 Nullpointer Exception in FragmentActivity while showing data in Spinner from database
By : Adrian
Date : March 29 2020, 07:55 AM
Does that help I am getting a problem in FrameActivity with FragmentPagerAdapter to declare my swipe-able tabs. In one of tabs contain Spinner in which i want to collect data from database. First i am going to post my FrameActivity code :
Spinner is not define in above TranscationMain's layout, It define in below Fragment
Spinner spinner_question;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.new_entry, container, false);
spinner_question = (Spinner)rootView.findViewById(R.id.spinner_category);
return rootView;
}
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Using Spinner from String Array:NullPointer Exception
By : abam1817
Date : March 29 2020, 07:55 AM
I wish this helpful for you I am new to Android and don't know much. Please help me with this problem , You should initiate spinner: code :
spinner1 = (Spinner)rootView.findViewById(R.id.spinner1);
spinner1.setAdapter(dataAdapter);
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(android) Nullpointer exception while setting a spinner
By : Pontakorn Sonchan
Date : March 29 2020, 07:55 AM
I hope this helps you . Finally i solved the problem. as was posted here: In my adaper I used: code :
view = inflater.inflate(android.R.layout.simple_spinner_dropdown_item, null);
view = inflater.inflate(android.R.layout.simple_spinner_dropdown_item, parent, false);
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 Android Spinner: Populate second and thrid spinner based on first spinner filter
By : user3312068
Date : March 29 2020, 07:55 AM
will help you The following is an example based upon some of the code from the question, that has 3 spinners the 2nd listing values as determined according to what is selected by spinner1. Likewise the 3rd listing values as determined by what is selected by spinner2. In short each spinner has a manageSprinner? method (? being 1, 2 and 3 respectively). code :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!" />
<Spinner
android:id="@+id/spinner1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<Spinner
android:id="@+id/spinner2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<Spinner
android:id="@+id/spinner3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
public class DatabaseHandler extends SQLiteOpenHelper {
// Database Version
public static final int DATABASE_VERSION = 1;
public static final String DATABASE_NAME = "spinnerExample";
private final Context myContext;
private SQLiteDatabase myDataBase;
// Database Name
// Labels table name
public static final String TABLE_LABELS = "labels"; //<<<< Made public
public static final String TABLE_LABELS1= "labels1";
public static final String TABLE_LABELS2= "labels2";
// Labels Table Columns names
public static final String KEY_ID4 = "input_label";
public static final String KEY_ID12 = "id2"; //<<<< Made public
public static final String KEY_ID = "id";
public static final String KEY_99 = "sno"; //<<<< Made public//<<<< Made public
public static final String KEY_NAME = "name"; //<<<< made public
public static final String KEY_ID1 = "id1"; //<<<< Made public
public static final String KEY_NAME1 = "name1";
public static final String KEY_1 = "number"; //<<<< Made public
public static final String KEY_2 = "outletname"; //<<<< made public
public static final String KEY_3 = "sunday"; //<<<< Made public
public static final String KEY_4 = "monday";
public static final String KEY_5 = "tuesday";
public static final String KEY_6 = "wednesday";
public static final String KEY_7 = "thursday";
