Develop Reference

Unable to calculate total price amount in cart using sqlite

I wanted to calculate the total price of the products in the cart using SQLite. When I set the price in textview using Settext(), it does not return the sum value. This is the gettotalprice method in DBhelper class.
public int getTotalExpenses()
{
int total = 0;
SQLiteDatabase database = this.getReadableDatabase();
Cursor cursor = database.rawQuery("SELECT SUM("+ OrderContract.OrderEntry.COLUMN_PRICE + ") FROM " + OrderContract.OrderEntry.TABLE_NAME, null);
if (cursor.moveToFirst())
{
total = cursor.getInt(4);
}
while (cursor.moveToNext());
return total;
}
OrderProvider class:
package com.example.myapp;
import android.content.ContentProvider;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
public class OrderProvider extends ContentProvider {
// this constant is needed in order to define the path of our modification in the table
public static final int ORDER=100;
public DBHelper mhelper;
public static UriMatcher sUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
static {
sUriMatcher.addURI(OrderContract.CONTENT_AUTHORITY,OrderContract.PATH,ORDER);
}
#Override
public boolean onCreate() {
mhelper = new DBHelper(getContext());
return true;
}
#Override
public Cursor query( Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
SQLiteDatabase database = mhelper.getReadableDatabase();
Cursor cursor;
int match = sUriMatcher.match(uri);
switch (match){
case ORDER:
cursor = database.query(OrderContract.OrderEntry.TABLE_NAME, projection, selection, selectionArgs, null,null, sortOrder);
break;
default:
throw new IllegalArgumentException("CANT QUERY");
}
cursor.setNotificationUri(getContext().getContentResolver(),uri);
return cursor;
}
#Override
public String getType(Uri uri) {
return null;
}
#Override
public Uri insert(Uri uri, ContentValues values) {
int match = sUriMatcher.match(uri);
switch (match) {
case ORDER:
return insertCart(uri, values);
default:
throw new IllegalArgumentException("Cant insert data");
}
}
private Uri insertCart(Uri uri, ContentValues values) {
String name = values.getAsString(OrderContract.OrderEntry.COLUMN_NAME);
if(name == null){
throw new IllegalArgumentException("Name is Required");
}
String quantity = values.getAsString(OrderContract.OrderEntry.COLUMN_QUANTITY);
if(quantity == null){
throw new IllegalArgumentException("Quantity is Required");
}
String price = values.getAsString(OrderContract.OrderEntry.COLUMN_PRICE);
if(price == null){
throw new IllegalArgumentException("Price is Required");
}
//insert values into order
SQLiteDatabase database = mhelper.getWritableDatabase();
long id = database.insert(OrderContract.OrderEntry.TABLE_NAME, null, values);
if(id == 0){
return null;
}
getContext().getContentResolver().notifyChange(uri,null);
return ContentUris.withAppendedId(uri,id);
}
#Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
//delete data once order is made
int rowsDeleted;
SQLiteDatabase database = mhelper.getWritableDatabase();
int match = sUriMatcher.match(uri);
switch (match) {
case ORDER:
rowsDeleted = database.delete(OrderContract.OrderEntry.TABLE_NAME, selection, selectionArgs);
break;
default:
throw new IllegalArgumentException("Cannot delete");
}
if (rowsDeleted!=0) {
getContext().getContentResolver().notifyChange(uri, null);
}
return rowsDeleted;
}
#Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
return 0;
}
}
OrderContract class:
public class OrderContract {
public OrderContract() {
}
//content authority requires package name
public static final String CONTENT_AUTHORITY = "com.example.myapp";
public static final Uri BASE_URI = Uri.parse(("content://" +CONTENT_AUTHORITY));
//same as table name
public static final String PATH = "orders" ;
public static abstract class OrderEntry implements BaseColumns{
public static final Uri CONTENT_URI = Uri.withAppendedPath(BASE_URI,PATH);
public static final String TABLE_NAME = "orders" ;
public static final String _ID = BaseColumns._ID ;
public static final String COLUMN_NAME = "name" ;
public static final String COLUMN_QUANTITY = "quantity" ;
public static final String COLUMN_PRICE = "price" ;
}
}
