Where to create business logic objects and maintain state?

Where to create business logic objects and maintain state? - android

My application relies on a core module of Android independent classes to carry out business logic. These objects need to be available to all parts of the app and also needs to maintain its state throughout the application.
I have been instantiating these objects in an Application subclass and using them throughout my activities and services. But when Android decides to kill my app to free up memory, those business logic objects are also killed and lose their state.
What is the best strategy for stateful business object models in an Android application?

Perfect solution for this is to use persistence storage. What I follow is bit complex but very useful.
It is divided in three parts :
SQLite Database
API Helper
Singleton Class ( Data Helper )
and following steps :
Retrieve all data from db to single instance classes.
Whenever I need to update it then update in class.
Dump it in database at some particular event. (like button click or back press).
By this way you have all of your data intact and easily available through out the app
Database : Not going to elaborate it. It can be any persistence storage like db or preference.
API Helper : Sample api helper class. It can be any thing depending on your storage.
public class AppsApi {
private static AppsApi appInstance;
private Context mContext;
public static AppsApi getInstance(Context context) {
if (appInstance == null)
appInstance = new AppsApi(context);
return appInstance;
}
public AppsApi(Context context) {
this.mContext = context;
}
public static String PROJECTION[];
static {
String[] arrayOfString = new String[5];
arrayOfString[0] = AppsTable.COLUMN_ID;
arrayOfString[1] = AppsTable.COLUMN_APP_NAME;
arrayOfString[2] = AppsTable.COLUMN_APP_PACKAGE_NAME;
arrayOfString[3] = AppsTable.COLUMN_APP_ACTIVITY_NAME;
arrayOfString[4] = AppsTable.COLUMN_IS_FROM_DASHBOARD;
PROJECTION = arrayOfString;
}
public int insertApp(ContentValues app) {
Uri uri = mContext.getContentResolver().insert(
DashDroidContentProvider.CONTENT_URI_APP, app);
System.out.println("APP Added URI :: " + uri);
return Integer.parseInt(uri.getLastPathSegment());
}
public Cursor getAllApps() {
return mContext.getContentResolver().query(
DashDroidContentProvider.CONTENT_URI_APP, AppsApi.PROJECTION,
null, null, null);
}
public Cursor getAllApp(boolean isFromDashBoard) {
int is = isFromDashBoard ? 1 : 0;
return mContext.getContentResolver().query(
DashDroidContentProvider.CONTENT_URI_APP, AppsApi.PROJECTION,
AppsTable.COLUMN_IS_FROM_DASHBOARD + " LIKE ?",
new String[] { is + "" }, null);
}
public void deleteApp(int id) {
mContext.getContentResolver().delete(
DashDroidContentProvider.CONTENT_URI_APP,
AppsTable.COLUMN_ID + " = ?", new String[] { id + "" });
}
public void deleteApp(String packageName) {
mContext.getContentResolver().delete(
DashDroidContentProvider.CONTENT_URI_APP,
AppsTable.COLUMN_APP_PACKAGE_NAME + " LIKE ?",
new String[] { packageName + "" });
}
public void updateApp(ContentValues app, int id) {
int uri = mContext.getContentResolver().update(
DashDroidContentProvider.CONTENT_URI_APP, app, "_id=?",
new String[] { id + "" });
System.out.println("App Updated URI ::" + uri);
}
public void clear() {
mContext.getContentResolver().delete(
DashDroidContentProvider.CONTENT_URI_APP, null, null);
}
public int count() {
return ((Cursor) mContext.getContentResolver().query(
DashDroidContentProvider.CONTENT_URI_APP,
new String[] { AppsTable.COLUMN_ID }, null, null, null))
.getCount();
}
public Cursor filterApp(String selection, String[] selectionArgs) {
return mContext.getContentResolver().query(
