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pass data from one activity to another and save it

i have two activities, each one have a listview. The first one contain the data and i want the other one to be as a favorite list. Right now i can pass the data with intent but its not saving. it shows when i start the intent but when i exit the second activity and go back to it with a custom button nothing is saved in the listview. Please tell me what to do. here is my code
public class MainActivity extends AppCompatActivity {
DB_Sqlite dbSqlite;
ListView listView;
String fav_name;
long fav_id;
ArrayAdapter adapter;
ArrayList arrayList;
String[] number;
Button button;
StringResourcesHandling srh;
Cursor getAllDataInCurrentLocale,getDataInCurrentLocaleById;
SimpleCursorAdapter favourites_adapter,non_favourites_adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.list_view);
SharedPreferences mPrefs = getPreferences(MODE_PRIVATE);
arrayList = new ArrayList<String>();
listView.setAdapter(adapter);
button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(MainActivity.this, cc.class);
startActivity(intent);
}
});
/* Show the resources for demo */
for (String s : StringResourcesHandling.getAllStringResourceNames()) {
Log.d("RESOURCEDATA", "String Resource Name = " + s +
"\n\tValue = " + StringResourcesHandling.getStringByName(this, s)
);
}
dbSqlite = new DB_Sqlite(this);
Cursor csr = dbSqlite.getAllDataInCurrentLocale(this);
DatabaseUtils.dumpCursor(csr);
csr.close();
}
#Override
protected void onDestroy() {
super.onDestroy();
getAllDataInCurrentLocale.close();
}
#Override
protected void onResume() {
super.onResume();
manageNonFavouritesListView();
}
private void manageNonFavouritesListView() {
getAllDataInCurrentLocale = dbSqlite.getAllDataInCurrentLocale(this);
if (non_favourites_adapter == null) {
non_favourites_adapter = new SimpleCursorAdapter(
this,
R.layout.textview,
getAllDataInCurrentLocale,
new String[]{FAVOURITES_COL_NAME},
new int[]{R.id.textview10},
0
);
listView.setAdapter(non_favourites_adapter);
setListViewHandler(listView,false);
} else {
non_favourites_adapter.swapCursor(getAllDataInCurrentLocale);
}
}
private void setListViewHandler(ListView listView, boolean favourite_flag) {
if (!favourite_flag) {
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
if (i == 0) {
Intent intent = new Intent(MainActivity.this,tc.class);
startActivity(intent);
}
if (i == 1) {
Intent intent = new Intent(MainActivity.this,vc.class);
startActivity(intent);
}
}
});
listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long l) {
if (position == 0) {
Intent intent = new Intent(MainActivity.this, cc.class);
intent.putExtra("EXTRAKEY_ID",l); // THIS ADDED
startActivity(intent);}
String name = getAllDataInCurrentLocale.getString(getAllDataInCurrentLocale.getColumnIndex(FAVOURITES_COL_NAME));
Toast.makeText(MainActivity.this, name+" Added To Favorite", Toast.LENGTH_SHORT).show();
return true;
}
});
}}
}
public class DB_Sqlite extends SQLiteOpenHelper {
public static final String BDname = "data.db";
public static final int DBVERSION = 1; /*<<<<< ADDED BUT NOT NEEDED */
public static final String TABLE_FAVOURITES = "mytable";
public static final String FAVOURITES_COL_ID = BaseColumns._ID; /*<<<< use the Android stock ID name*/
public static final String FAVOURITES_COL_NAME = "name";
public static final String FAVOURITES_COL_FAVOURITEFLAG = "favourite_flag"; /*<<<<< NEW COLUMN */
public DB_Sqlite(#Nullable Context context) {
super(context, BDname, null, DBVERSION /*<<<<< used constant above */);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table " + TABLE_FAVOURITES + " (" +
FAVOURITES_COL_ID + " INTEGER PRIMARY KEY," + /*<<<<< AUTOINCREMENT NOT NEEDED AND IS INEFFICIENT */
FAVOURITES_COL_NAME + " TEXT, " +
FAVOURITES_COL_FAVOURITEFLAG + " INTEGER DEFAULT 0" + /*<<<<< COLUMN ADDED */
")");
/* CHANGES HERE BELOW loop adding all Resource names NOT VALUES */
ContentValues cv = new ContentValues();
for (String s: StringResourcesHandling.getAllStringResourceNames()) {
cv.clear();
cv.put(FAVOURITES_COL_NAME,s);