Cart activity:
sofaname=findViewById(R.id.sofaname);
sofaprice=findViewById(R.id.sofaprice);
sofadesc=findViewById(R.id.sofadesc);
plusquantity = findViewById(R.id.addquantity);
minusquantity = findViewById(R.id.subquantity);
quantitynumber = findViewById(R.id.quantity);
addtocart = findViewById(R.id.addtocart);
ImageSlider imageSlider = findViewById(R.id.sofaslider1);
List<SlideModel> slideModels = new ArrayList<>();
slideModels.add(new SlideModel(R.drawable.card14));
slideModels.add(new SlideModel(R.drawable.card6));
slideModels.add(new SlideModel(R.drawable.card7));
imageSlider.setImageList(slideModels,false);
imageSlider.setClickable(false);
DB = new DBHelper(Sofa1.this);
String Name = DB.getProductNamePrice("SELECT F_Name FROM Furniture WHERE F_Type = 'Sofa';");
String Price = DB.getProductNamePrice("SELECT F_Price FROM Furniture WHERE F_Type = 'Sofa';");
String Desc = DB.getProductNamePrice("SELECT F_Description FROM Furniture WHERE F_Type = 'Sofa';");
sofaname.setText(Name);
sofaprice.setText(Price);
sofadesc.setText(Desc);
plusquantity.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(quantity<5){
//sofaprice
int baseprice= Integer.parseInt(sofaprice.getText().toString());
quantity++;
displayquantity();
totalprice = baseprice * quantity;
String setnewprice = (String.valueOf(totalprice));
sofaprice.setText(setnewprice);
}
}
});
minusquantity.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int baseprice=0;
String Price = DB.getProductNamePrice("SELECT F_Price FROM Furniture WHERE F_Type = 'Sofa';");
baseprice = Integer.parseInt(Price);
if(quantity>1) {
quantity--;
displayquantity();
totalprice = baseprice * quantity;
String setnewprice = (String.valueOf(totalprice));
sofaprice.setText(setnewprice);
}
}
});
addtocart.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent =new Intent(Sofa1.this,Cart.class);
startActivity(intent);
// once this button is clicked we want to save our values in the database and send those values
// right away to summary activity where we display the order info
SaveCart();
totalamount = (TextView) findViewById(R.id.total);
int totalAmount = DB.getTotalExpenses();
totalamount.setText(String.valueOf(totalAmount));
}
});
}
private boolean SaveCart() {
String name = sofaname.getText().toString();
String price = sofaprice.getText().toString();
String quantity = quantitynumber.getText().toString();
ContentValues values = new ContentValues();
values.put(OrderContract.OrderEntry.COLUMN_NAME,name);
values.put(OrderContract.OrderEntry.COLUMN_PRICE,price);
values.put(OrderContract.OrderEntry.COLUMN_QUANTITY,quantity);
if(mcurrentcarturi == null){
Uri newUri = getContentResolver().insert(OrderContract.OrderEntry.CONTENT_URI, values);
if(newUri == null){
Toast.makeText(this, "Failed to add to cart", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(this, "Product added to cart", Toast.LENGTH_SHORT).show();
}
}
hasallrequiredvalues = true;
return hasallrequiredvalues;
}
private void displayquantity() {
quantitynumber.setText(String.valueOf(quantity));
}
#Override
public #NotNull Loader<Cursor> onCreateLoader(int id, Bundle args) {
String[] projection = {OrderContract.OrderEntry._ID,
OrderContract.OrderEntry.COLUMN_NAME,
OrderContract.OrderEntry.COLUMN_PRICE,
OrderContract.OrderEntry.COLUMN_QUANTITY};
return new CursorLoader(this, mcurrentcarturi, projection, null, null, null);
}
#Override
public void onLoadFinished(#NotNull Loader<Cursor> loader, Cursor cursor) {
if(cursor==null || cursor.getCount() < 1){
return;
}
if(cursor.moveToFirst()){
int name = cursor.getColumnIndex(OrderContract.OrderEntry.COLUMN_NAME);
int price = cursor.getColumnIndex(OrderContract.OrderEntry.COLUMN_PRICE);
int quantity = cursor.getColumnIndex(OrderContract.OrderEntry.COLUMN_QUANTITY);
String nameofsofa = cursor.getString(name);
String priceofsofa = cursor.getString(price);
String quantityofsofa = cursor.getString(quantity);
sofaname.setText(nameofsofa);
sofaprice.setText(priceofsofa);
quantitynumber.setText(quantityofsofa);
}
}
#Override
public void onLoaderReset(#NotNull Loader<Cursor> loader) {
sofaname.setText("");
sofaprice.setText("");
quantitynumber.setText("");
}