DashDroidContentProvider.CONTENT_URI_APP, AppsApi.PROJECTION,
selection, selectionArgs, null);
}
public int insertBulkApps(ContentValues[] apps) {
int noOfRecordInserted = mContext.getContentResolver().bulkInsert(
DashDroidContentProvider.CONTENT_URI_APP, apps);
System.out.println("Inserted Record Count :: " + noOfRecordInserted);
return noOfRecordInserted;
}
}
Data Helper : It is a single instance class. Provides you with data through out the app. It is huge but simple.
public class AppsHelper {
public static final int TYPE_SAVE = 0;
public static final int TYPE_GET = 1;
public static final int TYPE_UPDATE = 2;
private AppsData[] appsDashBoard;
private AppsData[] appsMoreApps;
private AppsApi appsProvider;
private OnDataBaseUpdateListener mListener;
private static AppsHelper mHelper;
public AppsHelper(Context context) {
appsProvider = AppsApi.getInstance(context);
initData();
if (appsProvider.count() == 0) {
new saveDataTask().execute();
} else {
updateAppsFromDatabase();
}
}
public static AppsHelper getInstance(Context context) {
if (mHelper == null)
mHelper = new AppsHelper(context);
return mHelper;
}
private void initData() {
appsDashBoard = new AppsData[DashDroidConstants.NO_OF_DASH_BOARD_APPS];
appsMoreApps = new AppsData[DashDroidConstants.NO_OF_MORE_APPS];
for (int i = 0; i < appsDashBoard.length; i++) {
appsDashBoard[i] = new AppsData(i, "null", "null", "null");
}
for (int i = appsDashBoard.length; i < (appsMoreApps.length + appsDashBoard.length); i++) {
appsMoreApps[i - appsDashBoard.length] = new AppsData(i, "null",
"null", "null");
}
}
public void updateMoreApp(String appName, String activityName,
String appPackageName, int index) {
appsMoreApps[index].setData(appName, activityName, appPackageName);
new updateDataTask(false, index).execute();
}
public void updateMoreApp(String appName, String activityName,
String appPackageName, int index, OnDataBaseUpdateListener listener) {
appsMoreApps[index].setData(appName, activityName, appPackageName);
this.mListener = listener;
new updateDataTask(false, index).execute();
}
public void updateDashBoardApp(String appName, String activityName,
String appPackageName, int index) {
appsDashBoard[index].setData(appName, activityName, appPackageName);
new updateDataTask(true, index).execute();
}
public void updateDashBoardApp(String appName, String activityName,
String appPackageName, int index, OnDataBaseUpdateListener listener) {
appsDashBoard[index].setData(appName, activityName, appPackageName);
this.mListener = listener;
new updateDataTask(true, index).execute();
}
public void updateAppsFromDatabase() {
new getDataTask().execute();
}
public AppsData[] getDashBoardApps() {
return appsDashBoard;
}
public AppsData[] getMoreApps() {
return appsMoreApps;
}
private void updateAppInDatabase(boolean isDashBoardApp, int index) {
ContentValues cv = new ContentValues();
cv = new ContentValues();
if (isDashBoardApp) {
cv.put(AppsTable.COLUMN_APP_PACKAGE_NAME,
appsDashBoard[index].getPackageName());
cv.put(AppsTable.COLUMN_APP_ACTIVITY_NAME,
appsDashBoard[index].getActivityName());
cv.put(AppsTable.COLUMN_APP_NAME, appsDashBoard[index].getAppName());
} else {
cv.put(AppsTable.COLUMN_APP_PACKAGE_NAME,
appsMoreApps[index].getPackageName());
cv.put(AppsTable.COLUMN_APP_ACTIVITY_NAME,
appsMoreApps[index].getActivityName());
cv.put(AppsTable.COLUMN_APP_NAME, appsMoreApps[index].getAppName());
}
int dbIndex = isDashBoardApp ? index : index + appsDashBoard.length;
appsProvider.updateApp(cv, dbIndex);
}
private int saveDataInDatabase() {
ContentValues[] cv = new ContentValues[appsDashBoard.length
+ appsMoreApps.length];
for (int i = 0; i < appsDashBoard.length; i++) {
cv[i] = new ContentValues();
