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listView cannot update dynamically

I am using sqlite for database. When i add data in ListView. Data added correctly. But when i close app then updated list lost data which i added before. With code Statically added data shows but using app when create reminder then data added successfully in ListView. But when i restart app new data lost after restart app I mean creating reminder delete automatically after restart app.
Even I delete reminders which added by code after restart app all deleted reminders showing in ListView again. But Dynamically added data not show.
Please help me to solve this problem.
Here is my Activity code
RemindersActivity.java
package com.example.remindersapp;
import androidx.annotation.NonNull;
import androidx.appcompat.app.ActionBar;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import android.annotation.TargetApi;
import android.app.AlarmManager;
import android.app.Dialog;
import android.app.PendingIntent;
import android.app.TimePickerDialog;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.ActionMode;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.Window;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.Toast;
import java.util.Calendar;
import java.util.Date;
public class RemindersActivity extends AppCompatActivity {
private ListView mlistView;
private RemindersDbAdapter remindersDbAdapter;
private ReminderSimpleCursorAdapter reminderSimpleCursorAdapter;
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_reminders);
ActionBar actionBar = getSupportActionBar();
actionBar.setHomeButtonEnabled(true);
actionBar.setDisplayShowHomeEnabled(true);
actionBar.setIcon(R.mipmap.ic_launcher_reminder);
mlistView = (ListView) findViewById(R.id.reminder_listView);
// mlistView.setDivider(null);
remindersDbAdapter = new RemindersDbAdapter(this);
remindersDbAdapter.open();
if (savedInstanceState == null) {
//clear all data
remindersDbAdapter.deleteAllReminders();
//add some data
insertSomeReminders();
}
Cursor cursor = remindersDbAdapter.fetchAllReminders();
//from columns defined in the db
String[] from = new String[]{remindersDbAdapter.COL_CONTENT};
//to the ids of views in the layout
int[] to = new int[]{R.id.row_text};
reminderSimpleCursorAdapter = new ReminderSimpleCursorAdapter(
RemindersActivity.this,
//the layout of the row
R.layout.reminders_row,
cursor,
//from columns defined in the db
from,
//to the ids of views in the layout
to,
//flag - not used
0);
// ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(
// this,
// R.layout.reminders_row,
// R.id.row_text,
// new String[]{"fisrt record", "second record", "third record"
// , "fourth record", "fifth record"});
mlistView.setAdapter(reminderSimpleCursorAdapter);
//Adapter is a
//special Java class defined as part of the Android SDK that functions as the Controller in
//the Model-View-Controller relationship
//when we click an individual item in the listview
mlistView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int masterposition, long id) {
AlertDialog.Builder builder = new AlertDialog.Builder(RemindersActivity.this);
ListView modeListView = new ListView(RemindersActivity.this);
String[] modes = new String[]{"Edit Reminder", "Delete Reminder", "Scheduled Reminder"};
ArrayAdapter<String> modeAdapter = new ArrayAdapter<>(RemindersActivity.this,
android.R.layout.simple_list_item_1, android.R.id.text1, modes);
modeListView.setAdapter(modeAdapter);
builder.setView(modeListView);
final Dialog dialog = builder.create();
dialog.show();
modeListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//edit reminder
// if (position == 0) {
// Toast.makeText(RemindersActivity.this, "edit" + masterposition, Toast.LENGTH_SHORT).show();
// } else {
// Toast.makeText(RemindersActivity.this, "delete" + masterposition, Toast.LENGTH_SHORT).show();
// }
// dialog.dismiss();
int nId = getIdFromPosition(masterposition);
final Reminder reminder = remindersDbAdapter.fetchReminderById(nId);
if (position == 0) {
fireCustomDialog(reminder);
//delete reminder
} else if (position == 1) {
remindersDbAdapter.deleteReminderById(getIdFromPosition(masterposition));
reminderSimpleCursorAdapter.changeCursor(remindersDbAdapter.fetchAllReminders());
}
else {
// final Date today = new Date();
// new TimePickerDialog(RemindersActivity.this,null,today.getHours(),today.getMinutes(),
// false).show();
TimePickerDialog.OnTimeSetListener listener = new TimePickerDialog.OnTimeSetListener() {
#Override
public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
// Date alarm = new Date(today.getYear(), today.getMonth(), today.getDate(), hourOfDay, minute);
// scheduleReminder(alarm.getTime(), reminder.getmContent());
//This creates a listener for the time picker dialog box. Inside this listener, you use today’s
//date as the base time for your alarm. You then include the hour and minute chosen from
//the dialog box to create the alarm date variable for your reminder. You use both the alarm
//time and the reminder’s content in a new scheduleReminder() method
//Fix the deprecation warnings
final Calendar alarmTime = Calendar.getInstance();
alarmTime.set(Calendar.HOUR, hourOfDay);
alarmTime.set(Calendar.MINUTE, minute);
scheduleReminder(alarmTime.getTimeInMillis(), reminder.getmContent());
}
};
final Calendar today = Calendar.getInstance();
// new TimePickerDialog(RemindersActivity.this, null,
// today.get(Calendar.HOUR), today.get(Calendar.MINUTE), false).show();
//the following change to connect the
//listener that invokes the BroadcastReceiver to the TimePickerDialog
new TimePickerDialog(RemindersActivity.this, listener,
today.get(Calendar.HOUR), today.get(Calendar.MINUTE), false).show();
}
dialog.dismiss();
}
});
}
});
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
mlistView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
mlistView.setMultiChoiceModeListener(new AbsListView.MultiChoiceModeListener() {
//The preceding logic defines a MultiChoiceModeListener and attaches it to the ListView.
//Whenever you long-press an item in the ListView, the runtime invokes the onCreateActionMode()
//method on the MultiChoiceModeListener. If the method returns with the boolean true value,
//multichoice action mode is entered.
#Override
public void onItemCheckedStateChanged(ActionMode mode, int position, long id, boolean checked) {
}
#Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
MenuInflater inflater = mode.getMenuInflater();
inflater.inflate(R.menu.cam_menu, menu);
return true;
}
#Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
return false;
}
#Override
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_item_delete_reminder:
for (int nC = reminderSimpleCursorAdapter.getCount() - 1; nC >= 0; nC--) {
if (mlistView.isItemChecked(nC)) {
remindersDbAdapter.deleteReminderById(getIdFromPosition(nC));
}
}
mode.finish();
reminderSimpleCursorAdapter.changeCursor(remindersDbAdapter.fetchAllReminders());
return true;
}
return false;
}
#Override
public void onDestroyActionMode(ActionMode mode) {
}
});
}
}
private void scheduleReminder(long time, String getmContent) {
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent alarmIntent = new Intent(this, ReminderAlarmReceiver.class);
alarmIntent.putExtra(ReminderAlarmReceiver.REMINDER_TEXT, getmContent);
PendingIntent broadcast = PendingIntent.getBroadcast(this, 0, alarmIntent, 0);
alarmManager.set(AlarmManager.RTC_WAKEUP, time, broadcast);
}
private int getIdFromPosition(int nC) {
return (int) reminderSimpleCursorAdapter.getItemId(nC);
}
private void insertSomeReminders() {
remindersDbAdapter.createReminder("Learn android Development", true);
remindersDbAdapter.createReminder("data Mining Assignment", false);
remindersDbAdapter.createReminder("Networking Assignment", false);
remindersDbAdapter.createReminder("English Assignment", true);
// //There are several calls to the createReminder() method, each taking a String value