As your query is effectively
SELECT SUM(price) FROM orders;
Only a single column will be returned, thus using total = cursor.getInt(4); should result in an exception as the column is out of bounds, there will only be 1 column and it's index will be 0.
Thus try changing to use :-
public int getTotalExpenses()
{
int total = 0;
SQLiteDatabase database = this.getReadableDatabase();
Cursor cursor = database.rawQuery("SELECT SUM("+ OrderContract.OrderEntry.COLUMN_PRICE + ") FROM " + OrderContract.OrderEntry.TABLE_NAME, null);
if (cursor.moveToFirst())
{
total = cursor.getInt(0); //<<<<<<<<<< CHANGED
}
//while (cursor.moveToNext()); //<<<<<<<<<< COMMENTED OUT NOT NEEDED
cursor.close(); //<<<<<<<<<< ADDED should always close cursor when finished with them
return total;
}

Android how to get clicked itemid from Listview and update another column value on this row

I am making small app. It has 2 listview on MainActivity.
DB is SQLLite and has tree cloumns id(int), person(text), status(text).
Firt listview will be show informations from DB with this query
select * from DB where status=B
And next ListView will show information where status=A.
lv1.status=b | lv2.status=a
Person 1 | Person 2
Person 3 | Person 4
When i click lv2 on item, value of clicked lv2 field 'status' must change to 'b'.
But I can not write right query for db.
public void changeUser(){
db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_STATUS, "B");
db.update(TABLE_ORDER, values, null, null);
db.close();
}
Thanks
Here is my code
lvB = (ListView)findViewById(R.id.lvB);
listClientB();
lvA = (ListView)findViewById(R.id.lvA);
listClientA();
lvA.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
User user = (User)adapterView.getAdapter().getItem(i);
int id = user.get_id();
if (user.getStatus().contains("A")){
dbHelper.changeUser();
}
Toast.makeText(getApplicationContext(), id + "-NUMBER id", Toast.LENGTH_LONG).show();
Log.d(String.valueOf(user.get_id()), "-NUMBER id");
listClientA();
Log.d(user.getStatus(), "Pressed");
}
});
}
private void listClientA(){
list = dbHelper.allUsersA();
klientStatusAdapter = new KlientStatusAdapter(MainActivity.this, list);
lvA.setAdapter(klientStatusAdapter);
lvA.setTextFilterEnabled(true);
}
private void listClientB(){
list = dbHelper.allUsersB();
klientStatusAdapter = new KlientStatusAdapter(MainActivity.this, list);
lvB.setAdapter(klientStatusAdapter);
lvB.setTextFilterEnabled(true);
}
Here is from DB
public List<User> allUsersA(){
db = this.getReadableDatabase();
List<User> users = new ArrayList<User>();
String s = "select * from " + TABLE_ORDER + " where status = 'A'";
Cursor cursor = db.rawQuery(s, null);
if (cursor.moveToFirst()){
do {
User user = new User();
user.set_id(Integer.parseInt(cursor.getString(0)));
user.setClientName(cursor.getString(1));
user.setCleintOrderedFood(cursor.getString(2));
user.setStatus(cursor.getString(3));
users.add(user);
}while (cursor.moveToNext());
}
db.close();
return users;
}
public List<User> allUsersB(){
db = this.getReadableDatabase();
List<User> users = new ArrayList<User>();
String s = "select * from " + TABLE_ORDER + " where status = 'B'";
Cursor cursor = db.rawQuery(s, null);
if (cursor.moveToFirst()){
do {
User user = new User();
user.set_id(Integer.parseInt(cursor.getString(0)));
user.setClientName(cursor.getString(1));
user.setCleintOrderedFood(cursor.getString(2));
user.setStatus(cursor.getString(3));
users.add(user);
}while (cursor.moveToNext());
}
db.close();
return users;
}
public void changeUser(){
db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_STATUS, "B");
db.update(TABLE_ORDER, values, null, null);
db.close();
}
Here is adapter
public class ClientStatusAdapter extends BaseAdapter{
LayoutInflater inflater;
Context context;
List<User> wordsList;
DbHelper dbHelper;
public ClientStatusAdapter(Context context1, List<User> wordsList) {
this.context = context1;
this.wordsList = wordsList;
inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
dbHelper = new DbHelper(context);
}
#Override
public int getCount() {
return wordsList.size();
}
#Override
public Object getItem(int i) {
return wordsList.get(i);
}
#Override
public long getItemId(int i) {
return i;
}
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
if (view == null){
view = inflater.inflate(R.layout.kliyent_status_adapter, null);
}
TextView txtIsmAdapter = (TextView)view.findViewById(R.id.txtIsmAdapter);
TextView txtOvqatAdapter = (TextView)view.findViewById(R.id.txtOvqatAdapter);
final User user = wordsList.get(i);
TextView txtCliyentNames = (TextView)view.findViewById(R.id.txtCliyentNames);
txtCliyentNames.setText(user.getClientName());
TextView txtCliyentOrderedFoood = (TextView)view.findViewById(R.id.txtCliyentOrderedFoood);
txtCliyentOrderedFoood.setText(user.getCleintOrderedFood());
TextView txtStatusAdapter = (TextView)view.findViewById(R.id.txtStatusAdapter);
txtStatusAdapter.setText(user.getStatus());
notifyDataSetChanged();
ImageView imgOn = (ImageView) view.findViewById(R.id.imgOn);
return view;
}
}
Here is entity User
public class User {
private int _id;
private String clientName;
private String cleintOrderedFood;
private String status = "A";
public User() {
}
public User(int _id, String clientName, String cleintOrderedFood) {
this._id = _id;
this.clientName = clientName;
this.cleintOrderedFood = cleintOrderedFood;
}
public User(int _id, String clientName, String cleintOrderedFood, String status) {
this._id = _id;
this.clientName = clientName;
this.cleintOrderedFood = cleintOrderedFood;
this.status = status;
}
public int get_id() {
return _id;
}
public void set_id(int _id) {
this._id = _id;
}
public String getClientName() {
return clientName;
}
public void setClientName(String clientName) {
this.clientName = clientName;
}
public String getCleintOrderedFood() {
return cleintOrderedFood;
}
public void setCleintOrderedFood(String cleintOrderedFood) {
this.cleintOrderedFood = cleintOrderedFood;
}
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
}

If you look closely at the SQLiteDatabase.update() method, you will see it is declared as
int update (String table,
ContentValues values,
String whereClause,
String[] whereArgs)
Note the last two parameters. These are how you select which rows to update. For example, you can specify to only update rows with a given id:
public void changeUser(int userId){
db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_STATUS, "B");
String whereClause = "_id = ?";
String where = new String[] {Integer.toString(userId)};
db.update(TABLE_ORDER, values, whereClause, where);
db.close();
}
Here I am assuming you use the conventional column name _id. Of course, you can change this to suit your needs if you have a different column name.
Note that you will now need to pass a parameter to changeUser(). However, you have not shown how nor where you currently call it, so I am unable to provide any advice how to change this.