cv[i].put(AppsTable.COLUMN_ID, appsDashBoard[i].getId());
cv[i].put(AppsTable.COLUMN_APP_PACKAGE_NAME,
appsDashBoard[i].getPackageName());
cv[i].put(AppsTable.COLUMN_APP_ACTIVITY_NAME,
appsDashBoard[i].getActivityName());
cv[i].put(AppsTable.COLUMN_APP_NAME, appsDashBoard[i].getAppName());
cv[i].put(AppsTable.COLUMN_IS_FROM_DASHBOARD, "1");
}
for (int i = appsDashBoard.length; i < (appsMoreApps.length + appsDashBoard.length); i++) {
cv[i] = new ContentValues();
cv[i].put(AppsTable.COLUMN_ID, appsMoreApps[i
- appsDashBoard.length].getId());
cv[i].put(AppsTable.COLUMN_APP_PACKAGE_NAME, appsMoreApps[i
- appsDashBoard.length].getPackageName());
cv[i].put(AppsTable.COLUMN_APP_ACTIVITY_NAME, appsMoreApps[i
- appsDashBoard.length].getActivityName());
cv[i].put(AppsTable.COLUMN_APP_NAME, appsMoreApps[i
- appsDashBoard.length].getAppName());
cv[i].put(AppsTable.COLUMN_IS_FROM_DASHBOARD, "0");
}
return appsProvider.insertBulkApps(cv);
}
private void getDataFromDatabase() {
Cursor appCursor = appsProvider.getAllApps();
appCursor.moveToFirst();
for (int i = 0; i < appsDashBoard.length; i++) {
appsDashBoard[i]
.setData(
appCursor.getString(appCursor
.getColumnIndex(AppsTable.COLUMN_APP_NAME)),
appCursor.getString(appCursor
.getColumnIndex(AppsTable.COLUMN_APP_ACTIVITY_NAME)),
appCursor.getString(appCursor
.getColumnIndex(AppsTable.COLUMN_APP_PACKAGE_NAME)));
appCursor.moveToNext();
}
for (int i = 0; i < appsMoreApps.length; i++) {
appsMoreApps[i]
.setData(
appCursor.getString(appCursor
.getColumnIndex(AppsTable.COLUMN_APP_NAME)),
appCursor.getString(appCursor
.getColumnIndex(AppsTable.COLUMN_APP_ACTIVITY_NAME)),
appCursor.getString(appCursor
.getColumnIndex(AppsTable.COLUMN_APP_PACKAGE_NAME)));
appCursor.moveToNext();
}
}
private class saveDataTask extends AsyncTask<Void, Void, Integer> {
#Override
protected Integer doInBackground(Void... params) {
return saveDataInDatabase();
}
#Override
protected void onPostExecute(Integer result) {
if (mListener != null)
mListener.onDataUpdate(TYPE_SAVE);
super.onPostExecute(result);
}
}
private class getDataTask extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... params) {
getDataFromDatabase();
return null;
}
#Override
protected void onPostExecute(Void result) {
if (mListener != null)
mListener.onDataUpdate(TYPE_GET);
super.onPostExecute(result);
}
}
private class updateDataTask extends AsyncTask<Void, Void, Void> {
boolean isFromDashBoard;
int index;
public updateDataTask(boolean isFromDashBoard, int index) {
this.isFromDashBoard = isFromDashBoard;
this.index = index;
}
#Override
protected Void doInBackground(Void... params) {
updateAppInDatabase(isFromDashBoard, index);
return null;
}
#Override
protected void onPostExecute(Void result) {
if (mListener != null)
mListener.onDataUpdate(TYPE_UPDATE);
super.onPostExecute(result);
}
}
public static class AppsData {
int id;
String appName;
String activityName;
String packageName;
public AppsData(int id, String appName, String activityName,
String packageName) {
this.id = id;
this.appName = appName;
this.activityName = activityName;
this.packageName = packageName;
}
public void setData(String appName, String activityName,
String packageName) {
this.appName = appName;
this.activityName = activityName;
this.packageName = packageName;
}
public int getId() {
return id;
}
public String getAppName() {
return appName;
}
public String getPackageName() {
return packageName;
}
public String getActivityName() {
return activityName;
}
}
public interface OnDataBaseUpdateListener {
public void onDataUpdate(int updateType);
}
}
It helps you in creating a more structured code and always available data, just need to call AppsHelper.getInstance(context) and boom!!!. :)