public static final String KEY_8 = "saturday";
public static final String KEY_9 = "closed";
public static final String KEY_10 = "calling";
public static final String KEY_11 = "id3";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
myDataBase = this.getWritableDatabase();
this.myContext = context;
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
//boolean dbExist = checkDataBase();
// Category table create query
String CREATE_CATEGORIES_TABLE = "CREATE TABLE " + TABLE_LABELS + "("+ KEY_99 + " INTEGER,"
+ KEY_ID1 + " TEXT," + KEY_ID + " TEXT," + KEY_NAME + " TEXT)";
String CREATE_CATEGORIES_TABLE1 = "CREATE TABLE " + TABLE_LABELS1 + "("
+ KEY_ID1+ " TEXT," + KEY_NAME1+ " TEXT)";
String CREATE_CATEGORIES_TABLE2 = "CREATE TABLE " + TABLE_LABELS2 + "("
+ KEY_11+ " INTEGER PRIMARY KEY AUTOINCREMENT," + KEY_1+ " TEXT," + KEY_2+ " TEXT," + KEY_3+ " INTEGER," + KEY_4+ " INTEGER,"+ KEY_5+ " INTEGER," + KEY_6+ " INTEGER," + KEY_7+ " INTEGER," + KEY_8+ " INTEGER," + KEY_9+ " INTEGER," + KEY_10+ " TEXT)";
db.execSQL(CREATE_CATEGORIES_TABLE);
db.execSQL(CREATE_CATEGORIES_TABLE1);
db.execSQL(CREATE_CATEGORIES_TABLE2);
}
// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LABELS);
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LABELS1);
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LABELS2);
// Create tables again
onCreate(db);
}
/**
* Inserting new lable into lables table
* */
public void insertLabel(String message1, String message2,String message3,String message4,String message5,String message6,String message7,String message8,String message9,String message10){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_1, message1);
values.put(KEY_2, message2);
values.put(KEY_10,message10);
values.put(KEY_4,message4);
values.put(KEY_5,message5);
values.put(KEY_6,message6);
values.put(KEY_7,message7);
values.put(KEY_3,message3);
values.put(KEY_9,message9);
values.put(KEY_8,message8);
// Inserting Row
db.insert(TABLE_LABELS2, null, values);
//db.close(); // Closing database connection
}
public void insertLabel1(String label){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME1, label);
db.insert(TABLE_LABELS1, null, values);
//db.close(); // Closing database connection
}
public void insertLabel2(String label){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, label);
db.insert(TABLE_LABELS, null, values);
db.close(); // Closing database connection
}
public Cursor getAllLabelsForSpinner1AsCursor() {
String[] columns = new String[]{"rowid AS _id, *"}; // Need _id column for SimpleCursorAdapter
return this.getWritableDatabase().query(TABLE_LABELS2,columns,null,null,null,null,null);
}
public Cursor getAllLabelsForSpinner2AsCursor(String keyFromSinner1) {
String[] columns = new String[]{"rowid AS _id, *"}; // Need _id column for SimpleCursorAdapter
return this.getWritableDatabase().query(
TABLE_LABELS1,columns,
DatabaseHandler.KEY_NAME1 + " LIKE ?",
new String[]{keyFromSinner1+"%"},
null,null,null
);
}
public Cursor getAllLabelsForSpinner3AsCursor(String keyFromSpinner2) {
String[] columns = new String[]{"rowid AS _id, *"}; // Need _id column for SimpleCursorAdapter
return this.getWritableDatabase().query(
TABLE_LABELS,columns,
DatabaseHandler.KEY_NAME + " LIKE ?",
new String[]{keyFromSpinner2 + "%"},
null,null,null);
}
}
public class MainActivity extends AppCompatActivity {
DatabaseHandler mDH;
Spinner mSpinner1,mSpinner2,mSpinner3;
Cursor mSpinner1Csr,mSpinner2Csr,mSpinner3Csr;
SimpleCursorAdapter mSpinner1Adapter,mSpinner2Adapter,mSpinner3Adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSpinner1 = this.findViewById(R.id.spinner1);
