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Android recyleview listing using with database not working

I am developing an app for listing details in database. The listing is not working. but it is showing in log as fine. Why my recyclerview listling is not working. when i am using bean1 = new Bean(cn.getName(), cn.getNumber(), cn.getSpeeddial()) it shows error.
My codes are shown below.
SpeedDialViewActivity.java
public class SpeedDialViewActivity extends AppCompatActivity {
private List<Bean> beanList = new ArrayList<>();
private RecyclerView recyclerView;
private ViewAdapter mAdapter;
Context context;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_speed_dial_view);
recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
mAdapter = new ViewAdapter(beanList);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(mAdapter);
prepareData();
}
private void prepareData() {
DatabaseHandler handler = new DatabaseHandler(getApplicationContext());
Log.d("Reading: ", "Reading all contacts..");
List<Bean> beanList = handler.getAllContacts();
//Cursor cursor = (Cursor) handler.getAllContacts();
//Bean bean1;
for (Bean cn : beanList) {
String log = "Id: " + cn.getId() + " ,Name: " + cn.getName() + " ,Phone: " + cn.getNumber();
// Writing Contacts to log
Log.d("Name: ", log);
// bean1 = new Bean(cn.getName(), cn.getNumber(), cn.getSpeeddial()); // Error occurring
// beanList.add(bean1);
}
}
}
DatabaseHandler.java
public class DatabaseHandler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "speeddial";
private static final String TABLE_CONTACTS = "contacts";
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_PH_NO = "phone_number";
private static final String KEY_SPEED_DIAL = "speed_dial_number";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
+ KEY_PH_NO + " TEXT" + KEY_SPEED_DIAL + " TEXT" + ")";
db.execSQL(CREATE_CONTACTS_TABLE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);
// Create tables again
onCreate(db);
}
void addContact(Bean bean) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, bean.getName()); // Contact Name
values.put(KEY_PH_NO, bean.getNumber()); // Contact Phone
values.put(KEY_PH_NO, bean.getSpeeddial()); // Contact Phone
// Inserting Row
db.insert(TABLE_CONTACTS, null, values);
db.close(); // Closing database connection
}
Bean getBean(int id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_CONTACTS, new String[] { KEY_ID,
KEY_NAME, KEY_PH_NO }, KEY_ID + "=?",
new String[] { String.valueOf(id) }, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
Bean bean = new Bean(Integer.parseInt(cursor.getString(0)),cursor.getString(1), cursor.getString(2), cursor.getString(3));
// return contact
return bean;
}
public List<Bean> getAllContacts() {
List<Bean> contactList = new ArrayList<Bean>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_CONTACTS;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Bean contact = new Bean();
contact.setId(Integer.parseInt(cursor.getString(0)));
contact.setName(cursor.getString(1));
contact.setNumber(cursor.getString(2));
// Adding contact to list
contactList.add(contact);
} while (cursor.moveToNext());
}
// return contact list
return contactList;
}
}
ViewAdapter.java
public class ViewAdapter extends RecyclerView.Adapter<ViewAdapter.MyViewHolder> {
private List<Bean> beanList;
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView name, number, speeddial_number;
public MyViewHolder(View view) {
super(view);
name = (TextView) view.findViewById(R.id.name);
number = (TextView) view.findViewById(R.id.number);
speeddial_number = (TextView) view.findViewById(R.id.speeddialNumber);
}
}
public ViewAdapter(List<Bean> beanList){
this.beanList = beanList;
}
#Override
public ViewAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.speeddial_list_row, parent, false);
return new MyViewHolder(itemView);
}
#Override
public void onBindViewHolder(ViewAdapter.MyViewHolder holder, int position) {
Bean bean = beanList.get(position);
holder.name.setText(bean.getName());
holder.number.setText(bean.getNumber());
holder.speeddial_number.setText(bean.getSpeeddial());
}
#Override
public int getItemCount() {
return beanList.size();
}
}
Bean.java
public class Bean{
private int id;
private String name;
private String number;
private String speeddial;
public Bean(int id, String name, String number, String speeddial) {
this.id=id;
this.name=name;
this.number=number;
this.speeddial=speeddial;
}
public Bean(String name, String number, String speeddial) {
this.name=name;
this.number=number;
this.speeddial=speeddial;
}
public Bean() {
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getNumber() {
return number;
}
public void setNumber(String number) {
this.number = number;
}
public String getSpeeddial() {
return speeddial;
}
public void setSpeeddial(String speeddial) {
this.speeddial = speeddial;
}
}
The error is java.lang.RuntimeException: Unable to start activity ComponentInfo{com.app.appname/com.app.appname}: java.util.ConcurrentModificationException
Please help me

You are not adding the contacts you are fetching in the list and not doing notify data set changed. Change your onPrepare() method as follows
private void prepareData() {
DatabaseHandler handler = new DatabaseHandler(getApplicationContext());
Log.d("Reading: ", "Reading all contacts..");
List<Bean> beanList = handler.getAllContacts();
this.beanList.addAll(beanList);
mAdapter.notifyDatasetChanged();
}

pass the same list in prepareData(beanList) and add items in this list. And change your method to something likeprepareData(List<Bean> beanList>).after successfully adding, simply call mAdapter.notifyDataSetChanged() method so your adapter could know that some items have been added into the list.