//with the reminder text and a boolean value flagging the reminder as important. We set
//a few values to true to provide a good visual effect.
}
private void fireCustomDialog(final Reminder reminder) {
// custom dialog
Dialog dialog = new Dialog(this);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setContentView(R.layout.dialog_custom);
TextView titleView = (TextView) dialog.findViewById(R.id.custom_title);
final EditText editCustom = (EditText) dialog.findViewById(R.id.custom_edit_reminder);
Button commitButton = (Button) dialog.findViewById(R.id.custom_button_commit);
final CheckBox checkBox = (CheckBox) dialog.findViewById(R.id.custom_check_box);
// checkBox.setChecked(true);
LinearLayout rootLayout = (LinearLayout) dialog.findViewById(R.id.custom_root_layout);
final boolean isEditOperation = (reminder != null);
//this is for an edit
if (isEditOperation) {
titleView.setText("Edit Reminder");
checkBox.setChecked(reminder.getImportant() == 1);
editCustom.setText(reminder.getmContent());
rootLayout.setBackgroundColor(getResources().getColor(R.color.check_box));
}
commitButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String reminderText = editCustom.getText().toString();
if (isEditOperation) {
Reminder reminderEdit = new Reminder(reminder.getmId(),
reminderText, checkBox.isChecked() ? 1 : 0);
remindersDbAdapter.updateReminder(reminderEdit);
} else {
remindersDbAdapter.createReminder(reminderText, checkBox.isChecked());
}
reminderSimpleCursorAdapter.changeCursor(remindersDbAdapter.fetchAllReminders());
dialog.dismiss();
}
});
Button buttonCancel = (Button) dialog.findViewById(R.id.custom_button_cancel);
buttonCancel.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dialog.dismiss();
}
});
dialog.show();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.reminder_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.action_new:
//create new reminder
Log.d(getLocalClassName(), "create new reminder");
fireCustomDialog(null);
return true;
case R.id.action_exit:
finish();
return true;
case R.id.action_about:
fireAboutDialog();
return true;
default:
return false;
}
}
private void fireAboutDialog() {
final Dialog dialog = new Dialog(this);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setContentView(R.layout.dialog_about);
dialog.show();
}
}
RemindersDbAdapter.java
package com.example.remindersapp;
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;
public class RemindersDbAdapter {
//these are the column names
public static final String COL_ID = "_id";
public static final String COL_CONTENT = "content" ;
public static final String COL_IMPORTANT = "important";
//these are the corresponding indices
private static final int INDEX_ID = 0;
private static final int INDEX_CONTENT = INDEX_ID + 1;
private static final int INDEX_IMPORTANT = INDEX_ID + 2;
//used for logging
private static final String TAG = "RemindersDbAdapter";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
private static final String DATABASE_NAME = "dba_reminder";
private static final String TABLE_NAME = "table_reminder";
private static final int DATABASE_VERSION = 3;
private final Context mCtx;
////SQL statement used to create the database
private static final String DATABSE_CREATE = "CREATE TABLE if not exists " + TABLE_NAME + " ( " +
COL_ID + " INTEGER PRIMARY KEY autoincrement, " +
COL_CONTENT + " TEXT, " +
COL_IMPORTANT + " INTEGER );";
public RemindersDbAdapter(Context Ctx) {
//The constructor saves an instance of Context, which is passed to DatabaseHelper
this.mCtx = Ctx;
}
//The open()
//method initializes the helper and uses it to get an instance of the database,
public void open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
}
//the close()
//method uses the helper to close the database.
public void close() throws SQLException {
if (mDbHelper != null) {
mDbHelper.close();
}
}
//CREATE
//note that the id will be created for you automatically
public void createReminder(String name, boolean important) {
ContentValues values = new ContentValues();
values.put(COL_CONTENT, name);
values.put(COL_IMPORTANT, important ? 1 : 0);
mDb.insert(TABLE_NAME, null, values);
}
////overloaded to take a reminder
public long createReminder(Reminder reminder) {
ContentValues values = new ContentValues();
values.put(COL_CONTENT, reminder.getmContent()); //Contact name
values.put(COL_IMPORTANT, reminder.getImportant()); //Contact phone number
//// Inserting Row
return mDb.insert(TABLE_NAME, null, values);
}
//READ
public Reminder fetchReminderById(int id) {
Cursor cursor = mDb.query(TABLE_NAME,
new String[]{COL_ID, COL_CONTENT, COL_IMPORTANT},
COL_ID + " =? ",
new String[]{String.valueOf(id)},
null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
return new Reminder(
cursor.getInt(INDEX_ID),
cursor.getString(INDEX_CONTENT),
cursor.getInt(INDEX_IMPORTANT));
}
public Cursor fetchAllReminders() {
Cursor mcursor = mDb.query(TABLE_NAME, new String[]{COL_ID, COL_CONTENT, COL_IMPORTANT},
null, null, null, null, null);
if (mcursor != null) {
mcursor.moveToFirst();
}
return mcursor;
}
//UPDATE
public void updateReminder(Reminder reminder) {
ContentValues values = new ContentValues();
values.put(COL_CONTENT, reminder.getmContent());
values.put(COL_IMPORTANT, reminder.getImportant());
mDb.update(TABLE_NAME, values, COL_ID + " =? ", new String[]{String.valueOf(reminder.getmId())});
}
//DELETE
public void deleteReminderById(int id){
mDb.delete(TABLE_NAME,COL_ID + "=?", new String[]{String.valueOf(id)});
}
public void deleteAllReminders(){
mDb.delete(TABLE_NAME,null,null);
}
//sqlite open helper
private static class DatabaseHelper extends SQLiteOpenHelper {
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
Log.w(TAG, DATABSE_CREATE);
db.execSQL(DATABSE_CREATE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + "to " + newVersion + ",which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
#Override
public void onOpen(SQLiteDatabase db) {
super.onOpen(db);
onCreate(db);
}
}
}
ReminderSimpleCursorAdapter.java
package com.example.remindersapp;
import android.content.Context;
import android.database.Cursor;
import android.view.View;
import android.view.ViewGroup;
import android.widget.SimpleCursorAdapter;
import androidx.recyclerview.widget.RecyclerView;
public class ReminderSimpleCursorAdapter extends SimpleCursorAdapter {
public ReminderSimpleCursorAdapter(Context context, int layout, Cursor c, String[] from, int[] to, int i) {
super(context, layout, c, from, to,i);
}
////to use a viewholder, you must override the following two methods and define a ViewHolder class
#Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
return super.newView(context, cursor, parent);
}
#Override
public void bindView(View view, Context context, Cursor cursor) {
super.bindView(view, context, cursor);
ViewHolder holder=(ViewHolder)view.getTag();
if (holder == null){
holder=new ViewHolder();
holder.colImp=cursor.getColumnIndexOrThrow(RemindersDbAdapter.COL_IMPORTANT);
holder.listTab=view.findViewById(R.id.row_tab);
view.setTag(holder);
}
if (cursor.getInt(holder.colImp) > 0){
holder.listTab.setBackgroundColor(context.getResources().getColor(R.color.false_result));
}else {
holder.listTab.setBackgroundColor(context.getResources().getColor(R.color.txt_color));
}
}
//Here you see an example of the ViewHolder pattern. This is a well-known Android pattern
//in which a small ViewHolder object is attached as a tag on each view. This object adds
//decoration for View objects in the list by using values from the data source, which in this
//example is the Cursor. The ViewHolder is defined as a static inner class with two instance
//variables, one for the index of the Important table column and one for the row_tab view you
//defined in the layout.
static class ViewHolder{
//store the column index
int colImp;
//store the view
View listTab;
}
}

How to Retrieve Multiple data when clicked on listview?