contentProvider and search by name and not ID Android

it's the first time I'm using the content provider.
so I have this:
public class ContactsContentProvider extends ContentProvider {
private ContactsDatabaseHelper dbHelper;
private static final UriMatcher uriMatcher =
new UriMatcher(UriMatcher.NO_MATCH);
private static final int ONE_CONTACT = 1;
private static final int CONTACTS = 2;
private static final int CONTACT = 3;
static {
uriMatcher.addURI(ContactsDatabaseDescription.AUTHORITY,
Contact.TABLE_NAME + "/#", ONE_CONTACT);
uriMatcher.addURI(ContactsDatabaseDescription.AUTHORITY,
Contact.TABLE_NAME, CONTACTS);
uriMatcher.addURI(ContactsDatabaseDescription.AUTHORITY,
Contact.TABLE_NAME + "/*" , CONTACT);
}
#Override
public boolean onCreate() {
dbHelper = new ContactsDatabaseHelper(getContext());
return true;
}
#Override
public String getType(Uri uri) {
return null;
}
#Override
public Cursor query(Uri uri, String[] projection,
String selection, String[] selectionArgs, String sortOrder) {
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
queryBuilder.setTables(Contact.TABLE_NAME);
switch (uriMatcher.match(uri)) {
case ONE_CONTACT:
queryBuilder.appendWhere(
Contact._ID + "=" + uri.getLastPathSegment());
break;
case CONTACTS:
break;
default:
throw new UnsupportedOperationException(
getContext().getString(R.string.invalid_query_uri) + uri);
}
Cursor cursor = queryBuilder.query(dbHelper.getReadableDatabase(),
projection, selection, selectionArgs, null, null, sortOrder);
cursor.setNotificationUri(getContext().getContentResolver(), uri);
return cursor;
}
// insert a new contact in the database
#Override
public Uri insert(Uri uri, ContentValues values) {
Uri newContactUri = null;
switch (uriMatcher.match(uri)) {
case CONTACTS:
// insert the new contact--success yields new contact's row id
long rowId = dbHelper.getWritableDatabase().insert(
Contact.TABLE_NAME, null, values);
if (rowId > 0) {
newContactUri = Contact.buildContactUri(rowId);
getContext().getContentResolver().notifyChange(uri, null);
}
else
throw new SQLException(
getContext().getString(R.string.insert_failed) + uri);
break;
default:
throw new UnsupportedOperationException(
getContext().getString(R.string.invalid_insert_uri) + uri);
}
return newContactUri;
}
#Override
public int update(Uri uri, ContentValues values,
String selection, String[] selectionArgs) {
int numberOfRowsUpdated; // 1 if update successful; 0 otherwise
switch (uriMatcher.match(uri)) {
case ONE_CONTACT:
String id = uri.getLastPathSegment();
numberOfRowsUpdated = dbHelper.getWritableDatabase().update(
Contact.TABLE_NAME, values, Contact._ID + "=" + id,
selectionArgs);
break;
default:
throw new UnsupportedOperationException(
getContext().getString(R.string.invalid_update_uri) + uri);
}
if (numberOfRowsUpdated != 0) {
getContext().getContentResolver().notifyChange(uri, null);
}
return numberOfRowsUpdated;
}
#Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
int numberOfRowsDeleted;
switch (uriMatcher.match(uri)) {
case ONE_CONTACT:
String id = uri.getLastPathSegment();
numberOfRowsDeleted = dbHelper.getWritableDatabase().delete(
Contact.TABLE_NAME, Contact._ID + "=" + id, selectionArgs);
break;
default:
throw new UnsupportedOperationException(
getContext().getString(R.string.invalid_delete_uri) + uri);
}
if (numberOfRowsDeleted != 0) {
getContext().getContentResolver().notifyChange(uri, null);
}
return numberOfRowsDeleted;
}
}
My database is
public class ContactsDatabaseDescription {
public static final String AUTHORITY =
"com.example.afran.bdcontacts.data";
private static final Uri BASE_CONTENT_URI =
Uri.parse("content://" + AUTHORITY);
public static final class Contact implements BaseColumns {
public static final String TABLE_NAME = "contacts"; // table's name
public static final Uri CONTENT_URI =
BASE_CONTENT_URI.buildUpon().appendPath(TABLE_NAME).build();
public static final String COLUMN_FIRST_NAME = "firstName";
public static final String COLUMN_LAST_NAME = "lastName";
public static final String COLUMN_EMAIL = "email";
public static final String COLUMN_TYPE = "type";
public static Uri buildContactUri(long id) {
return ContentUris.withAppendedId(CONTENT_URI, id);
}
}
}
and on this fragment I read one last name (search) and I want to find the contact and I do not know how
public class DetailFragment extends Fragment
implements LoaderManager.LoaderCallbacks<Cursor> {
public interface DetailFragmentListener {
void onContactDeleted();
void onEditContact(Uri contactUri);
}
private static final int CONTACT_LOADER = 0;
private DetailFragmentListener listener;
private Uri contactUri;
private TextView prenomTextView;
private TextView nomTextView;
private TextView emailTextView;
private TextView typeTextView;
#Override
public void onAttach(Context context) {
super.onAttach(context);
listener = (DetailFragmentListener) context;
}
#Override
public void onDetach() {
super.onDetach();
listener = null;
}
#Override
public View onCreateView(
LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
setHasOptionsMenu(true);
Bundle arguments = getArguments();
if (arguments != null)
contactUri = arguments.getParcelable(MainActivity.CONTACT_URI);
View view =
inflater.inflate(R.layout.fragment_detail, container, false);
prenomTextView = (TextView) view.findViewById(R.id.firstNameTextView);
nomTextView = (TextView) view.findViewById(R.id.lastNameTextView);
emailTextView = (TextView) view.findViewById(R.id.emailTextView);
typeTextView = (TextView) view.findViewById(R.id.typeTextView);
getLoaderManager().initLoader(CONTACT_LOADER, null, this);
return view;
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
super.onCreateOptionsMenu(menu, inflater);
inflater.inflate(R.menu.menu_main, menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_edit:
listener.onEditContact(contactUri);
return true;
case R.id.action_delete:
deleteContact();
return true;
case R.id.action_search:
searchContact();
return true;
}
return super.onOptionsItemSelected(item);
}
private void searchContact() {
final EditText input = new EditText(getContext());
final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle(R.string.menuitem_recherche);
builder.setMessage(R.string.label_lastName);
builder.setView(input);
builder.setPositiveButton(R.string.button_ok, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int whichButton) {
String value = input.getText().toString();
return;
}
});
builder.setNegativeButton(R.string.button_cancel, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
return;
}
});
builder.create().show();
}
private void deleteContact() {
final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle(R.string.confirm_title);
builder.setMessage(R.string.confirm_message);
builder.setPositiveButton(R.string.button_delete, new DialogInterface.OnClickListener() {
#Override
public void onClick(
DialogInterface dialog, int button) {
getActivity().getContentResolver().delete(
contactUri, null, null);
listener.onContactDeleted();
}
}
);
builder.setNegativeButton(R.string.button_cancel, null);
builder.create().show();
}
#Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
CursorLoader cursorLoader;
switch (id) {
case CONTACT_LOADER:
cursorLoader = new CursorLoader(getActivity(),
contactUri,
null,
null,
null,
null);
break;
default:
cursorLoader = null;
break;
}
return cursorLoader;
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
if (data != null && data.moveToFirst()) {
int firstIndex = data.getColumnIndex(ContactsDatabaseDescription.Contact.COLUMN_FIRST_NAME);
int lastIndex = data.getColumnIndex(ContactsDatabaseDescription.Contact.COLUMN_LAST_NAME);
int emailIndex = data.getColumnIndex(ContactsDatabaseDescription.Contact.COLUMN_EMAIL);
int typeIndex = data.getColumnIndex(ContactsDatabaseDescription.Contact.COLUMN_TYPE);
prenomTextView.setText(data.getString(firstIndex));
nomTextView.setText(data.getString(lastIndex));
emailTextView.setText(data.getString(emailIndex));
typeTextView.setText(data.getString(typeIndex));
}
}
#Override
public void onLoaderReset(Loader<Cursor> loader) { }
}

