, paused 76ms+16ms, total 141ms 04-28 17:27:16.324: D/dalvikvm(721): GC_FOR_ALLOC freed 0K, 2% free 11441K/11655K, paused 29ms, total 29ms 04-28 17:27:16.334: I/dalvikvm-heap(721): Grow heap (frag case) to 12.245MB for 1093136-byte allocation 04-28 17:27:16.474: D/dalvikvm(721): GC_CONCURRENT freed 0K, 2% free 12508K/12743K, paused 75ms+6ms, total 132ms 04-28 17:27:16.544: D/AndroidRuntime(721): Shutting down VM 04-28 17:27:16.544: W/dalvikvm(721): threadid=1: thread exiting with uncaught exception (group=0x40a13300) 04-28 17:27:16.556: E/AndroidRuntime(721): FATAL EXCEPTION: main 04-28 17:27:16.556: E/AndroidRuntime(721): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.database/com.example.database.DBUse}: java.lang.NullPointerException 04-28 17:27:16.556: E/AndroidRuntime(721): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059) 04-28 17:27:16.556: E/AndroidRuntime(721): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 04-28 17:27:16.556: E/AndroidRuntime(721): at android.app.ActivityThread.access$600(ActivityThread.java:130) 04-28 17:27:16.556: E/AndroidRuntime(721): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 04-28 17:27:16.556: E/AndroidRuntime(721): at android.os.Handler.dispatchMessage(Handler.java:99) 04-28 17:27:16.556: E/AndroidRuntime(721): at android.os.Looper.loop(Looper.java:137) 04-28 17:27:16.556: E/AndroidRuntime(721): at android.app.ActivityThread.main(ActivityThread.java:4745) 04-28 17:27:16.556: E/AndroidRuntime(721): at java.lang.reflect.Method.invokeNative(Native Method) 04-28 17:27:16.556: E/AndroidRuntime(721): at java.lang.reflect.Method.invoke(Method.java:511) 04-28 17:27:16.556: E/AndroidRuntime(721): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 04-28 17:27:16.556: E/AndroidRuntime(721): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 04-28 17:27:16.556: E/AndroidRuntime(721): at dalvik.system.NativeStart.main(Native Method) 04-28 17:27:16.556: E/AndroidRuntime(721): Caused by: java.lang.NullPointerException 04-28 17:27:16.556: E/AndroidRuntime(721): at com.example.database.DBUse.onCreate(DBUse.java:67) 04-28 17:27:16.556: E/AndroidRuntime(721): at android.app.Activity.performCreate(Activity.java:5008) 04-28 17:27:16.556: E/AndroidRuntime(721): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079) 04-28 17:27:16.556: E/AndroidRuntime(721): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023) 04-28 17:27:16.556: E/AndroidRuntime(721): ... 11 more 04-28 17:27:18.624: I/Process(721): Sending signal. PID: 721 SIG: 9 </code></pre>
 

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