if you want to save them when user closes the application , you must save them in shared preferences or database or in a file in phone memory!
and for inside application, you can simply define them in a class that extends from Serializable or Parcelable and pass them between activities/fragments/etc

Related

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

Recyclerview not refreshing

I am working on a project where user adds data at runtime.The problem is whenever user inserts the fist element it is adding to the database and displaying in recyclerview.But when user adds more data the recyclerview keeps displaying firstelement over and over again.
If the user adds Apple it is adding to database and recyclerview is displaying Apple.Now if the user adds orange it is adding to database but the recyclerview is displaying Apple two times.
I am using Cursorloader to load data,Contentprovider to add data,and CustomCursoradapter(https://gist.github.com/skyfishjy/443b7448f59be978bc59) to set the data to recyclerview
addDetails() method execute when user adds data
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");
}
}
Detils class:
public class Details
{
String name,date;
double amount;
public Details(String name, double amount, String date) {
this.name = name;
this.amount = amount;
this.date = date;
}
public Details() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getAmount() {
return amount;
}
public void setAmount(double amount) {
this.amount = amount;
}
public String getDate() {
return date;
}
public void setDate(String date) {
this.date = date;
}
public static Details from(Cursor cursor)
{
cursor.moveToFirst();
do {
Details details = new Details(cursor.getString(1),cursor.getDouble(3),cursor.getString(4));
return details;
}while (cursor.moveToNext());
}
}
Adapter class :
public class DetailsAdapter extends CursorRecyclerViewAdapter<DetailsAdapter.View_Holder>
{
public DetailsAdapter(Context context, Cursor cursor) {
super(context, cursor);
}
public static class View_Holder extends RecyclerView.ViewHolder
{
TextView mName,mAmount,mDate;
public View_Holder(View itemView)
{
super(itemView);
mName = (TextView)itemView.findViewById(R.id.DetailName);
mAmount = (TextView)itemView.findViewById(R.id.DetailAmount);
mDate = (TextView)itemView.findViewById(R.id.DetailDate);
}
}
#Override
public DetailsAdapter.View_Holder onCreateViewHolder(ViewGroup parent, int viewType)
{
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.addloglistlayout,parent,false);
View_Holder viewHolder = new View_Holder(view);
return viewHolder;
}
#Override
public void onBindViewHolder(DetailsAdapter.View_Holder viewHolder, Cursor cursor)
{
Details details = Details.from(cursor);
viewHolder.mName.setText(details.getName());
viewHolder.mAmount.setText(String.valueOf(details.getAmount()));
viewHolder.mDate.setText(details.getDate());
}
}
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
}
}
}
Thank you

Probably from method in Details causing issue due to cursor.moveToFirst(); and do-while loop. change it as:
public static Details from(Cursor cursor)
{
Details details = new Details(cursor.getString(1),
cursor.getDouble(3),
cursor.getString(4));
return details;
}

I have checked your adapter and all, so you are already moving your cursor to particular position from Adapter, so you don't need to set it moveToFist, so just remove the line cursor.moveToFirst() from Details Class and check result.

Android How to detect contact list is changed?