It is simple to search for a match of any column in your table. You simply need the contentUri, and where and whereArgs parameters for the query. Ensure your Uri points to the whole table. Assuming you want to match columns called "first_name" and "surname" with Strings called firstName and surname.
String where = "first_name =? and surname =?";
String[] whereArgs = {firstName, surname};
You can use parentheses and "and" and "or" to construct more complex queries. With numerical fields you can use > and < etc. You must ensure whereArgs has as many elements as where has "?"

How to update Recyclerview data from another activity

I have two activities MainActivity and Addlogactivity i am updating a data in Addlogactivity which should be displayed in mainactivity recyclerview the data is not updating in database
MianActivityClass :
public class MainActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor>{
RecyclerView recyclerView;
Intent addDisplay;
Mainrow_Adapter adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView)findViewById(R.id.listView);
addDisplay = new Intent(this,AddLog.class);
Toolbar toolbar = (Toolbar)findViewById(R.id.maintoolbar);
setSupportActionBar(toolbar);
toolbar.setTitle("Account's");
getSupportLoaderManager().initLoader(1,null,this);
adapter = new Mainrow_Adapter(this,null);
recyclerView.setAdapter(adapter);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
}
public void createID(View view)
{
ContentValues values = new ContentValues();
values.put(DataProvider.Pname,"1");
values.put(DataProvider.Pphone,"1");
values.put(DataProvider.Paddress,"1");
values.put(DataProvider.PCategory,"1");
values.put(DataProvider.Pamount,"1");
getContentResolver().insert(DataProvider.ContentUri_Person,values);
long id = DataProvider.insertId;
addDisplay.putExtra("ID",id);
Toast.makeText(MainActivity.this,String.valueOf(id), Toast.LENGTH_SHORT).show();
startActivity(addDisplay);
finish();
}
#Override
protected void onResume() {
super.onResume();
adapter.notifyDataSetChanged();
}
#Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
String[] Prjection = {DataProvider.PID,DataProvider.Pname,DataProvider.Pphone,DataProvider.Paddress,DataProvider.PCategory,DataProvider.Pamount};
return new CursorLoader(this,DataProvider.ContentUri_Person,Prjection,null,null,null);
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data)
{
adapter.swapCursor(data);
}
#Override
public void onLoaderReset(Loader<Cursor> loader)
{
adapter.swapCursor(null);
}
}
AddLog activity class :
public class AddLog extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor>{
TextView TotalAmount,Date;
EditText name,mobile,city,detailname,detailamount;
RecyclerView adddetailtolist;
DetailsAdapter adapter;
Intent returnback;
double totamount;
long logid;
String Debt = "Debt";
String Paid = "Paid";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_log);
Toolbar toolbar = (Toolbar)findViewById(R.id.addlogtoolbar);
setSupportActionBar(toolbar);
toolbar.setTitle("Add Log");
returnback = new Intent(this,MainActivity.class);
Intent intent = getIntent();
logid = intent.getExtras().getLong("ID");
TotalAmount = (TextView)findViewById(R.id.totalAmount);
Date = (TextView)findViewById(R.id.addlogDate);
name = (EditText)findViewById(R.id.AddName);
mobile = (EditText)findViewById(R.id.AddPhone);
city = (EditText)findViewById(R.id.Addcity);
detailname = (EditText)findViewById(R.id.Detailname);
detailamount = (EditText)findViewById(R.id.Detailamount);
adddetailtolist = (RecyclerView)findViewById(R.id.addloglist);
Date.setText(getDate());
getSupportLoaderManager().initLoader(1,null,this);
adapter = new DetailsAdapter(this,null);
adddetailtolist.setAdapter(adapter);
adddetailtolist.setLayoutManager(new LinearLayoutManager(this));
}
private String getDate()
{
Calendar calendar = Calendar.getInstance();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("EEE,dd-MMM-yyyy");
String date = simpleDateFormat.format(calendar.getTime());
return date;
}
public void addDetails(View view)
{
String Name = detailname.getText().toString();
String Amount = detailamount.getText().toString();
String date = Date.getText().toString();
ContentValues contentValues = new ContentValues();
contentValues.put(DataProvider.Dname,Name);
contentValues.put(DataProvider.DCategory,Debt);
contentValues.put(DataProvider.Damount,Amount);
contentValues.put(DataProvider.Ddate,date);
contentValues.put(DataProvider.Per_In,logid);
Uri uri = getContentResolver().insert(DataProvider.ContentUri_Details,contentValues);
Toast.makeText(AddLog.this, uri.toString()+"Value Inserted", Toast.LENGTH_SHORT).show();
NumberFormat currency = changeamount();
TotalAmount.setText(currency.format(getAmount()));
}
private double getAmount()
{
ContentProviderClient client = getContentResolver().acquireContentProviderClient(DataProvider.ContentUri_Details);
SQLiteDatabase db = ((DataProvider)client.getLocalContentProvider()).sqLiteDatabase;
String query = "SELECT SUM(DAmount) FROM Details WHERE Per_In = "+logid;
Cursor cursor = db.rawQuery(query, null);
cursor.moveToFirst();
double amount = cursor.getDouble(0);
cursor.close();
client.release();
return amount;
}
public NumberFormat changeamount()
{
Locale locale = new Locale("en","IN");
NumberFormat currencyformat = NumberFormat.getCurrencyInstance(locale);
return currencyformat;
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater menuinflate = getMenuInflater();