I want all edit text content that I have saved in SQL to be displayed on the edit bills activity when I click on the list item, but I am only able to retrieve the name and display it again in the intent. Rather than saving another data it should update the record with the new data if I save the existing record another time in the editbills_activity.
Here is my DBAdapter.java
package com.example.dhruv.bills;
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;
public class DBAdapter {
public static final String KEY_ROWID = "id";
public static final String KEY_NAME = "name";
public static final String KEY_AMOUNT = "amount";
public static final String KEY_DUEDATE = "duedate";
private static final String TAG = "DBAdapter";
private static final String DATABASE_NAME = "billsdb";
private static final String DATABASE_TABLE = "bills";
private static final int DATABASE_VERSION = 2;
private static final String DATABASE_CREATE =
"create table if not exists assignments (id integer primary key autoincrement, "
+ "name VARCHAR not null, amount VARCHAR, duedate date );";
// Replaces DATABASE_CREATE using the one source definition
private static final String TABLE_CREATE =
"CREATE TABLE IF NOT EXISTS " + DATABASE_TABLE + "(" +
KEY_ROWID + " INTEGER PRIMARY KEY, " + // AUTOINCREMENT NOT REQD
KEY_NAME + " DATE NOT NULL, " +
KEY_AMOUNT + " VARCHAR ," +
KEY_DUEDATE + " DATE " +
")";
private final Context context;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public DBAdapter(Context ctx)
{
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db)
{
db.execSQL(TABLE_CREATE); // NO need to encapsulate in try clause
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS contacts"); //????????
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
onCreate(db);
}
}
//---opens the database---
public DBAdapter open() throws SQLException
{
db = DBHelper.getWritableDatabase();
return this;
}
//---closes the database---
public void close()
{
DBHelper.close();
}
//---insert a record into the database---
public long insertRecord(String name, String amount, String duedate)
{
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_NAME, name);
initialValues.put(KEY_AMOUNT, amount);
initialValues.put(KEY_DUEDATE, duedate);
//return db.insert(DATABASE_TABLE, null, initialValues);
// Will return NULL POINTER EXCEPTION as db isn't set
// Replaces commented out line
return DBHelper.getWritableDatabase().insert(DATABASE_TABLE,
null,
initialValues
);
}
//---deletes a particular record---
public boolean deleteContact(long rowId)
{
return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
//---retrieves all the records--- SEE FOLLOWING METHOD
public Cursor getAllRecords()
{SQLiteDatabase db = DBHelper.getWritableDatabase();
String query ="SELECT * FROM " + DATABASE_TABLE;
Cursor data = db.rawQuery(query,null);
return data;
}
//As per getAllRecords but using query convenience method
public Cursor getAllAsCursor() {
return DBHelper.getWritableDatabase().query(
DATABASE_TABLE,
null,null,null,null,null,null
);
}
public Cursor getItemID(String name) {
SQLiteDatabase db = DBHelper.getWritableDatabase();
String query = "SELECT " + KEY_ROWID + " FROM " + DATABASE_TABLE +
" WHERE " + KEY_NAME + " = '" + name + "'";
Cursor data = db.rawQuery(query, null);
return data;
}
//---retrieves a particular record--- THIS WILL NOT WORK - NO SUCH TABLE
/* public Cursor getRecord()
{String query1 ="SELECT * FROM" + KEY_TITLE;
Cursor mCursor = db.rawQuery(query1,null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}*/
// Retrieve a row (single) according to id
public Cursor getRecordById(long id) {
return DBHelper.getWritableDatabase().query(
DATABASE_TABLE,
null,
KEY_ROWID + "=?",
new String[]{String.valueOf(id)},
null,null,null
);
}
//---updates a record---
/* public boolean updateRecord(long rowId, String name, String amount, String duedate)
{
ContentValues args = new ContentValues();
args.put(KEY_NAME, name);
args.put(KEY_AMOUNT, amount);
args.put(KEY_DUEDATE, duedate);
String whereclause = KEY_ROWID + "=?";
String[] whereargs = new String[]{String.valueOf(rowId)};
// Will return NULL POINTER EXCEPTION as db isn't set
//return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
// Replaces commented out line
return DBHelper.getWritableDatabase().update(DATABASE_TABLE,
args,
whereclause,
whereargs
) > 0;
}*/
}
Here is my Bills.java
(MainActivity)
Problem: Bills.java has the list view that shows the intent whenever the item in list view is clicked, but it does not put the amount and date or update the record. Instead it saves another record.
Solution: I want to retrieve it and display all (name ,amount,duedate) and instead of saving another record it should update it.
package com.example.dhruv.bills;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
public class bills extends AppCompatActivity {
DBAdapter dbAdapter;
ListView mrecycleview;
private static final String TAG ="assignments";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bills);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mrecycleview =(ListView) findViewById(R.id.mRecycleView);
dbAdapter = new DBAdapter(this);
// mlistview();
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent i = new Intent(getApplicationContext(),Editbills.class);
startActivity(i);
}
});
mlistview();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_bills, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
private void mlistview(){
Log.d(TAG,"mlistview:Display data in listview");
Cursor mCursor = dbAdapter.getAllRecords();
ArrayList<String> listData = new ArrayList<>();
while (mCursor.moveToNext()){
listData.add(mCursor.getString(1));
}
ListAdapter adapter = new ArrayAdapter<>(this,android.R.layout.simple_list_item_1,listData);
mrecycleview.setAdapter(adapter);
mrecycleview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String name = adapterView.getItemAtPosition(i).toString();
Log.d(TAG, "onItemClick: You Clicked on " + name);
Cursor data = dbAdapter.getItemID(name); //get the id associated with that name
int itemID = -1;
while(data.moveToNext()){
itemID = data.getInt(0);
}
if(itemID > -1){
Log.d(TAG, "onItemClick: The ID is: " + itemID);
Intent editScreenIntent = new Intent(bills.this, Editbills.class);
editScreenIntent.putExtra("id",itemID);
editScreenIntent.putExtra("name",name);
startActivity(editScreenIntent);
}
else{
}
}
});
}
}
here is my editbills.java code
package com.example.dhruv.bills;
import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
public class Editbills extends AppCompatActivity {
Button button;
private static final String Tag= "assignments";
DBAdapter db = new DBAdapter(this);
private String selectedName;
private int selectedID;
DBAdapter dbAdapter;
private EditText editText,editText2,editText3;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_editbills);
button=(Button)findViewById(R.id.button);
editText =(EditText)findViewById(R.id.editText);
editText2=(EditText)findViewById(R.id.editText2);
editText3 =(EditText)findViewById(R.id.editText3);
//get the intent extra from the ListDataActivity
Intent receivedIntent = getIntent();
//now get the itemID we passed as an extra
selectedID = receivedIntent.getIntExtra("id",-1); //NOTE: -1 is just the default value
//now get the name we passed as an extra
selectedName = receivedIntent.getStringExtra("name");
//set the text to show the current selected name
editText.setText(selectedName);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Log.d("test", "adding");
db.open();
long id = db.insertRecord(editText.getText().toString(), editText2.getText().toString(), editText3.getText().toString());
db.close();
Toast.makeText(Editbills.this," Added", Toast.LENGTH_LONG).show();
Intent q = new Intent(getApplicationContext(),bills.class);
startActivity(q);
}
});
}
}

