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POCan't show data on spinner? throws Null Pointer Exception
 

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  1. POCan't show data on spinner? throws Null Pointer Exception
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    <p>can anyone tell wats wrong in this code... I put code bellow.</p> <pre><code>mySQLiteAdapter = new SQLiteAdapter(this); cursor = mySQLiteAdapter.displayCategory(); startManagingCursor(cursor); String[] from = new String[] { SQLiteAdapter.KEY_ID, SQLiteAdapter.KEY_CATEGORY }; int[] to = new int[] { android.R.id.text1 }; mCategory = (Spinner) findViewById(R.id.choose_category); SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, android.R.layout.simple_spinner_item, cursor, from, to); adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); mCategory.setAdapter(adapter); </code></pre> <p>MyAdapter class having following code </p> <pre><code>public Cursor displayCategory() { String[] columns = new String[]{KEY_ID, KEY_CATEGORY}; Cursor cursor = sqLiteDatabase.query(MYCATEGORY_TABLE, columns, null, null, null, null, null); return cursor; </code></pre> <p>Null pointer Exception. How to avoid it. This is the error on log cat</p> <pre><code> 09-09 15:49:16.535: ERROR/AndroidRuntime(6526): Uncaught handler: thread main exiting due to uncaught exception 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.mpt.receiptor/com.android.mpt.receiptor.SearchReceipt}: java.lang.NullPointerException 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at android.app.ActivityThread.access$2200(ActivityThread.java:119) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at android.os.Handler.dispatchMessage(Handler.java:99) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at android.os.Looper.loop(Looper.java:123) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at android.app.ActivityThread.main(ActivityThread.java:4363) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at java.lang.reflect.Method.invokeNative(Native Method) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at java.lang.reflect.Method.invoke(Method.java:521) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at dalvik.system.NativeStart.main(Native Method) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): Caused by: java.lang.NullPointerException 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at com.android.mpt.receiptor.SQLiteAdapter.displayCategory(SQLiteAdapter.java:135) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at com.android.mpt.receiptor.SearchReceipt.onCreate(SearchReceipt.java:96) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 09-09 15:49:16.545: ERROR/AndroidRuntime(6526): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459) </code></pre> <p>Pls someone help me.</p> <p>Thanks in advance</p>
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    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USRia
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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    1. CO"How to avoid it." ... don't use `SomeObject obj = functionThatReturnsNull(); obj.DoSmthing();`
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      1. USSelvin
    2. COthen how to use
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    3. CO`SomeObject obj = functionThatReturnsNull(); if(obj != null) { obj.DoSmthing(); }` or check why `functionThatReturnsNull()` returns null ... well reading/analyzing the code is far more difficult than just copy/paste ...
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      1. POCan't show data on spinner? throws Null Pointer Exception
      1. USSelvin
 

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