menuinflate.inflate(R.menu.addlogmenu,menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case R.id.done:
saveData();
}
return super.onOptionsItemSelected(item);
}
private void saveData()
{
String name1 = name.getText().toString();
String phone = mobile.getText().toString();
String address = city.getText().toString();
if (TextUtils.isEmpty(name1)||TextUtils.isEmpty(phone)||TextUtils.isEmpty(address))
{
if (TextUtils.isEmpty(name1))
{
name.setError("Feild can not be Empty");
}
else if (TextUtils.isEmpty(phone))
{
mobile.setError("Feild can not be Empty");
}
else if (TextUtils.isEmpty(address))
{
city.setError("Feild can not be Empty");
}
}
else
{
ContentValues values = new ContentValues();
values.put(DataProvider.Pname,name1);
values.put(DataProvider.Pphone,phone);
values.put(DataProvider.Paddress,address);
values.put(DataProvider.PCategory,"Debt");
values.put(DataProvider.Pamount,totamount);
String where = DataProvider.PID+"=?";
String[] whereargs = {String.valueOf(logid)};
int a = getContentResolver().update(DataProvider.ContentUri_Person,values,where,whereargs);
Toast.makeText(AddLog.this, String.valueOf(1)+"Value updated", Toast.LENGTH_SHORT).show();
startActivity(returnback);
finish();
}
}
#Override
public Loader<Cursor> onCreateLoader(final int id, Bundle args)
{
String[] Projection = new String[]{DataProvider.DID,DataProvider.Dname,DataProvider.DCategory,DataProvider.Damount,DataProvider.Ddate};
String selection = DataProvider.Per_In+"=?";
String[] selectionargs = new String[]{String.valueOf(logid)};
return new CursorLoader(this,DataProvider.ContentUri_Details,Projection,selection,selectionargs,null);
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data)
{
adapter.swapCursor(data);
}
#Override
public void onLoaderReset(Loader<Cursor> loader)
{
adapter.swapCursor(null);
}
}
Content Provider class:
public class DataProvider extends ContentProvider
{
static final String ProviderName = "com.example.mrudu.accounts.provider";
static final String URLPerson = "content://"+ProviderName+"/Person_Detail";
static final String URLDetails = "content://"+ProviderName+"/Details";
static final Uri ContentUri_Person = Uri.parse(URLPerson);
static final Uri ContentUri_Details = Uri.parse(URLDetails);
//Tables
private static String PTableName = "Person_Detail";
private static String DTableName = "Details";
public static long insertId = 0;
//Person_Detail Coloumns
public static String PID = "_id";
public static String Pname = "PName";
public static String Pphone = "PMobile";
public static String Paddress = "PCity";
public static String PCategory = "PCategory";
public static String Pamount = "PAmount";
//Details coloumn
public static String DID = "_id";
public static String Dname = "DName";
public static String Damount = "DAmount";
public static String Ddate = "DDate";
public static String DCategory = "DCategory";
public static String Per_In = "Per_In";
private static final int Person = 1;
private static final int Person_ID = 2;
private static final int Details = 3;
private static final int Details_Id = 4;
static UriMatcher uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
static
{
uriMatcher.addURI(ProviderName,PTableName,Person);
uriMatcher.addURI(ProviderName,PTableName+"/#",Person_ID);
uriMatcher.addURI(ProviderName,DTableName,Details);
uriMatcher.addURI(ProviderName,DTableName+"/#",Details_Id);
}
public static SQLiteDatabase sqLiteDatabase;
private static String Databasename = "Accounts";
private static int DatabaseVersion = 1;
private class DatabaseHelper extends SQLiteOpenHelper
{
public DatabaseHelper(Context context)
{
super(context, Databasename, null, DatabaseVersion);
}
#Override
public void onCreate(SQLiteDatabase sqLiteDatabase)
{
String Create_Person = " Create Table "+PTableName+"("+PID+" INTEGER PRIMARYKEY ,"+Pname+" TEXT ,"+Pphone+" TEXT ,"+Paddress+" TEXT ,"+PCategory+" TEXT ,"+Pamount+" REAL"+")";
String Create_Details = " Create Table "+DTableName+"("+DID+" INTEGER PRIMARYKEY ,"+Dname+" TEXT ,"+DCategory+" TEXT ,"+Damount+" REAl ,"+Ddate+" TEXT ,"+Per_In+" INTEGER )";
sqLiteDatabase.execSQL(Create_Person);
sqLiteDatabase.execSQL(Create_Details);
}
#Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1)
{
sqLiteDatabase.execSQL("Drop TABLE if exists"+PTableName);
sqLiteDatabase.execSQL("Drop TABLE if exists"+DTableName);
onCreate(sqLiteDatabase);
}
}
#Override
public boolean onCreate()
{
Context context = getContext();
DatabaseHelper databaseHelper = new DatabaseHelper(context);
sqLiteDatabase = databaseHelper.getWritableDatabase();
return (sqLiteDatabase==null)?false:true;
}
#Override
public Uri insert(Uri uri, ContentValues values)
{
switch (uriMatcher.match(uri))
{
case Person:
long rowId = sqLiteDatabase.insert(PTableName,null,values);
insertId = rowId;
if (rowId>0)
{
Uri _uri = ContentUris.withAppendedId(ContentUri_Person,rowId);
getContext().getContentResolver().notifyChange(_uri,null);
return _uri;
}
break;
case Details:
long rowId1 = sqLiteDatabase.insert(DTableName,null,values);
if (rowId1>0)
{
Uri _uri = ContentUris.withAppendedId(ContentUri_Details,rowId1);
getContext().getContentResolver().notifyChange(_uri,null);
return _uri;
}
break;
}
return null;
}
#Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder)
{
SQLiteQueryBuilder sqLiteQueryBuilder = new SQLiteQueryBuilder();
switch (uriMatcher.match(uri))
{
case Person_ID:
sqLiteQueryBuilder.setTables(PTableName);
sqLiteQueryBuilder.appendWhere(PID+ "="+ uri.getPathSegments().get(1));
break;
case Person:
sqLiteQueryBuilder.setTables(PTableName);