There are two parts/questions.
First to retrieve the data, so that it can be displayed in the editbills activity, you can utilise the row's id that is passed to the activity in conjunction with the getRecordById method.
I'd suggest that adding a method to the editbills class will simplyfy matters.
private void populateDisplay(int id) {
Cursor csr = dbAdapter.getRecordById(id);
if (csr.moveToFirst()) {
editText.setText(csr.getString(csr.getColumnIndex(DBAdapter.KEY_NAME)));
editText2.setText(csr.getString(csr.getColumnIndex(DBAdapter.KEY_AMOUNT)));
editText3.setText(csr.getString(csr.getColumnIndex(DBAdapter.KEY_DUEDATE)));
}
csr.close();
}
You could invoke the above method after retrieving the id from the Intent using :-
populateDisplay(selectedID);
To update based upon the content's of the EditTexts un-comment the updateRecord method in DBAdapter.java and the change :-
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Log.d("test", "adding");
db.open();
long id = db.insertRecord(editText.getText().toString(), editText2.getText().toString(), editText3.getText().toString());
db.close();
Toast.makeText(Editbills.this," Added", Toast.LENGTH_LONG).show();
Intent q = new Intent(getApplicationContext(),bills.class);
startActivity(q);
}
});
to :-
mButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (dbAdapter.updateRecord(
selectedId,
editText.getText().toString(),
editText2.getText().toString(),
editText3.getText().toString())
) {
Log.d("TEST","Row successfully updated.");
Toast.makeText(getApplicationContext(),"Row Updated.",Toast.LENGTH_LONG).show();
populateDisplay(selectedId);
} else {
Toast.makeText(getApplicationContext(),"Row not Updated",Toast.LENGTH_LONG).show();
}
Intent q = new Intent(getApplicationContext(),bills.class);
startActivity(q);
}
});
You will additionally have to add a line initialise the dbAdapter i.e. dbAdapter = new DBAdapter(this); i.d suggest adding this line immediately after the line setContentView(R.layout.activity_editbills);
Note the above code is in-principle and has not been thoroughly tested so it may contains errors.
Edit complete working example :-
The following code is basically an implementation of the above, except modified to utilise a Bill class. Rather than an ArrayList<String> as the source for the Adapter it has ArrayList<Bill>.
Thus all the data (id, name, amount and duedate) is available.
You should notice that I've overridden the toString method to return a String that combines the name, amount and duedate. The ArrayAdapter uses the object's toString method to populate the view.
Saying that the critical value is the rowid or an alias of rowid as this can be used to identify a row even if the other data is identical (as would happen when running this example more than once due to the addSomeData method). Hence, only the id is extracted and passed to the Editbills activity when an item in the list is long clicked (changed from just clicked to reduce the potential for accidental use).
Bill.java
public class Bill {
private long id;
private String name;
private String amount;
private String duedate;
public Bill(long id, String name, String amount, String duedate) {
this.id = id;
this.name = name;
this.amount = amount;
this.duedate = duedate;
}
/*
Note if this Constructor used then setId should be used
*/
public Bill(String name, String amount, String duedate) {
new Bill(0,name,amount,duedate);
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAmount() {
return amount;
}
public void setAmount(String amount) {
this.amount = amount;
}
public String getDuedate() {
return duedate;
}
public void setDuedate(String duedate) {
this.duedate = duedate;
}
/*
As ArrayAdapter uses toString method change this
to return all items
*/
#Override
public String toString() {
return name + " " + amount + " " + duedate;
}
}
MainActivity.java
This is the equivalent to your Bills.java without a lot of the bloat such as FAB. :-
public class MainActivity extends AppCompatActivity {
public static final String ID_INTENTEXTRA = DBAdapter.KEY_ROWID + "_INTENTEXTRA"; //<<<< ADDED
DBAdapter mDBAdapter;
Cursor mCsr;
ListView mrecycleview;
ArrayAdapter adapter; //<<<< NOT ListAdapter
Context context; // ADDED
private static final String TAG ="assignments";
ArrayList<Bill> mBillList = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context = this;
mrecycleview = this.findViewById(R.id.mRecycleView);
mDBAdapter = new DBAdapter(this);
addSomeData();
adapter = new ArrayAdapter<Bill>(
this,
android.R.layout.simple_list_item_1,
mBillList
);
mrecycleview.setAdapter(adapter);
mrecycleview.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
Bill b = (Bill) adapter.getItem(position);
Intent i = new Intent(context,Editbills.class);
i.putExtra(ID_INTENTEXTRA,b.getId()); //Get ID
startActivity(i);
return true;
}
});
rebuildBillList();
}
//<<<< ADDED Method to refresh the ListView resumed
#Override
protected void onResume() {
super.onResume();
rebuildBillList();
}
// Add some data (note will add 2 rows each time it is run)
private void addSomeData() {
mDBAdapter.insertRecord("Bill1","2018-10-02","English");
mDBAdapter.insertRecord("Bill2","2018-09-03","Mathematics");
mDBAdapter.insertRecord("Bill3","2018-11-04", "Geography");
}
public void rebuildBillList() {
mBillList.clear();
mCsr = mDBAdapter.getAllAsCursor();
while (mCsr.moveToNext()) {
mBillList.add(new Bill(
mCsr.getLong(mCsr.getColumnIndex(DBAdapter.KEY_ROWID)),
mCsr.getString(mCsr.getColumnIndex(DBAdapter.KEY_NAME)),
mCsr.getString(mCsr.getColumnIndex(DBAdapter.KEY_AMOUNT)),
mCsr.getString(mCsr.getColumnIndex(DBAdapter.KEY_DUEDATE))
)
);
}
adapter.notifyDataSetChanged();
}
}
Note the above adds 3 rows each time it is run.
Editbills.java
public class Editbills extends AppCompatActivity {
Button button;
private static final String Tag = "assignments";
DBAdapter db = new DBAdapter(this);
private String selectedName;
private long selectedID;
DBAdapter dbAdapter;