You have not mention android:name in application tag in manifest file.
So you simple use context object or use SpeedDialViewActivity.this
DatabaseHandler handler = new DatabaseHandler(mContext);
or
DatabaseHandler handler = new DatabaseHandler(SpeedDialViewActivity.this);
private void prepareData() {
DatabaseHandler handler = new DatabaseHandler(SpeedDialViewActivity.this);
Log.d("Reading: ", "Reading all contacts..");
List<Bean> beanList = handler.getAllContacts();
//Cursor cursor = (Cursor) handler.getAllContacts();
//Bean bean1;
for (Bean cn : beanList) {
String log = "Id: " + cn.getId() + " ,Name: " + cn.getName() + " ,Phone: " + cn.getNumber();
// Writing Contacts to log
Log.d("Name: ", log);
// bean1 = new Bean(cn.getName(), cn.getNumber(), cn.getSpeeddial()); // Error occurring
// beanList.add(bean1);
}
}

Display Data from SQL in custom ListView via SimpleCursorAdapter

i created a SQL Database and was able to safe data from three EditText Views and display it in a single TextView.
Then i thought it would be way better to display the data in a custom ListView, so i followed the developer guide and tried to display the data by a simpleCursorAdapter. But it did not work...i do not get any errors or anything, the data is just not shown...I guess there must be some missing connection between the Cursor, the Adapter or the DB...
i know that this kind of question is asked quite frequently, but i am unable to find my mistake, any help would be greatly appreciated:
MyDBHandlerFaecher.java:
public class MyDBHandlerFaecher extends SQLiteOpenHelper{
private static final int DATABASE_VERSION = 5;
private static final String DATABASE_NAME = "faecher.db";
public static final String TABLE_FAECHER = "Faechertable";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_NAME = "_faechername";
public static final String COLUMN_RAUM = "_faecherraum";
public static final String COLUMN_COLOR = "_faecherfarbe";
public MyDBHandlerFaecher(FaecherActivity context, String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, DATABASE_NAME, factory, DATABASE_VERSION);
}
//Create the table
#Override
public void onCreate(SQLiteDatabase db) {
String query = "CREATE TABLE " + TABLE_FAECHER + "(" +
COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
COLUMN_NAME + " TEXT, " +
COLUMN_RAUM + " TEXT, " +
COLUMN_COLOR + " TEXT " +
");";
db.execSQL(query);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_FAECHER);
onCreate(db);
}
//Add a new row to the DB
public void addFach(Faecher fach){
ContentValues values = new ContentValues();
values.put(COLUMN_NAME, fach.get_faechername());
values.put(COLUMN_RAUM, fach.get_faecherraum());
values.put(COLUMN_COLOR, fach.get_faecherfarbe());
SQLiteDatabase db = getWritableDatabase();
db.insert(TABLE_FAECHER, null, values);
db.close();
}
//Delete row from DB
public void deleteFach(String name){
SQLiteDatabase db = getWritableDatabase();
//Delete the line in which the COLUMN_NAME is equal to the input
db.execSQL("DELETE FROM " + TABLE_FAECHER + " WHERE " + COLUMN_NAME + "=" + "\"" + name + "\"" + ";");
}
FaecherActivity.java
public class FaecherActivity extends AppCompatActivity{
EditText et_facheintrag;
EditText et_raumeintrag;
EditText et_farbeintrag;
ListView lv_faecher;
MyDBHandlerFaecher dbHandlerFaecher;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_faecher);
et_facheintrag = (EditText) findViewById(R.id.et_facheintrag);
et_raumeintrag = (EditText) findViewById(R.id.et_raumeintrag);
et_farbeintrag = (EditText) findViewById(R.id.et_farbeintrag);
lv_faecher = (ListView) findViewById(R.id.lv_faecher);
dbHandlerFaecher = new MyDBHandlerFaecher(this, null, null, 1);
printDatabase();
}
//Add fach to database
public void addButtonClicked(View view){
Faecher fach = new Faecher(et_facheintrag.getText().toString(), et_raumeintrag.getText().toString(), et_farbeintrag.getText().toString());
dbHandlerFaecher.addFach(fach);
printDatabase();
}
//delete fach from database
public void deleteButtonClicked(View view){
String inputText = et_facheintrag.getText().toString();
dbHandlerFaecher.deleteFach(inputText);
printDatabase();
}
public void printDatabase(){
String[] fromColumns = new String[]{"_faechername", "_faecherraum", "_faecherfarbe"};
int[] toViews = new int[]{R.id.facheintrag, R.id.raumeintrag, R.id.farbeintrag};
Cursor cursor;
cursor = getContentResolver().query(Uri.parse(MyDBHandlerFaecher.TABLE_FAECHER),null, null, null, null);
SimpleCursorAdapter fachadapter = new SimpleCursorAdapter(this, R.layout.faecher_row, cursor, fromColumns,toViews, 0);
lv_faecher.setAdapter(fachadapter);
}
}