break;
case Details_Id:
sqLiteQueryBuilder.setTables(DTableName);
sqLiteQueryBuilder.appendWhere(Per_In +"="+ uri.getPathSegments().get(1));
break;
case Details:
sqLiteQueryBuilder.setTables(DTableName);
break;
default:
throw new UnsupportedOperationException("Not yet implemented");
}
Cursor cursor = sqLiteQueryBuilder.query(sqLiteDatabase,projection,selection,selectionArgs,null,null,sortOrder);
cursor.setNotificationUri(getContext().getContentResolver(),uri);
return cursor;
}
#Override
public int update(Uri uri, ContentValues values, String selection,
String[] selectionArgs)
{
int count = 0;
switch (uriMatcher.match(uri))
{
case Person:
count = sqLiteDatabase.update(PTableName,values,selection,selectionArgs);
break;
case Person_ID:
count = sqLiteDatabase.update(PTableName,values,PID+" = "+uri.getPathSegments().get(1)+(!TextUtils.isEmpty(selection)?" AND (" + selection + ')':""),selectionArgs);
break;
case Details:
count = sqLiteDatabase.update(DTableName,values,selection,selectionArgs);
break;
case Details_Id:
count = sqLiteDatabase.update(DTableName,values,Per_In+" = "+uri.getPathSegments().get(1)+(!TextUtils.isEmpty(selection)?" AND (" + selection + ')':""),selectionArgs);
break;
default:
throw new IllegalArgumentException("Unknown URI " + uri );
}
getContext().getContentResolver().notifyChange(uri,null);
return count;
}
#Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
// Implement this to handle requests to delete one or more rows.
throw new UnsupportedOperationException("Not yet implemented");
}
#Override
public String getType(Uri uri) {
// TODO: Implement this to handle requests for the MIME type of the data
// at the given URI.
throw new UnsupportedOperationException("Not yet implemented");
}
Cursor Recyclerview Adapter class:
public abstract class CursorRecyclerViewAdapter<VH extends RecyclerView.ViewHolder> extends RecyclerView.Adapter<VH> {
private Context mContext;
private Cursor mCursor;
private boolean mDataValid;
private int mRowIdColumn;
private DataSetObserver mDataSetObserver;
public CursorRecyclerViewAdapter(Context context, Cursor cursor) {
mContext = context;
mCursor = cursor;
mDataValid = cursor != null;
mRowIdColumn = mDataValid ? mCursor.getColumnIndex("_id") : -1;
mDataSetObserver = new NotifyingDataSetObserver();
if (mCursor != null) {
mCursor.registerDataSetObserver(mDataSetObserver);
}
}
public Cursor getCursor() {
return mCursor;
}
#Override
public int getItemCount() {
if (mDataValid && mCursor != null) {
return mCursor.getCount();
}
return 0;
}
#Override
public long getItemId(int position) {
if (mDataValid && mCursor != null && mCursor.moveToPosition(position)) {
return mCursor.getLong(mRowIdColumn);
}
return 0;
}
#Override
public void setHasStableIds(boolean hasStableIds) {
super.setHasStableIds(true);
}
public abstract void onBindViewHolder(VH viewHolder, Cursor cursor);
#Override
public void onBindViewHolder(VH viewHolder, int position) {
if (!mDataValid) {
throw new IllegalStateException("this should only be called when the cursor is valid");
}
if (!mCursor.moveToPosition(position)) {
throw new IllegalStateException("couldn't move cursor to position " + position);
}
onBindViewHolder(viewHolder, mCursor);
}
/**
* Change the underlying cursor to a new cursor. If there is an existing cursor it will be
* closed.
*/
public void changeCursor(Cursor cursor) {
Cursor old = swapCursor(cursor);
if (old != null) {
old.close();
}
}
/**
* Swap in a new Cursor, returning the old Cursor. Unlike
* {#link #changeCursor(Cursor)}, the returned old Cursor is <em>not</em>
* closed.
*/
public Cursor swapCursor(Cursor newCursor) {
if (newCursor == mCursor) {
return null;
}
final Cursor oldCursor = mCursor;
if (oldCursor != null && mDataSetObserver != null) {
oldCursor.unregisterDataSetObserver(mDataSetObserver);
}
mCursor = newCursor;
if (mCursor != null) {
if (mDataSetObserver != null) {
mCursor.registerDataSetObserver(mDataSetObserver);
}
mRowIdColumn = newCursor.getColumnIndexOrThrow("_id");
mDataValid = true;
notifyDataSetChanged();
} else {
mRowIdColumn = -1;
mDataValid = false;
notifyDataSetChanged();
//There is no notifyDataSetInvalidated() method in RecyclerView.Adapter
}
return oldCursor;
}
private class NotifyingDataSetObserver extends DataSetObserver {
#Override
public void onChanged() {
super.onChanged();
mDataValid = true;
notifyDataSetChanged();
}
#Override
public void onInvalidated() {
super.onInvalidated();
mDataValid = false;
notifyDataSetChanged();
//There is no notifyDataSetInvalidated() method in RecyclerView.Adapter
}
}
}
Main Adapter class:
public class Mainrow_Adapter extends CursorRecyclerViewAdapter<Mainrow_Adapter.ViewHolder>
{
public Mainrow_Adapter(Context context, Cursor cursor) {
super(context, cursor);
}
public static class ViewHolder extends RecyclerView.ViewHolder
{
TextView mName,mAmount;
public ViewHolder(View itemView) {
super(itemView);
mName = (TextView)itemView.findViewById(R.id.mainrowname);
mAmount = (TextView)itemView.findViewById(R.id.mainrowAmount);
}
}
#Override
public Mainrow_Adapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.mainrow_layout,parent,false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
#Override
public void onBindViewHolder(Mainrow_Adapter.ViewHolder viewHolder, Cursor cursor)
{
PersonDetails personDetails = PersonDetails.from(cursor);
viewHolder.mName.setText(personDetails.getName());
viewHolder.mAmount.setText(String.valueOf(personDetails.getAmount()));
}
}