private EditText editText,editText2,editText3;
Context context;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_editbills);
context = this;
dbAdapter = new DBAdapter(this); //<<<< ADDED
button=(Button)findViewById(R.id.button);
editText =(EditText)findViewById(R.id.edittext);
editText2=(EditText)findViewById(R.id.edittext2);
editText3 =(EditText)findViewById(R.id.edittext3);
//get the intent extra from the ListDataActivity
Intent receivedIntent = getIntent();
//now get the itemID we passed as an extra
selectedID = receivedIntent.getLongExtra(MainActivity.ID_INTENTEXTRA,-1L); //NOTE: -1 is just the default value
populateDisplay(selectedID);
//now get the name we passed as an extra
//selectedName = receivedIntent.getStringExtra("name");
//set the text to show the current selected name
//editText.setText(selectedName); <<<< commented out
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
/*
Log.d("test", "adding");
db.open();
long id = db.insertRecord(editText.getText().toString(), editText2.getText().toString(), editText3.getText().toString());
db.close();
Toast.makeText(Editbills.this," Added", Toast.LENGTH_LONG).show();
*/
/*
* <<<< Not the way as it ends/closes the existing activity
Intent q = new Intent(getApplicationContext(),MainActivity.class);
startActivity(q);
*/
String toast = "Updated.";
if (dbAdapter.updateRecord(selectedID,
editText.getText().toString(),
editText2.getText().toString(),
editText3.getText().toString())) {
} else {
toast = "Not Updated.";
}
Toast.makeText(context,toast,Toast.LENGTH_LONG).show();
finish(); //<<<< ends/closes this activity and returns to calling activity
}
});
}
private void populateDisplay(long id) {
Cursor csr = dbAdapter.getRecordById(id);
if (csr.moveToFirst()) {
editText.setText(csr.getString(csr.getColumnIndex(DBAdapter.KEY_NAME)));
editText2.setText(csr.getString(csr.getColumnIndex(DBAdapter.KEY_AMOUNT)));
editText3.setText(csr.getString(csr.getColumnIndex(DBAdapter.KEY_DUEDATE)));
}
csr.close();
}
}
Basically as per the original answer.
DBAdapter.java
public class DBAdapter {
public static final String KEY_ROWID = "id";
public static final String KEY_NAME = "name";
public static final String KEY_AMOUNT = "amount";
public static final String KEY_DUEDATE = "duedate";
private static final String TAG = "DBAdapter";
private static final String DATABASE_NAME = "billsdb";
private static final String DATABASE_TABLE = "bills";
private static final int DATABASE_VERSION = 2;
// Replaces DATABASE_CREATE using the one source definition
private static final String TABLE_CREATE =
"CREATE TABLE IF NOT EXISTS " + DATABASE_TABLE + "(" +
KEY_ROWID + " INTEGER PRIMARY KEY, " + // AUTOINCREMENT NOT REQD
KEY_NAME + " DATE NOT NULL, " +
KEY_AMOUNT + " VARCHAR ," +
KEY_DUEDATE + " DATE " +
")";
private Context context;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public DBAdapter(Context ctx)
{
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db)
{
db.execSQL(TABLE_CREATE); // NO need to encapsulate in try clause
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS contacts"); //????????
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
onCreate(db);
}
}
//---opens the database--- NOT NEEDED
public DBAdapter open() throws SQLException
{
db = DBHelper.getWritableDatabase();
return this;
}
//---closes the database--- NOT NEEDED
public void close()
{
DBHelper.close();
}
//---insert a record into the database---
public long insertRecord(String name, String amount, String duedate)
{
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_NAME, name);
initialValues.put(KEY_AMOUNT, amount);
initialValues.put(KEY_DUEDATE, duedate);
return DBHelper.getWritableDatabase().insert(DATABASE_TABLE,
null,
initialValues
);
}
//---deletes a particular record---
public boolean deleteContact(long rowId)
{
return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
//---retrieves all the records--- SEE FOLLOWING METHOD
public Cursor getAllRecords()
{SQLiteDatabase db = DBHelper.getWritableDatabase();
String query ="SELECT * FROM " + DATABASE_TABLE;
Cursor data = db.rawQuery(query,null);
return data;
}
//As per getAllRecords but using query convenience method
public Cursor getAllAsCursor() {
return DBHelper.getWritableDatabase().query(
DATABASE_TABLE,
null,null,null,null,null,null
);
}
public Cursor getItemID(String name) {
SQLiteDatabase db = DBHelper.getWritableDatabase();
String query = "SELECT " + KEY_ROWID + " FROM " + DATABASE_TABLE +
" WHERE " + KEY_NAME + " = '" + name + "'";
Cursor data = db.rawQuery(query, null);
return data;
}
// Retrieve a row (single) according to id
public Cursor getRecordById(long id) {
return DBHelper.getWritableDatabase().query(
DATABASE_TABLE,
null,
KEY_ROWID + "=?",
new String[]{String.valueOf(id)},
null,null,null
);
}
//---updates a record---
public boolean updateRecord(long rowId, String name, String amount, String duedate) {
ContentValues args = new ContentValues();
args.put(KEY_NAME, name);
args.put(KEY_AMOUNT, amount);
args.put(KEY_DUEDATE, duedate);
String whereclause = KEY_ROWID + "=?";
String[] whereargs = new String[]{String.valueOf(rowId)};
return DBHelper.getWritableDatabase().update(DATABASE_TABLE,
args,
whereclause,
whereargs
) > 0;
}
}
Basically as was except that upDateRecord has been un-commented, again as per the original answer.
Results
1st Run - MainActivity (Bills) :-
Long Click Bill2 (note changed from Click as Long Click is less prone to accidental use)
Change data (Update button not clicked)
Update Button Clicked (Toast was Updated.)
Note use of finish() to return to the invoking activity and then the use of onResume to refresh the list according to the updated data (possibly your next question).
using startActivity will simply result in issues.
Note Values are date and course rather then amount and duedate because I didn't change the values in the addSomeData method (easily done).
the actual data itself is irrelevant to the process.