i found code that works for me: i found out that the cursor in my DBHandler class was not empty, but it was empty in my FaecherActivity...so i created a custom SimpleCursorAdapter, and modified my code this way:
FaecherActivity:
public class FaecherActivity extends AppCompatActivity{
EditText et_facheintrag;
EditText et_raumeintrag;
EditText et_farbeintrag;
ListView lv_faecher;
MyDBHandlerFaecher dbHandlerFaecher;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_faecher);
et_facheintrag = (EditText) findViewById(R.id.et_facheintrag);
et_raumeintrag = (EditText) findViewById(R.id.et_raumeintrag);
et_farbeintrag = (EditText) findViewById(R.id.et_farbeintrag);
lv_faecher = (ListView) findViewById(R.id.lv_faecher);
dbHandlerFaecher = new MyDBHandlerFaecher(this, null, null, 1);
printDatabase();
}
//Add fach to database
public void addButtonClicked(View view){
Faecher fach = new Faecher(et_facheintrag.getText().toString(), et_raumeintrag.getText().toString(),
et_farbeintrag.getText().toString());
dbHandlerFaecher.addFach(fach);
printDatabase();
}
public void deleteButtonClicked(View view){
String inputText = et_facheintrag.getText().toString();
dbHandlerFaecher.deleteFach(inputText);
printDatabase();
}
public void printDatabase(){
String[] fromColumns = dbHandlerFaecher.databaseToStringArray();
int[] toViews = new int[]{R.id.facheintrag, R.id.raumeintrag, R.id.farbeintrag};
Cursor cursor;
cursor = dbHandlerFaecher.getWritableDatabase().rawQuery(" SELECT * FROM " + MyDBHandlerFaecher.TABLE_FAECHER + " WHERE 1 ", null);
//check if cursor is empty
if (cursor != null && cursor.getCount()>0) {
Log.d("Event", "Records do exist2");
}
else {
Log.d("Event", "Records do not exist2");
}
SimpleCursorAdapter fachadapter = new FaecherRowAdapter(this, R.layout.faecher_row, cursor, fromColumns,toViews, 0);
lv_faecher.setAdapter(fachadapter);
MyDBHandlerFaecher:
public class MyDBHandlerFaecher extends SQLiteOpenHelper{
private static final int DATABASE_VERSION = 5;
private static final String DATABASE_NAME = "faecher.db";
public static final String TABLE_FAECHER = "Faechertable";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_NAME = "_faechername";
public static final String COLUMN_RAUM = "_faecherraum";
public static final String COLUMN_COLOR = "_faecherfarbe";
public MyDBHandlerFaecher(FaecherActivity context, String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, DATABASE_NAME, factory, DATABASE_VERSION);
}
//Create the table
#Override
public void onCreate(SQLiteDatabase db) {
String query = "CREATE TABLE " + TABLE_FAECHER + "(" +
COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
COLUMN_NAME + " TEXT, " +
COLUMN_RAUM + " TEXT, " +
COLUMN_COLOR + " TEXT " +
");";
db.execSQL(query);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_FAECHER);
onCreate(db);
}
//Add a new row to the DB
public void addFach(Faecher fach){
ContentValues values = new ContentValues();
values.put(COLUMN_NAME, fach.get_faechername());
values.put(COLUMN_RAUM, fach.get_faecherraum());
values.put(COLUMN_COLOR, fach.get_faecherfarbe());
SQLiteDatabase db = getWritableDatabase();
db.insert(TABLE_FAECHER, null, values);
db.close();
}
//Delete row from DB
public void deleteFach(String name){
SQLiteDatabase db = getWritableDatabase();
db.execSQL("DELETE FROM " + TABLE_FAECHER + " WHERE " + COLUMN_NAME + "=" + "\"" + name + "\"" + ";");
}
public String[] databaseToStringArray() {
String[] fromColumns = new String[]{COLUMN_NAME, COLUMN_RAUM, COLUMN_COLOR};
SQLiteDatabase db = getWritableDatabase();
Cursor cursor = db.rawQuery(" SELECT * FROM " + TABLE_FAECHER + " WHERE 1 ", null);
//check if cursor is empty or not
if (cursor != null && cursor.getCount()>0) {
Log.d("Event", "Records do exist");
}
else {
Log.d("Event", "Records do not exist");
}
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
cursor.moveToNext();
}
db.close();
return fromColumns;
}
}
FaecherRowAdapter:
public class FaecherRowAdapter extends SimpleCursorAdapter {
private int layout;
private Context context;
public FaecherRowAdapter(Context context, int layout, Cursor c, String[] from, int[] to, int flags) {
super(context, layout, c, from, to, flags);
this.layout = layout;
this.context = context;
}
#Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
Cursor c = getCursor();
final LayoutInflater inflater = LayoutInflater.from(context);
View v = inflater.inflate(R.layout.faecher_row, parent, false);
bindView(v, context, c);
return v;
}
#Override
public void bindView(View v, Context context, Cursor c) {
int fachNameColumn = c.getColumnIndex(MyDBHandlerFaecher.COLUMN_NAME);
int fachRaumColumn = c.getColumnIndex(MyDBHandlerFaecher.COLUMN_RAUM);
int fachFarbeColumn = c.getColumnIndex(MyDBHandlerFaecher.COLUMN_COLOR);
String fachName = c.getString(fachNameColumn);
String fachRaum = c.getString(fachRaumColumn);
String fachFarbe = c.getString(fachFarbeColumn);
//set the name of the entry
TextView facheintrag = (TextView) v.findViewById(R.id.facheintrag);
if (facheintrag != null){
facheintrag.setText(fachName);
}
TextView raumeintrag = (TextView) v.findViewById(R.id.raumeintrag);
if (raumeintrag != null){
raumeintrag.setText(fachRaum);
}
TextView farbeintrag = (TextView) v.findViewById(R.id.farbeintrag);
if (farbeintrag != null){
farbeintrag.setText(fachFarbe);
}
}
}