I have implemented a ContentObserver, using this method I'm only able to be notified if a change occurs on a contact
but I don't know which contact has been added , deleted or updated ??
! Any suggestions ? how do i know which particular contact is modified ?
i am getting all contact list by using following method .
public void readContacts() {
System.out.println(" reading contact ");
String phoneNumber = null;
Uri CONTENT_URI = ContactsContract.Contacts.CONTENT_URI;
String _ID = ContactsContract.Contacts._ID;
String DISPLAY_NAME = ContactsContract.Contacts.DISPLAY_NAME;
String HAS_PHONE_NUMBER = ContactsContract.Contacts.HAS_PHONE_NUMBER;
Uri PhoneCONTENT_URI = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;
String Phone_CONTACT_ID = ContactsContract.CommonDataKinds.Phone.CONTACT_ID;
String NUMBER = ContactsContract.CommonDataKinds.Phone.NUMBER;
StringBuffer output = new StringBuffer();
ContentResolver contentResolver = getContentResolver();
Cursor cursor = contentResolver.query(CONTENT_URI, null, null, null,
null);
if (cursor.getCount() > 0) {
while (cursor.moveToNext()) {
String contact_id = cursor
.getString(cursor.getColumnIndex(_ID));
String name = cursor.getString(cursor
.getColumnIndex(DISPLAY_NAME));
// int id =
// Integer.parseInt(cursor.getString(cursor.getColumnIndex(
// HAS_PHONE_NUMBER )));
int hasPhoneNumber = Integer.parseInt(cursor.getString(cursor
.getColumnIndex(HAS_PHONE_NUMBER)));
if (hasPhoneNumber > 0) {
output.append("\n First Name:" + name);
System.out.println(" CONTACT NAME : " + name);
Contact_Name.add(name);
// Query and loop for every phone number of the contact
Cursor phoneCursor = contentResolver.query(
PhoneCONTENT_URI, null, Phone_CONTACT_ID + " = ?",
new String[] { contact_id }, null);
phoneCursor.moveToNext();
phoneNumber = phoneCursor.getString(phoneCursor
.getColumnIndex(NUMBER));
output.append("\n Phone number:" + phoneNumber);
System.out.println(" CONTACT number : " + phoneNumber);
phoneNumber = phoneNumber.replaceAll("\\s", "");
// phoneNumber = phoneNumber.substring(phoneNumber.length()
// - 10);
// System.err.println("Mobile no."+phoneNumber);
Contact_Number.add(phoneNumber);
phoneCursor.close();
}
output.append("\n");
}
}
}
and i am observing contact list is being some changed by regestring and using following code .
this.getContentResolver().registerContentObserver(
ContactsContract.Contacts.CONTENT_URI, true, mObserver);
private ContentObserver mObserver = new ContentObserver(new Handler()) {
#Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
final int currentCount = getContactCount();
if (currentCount < mContactCount) {
System.out.println(" Deleted contact");
} else if (currentCount == mContactCount) {
System.out.println(" upated contact");
} else {
System.out.println(" inserted contact");
}
mContactCount = currentCount;
}
};

Check if the version is greater than the one you have already (for the current contact). This is fast and more accurate then the current process your are following, since OnChange is called for all the items (delete, add or update).
So counting the # of contacts doesn't make much sense because a contact would have been updated then deleted and new contact added. the count is same in this case.
http://developer.android.com/reference/android/provider/ContactsContract.SyncColumns.html#VERSION

Try to use this implementation for you Contacts array
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
public class ActiveList<T> extends ArrayList<T> implements Serializable {
private static final long serialVersionUID = 870605912858223939L;
transient private List<ActiveListListener<T>> listeners;
public interface ActiveListListener<T> {
void onAdd(T item);
void onInsert(int location, T item);
void onAddAll(Collection<? extends T> items);
void onClear();
}
#Override
public synchronized void clear() {
super.clear();
fireChangedEvent();
}
#Override
public synchronized int size() {
return super.size();
}
#Override
public synchronized T get(int index) {
return super.get(index);
}
#Override
public synchronized boolean add(T item) {
boolean success = super.add(item);
if (success) {
fireAddEvent(item);
}
return success;
}
#Override
public synchronized void add(int index, T item) {
super.add(index, item);
fireInsertEvent(index, item);
}
#Override
public synchronized boolean addAll(int index, Collection<? extends T> items) {
boolean success = super.addAll(index, items);
if (success) {
fireAddAllEvent(items);
}
return success;
}
#Override
public synchronized boolean addAll(Collection<? extends T> items) {
boolean success = super.addAll(items);
if (success) {
fireAddAllEvent(items);
}
return success;
}
public synchronized void addListener(ActiveListListener<T> listener) {
if (this.listeners == null) {
listeners = Lists.newArrayList();
}
this.listeners.add(listener);
}
public synchronized void removeListener(ActiveListListener<T> listener) {
if (this.listeners != null) {
this.listeners.remove(listener);
}
}
private void fireChangedEvent() {
if (this.listeners == null)
return;
for (ActiveListListener<T> listener : listeners) {
listener.onClear();
}
}
private void fireInsertEvent(int location, T item) {
if (this.listeners == null)
return;
for (ActiveListListener<T> listener : listeners) {
listener.onInsert(location, item);
}
}
private void fireAddEvent(T item) {
if (this.listeners == null)
return;
for (ActiveListListener<T> listener : listeners) {
listener.onAdd(item);
}
}
private void fireAddAllEvent(Collection<? extends T> items) {
if (this.listeners == null)
return;
for (ActiveListListener<T> listener : listeners) {
listener.onAddAll(items);
}
}
}
In your Activity or Adapter
protected ActiveList.ActiveListListener<Contact> activeListListener = new ActiveList.ActiveListListener<Contact>() {
#Override
public void onAdd(Contact c) {
// do something
}
#Override
public void onInsert(final int location, final Contact c) {
// do something
}
#Override
public void onClear() {
// do something
}
#Override
public void onAddAll(List<Contact> cs) {
// do something
}
};
and in your Array
((ActiveList<Contact>) this.contacts).addListener(activeListListener);
See example https://github.com/davidevallicella/UnivrApp/