Accessing Methods from Another Class Android

I am creating an android application that will be using a SQLite database. I have created a separate class called DBAdapter that holds all the methods relating to the database.
My issue comes when I try to access these methods from the main activity. I am still learning but I would normally instantiate the DBAdapter class and then I would be able to reference the methods. However the approach I am taking isnt working. Below is the single line of how I am trying to instantiate the class and under that is the rest of the class.
The error I am getting is cannot resolve method 'open()'
Instantiate Line and method
DBAdapter db = new DBAdapter(this);
db.open();
Main Class
import android.app.Dialog;
import android.content.Context;
import android.content.SharedPreferences;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.ContentFrameLayout;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
final Context context = this;
private FloatingActionButton fab;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DBAdapter db = new DBAdapter(this);
db.open();
fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
final Dialog dialog = new Dialog(context);
dialog.setContentView(R.layout.dialog_box);
dialog.setTitle("Add new Location!");
dialog.show();
final EditText NameEdit = (EditText) findViewById(R.id.NameInput);
final EditText LatEdit = (EditText) findViewById(R.id.LatInput);
final EditText LongEdit = (EditText) findViewById(R.id.LongInput);
final EditText PhoneEdit = (EditText) findViewById(R.id.PhoneInput);
final Button OkButton = (Button) dialog.findViewById(R.id.dialogButtonOK);
final Button CancelButton = (Button) dialog.findViewById(R.id.dialogButtonCancel);
OkButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String RealName = NameEdit.getText().toString();
String Lat = LatEdit.getText().toString();
Float realLat = Float.parseFloat(Lat);
String Long = LongEdit.getText().toString();
Float realLong = Float.parseFloat(Long);
String Phone = PhoneEdit.getText().toString();
Double realPhone = Double.parseDouble(Phone);
//Use above to create a new Geofence
}
});
CancelButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
dialog.dismiss();
}
});
}
});
}
}
DBAdpater Class
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;
/**
* Created by Rory on 09/09/2016.
*/
public class DBAdapter {
private final Context context;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
//Database Version & name
private static final String DATABASE_NAME = "OpenSesame";
private static final int DATABASE_VERSION = 1;
private static final String TAG = "DBMain";
private static final String GEOTABLE = "geoTable";
private static final String KEY_ID = "_id";
private static final String KEY_NAME = "name";
private static final String KEY_LAT = "lat";
private static final String KEY_LONG = "long";
private static final String KEY_RADIUS = "radius";
private static final String KEY_PHONE = "phone";
private static final String CREATE_GEO_TABLE = "CREATE TABLE "
+ GEOTABLE + "("
+ KEY_ID + " INTEGER PRIMARY KEY AUTO INCREMENT,"
+ KEY_NAME + " TEXT,"
+ KEY_LAT + " FLOAT,"
+ KEY_LONG + " FLOAT,"
+ KEY_RADIUS + " INTEGER,"
+ KEY_PHONE + " INTEGER" + ")";
public DBAdapter(Context ctx) {
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
/**
* Method to create each of the tables defined above
* #param db
*/
#Override
public void onCreate(SQLiteDatabase db)
{
try {
db.execSQL(CREATE_GEO_TABLE);
} catch (SQLException e) {
e.printStackTrace();
}
}
/**
* Method for updating the database
* #param db
* #param newVersion
* #param oldVersion
*/
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS contacts");
onCreate(db);
}
public DatabaseHelper open() throws SQLException
{
db = DBHelper.getWritableDatabase();
return this;
}
public void close() {
DBHelper.close();
}
public Cursor DeleteGeo(String name) {
return db.rawQuery("delete from geoTable where name = " + name, null);
}
public long AddGeo(String name, float lat, float lon, double phone, int radius) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_NAME, name);
initialValues.put(KEY_LAT, lat);
initialValues.put(KEY_LONG, lon);
initialValues.put(KEY_PHONE, phone);
initialValues.put(KEY_RADIUS, radius);
return db.insert(GEOTABLE, null, initialValues);
}
public Cursor GetAllGeos() {
return db.rawQuery("select * from geoTable order by name ASC", null);
}
}
}

Your DBAdapter class does not have the open() method. It is the private inner class DatabaseHelper that has that method. You have two options to expose open() to be able to call it the way you are expecting.
Option 1: add an open() method to DBAdapter that calls DatabaseHelper's open() method
public void open() {
DBHelper.open();
}
Option 2: remove DatabaseHelper entirely, and have DBAdapter extends SQLiteOpenHelper instead
public class DBAdapter extends SQLiteOpenHelper {
...
public DBAdapter(Context ctx) {
this.context = ctx;
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// add all the code from inside DatabaseHelper below
/**
* Method to create each of the tables defined above
* #param db
*/
#Override
public void onCreate(SQLiteDatabase db)
{
try {
db.execSQL(CREATE_GEO_TABLE);
} catch (SQLException e) {
e.printStackTrace();
}
}
// you will have to change this method to work
public DBAdapter open() throws SQLException
{
db = getWritableDatabase();
return this;
}
...
}

Index 0 requested, with a size of 0

I'm trying to code a simple randomizer app. I had the randomizer button working, but then I changed some code (which I thought was irrelevant to the randomizer button) and it started crashing and getting the "CursorIndexOutOfBoundsException Index 0 requested, with a size of 0" error. I couldn't find any fixes to this that apply to my code. Can anyone help me fix this?
Here is my main class with the button:
package com.example.randomgamechooser;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.TextView;
public class MainScreen extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_screen);
}
public void chooseGame (View view) {
GameList dbUtil = new GameList(this);
dbUtil.open();
String string = dbUtil.getRandomEntry();
//TextView textView = new TextView(this);
TextView textView = (TextView) findViewById(R.id.chosenbox);
textView.setTextSize(40);
textView.setText(string);
//setContentView (textView);
dbUtil.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_screen, menu);
return true;
}
//starts the Game Selection activity
public void openGames (View view) {
Intent intent = new Intent(this, GameSelction.class);
startActivity(intent);
}
}
Here is the GameList class:
package com.example.randomgamechooser;
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 java.util.Random;
public class GameList {
private static final String TAG = "GameList";
//database name
private static final String DATABASE_NAME = "game_list";
//database version
private static final int DATABASE_VERSION = 1;
//table name
private static final String DATABASE_TABLE = "game_list";
//table columns
public static final String KEY_NAME = "name";
public static final String KEY_GENRE = "genre";
public static final String KEY_ROWID = "_id";
//database creation sql statement
private static final String CREATE_GAME_TABLE =
"create table " + DATABASE_TABLE + " (" + KEY_ROWID + " integer primary key autoincrement, "
+ KEY_NAME +" text not null, " + KEY_GENRE + " text not null);";
//Context
private final Context mCtx;
private DatabaseHelper mDbHelper;
private static SQLiteDatabase mDb;
//Inner private class. Database Helper class for creating and updating database.
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// onCreate method is called for the 1st time when database doesn't exists.
#Override
public void onCreate(SQLiteDatabase db) {
Log.i(TAG, "Creating DataBase: " + CREATE_GAME_TABLE);
db.execSQL(CREATE_GAME_TABLE);
}
//onUpgrade method is called when database version changes.
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion);
}
}
//Constructor - takes the context to allow the database to be opened/created
//#param ctx the Context within which to work
public GameList(Context ctx) {
this.mCtx = ctx;
}
//This method is used for creating/opening connection
//#return instance of GameList
//#throws SQLException
public GameList open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
//This method is used for closing the connection.
public void close() {
mDbHelper.close();
}
//This method is used to create/insert new game.
//#param name
// #param genre
// #return long
public long createGame(String name, String genre) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_NAME, name);
initialValues.put(KEY_GENRE, genre);
return mDb.insert(DATABASE_TABLE, null, initialValues);
}
// This method will delete game.
// #param rowId
// #return boolean
public static boolean deleteGame(long rowId) {
return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
// This method will return Cursor holding all the games.
// #return Cursor
public Cursor fetchAllGames() {
return mDb.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_NAME,
KEY_GENRE}, null, null, null, null, null);
}
// This method will return Cursor holding the specific game.
// #param id
// #return Cursor
// #throws SQLException
public Cursor fetchGame(long id) throws SQLException {
Cursor mCursor =
mDb.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
KEY_NAME, KEY_GENRE}, KEY_ROWID + "=" + id, null,
null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
public int getAllEntries()
{
Cursor cursor = mDb.rawQuery(
"SELECT COUNT(name) FROM game_list", null);
if(cursor.moveToFirst()) {
return cursor.getInt(0);
}
return cursor.getInt(0);
}
public String getRandomEntry()
{
//id = getAllEntries();
Random random = new Random();
int rand = random.nextInt(getAllEntries());
if(rand == 0)
++rand;
Cursor cursor = mDb.rawQuery(
"SELECT name FROM game_list WHERE _id = " + rand, null);
if(cursor.moveToFirst()) {
return cursor.getString(0);
}
return cursor.getString(0);
}
// This method will update game.
// #param id
// #param name
// #param standard
// #return boolean
public boolean updateGame(int id, String name, String standard) {
ContentValues args = new ContentValues();
args.put(KEY_NAME, name);
args.put(KEY_GENRE, standard);
return mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + id, null) > 0;
}
}
And here is the cause part of the error log:
08-01 13:03:38.325: E/AndroidRuntime(278): Caused by: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
08-01 13:03:38.325: E/AndroidRuntime(278): at android.database.AbstractCursor.checkPosition(AbstractCursor.java:580)
08-01 13:03:38.325: E/AndroidRuntime(278): at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:214)
08-01 13:03:38.325: E/AndroidRuntime(278): at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:41)
08-01 13:03:38.325: E/AndroidRuntime(278): at com.example.randomgamechooser.GameList.getRandomEntry(GameList.java:153)
EDIT: Here is the ListView class:
public class GameSelction extends Activity
{
GameList dbUtil = new GameList(this);
private SimpleCursorAdapter dataAdapter;
//#SuppressWarnings("deprecation")
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game_selction);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB){
getActionBar() .setDisplayHomeAsUpEnabled(true);
}
displayListView();
}
private void displayListView() {
dbUtil.open();
Cursor cursor = dbUtil.fetchAllGames();
// The desired columns to be bound
String[] columns = new String[] {
GameList.KEY_NAME,
GameList.KEY_GENRE,
};
// the XML defined views which the data will be bound to
int[] to = new int[] {
R.id.name,
R.id.genre,
};
// create the adapter using the cursor pointing to the desired data
//as well as the layout information
dataAdapter = new SimpleCursorAdapter(
this, R.layout.game_info,
cursor,
columns,
to,
0);
ListView listView = (ListView) findViewById(R.id.listView1);
// Assign adapter to ListView
listView.setAdapter(dataAdapter);
listView.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> listView, View view,
int position, long rowId) {
// Get the cursor, positioned to the corresponding row in the result set
//Cursor cursor = (Cursor) listView.getItemAtPosition(position);
GameList.deleteGame(rowId);
}
});
}
/**
* Set up the {#link android.app.ActionBar}, if the API is available.
*/
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
private void setupActionBar() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
getActionBar().setDisplayHomeAsUpEnabled(true);
}
}
//opens the AddGame activity
public void openAddgame (View view) {
Intent intent = new Intent(this, AddGame.class);
startActivity(intent);
}
public void buttonBackMain (View view) {
Intent intent = new Intent(this, MainScreen.class);
startActivity(intent);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.game_selction, menu);
return true;
}
}