User Login with SQLite database java.lang.NullPointerException

I'm having a problem using my database to check the username and password of the user. I'm using a query to select the specific row and then check the password against what was entered by the user. The error I am getting is a java.lang.NullPointerException in my login page when i call the
Users userlogin = db.userlogin(usernameinput);
After looking at the method I'm thinking its the first cursor that causes it to fail
cursor.getInt(0);
What I'm wondering is am I right in thinking this and what can I do to change it?
I've tried changing the if statement to
If(cursor.getcount() > 0)
and still no luck.
public class LoginPage extends ActionBarActivity {
Button loginbutton;
EditText usernameuser, passworduser;
DatabaseHandler db;
String usernameinput, passwordinput;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login_page);
loginbutton = (Button) findViewById(R.id.loginbtn);
usernameuser = (EditText) findViewById(R.id.usernameInsert);
passworduser = (EditText) findViewById(R.id.passwordInsert);
loginbutton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
usernameinput = usernameuser.getText().toString();
passwordinput = passworduser.getText().toString();
Users userlogin = db.userLogin(usernameinput);
if (usernameinput.equals(userlogin.get_username()) && passwordinput.equals(userlogin.get_password())) {
startActivity(new Intent(getApplicationContext(), Home_Page.class));
}
else {
Toast.makeText(getApplicationContext(), "Error", Toast.LENGTH_SHORT).show();
}
}
});
Database handler Query used to check login:
public Users userLogin(String username) {
SQLiteDatabase db = this.getReadableDatabase();
String[] projection = {KEY_USER_ID, KEY_USERNAME, KEY_PASSWORD};
String selection = KEY_USERNAME + " =?";
String[] selectionargs = {username};
Cursor cursor = db.query(TABLE_USERS, projection, selection, selectionargs, null, null,null );
if (cursor != null)
cursor.moveToFirst();
Users users = new Users(
cursor.getInt(0),
cursor.getString(1),
cursor.getString(2),
cursor.getInt(3),
cursor.getString(4),
cursor.getString(5),
cursor.getDouble(6),
cursor.getDouble(7),
cursor.getDouble(8),
cursor.getDouble(9),
cursor.getDouble(10),
cursor.getDouble(11),
cursor.getDouble(12),
cursor.getDouble(13),
cursor.getDouble(14),
cursor.getDouble(15),
cursor.getDouble(16),
cursor.getDouble(17),
cursor.getDouble(18),
cursor.getDouble(19));
cursor.close();
return users;
}
04-08 13:05:33.194 2565-2565/com.example.john.fitnessapp E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.john.fitnessapp, PID: 2565
java.lang.NullPointerException
at com.example.john.fitnessapp.LoginPage$1.onClick(LoginPage.java:42)
at android.view.View.performClick(View.java:4569)
at android.view.View$PerformClick.run(View.java:18553)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:212)
at android.app.ActivityThread.main(ActivityThread.java:5137)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:902)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:718)
at dalvik.system.NativeStart.main(Native Method)
user class:
public class Users {
int _id, _age;
String _username, _password, _email, _gender;
double _startWeight, _currentWeight, _weightChange, _height, _BMI, _BMR, _reqCal, _monCal, _tuesCal, _wedCal, _thurCal, _friCal, _satCal, _sunCal;
public Users(){}
public Users(int _id, String _username, String _password, int _age, String _email, String _gender, double _height, double _startWeight,
double _currentWeight, double _weightChange, double _BMI, double _BMR, double _reqCal, double _monCal, double _tuesCal, double _wedCal,
double _thurCal, double _friCal, double _satCal, double _sunCal){
this._id = _id;
this._username = _username;
this._password = _password;
this._age = _age;
this._email = _email;
this._gender = _gender;
this._height = _height;
this._startWeight = _startWeight;
this._currentWeight = _currentWeight;
this._weightChange = _weightChange;
this._BMI = _BMI;
this._BMR = _BMR;
this._reqCal = _reqCal;
this._monCal = _monCal;
this._tuesCal = _tuesCal;
this._wedCal = _wedCal;
this._thurCal = _thurCal;
this._friCal = _friCal;
this._satCal = _satCal;
this._sunCal = _sunCal;
}
public int get_id(){
return this._id;
}
public void set_id(int id){
this._id = id;
}
public String get_username(){
return this._username;
}
public void set_username(String username){
this._username = username;
}
public String get_password(){
return this._password;
}
public void set_password(String password){
this._password = password;
}
public int get_age(){
return this._age;
}
public void set_age(int age){
this._age = age;
}
public String get_email(){
return this._email;
}
public void set_email(String email){
this._email = email;
}
public String get_gender(){
return this._gender;
}
public void set_gender(String gender){