Write APN Settings on Android 4.4

Is it possible to write APN programmatically on Android 4.4?
I noticed that the Telephony.Carriers is available for API level 19.

I have a software with APN write feature. Since Android 4.0 you can write APN settings only if you have system permissions. My software was designed to be a system software, so I can write APN and other settings. But, this feature is no longer working in Android 4.4 and I don't know why yet.
After read the Telephony.Carriers class, I could not find a new way to write APN. It's just a class to tell you informations but can't change them.
My code to write APN is:
public class APN {
public static final int AUTH_TYPE_UNKNOW = -1;
public static final int AUTH_TYPE_NONE = 0;
public static final int AUTH_TYPE_PAP = 1;
public static final int AUTH_TYPE_CHAP = 2;
public static final int AUTH_TYPE_PAP_OR_CHAP = 3;
private int id;
private String name;
private String user;
private String password;
private String apn;
private String mcc;
private String mnc;
private String type;
private String server;
private String proxy;
private String port;
private String mmsProxy;
private String mmsPort;
private String mmsc;
private String current;
private int authType;
public APN() {
id = -1;
name = "";
user = "";
password = "";
apn = "";
mcc = "";
mnc = "";
type = "default,supl";
server = "";
proxy = "";
port = "";
mmsProxy = "";
mmsPort = "";
mmsc = "";
current = "";
authType = AUTH_TYPE_NONE;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getUser() {
return user;
}
public void setUser(String user) {
this.user = user;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getApn() {
return apn;
}
public void setApn(String apn) {
this.apn = apn;
}
public String getMcc() {
return mcc;
}
public void setMcc(String mcc) {
this.mcc = mcc;
}
public String getMnc() {
return mnc;
}
public void setMnc(String mnc) {
this.mnc = mnc;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getServer() {
return server;
}
public void setServer(String server) {
this.server = server;
}
public String getProxy() {
return proxy;
}
public void setProxy(String proxy) {
this.proxy = proxy;
}
public String getMmsProxy() {
return mmsProxy;
}
public void setMmsProxy(String mmsProxy) {
this.mmsProxy = mmsProxy;
}
public String getMmsPort() {
return mmsPort;
}
public void setMmsPort(String mmsPort) {
this.mmsPort = mmsPort;
}
public String getMmsc() {
return mmsc;
}
public void setMmsc(String mmsc) {
this.mmsc = mmsc;
}
public String getCurrent() {
return current;
}
public void setCurrent(String current) {
this.current = current;
}
public String getPort() {
return port;
}
public void setPort(String port) {
this.port = port;
}
public int getAuthType() {
return authType;
}
public void setAuthType(int authType) {
this.authType = authType;
}
}
and:
public class APNUtils {
private static final Uri APN_TABLE_URI = Uri.parse("content://telephony/carriers");
private static final Uri APN_PREFER_URI = Uri.parse("content://telephony/carriers/preferapn");
private static ContentValues prepareValues(APN apn) {
ContentValues values = new ContentValues();
if (!apn.getName().trim().equals(""))
values.put("name", apn.getName());
if (!apn.getApn().trim().equals(""))
values.put("apn", apn.getApn());
if (!apn.getMcc().trim().equals(""))
values.put("mcc", apn.getMcc());
if (!apn.getMnc().trim().equals(""))
values.put("mnc", apn.getMnc());
if (!apn.getMcc().trim().equals("") && !apn.getMnc().trim().equals(""))