The problem is in this section of code:
public String getRandomEntry()
{
//...
Cursor cursor = mDb.rawQuery(
"SELECT name FROM game_list WHERE _id = " + rand, null);
if(cursor.moveToFirst()) {
return cursor.getString(0);
}
return cursor.getString(0);
}
What you ended up doing was saying return cursor.getString(0); whether or not there were results in the cursor. So remove the second occurrence, and it should work.
EDIT:
After scanning your code, it seems that the only place you use this method is to fill a TextView. In that case you can use this as a chance to communicate a visual error message to yourself or your users, or do anything else with it that you want. So I would suggest using something to the effect of
public String getRandomEntry()
{
//EDIT: This will make your random generator less biased toward 1.
Random random = new Random();
int rand = random.nextInt(getAllEntries()) + 1;
/* Assuming your _id starts at 1 and auto-increments, this will
* start the random digits at 1 and go as high as your highest _id */
Cursor cursor = mDb.rawQuery(
"SELECT name FROM game_list WHERE _id = " + rand, null);
if(cursor.moveToFirst()) {
return cursor.getString(0);
}
return "There were no games in the database to choose from.";
}
EDIT:
Try using this. Notice that this code uses mDb.query(), which you used elsewhere. I'm not sure why rawQuery() would refuse to work, but maybe this will do it.
public String getRandomEntry()
{
Random random = new Random();
int rand = random.nextInt(getAllEntries()) + 1;
Cursor cursor = mDb.query(true, DATABASE_TABLE, new String[] {KEY_NAME},
KEY_ROWID + "=" + rand, null, null, null, null, null);
if(cursor.moveToFirst()) {
return cursor.getString(0);
}
return "There were no games in the database to choose from.";
}

Based on the initial look, the SQLiteDatabase object represented by mDB appears to be empty, as that's what is throwing the error.
What the error is saying is that your code is requesting the item at index 0 (basically, the first item), but the size of your index is 0 (basically, there are no items in the index).
Somewhere along the line, your database object is either emptied or not populated. To test this, run your fetchAllGames method and verify the contents of the index.

Didn't read the whole code, but I guess the problem is that, you are trying to get first element, from empty database.
Just check if the size of cursor greater than 0, before getting element.
if (cursor.getColumnCount() > 0)
return cursor.getString(0);
else return "no items";