this._gender = gender;
}
public double get_height(){
return this._height;
}
public void set_height(double height){
this._height = height;
}
public double get_startWeight(){
return this._startWeight;
}
public void set_startWeight(double startWeight){
this._startWeight = startWeight;
}
public double get_currentWeight(){
return this._currentWeight;
}
public void set_currentWeight(double currentWeight){
this._currentWeight = currentWeight;
}
public double get_weightChange(){
return this._weightChange;
}
public void set_weightChange(){
this._weightChange = _currentWeight - _startWeight;
}
public double get_BMI(){
return this._BMI;
}
public void set_BMI(double BMI){
this._BMI = BMI;
}
public double get_BMR(){
return this._BMR;
}
public void set_BMR(double BMR){
this._BMR = BMR;
}
public double get_reqCal(){
return this._reqCal;
}
public void set_reqCal(double reqCal){
this._reqCal = reqCal;
}
public double get_monCal(){
return this._monCal;
}
public void set_monCal(double monCal){
this._monCal = monCal;
}
public double get_tuesCal(){
return this._tuesCal;
}
public void set_tuesCal(double tuesCal){
this._tuesCal = tuesCal;
}
public double get_wedCal(){
return this._wedCal;
}
public void set_wedCal(double wedCal){
this._wedCal = wedCal;
}
public double get_thurCal(){
return this._thurCal;
}
public void set_thurCal(double thurCal){
this._thurCal = thurCal;
}
public double get_friCal(){
return this._friCal;
}
public void set_friCal(double friCal){
this._friCal = friCal;
}
public double get_satCal(){
return this._satCal;
}
public void set_satCal(double satCal){
this._satCal = satCal;
}
public double get_sunCal(){
return this._sunCal;
}
public void set_sunCal(double sunCal){
this._sunCal = sunCal;
}
}
Databasehandler:
public class DatabaseHandler extends SQLiteOpenHelper {
public static final String TAG = "DBHelper";
//DATABASE VERSION
private static int DATABASE_VERSION = 1;
//DATABASE NAME
private static final String DATABASE_NAME = "AppDatabase";
//TABLE NAMES
private static final String TABLE_USERS = "Users_Table";
private static final String TABLE_PRODUCTS = "Products_Table";
//COMMON COLUMN NAMES
private static final String KEY_USER_ID = "User_ID";
private static final String KEY_PRODUCT_ID = "Product_ID";
//USER TABLE
private static final String KEY_USERNAME = "Username";
private static final String KEY_PASSWORD = "Password";
private static final String KEY_AGE = "Age";
private static final String KEY_EMAIL = "Email";
private static final String KEY_GENDER = "Gender";
private static final String KEY_HEIGHT = "Height";
private static final String KEY_CURRENT_WEIGHT = "Current_Weight";
private static final String KEY_START_WEIGHT = "Start_Weight";
private static final String KEY_WEIGHT_CHANGE = "Weight_Change";
private static final String KEY_BMI = "BMI";
private static final String KEY_BMR = "BMR";
private static final String KEY_REQ_CAL = "Required_Calories";
private static final String KEY_MON_CAL = "Monday_Calories";
private static final String KEY_TUES_CAL = "Tuesday_Calories";
private static final String KEY_WED_CAL = "Wednesday_Calories";
private static final String KEY_THUR_CAL = "Thursday_Calories";
private static final String KEY_FRI_CAL = "Friday_Calories";
private static final String KEY_SAT_CAL = "Saturday_Calories";
private static final String KEY_SUN_CAL = "Sunday_Calories";
//PRODUCT TABLE
private static final String KEY_ITEMNAME = "Item_name";
private static final String KEY_ITEMCALORIES = "Item_Calories";
//
private static final String CREATE_USER_TABLE = "CREATE TABLE " + TABLE_USERS + "( "
+ KEY_USER_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ KEY_USERNAME + " TEXT, "
+ KEY_PASSWORD + " TEXT, "
+ KEY_AGE + " INTEGER, "
+ KEY_EMAIL + " TEXT, "
+ KEY_GENDER + " TEXT, "
+ KEY_HEIGHT + " DOUBLE, "
+ KEY_START_WEIGHT + " DOUBLE, "
+ KEY_CURRENT_WEIGHT + " DOUBLE, "
+ KEY_WEIGHT_CHANGE + " DOUBLE, "
+ KEY_BMI + " DOUBLE, "
+ KEY_BMR + " DOUBLE, "
+ KEY_REQ_CAL + " DOUBLE, "
+ KEY_MON_CAL + " DOUBLE, "
+ KEY_TUES_CAL + " DOUBLE, "
+ KEY_WED_CAL + " DOUBLE, "
+ KEY_THUR_CAL + " DOUBLE, "
+ KEY_FRI_CAL + " DOUBLE, "
+ KEY_SAT_CAL + " DOUBLE, "
+ KEY_SUN_CAL + " DOUBLE ); ";
private static final String CREATE_PRODUCT_TABLE = "CREATE TABLE " + TABLE_PRODUCTS + "( " + KEY_PRODUCT_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ KEY_ITEMNAME + " TEXT, "
+ KEY_ITEMCALORIES + " DOUBLE );";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
public void onCreate(SQLiteDatabase db) {
db.execSQL(CREATE_USER_TABLE);
db.execSQL(CREATE_PRODUCT_TABLE);
}
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG,
"Upgrading the database from version " + oldVersion + " to " + newVersion);
DATABASE_VERSION = 2;
db.execSQL("DROP TABLE IF IT EXISTS " + TABLE_USERS);
db.execSQL("DROP TABLE IF IT EXISTS " + TABLE_PRODUCTS);
onCreate(db);
}