values.put("numeric", apn.getMcc() + apn.getMnc());
if (!apn.getUser().trim().equals(""))
values.put("user", apn.getUser());
if (!apn.getPassword().trim().equals(""))
values.put("password", apn.getPassword());
if (!apn.getServer().trim().equals(""))
values.put("server", apn.getServer());
if (!apn.getProxy().trim().equals(""))
values.put("proxy", apn.getProxy());
if (!apn.getPort().trim().equals(""))
values.put("port", apn.getPort());
if (!apn.getMmsProxy().trim().equals(""))
values.put("mmsproxy", apn.getMmsProxy());
if (!apn.getMmsPort().trim().equals(""))
values.put("mmsport", apn.getMmsPort());
if (!apn.getMmsc().trim().equals(""))
values.put("mmsc", apn.getMmsc());
if (!apn.getType().trim().equals(""))
values.put("type", apn.getType());
if (!apn.getCurrent().trim().equals(""))
values.put("current", apn.getCurrent());
values.put("authtype", apn.getAuthType());
return values;
}
public static int createNewApn(Context context, APN apn, boolean setAsDefaultAPN) {
Logs.infoLog("APNutils.createNewApn.");
int apnid = -1;
try {
if (apn != null) {
Logs.infoLog("APNutils.createNewApn. Reading APN list.");
Uri APN_URI = Uri.parse("content://telephony/carriers");
ContentResolver resolver = context.getContentResolver();
Logs.infoLog("APNutils.createNewApn. Creating new registry based on parameters.");
ContentValues values = prepareValues(apn);
Logs.infoLog("APNutils.createNewApn. Inserting new APN.");
Cursor c = null;
Uri newRow = resolver.insert(APN_URI, values);
if(newRow != null) {
Logs.infoLog("APNutils.createNewApn. Getting new ID.");
c = resolver.query(newRow, null, null, null, null);
int tableIndex = c.getColumnIndex("_id");
c.moveToFirst();
apnid = c.getShort(tableIndex);
} else
Logs.warningLog("APNutils.createNewApn. New APN was not found. Inserting failed?");
if(c != null){
c.close();
}
if (apnid > -1 && setAsDefaultAPN) {
Logs.infoLog("APNutils.createNewApn. Setting new APN as default.");
ContentValues v = new ContentValues(1);
v.put("apn_id", apnid);
context.getContentResolver().update(APN_PREFER_URI, v, null, null);
}
} else
Logs.warningLog("APNutils.createNewApn. Invalid apn (null).");
} catch (Exception e) {
Logs.errorLog("createNewApn: error", e);
}
Logs.infoLog("APNutils.createNewApn. Returning ID " + String.valueOf(apnid));
return apnid;
}
public static boolean updateApn(Context context, int id, APN apn) {
Logs.infoLog("APNutils.updateApn.");
if (apn != null) {
try {
Logs.infoLog("APNutils.updateApn. Reading APN list.");
Uri APN_URI = Uri.parse("content://telephony/carriers");
ContentResolver resolver = context.getContentResolver();
Logs.infoLog("APNutils.updateApn. Creating new registry based on parameters.");
ContentValues values = prepareValues(apn);
Logs.infoLog("APNutils.updateApn. Inserting new APN.");
int result = resolver.update(APN_URI, values, "_id = " + String.valueOf(id), null);
if (result != -1) {
Logs.infoLog("APNutils.updateApn. APN updated.");
return true;
} else {
Logs.warningLog("APNutils.updateApn. Invalid ID (" + String.valueOf(id) + ").");
return false;
}
} catch (Exception e) {
Logs.errorLog("APNUtils.updateApn error: ", e);
return false;
}
} else {
Logs.warningLog("APNutils.updateApn. Invalid apn (null).");
return false;
}
}
public static boolean verifyApn(Context context, String apn) {
Logs.infoLog("APNutils.verifyApn.");
return getApn(context, apn) > -1;
}
public static int getApn(Context context, String apn) {
Logs.infoLog("APNutils.getApn.");
int result = -1;