Android populate string array from SQLite database

I have tried to adapt the Google notepad tutorial ( http://developer.android.com/resources/tutorials/notepad/index.html ) for using SQLite databases to store GPS co-ords when the user tags current location. I've had no trouble getting the location added to the database but currently having trouble populating an array from the database in order to draw the locations on the map
private void fillData() {
/**
* Get all of the geotags from the database and populate the strarrlatitude and strarrlongitude arrays
* Also calls 'drawpins' to draw the geotags on the map
*/
Cursor c = mDbHelper.fetchAllNotes();
startManagingCursor(c);
strarrlatitude = new String[] { LocationsDbAdapter.COL_LATITUDE};
System.out.println(strarrlatitude);
strarrlongitude = new String[] { LocationsDbAdapter.COL_LONGITUDE };
drawpins();
}
I'm using a separate class called LocationsDbAdapter for handling database management as demonstrated in the notepad tutorial. The COL_LATITUDE and COL_LONGITUDE variables point to the column titles.
I've used a for loop to determine that nothing seems to be going into the strarrlatitude array but using the SQLite CLI I've checked that the database is being determined
Any help would be most gratefully received - if any more information is required I'll upload it as quick as possible
Many thanks
EDIT: Added the main two classes below for extra reference. I was trying not to overload with too much information but that was an error in judgement.
package com.nick.locationapp;
import java.util.List;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.drawable.Drawable;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.text.AlteredCharSequence;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
import com.google.android.maps.MyLocationOverlay;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;
import com.nick.androidsoar.R;
public class AndroidSoarActivity extends MapActivity {
/** Called when the activity is first created. */
LinearLayout linearLayout;
MapView mapView;
TextView LocationText;
double dbllatitude;
double dbllongitude;
double dblaltitude;
String debugstring;
String strlatitude = "0";
String strlongitude = "0";
String[] strarrlatitude;
String[] strarrlongitude;
String[] strarrlatitude1 = {"50.0","40.0","43.0","100.0"};
String[] strarrlongitude1 = {"12.4","123.4","60.2","72.0"};
Double[] debuglat = {50.0,40.0,43.0,100.0};
Double[] debuglong = {12.4,123.4,60.2,72.0};
Double dbllat;
Double dbllong;
int intlatitude;
int intlongitude;
private LocationsDbAdapter mDbHelper;
public static final int INSERT_ID = Menu.FIRST;
List<Overlay> mapOverlays;
Drawable drawable;
HelloItemizedOverlay itemizedOverlay;
#Override
protected boolean isRouteDisplayed() {
return false;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//Identifies the textview as variable 'LocationText'
LocationText = (TextView)findViewById(R.id.locationtext);
//mDbHelper points to the LocationsDbAdapter class used for handling the database
mDbHelper = new LocationsDbAdapter (this);
mDbHelper.open();
//defines the mapview as variable 'mapView' and enables zoom controls
mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
mapOverlays = mapView.getOverlays();
//points variable 'drawable' to the icon resource of a pushpin, used for marking tags on the map
drawable = this.getResources().getDrawable(R.drawable.pushpin);
//Adds a current location overlay to the map 'mapView' and turns on the map's compass
MyLocationOverlay myLocationOverlay = new MyLocationOverlay(this, mapView);
mapView.getOverlays().add(myLocationOverlay);
myLocationOverlay.enableMyLocation();
myLocationOverlay.enableCompass();
mapView.postInvalidate();
/**
* Code required to receive gps location. Activates GPS provider, and is set to update only after
* at least 10 seconds and a position change of at least 10 metres
*/
LocationListener locationListener = new MyLocationListener();
//setting up the location manager
LocationManager locman = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locman.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10000, 10, locationListener);
//fillData();
}
/**
* Generates the menu from the resource 'mainmenu.xml'
*/
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.mainmenu, menu);
return true;
}
/**
* Code to run depending on the menu button pressed
*/
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.new_tag:
createTag();
fillData();
//Toast.makeText(getApplicationContext(), "geotag added to db", Toast.LENGTH_SHORT).show();
return true;
case R.id.draw_pins:
//fillData();
drawpins();
return true;
case R.id.create_tag:
Intent intent = new Intent(AndroidSoarActivity.this, TagCreate.class);
startActivity(intent);
}
return super.onOptionsItemSelected(item);
}
/**
* Create a new geotag pin from the current location
*/
private void createTag() {
//String titleName = "title " + titleNumber++;
mDbHelper.createNote(strlatitude, strlongitude);
Toast.makeText(getApplicationContext(), "geotag of lat: "+dbllatitude+" long: "+dbllongitude+" added to db ", Toast.LENGTH_SHORT).show();
fillData();
}
private void fillData() {
/**
* Get all of the geotags from the database and populate the strarrlatitude and strarrlongitude arrays
* Also calls 'drawpins' to draw the geotags on the map
*/
System.out.println("Fetching data");
Cursor c = mDbHelper.fetchAllNotes();
System.out.println(c.toString());
startManagingCursor(c);
strarrlatitude = new String[] { LocationsDbAdapter.COL_LATITUDE };
//System.out.println(strarrlatitude);
strarrlongitude = new String[] { LocationsDbAdapter.COL_LONGITUDE };
}
/**
* Creates an array of geopoints, pulling the locations from strarrlatitude and strarrlongitude
* and creates a mapview overlay using the geopoints
*/
private void drawpins() {
itemizedOverlay = new HelloItemizedOverlay(drawable);
GeoPoint[] mapPoints = new GeoPoint[strarrlatitude.length];
OverlayItem[] mapItems = new OverlayItem[strarrlatitude.length];
for(int i=1; i<strarrlatitude.length;i++){
dbllat = Double.parseDouble(strarrlatitude[i]);
dbllong = Double.parseDouble(strarrlongitude[i]);
System.out.println(i);
mapPoints[i] = new GeoPoint((int) (dbllat * 1E6), (int) (dbllong * 1E6));
mapItems[i] = new OverlayItem(mapPoints[i], "", "");
itemizedOverlay.addOverlay(mapItems[i]);
mapOverlays.add(itemizedOverlay);
}
}
private final class MyLocationListener implements LocationListener {
/**
* Code to run when the listener receives a new location
*/
#Override
public void onLocationChanged(Location locFromGps) {
Toast.makeText(getApplicationContext(), "Location changed, Lat: "+locFromGps.getLatitude()+" Long: "+ locFromGps.getLongitude(), Toast.LENGTH_SHORT).show();
//LocationText.setText("Your Location: Latitude " +locFromGps.getLatitude() + " Longitude: " +locFromGps.getLongitude());
dbllatitude = locFromGps.getLatitude();
dbllongitude = locFromGps.getLongitude();
dblaltitude = locFromGps.getAltitude();
strlatitude = Double.toString(dbllatitude);
strlongitude = Double.toString(dbllongitude);
dblaltitude = (dblaltitude / 0.3048);
LocationText.setText("Your Location: Latitude " + dbllatitude + " Longitude: " +dbllongitude + " Altitude " + dblaltitude);
}
#Override
public void onProviderDisabled(String provider) {
// called when the GPS provider is turned off (user turning off the GPS on the phone)
}
#Override
public void onProviderEnabled(String provider) {
// called when the GPS provider is turned on (user turning on the GPS on the phone)
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// called when the status of the GPS provider changes
}
}
}
/**
* Following class has been adapted from Google's Android Notepad tutorial: http://developer.android.com/resources/tutorials/notepad/index.html
*
*/
package com.nick.locationapp;
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;
public class LocationsDbAdapter {
public static final String COL_LATITUDE = "latitude";
public static final String COL_LONGITUDE = "longitude";
//public static final String KEY_NOTE = "note";
public static final String COL_TITLE = "title";
public static final String COL_ROWID = "_id";
//public static final String TABLE_LOC = "locations";
private static final String TAG = "LocationsDbAdapter";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
/**
* Database creation sql statement
*/
private static final String DATABASE_CREATE =
"CREATE TABLE locations (_id integer primary key autoincrement, "
+ "latitude text not null, longitude text not null);";
private static final String DATABASE_NAME = "data";
private static final String DATABASE_TABLE = "locations";
private static final int DATABASE_VERSION = 1;
private final Context mCtx;
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
/**
* SQL for creating the table. Table and column names are declared as variables
*/
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE "+DATABASE_TABLE+" ("+COL_ROWID+ " INTEGER PRIMARY KEY AUTOINCREMENT, "+COL_LATITUDE+ " TEXT, "+COL_LONGITUDE+" TEXT "+COL_TITLE+" TEXT)");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS location");
onCreate(db);
}
}
public LocationsDbAdapter(Context ctx) {
this.mCtx = ctx;
}
public LocationsDbAdapter open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
mDbHelper.close();
}
/**
* Code for adding latitude and longitude into the database
* #param latitude
* #param longitude
* #return
*/
public long createNote(String latitude, String longitude) {
ContentValues geotagValues = new ContentValues();
geotagValues.put(COL_LATITUDE, latitude);
geotagValues.put(COL_LONGITUDE, longitude);
//geotagValues.put(COL_TITLE, title);
return mDb.insert(DATABASE_TABLE, null, geotagValues);
}
/**
* Query to return all data
* #return
*/
public Cursor fetchAllNotes() {
return mDb.query(DATABASE_TABLE, new String[] {COL_ROWID, COL_LATITUDE, COL_LONGITUDE}, null, null, null, null, null);
}
}

*
public void getData()
{
List<String> labels = new ArrayList<String>();
placeData = new PlaceDataSQL(MainActivity.this);
String selectQuery = "SELECT * FROM xmlTable;";
SQLiteDatabase db = placeData.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
{
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
labels.add(cursor.getString(1));
Log.i("imagespath",arr[i]);
i++;
} while (cursor.moveToNext());
}
cursor.close();enter code here
db.close();
}
}
*