Edit: Make sure you initialize your class that extends SQLiteOpenHelper.
Make sure you call:
db = new DatabaseHandler(this);
If you don't initialize db then it will be null when you call db.userLogin(usernameinput);, and that might be the cause of the NullPointerException that you're getting.
You could just call it in `onCreate()' like this:
public class LoginPage extends ActionBarActivity {
Button loginbutton;
EditText usernameuser, passworduser;
DatabaseHandler db;
String usernameinput, passwordinput;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login_page);
db = new DatabaseHandler(this); //initialize the DatabaseHandler
//........
In addition, it looks like you're only querying three columns of the database, and trying to access twenty columns in the cursor.
Also, you should check the return value of cursor.moveToFirst().
In general, the cursor will never be null.
This will probably make it work short term, but you might want to consider re-factoring your code such that you don't have to query all rows to make it work:
public Users userLogin(String username) {
Users users = null;
SQLiteDatabase db = this.getReadableDatabase();
//String[] projection = {KEY_USER_ID, KEY_USERNAME, KEY_PASSWORD};
String selection = KEY_USERNAME + " =?";
String[] selectionargs = {username};
Cursor cursor = db.query(TABLE_USERS, null, selection, selectionargs, null, null,null );
if (cursor.moveToFirst()){
users = new Users(
cursor.getInt(0),
cursor.getString(1),
cursor.getString(2),
cursor.getInt(3),
cursor.getString(4),
cursor.getString(5),
cursor.getDouble(6),
cursor.getDouble(7),
cursor.getDouble(8),
cursor.getDouble(9),
cursor.getDouble(10),
cursor.getDouble(11),
cursor.getDouble(12),
cursor.getDouble(13),
cursor.getDouble(14),
cursor.getDouble(15),
cursor.getDouble(16),
cursor.getDouble(17),
cursor.getDouble(18),
cursor.getDouble(19));
}
cursor.close();
return users;
}
Ideally you would create another constructor for your Users class that could just take the three parameters that you need in this case.
Your modified code would be something like this:
public Users userLogin(String username) {
Users users = null;
SQLiteDatabase db = this.getReadableDatabase();
String[] projection = {KEY_USER_ID, KEY_USERNAME, KEY_PASSWORD};
String selection = KEY_USERNAME + " =?";
String[] selectionargs = {username};
Cursor cursor = db.query(TABLE_USERS, projection, selection, selectionargs, null, null,null );
if (cursor.moveToFirst()){
users = new Users(
cursor.getInt(0),
cursor.getString(1),
cursor.getString(2))
}
cursor.close();
return users;
}
Also, it would be good to check for null return value from your userLogin() function:
loginbutton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
usernameinput = usernameuser.getText().toString();
passwordinput = passworduser.getText().toString();
Users userlogin = db.userLogin(usernameinput);
if (userlogin != null && usernameinput.equals(userlogin.get_username()) && passwordinput.equals(userlogin.get_password())) {
startActivity(new Intent(getApplicationContext(), Home_Page.class));
}
else {
Toast.makeText(getApplicationContext(), "Error", Toast.LENGTH_SHORT).show();
}
}
});