Logs.infoLog("APNutils.getApn. Looking for APN " + apn);
String columns[] = new String[] { "_ID", "NAME" };
String where = "name = ?";
String wargs[] = new String[] { apn };
String sortOrder = null;
Cursor cur = context.getContentResolver().query(APN_TABLE_URI, columns, where, wargs, sortOrder);
if (cur != null) {
int tableIndex = cur.getColumnIndex("_id");
if (cur.moveToFirst()) {
Logs.infoLog("APNutils.getApn. APN found.");
result = cur.getShort(tableIndex);
}
cur.close();
}
if (result == -1)
Logs.warningLog("APNutils.getApn. APN not found.");
return result;
}
public static boolean setPreferredApn(Context context, String apn) {
Logs.infoLog("APNutils.setPreferredApn.");
boolean changed = false;
Logs.infoLog("APNutils.setPreferredApn. Looking for APN " + apn);
String columns[] = new String[] { "_ID", "NAME" };
String where = "name = ?";
String wargs[] = new String[] { apn };
String sortOrder = null;
Cursor cur = context.getContentResolver().query(APN_TABLE_URI, columns, where, wargs, sortOrder);
if (cur != null) {
if (cur.moveToFirst()) {
Logs.infoLog("APNutils.setPreferredApn. APN found. Setting as default.");
ContentValues values = new ContentValues(1);
values.put("apn_id", cur.getLong(0));
if (context.getContentResolver().update(APN_PREFER_URI, values, null, null) == 1) {
Logs.infoLog("APNutils.setPreferredApn. APN marked as default.");
changed = true;
}
}
cur.close();
}
if (!changed)
Logs.warningLog("APNutils.setPreferredApn. APN not found or could not be marked as default.");
return changed;
}
public static APN[] getAllApnList(Context context) {
Logs.infoLog("APNutils.getAllApnList.");
APN[] result = null;
Uri contentUri = Uri.parse("content://telephony/carriers/");
Cursor cursor = null;
try
{
cursor = context.getContentResolver().query(contentUri,
new String[] {"_ID", "name", "apn", "mcc", "mnc", "numeric", "user", "password", "server", "proxy",
"port", "mmsproxy", "mmsport", "mmsc", "type", "current", "authtype "}, null, null, null);
if (cursor != null)
{
result = new APN[cursor.getCount()];
int i = 0;
while (cursor.moveToNext())
{
APN apn = new APN();
apn.setId(cursor.getInt(0));
apn.setName(cursor.getString(1));
apn.setApn(cursor.getString(2));
apn.setMcc(cursor.getString(3));
apn.setMnc(cursor.getString(4));
apn.setUser(cursor.getString(6));
apn.setPassword(cursor.getString(7));
apn.setServer(cursor.getString(8));
apn.setProxy(cursor.getString(9));
apn.setPort(cursor.getString(10));
apn.setMmsProxy(cursor.getString(11));
apn.setMmsPort(cursor.getString(12));
apn.setMmsc(cursor.getString(13));
apn.setType(cursor.getString(14));
apn.setCurrent(cursor.getString(15));
apn.setAuthType(cursor.getInt(16));
result[i] = apn;
i++;
}
}
}
catch (Exception ex)
{
//Handle exceptions here
return null;
}
finally
{
if (cursor != null)
cursor.close();
}
return result;
}
}

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.

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.

Where to create business logic objects and maintain state? - android

if you want to save them when user closes the application , you must save them in shared preferences or database or in a file in phone memory! and for inside application, you can simply define them in a class that extends from Serializable or Parcelable and pass them between activities/fragments/etc

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Write APN Settings on Android 4.4

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

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