Ok,
then move below three lines from onCreate method to onResume(),
getSupportLoaderManager().initLoader(1,null,this);
adapter = new Mainrow_Adapter(this,null);
recyclerView.setAdapter(adapter);
Hope this will work

Android: nullPointerException when using Parcelable interface in class with ArrayList<customObject>

I am trying to make the class called Music use parcelable so I can access an instance of Music in two different activities. I don't want to use serializable for speed purposes. I keep getting a nullPointerException when I try to pass it using:
Intent in = getIntent();
thisInstance = (Music) in.getExtras().get("MusicInstance");
Music Class: (the ArrayList is at the top and parcelable classes at the bottom)
public class Music implements Parcelable{
private static ArrayList<genericSongClass> songs = new ArrayList<genericSongClass>();
Cursor cursor;
static Context context;
public Music(Context context){
this.context = context;
}
public Music(Parcel in){
in.readTypedList(songs, genericSongClass.CREATOR);
}
public void BindAllSongs() {
/** Making custom drawable */
String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0";
final String[] projection = new String[] {
MediaStore.Audio.Media.DISPLAY_NAME,
MediaStore.Audio.Media.ARTIST,
MediaStore.Audio.Media.DATA,
MediaStore.Audio.Media.ALBUM};
final String sortOrder = MediaStore.Audio.AudioColumns.TITLE
+ " COLLATE LOCALIZED ASC";
try {
// the uri of the table that we want to query
Uri uri = android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
// query the db
cursor = context.getContentResolver().query(uri,
projection, selection, null, sortOrder);
if (cursor != null) {
songs = new ArrayList<genericSongClass>(cursor.getCount());
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
genericSongClass GSC = new genericSongClass();
GSC.songTitle = cursor.getString(0);
GSC.songArtist = cursor.getString(1);
GSC.songData = cursor.getString(2);
GSC.songAlbum = cursor.getString(3);
songs.add(GSC);
cursor.moveToNext();
}
}
} catch (Exception ex) {
} finally {
if (cursor != null) {
cursor.close();
}
}
}
public static Object[] toArray(ArrayList<Object> list){
Object[] toReturn = new Object[list.size()];
for (int i = 0; i < list.size(); i++){
toReturn[i] = list.get(i);
}
return toReturn;
}
public ArrayList<String> getArtists(){
ArrayList<String> artists = new ArrayList<String>();
for(genericSongClass gsc: songs){
if(!artists.contains(gsc.songArtist)){
artists.add(gsc.songArtist);
}
}
Alphabetize forArtists = new Alphabetize(artists);
return forArtists.getSortedArrayList();
}
public ArrayList<String> getAlbums(String artist){
ArrayList<String> albums = new ArrayList<String>();
for(genericSongClass gsc: songs){
if(gsc.songArtist == artist){
albums.add(gsc.songAlbum);
}
}
Alphabetize forAlbums = new Alphabetize(albums);
return forAlbums.getSortedArrayList();
}
//--- Parcel ------------------------------------------------
public static final Parcelable.Creator<Music> CREATOR = new Parcelable.Creator<Music>() {
public Music createFromParcel(Parcel in) {
return new Music(in);
}
#Override
public Music[] newArray(int size) {
return new Music[size];
}
};
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeList(songs);
}
}
genericSongClass:
public class genericSongClass implements Parcelable {
String songTitle = "";
String songArtist = "";
String songData = "";
String songAlbum = "";
public genericSongClass(){};
private genericSongClass(Parcel in){
songTitle = in.readString();
songArtist = in.readString();
songData = in.readString();
songAlbum = in.readString();
}
public static final Parcelable.Creator<genericSongClass> CREATOR = new Parcelable.Creator<genericSongClass>() {
#Override
public genericSongClass createFromParcel(Parcel source) {
return new genericSongClass(source);
}
#Override
public genericSongClass[] newArray(int size) {
return new genericSongClass[size];
}
};
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(songTitle);
dest.writeString(songArtist);
dest.writeString(songData);
dest.writeString(songAlbum);
}
}
Why am I getting the nullpointer and how do I remedy the situation?
This is my first time using Parcelable, so any help/advice is more than welcome. Thanks in advance!

initialize your list into constructor.use following code please.
public Music(Parcel in){
songs = new ArrayList<genericSongClass>();
in.readTypedList(songs, genericSongClass.CREATOR);
}
and get with this code:
thisInstance = getIntent().getParcelableExtra("MusicInstance");
and make sure you initialize thisInstance.

getParcelableArrayListExtra , getParcelableExtra
as well as
putParcelableArrayListExtra , putExtra(String name, Parcelable value)
are used to pass Parcelable's through intents.