Database using Eclipse

I am making a login screen which is connected to the database shown below, I have the class called DatabaseHelper which contains all my tables and functions, and the main.java contains the codes below, and the register.java contains the following codes :
package DatabaseHelper;
public class DatabaseHelper extends SQLiteOpenHelper {
//get reference to writable DB
SQLiteDatabase db = this.getWritableDatabase();
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "ExpenseManager";
// Table Names
private static final String TABLE_user = "user";
private static final String TABLE_income = "income";
private static final String TABLE_store = "store";
// Common column names
private static final String KEY_ID = "uid";
// user Table - column names
public static final String KEY_username = "username";
public static final String KEY_password = "password";
private static final String KEY_email = "email";
private static final String KEY_url = "url";
private static final String KEY_amountalert = "amountalert";
private static final String KEY_currency = "currency";
// income Table - column names
private static final String KEY_IID = "iid";
private static final String KEY_INCOMEDATE = "Incomedate";
private static final String KEY_AMOUNT = "amount";
private static final String KEY_INCOMETYPE = "Incometype";
// store Table - column names
private static final String KEY_EID = "eid";
private static final String KEY_ITEM = "item";
private static final String KEY_PRICE = "price";
private static final String KEY_TYPE = "type";
private static final String KEY_DATE = "date";
private static final String KEY_PLACE = "place";
// Table Create Statements
// user table create statement
private static final String CREATE_TABLE_user = "CREATE TABLE "
+ TABLE_user + "(" + KEY_ID + " INTEGER PRIMARY KEY,"
+ KEY_username + " TEXT," + KEY_password + " TEXT," + KEY_email
+ " TEXT, " + KEY_url + " TEXT," + KEY_amountalert + " FLOAT,"
+ KEY_INCOMETYPE + " TEXT," + KEY_currency + " TEXT," + ")";
// income table create statement
private static final String CREATE_TABLE_income = "CREATE TABLE "
+ TABLE_income + "(" + KEY_IID + " INTEGER PRIMARY KEY,"
+ KEY_AMOUNT + " TEXT," + KEY_ID + " INTEGER," + KEY_INCOMEDATE
+ " DATETIME," + KEY_INCOMETYPE + " TEXT, " + "FOREIGN KEY ("
+ KEY_ID + ") REFERENCES TABLE_user(uid))";
// store table create statement
private static final String CREATE_TABLE_store = "CREATE TABLE "
+ TABLE_store + "(" + KEY_EID + " INTEGER PRIMARY KEY," + KEY_ITEM
+ " TEXT," + KEY_PRICE + " FLOAT," + KEY_TYPE + " TEXT, "
+ KEY_PLACE + " TEXT, " + KEY_DATE + " DATETIME, " + KEY_ID
+ " INTEGER," + "FOREIGN KEY (" + KEY_ID
+ ") REFERENCES TABLE_user(uid))";
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
// creating required tables
db.execSQL(CREATE_TABLE_user);
db.execSQL(CREATE_TABLE_income);
db.execSQL(CREATE_TABLE_store);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// on upgrade drop older tables
db.execSQL("DROP TABLE IF EXISTS " + TABLE_user);
db.execSQL("DROP TABLE IF EXISTS " + TABLE_income);
db.execSQL("DROP TABLE IF EXISTS " + TABLE_store);
// create new tables
onCreate(db);
}
public DatabaseHelper open() {
return this;
}
public void close() {
db.close();
}
public void Login(String username,String password){
ContentValues values = new ContentValues();
String un = (String) values.get(username);
String ps = (String) values.get(password);
db.close();
}
public void insertEntry(String username,String password, String email, String url, String amountAlert){
ContentValues values = new ContentValues();
// Assign values for each row.
values.put("KEY_username", username);
values.put("KEY_password",password);
values.put("KEY_email",email);
values.put(KEY_url, url);
values.put(KEY_amountalert, amountAlert);
// Insert the row into your table
db.insert(TABLE_user, null, values);
db.close();
}
}
package com.example.dailyexpensemanager;
import info.androidhive.sqlite.model.user;
public class Main extends Activity {
private EditText username;
private EditText password;
private TextView attempts;
private Button login;
int counter = 3;
private DatabaseHelper dbHelper;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
username = (EditText) findViewById(R.id.editText1);
password = (EditText) findViewById(R.id.editText2);
attempts = (TextView) findViewById(R.id.textView5);
attempts.setText(Integer.toString(counter));
login = (Button) findViewById(R.id.button1);
TextView registerScreen = (TextView) findViewById(R.id.sign);
final String getUsername=username.getText().toString();
final String getPassword=password.getText().toString();
// Listening to register new account link
registerScreen.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Switching to Register screen
Intent i = new Intent(getApplicationContext(),RegisterActivity.class);
startActivity(i);
}
});
login.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
dbHelper = new DatabaseHelper(getBaseContext());
dbHelper.open();
dbHelper.Login(getUsername, getPassword);
if ((getUsername.equals(DatabaseHelper.KEY_username)) && (getPassword.equals(DatabaseHelper.KEY_password))) {
Toast.makeText(getApplicationContext(),"Redirecting...",Toast.LENGTH_SHORT).show();
Intent in=new Intent(Main.this,home.class);
startActivity(in);
} else {
Toast.makeText(Main.this, "Login failed", Toast.LENGTH_SHORT).show();
attempts.setBackgroundColor(Color.RED); counter--;
attempts.setText(Integer.toString(counter));
if(counter==0){
login.setEnabled(false); }
}
dbHelper.close();
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
package com.example.dailyexpensemanager;
public class RegisterActivity extends Activity {
private EditText username;
private EditText password;
private EditText passwordc;
private EditText email;
private EditText bank;
private EditText amount;
Button btnRegister;
DatabaseHelper dbHelper;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.register);
//Fill the spin
String array_spinner[];
array_spinner = new String[3];
array_spinner[0] = "Lebanese Lira (L.L)";
array_spinner[1] = "Dollar ($)";
array_spinner[2] = "Euro (€)";
Spinner s = (Spinner) findViewById(R.id.spin);
ArrayAdapter adapter = new ArrayAdapter(this,android.R.layout.simple_spinner_item, array_spinner);
s.setAdapter(adapter);
//end spin filling
// Get References of Views
username=(EditText)findViewById(R.id.reg_fullname);
password=(EditText)findViewById(R.id.reg_password);
passwordc=(EditText)findViewById(R.id.reg_passwordc);
email=(EditText)findViewById(R.id.reg_email);
bank=(EditText)findViewById(R.id.bank);
amount=(EditText)findViewById(R.id.amount);
btnRegister=(Button)findViewById(R.id.btnRegister);
btnRegister.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
String getUsername=username.getText().toString();
String getPassword=password.getText().toString();
String getconfirmPassword=passwordc.getText().toString();
String getEmail=email.getText().toString();
String getBank =bank.getText().toString();
String getAmount=amount.getText().toString();
dbHelper = new DatabaseHelper(getBaseContext());
dbHelper.open();
dbHelper.insertEntry(getUsername, getPassword, getEmail, getBank, getAmount);
// check if any of the fields are vacant
if(getUsername.equals("")||getPassword.equals("")||getconfirmPassword.equals("")||getEmail.equals("")
||getBank.equals("")||getAmount.equals(""))
{
Toast.makeText(getApplicationContext(), "Field Vaccant", Toast.LENGTH_LONG).show();
return;
}
// check if both password matches
if(!getPassword.equals(getconfirmPassword))
{
Toast.makeText(getApplicationContext(), "Password does not match", Toast.LENGTH_LONG).show();
return;
}
else
{
// Save the Data in Database
dbHelper.insertEntry(getUsername, getPassword, getEmail , getBank , getAmount );
Toast.makeText(getApplicationContext(), "Account Successfully Created ", Toast.LENGTH_LONG).show();
}
dbHelper.close();
}
});
}
}
When running the application, it runs normally, my problem is, when pressing on login or on register button, the application will stop unexpectally. Please I want a solution for this problem .