mSpinner2 = this.findViewById(R.id.spinner2);
mSpinner3 = this.findViewById(R.id.spinner3);
mDH = new DatabaseHandler(this);
addSomeTestingData(); // ADD testing data if none
manageSpinner1(); // Manages spinner1 not that spinner 1 invokes manage spinner2 and spinnr manages spinner3
}
private void addSomeTestingData() {
if(DatabaseUtils.queryNumEntries(mDH.getWritableDatabase(),DatabaseHandler.TABLE_LABELS) > 0) return;
// Data for LABELS2 table (spinner 1 (note 1st column listed in spinner))
mDH.insertLabel("A1","A2","A3","A4","A5","A6","A7","A8","A9","A10");
mDH.insertLabel("B1","B2","B3","B4","B5","B6","B7","B8","B9","B10");
mDH.insertLabel("L1","L2","L3","L4","L5","L6","L7","L8","L9","L10");
// Data for LABELS1 table (spinner 2)
mDH.insertLabel1("A1EXTRA1");
mDH.insertLabel1("A1EXTRA2");
mDH.insertLabel1("B1EXTRA1");
mDH.insertLabel1("B1EXTRA2");
mDH.insertLabel1("L1EXTRA1");
mDH.insertLabel1("L1EXTRA2");
// Data for LABELS table (spinner 3)
mDH.insertLabel2("A1EXTRA1MORE1");
mDH.insertLabel2("A1EXTRA1MORE2");
mDH.insertLabel2("A1EXTRA2MORE1");
mDH.insertLabel2("A1EXTRA2MORE2");
mDH.insertLabel2("B1EXTRA1MORE1");
mDH.insertLabel2("B1EXTRA1MORE2");
mDH.insertLabel2("B1EXTRA2MORE1");
mDH.insertLabel2("B1EXTRA2MORE2");
mDH.insertLabel2("L1EXTRA1MORE1");
mDH.insertLabel2("L1EXTRA1MORE2");
mDH.insertLabel2("L1EXTRA2MORE1");
mDH.insertLabel2("L1EXTRA2MORE2");
}
private void manageSpinner1() {
mSpinner1Csr = mDH.getAllLabelsForSpinner1AsCursor();
if (mSpinner1Adapter == null) {
mSpinner1Adapter = new SimpleCursorAdapter(
this,
android.R.layout.simple_list_item_1,
mSpinner1Csr,
new String[]{DatabaseHandler.KEY_1},
new int[]{android.R.id.text1},
0
);
mSpinner1.setAdapter(mSpinner1Adapter);
mSpinner1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
manageSpinner2(mSpinner1Csr.getString(mSpinner1Csr.getColumnIndex(DatabaseHandler.KEY_1)));
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
} else {
mSpinner1Adapter.swapCursor(mSpinner1Csr);
}
}
private void manageSpinner2(String keyFromSpinner1) {
mSpinner2Csr = mDH.getAllLabelsForSpinner2AsCursor(keyFromSpinner1);
if (mSpinner2Adapter == null) {
mSpinner2Adapter = new SimpleCursorAdapter(
this,
android.R.layout.simple_list_item_1,
mSpinner2Csr,
new String[]{DatabaseHandler.KEY_NAME1},
new int[]{android.R.id.text1},
0
);
mSpinner2.setAdapter(mSpinner2Adapter);
mSpinner2.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
manageSpinner3(mSpinner2Csr.getString(mSpinner2Csr.getColumnIndex(DatabaseHandler.KEY_NAME1)));
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
} else {
mSpinner2Adapter.swapCursor(mSpinner2Csr);
}
}
private void manageSpinner3(String keyForSpinner3) {
mSpinner3Csr = mDH.getAllLabelsForSpinner3AsCursor(keyForSpinner3);
if (mSpinner3Adapter == null) {
mSpinner3Adapter = new SimpleCursorAdapter(
this,
android.R.layout.simple_list_item_1,
mSpinner3Csr,
new String[]{DatabaseHandler.KEY_NAME},
new int[]{android.R.id.text1},
0
);
mSpinner3.setAdapter(mSpinner3Adapter);
} else {
mSpinner3Adapter.swapCursor(mSpinner3Csr);
}
}
}
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NullPointer on loading strings into spinner
By : ilyass
Date : March 29 2020, 07:55 AM
I hope this helps you . In the while statement, final2.add(read) is getting a nullpointer which leads me to believe that it is not reading the file correctly, so my question is the following am I obtaining the contents of the text file correctly? , You need to initialize your final2 variable.
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code :
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