There's an error here:
KEY_currency + " TEXT," + ")";
Please remove the extra comma:
KEY_currency + " TEXT" + ")";
[EDIT]
Here's another error (it occurs twice in your code)
REFERENCES TABLE_user(uid))";
It should be
REFERENCES user(uid))";

Access SQLiteOpenHelper onCreate Method from wrapping class

Right now i am calling an insertSomeContacts() function in the onCreate method of the MainActivity which obviously adds the given contacts every time the app is restarted (including screen roation)...since my SQLiteOpenHelper Sub-Class is part of my ContactsDBAdapter Class (which carries the insertSomeContacts() method) - how do i get this function to execute in the SQLiteOpenHelper onCreate so that it only executes once at creation of the database?
Really having problems understanding the scope of this and passing that scope around properly.
MainActivity.java:
public class MainActivity extends Activity {
Intent intent;
private ContactsDBAdapter dbHelper;
private SimpleCursorAdapter dataAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dbHelper = new ContactsDBAdapter(this);
dbHelper.open();
//dbHelper.deleteAll();
//dbHelper.insertSomeContacts();
displayListView();
}
private void displayListView(){
Cursor cursor = dbHelper.getAll();
String[] fromColumns = new String[]{
ContactsDBAdapter.COLUMN_TYPE,
ContactsDBAdapter.COLUMN_CLTYP,
ContactsDBAdapter.COLUMN_NAME,
ContactsDBAdapter.COLUMN_VNAME
};
int[] toViews = new int[]{
R.id.contactType,
R.id.contactCltype,
R.id.contactName,
R.id.contactVname
};
dataAdapter = new SimpleCursorAdapter(this, R.layout.contact_entry, cursor, fromColumns, toViews, 0);
ListView listview = (ListView) findViewById(R.id.list);
listview.setAdapter(dataAdapter);
}
ContactsDBAdapter.java:
public class ContactsDBAdapter{
public static final String COLUMN_ID = "_id";
public static final String COLUMN_TYPE = "type";
public static final String COLUMN_CLTYP = "cltyp";
public static final String COLUMN_MDT = "mdt";
public static final String COLUMN_OBJ = "obj";
public static final String COLUMN_VTR = "vtr";
public static final String COLUMN_FKZ = "fkz";
public static final String COLUMN_NAME = "name";
public static final String COLUMN_VNAME = "vname";
public static final String COLUMN_TEL = "tel";
public static final String COLUMN_FAX = "fax";
public static final String COLUMN_MOBIL = "mobil";
public static final String COLUMN_EMAIL = "email";
private static final String TAG = "ContactsDBAdapter";
private DBTools mDbHelper;
private SQLiteDatabase mDb;
private static final String DATABASE_NAME = "hvkontakte.db";
private static final String DATABASE = "hvkontakte";
private static final String TABLE_NAME = DATABASE;
private static final int DATABASE_VERSION = 1;
private final Context mCtx;
private static final String DATABASE_CREATE =
"CREATE TABLE " + TABLE_NAME + "(" + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
COLUMN_TYPE + ", " + COLUMN_CLTYP + ", " + COLUMN_MDT + ", " + COLUMN_OBJ + ", "
+ COLUMN_VTR + ", " + COLUMN_FKZ + ", " + COLUMN_NAME + ", " + COLUMN_VNAME + ", "
+ COLUMN_TEL + ", " + COLUMN_FAX + ", " + COLUMN_MOBIL + ", " + COLUMN_EMAIL + ")";
private static class DBTools extends SQLiteOpenHelper{
public DBTools(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase database) {
Log.w(TAG, DATABASE_CREATE);
database.execSQL(DATABASE_CREATE);
}
#Override
public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) {
database.execSQL("DROP TABLE IF EXISTS" + DATABASE);
onCreate(database);
}
}
public ContactsDBAdapter(Context ctx){
this.mCtx = ctx;
}
public ContactsDBAdapter open() throws SQLException{
mDbHelper = new DBTools(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close(){
if(mDbHelper != null){
mDbHelper.close();
}
}
public long createContact(String type, String cltyp, String mdt, String obj, String vtr,
String fkz, String name, String vname, String tel, String fax,
String mobil, String email) {
ContentValues initialValues = new ContentValues();
initialValues.put(COLUMN_TYPE, type);
initialValues.put(COLUMN_CLTYP, cltyp);
initialValues.put(COLUMN_MDT, mdt);
initialValues.put(COLUMN_OBJ, obj);
initialValues.put(COLUMN_VTR, vtr);
initialValues.put(COLUMN_FKZ, fkz);
initialValues.put(COLUMN_NAME, name);
initialValues.put(COLUMN_VNAME, vname);
initialValues.put(COLUMN_TEL, tel);
initialValues.put(COLUMN_FAX, fax);
initialValues.put(COLUMN_MOBIL, mobil);
initialValues.put(COLUMN_EMAIL, email);
return mDb.insert(TABLE_NAME, null, initialValues);
}
public boolean deleteAll() {
int doneDelete = 0;
doneDelete = mDb.delete(TABLE_NAME, null , null);
return doneDelete > 0;
}
public Cursor getAll() {
Cursor mCursor = mDb.query(TABLE_NAME, new String[] {COLUMN_ID,
COLUMN_TYPE, COLUMN_CLTYP, COLUMN_NAME, COLUMN_VNAME},
null, null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
public void insertSomeContacts(){
createContact("vtr","Tenant","1","82","1","2","Bennett","Tony","0911-123456","0911-123457","01577-12345678","info#email.com");
createContact("vtr","Owner","1","82","","","Smith","Brad","0911-1234567","0911-1234567","01577-84368365","info#email.com");
//createContact("","","","","","","","","","","","");
//createContact("","","","","","","","","","","","");
//createContact("","","","","","","","","","","","");
//createContact("","","","","","","","","","","","");
}
}

work with SharedPreferences. Set a init boolean. if init is false insert the contacts -> set the init to true. after restarting do noting when init is true.
But this is maybe not the best solution for your usecase...