db.insert(TABLE_FAVOURITES,null,cv);
}
}
#Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_FAVOURITES);
onCreate(db);
}
public boolean insertData(String name){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(FAVOURITES_COL_NAME, name);
long result = db.insert(TABLE_FAVOURITES,null, contentValues);
if (result == -1)
return false;
else
return true;
}
public Cursor getFavouriteRows(boolean favourites) {
SQLiteDatabase db = this.getWritableDatabase();
String whereclause = FAVOURITES_COL_FAVOURITEFLAG + "=?";
String compare = "<1";
if (favourites) {
compare =">0";
}
return db.query(
TABLE_FAVOURITES,null,
FAVOURITES_COL_FAVOURITEFLAG + compare,
null,null,null,null
);
}
private int setFavourite(long id, boolean favourite_flag) {
SQLiteDatabase db = this.getWritableDatabase();
String whereclause = FAVOURITES_COL_ID + "=?";
String[] whereargs = new String[]{String.valueOf(id)};
ContentValues cv = new ContentValues();
cv.put(FAVOURITES_COL_FAVOURITEFLAG,favourite_flag);
return db.update(TABLE_FAVOURITES,cv,whereclause,whereargs);
}
public int setAsFavourite(long id) {
return setFavourite(id,true);
}
public int setAsNotFavourite(long id) {
return setFavourite(id, false);
}
/* Getting everything and make MatrixCursor VALUES from Resource names from Cursor with Resource names */
public Cursor getAllDataInCurrentLocale(Context context) {
SQLiteDatabase db = this.getWritableDatabase();
Cursor csr = db.query(TABLE_FAVOURITES,null,null,null,null,null,null);
if (csr.getCount() < 1) return csr;
MatrixCursor mxcsr = new MatrixCursor(csr.getColumnNames(),csr.getCount());
while (csr.moveToNext()) {
mxcsr.addRow(convertCursorRow(context,csr,new String[]{FAVOURITES_COL_NAME}));
}
csr.close();
return mxcsr;
}
public Cursor getDataInCurrentLocaleById(Context context, long id) {
SQLiteDatabase db = this.getWritableDatabase();
String wherepart = FAVOURITES_COL_ID + "=?";
String[] args = new String[]{String.valueOf(id)};
Cursor csr = db.query(TABLE_FAVOURITES,null,wherepart,args,null,null,null);
if (csr.getCount() < 1) return csr;
MatrixCursor mxcsr = new MatrixCursor(csr.getColumnNames(),csr.getCount());
while (csr.moveToNext()) {
mxcsr.addRow(convertCursorRow(context,csr,new String[]{FAVOURITES_COL_NAME}));
}
csr.close();
return mxcsr;
}
/* This getting columns from Cursor into String array (no BLOB handleing)*/
private String[] convertCursorRow(Context context, Cursor csr, String[] columnsToConvert) {
String[] rv = new String[csr.getColumnCount()];
for (String s: csr.getColumnNames()) {
boolean converted = false;
for (String ctc: columnsToConvert) {
if (csr.getType(csr.getColumnIndex(s)) == Cursor.FIELD_TYPE_BLOB) {
//........ would have to handle BLOB here if needed (another question if needed)
}
if (ctc.equals(s)) {
rv[csr.getColumnIndex(s)] = StringResourcesHandling.getStringByName(context,csr.getString(csr.getColumnIndex(s)));
converted = true;
}
} if (!converted) {
rv[csr.getColumnIndex(s)] = csr.getString(csr.getColumnIndex(s));
}
}
return rv;
}
}
public class cc extends AppCompatActivity {
String fav_name;
long fav_id;
DB_Sqlite dbSqlite;
SimpleCursorAdapter favourites_adapter;
ListView listView1;
ArrayList<String> arrayList1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_cc);
listView1 = (ListView) findViewById(R.id.list_view1);
arrayList1 = new ArrayList<String>();
fav_id = getIntent().getLongExtra("EXTRAKEY_ID", 0);
if (fav_id == 0) {
}
dbSqlite = new DB_Sqlite(this);
Cursor cursor = dbSqlite.getDataInCurrentLocaleById(this, fav_id);
if (cursor.moveToFirst()) {
fav_name = cursor.getString(cursor.getColumnIndex(FAVOURITES_COL_NAME));
manageNonFavouritesListView();
}
cursor.close();
}
private void manageNonFavouritesListView() {
Cursor cursor = dbSqlite.getDataInCurrentLocaleById(this,fav_id);
if (favourites_adapter == null) {
favourites_adapter = new SimpleCursorAdapter(
this,
R.layout.textview,
cursor,
new String[]{FAVOURITES_COL_NAME},
new int[]{R.id.textview10},
0
);
listView1.setAdapter(favourites_adapter);
setListViewHandler(listView1,true);
} else {
favourites_adapter.swapCursor(cursor);
}
}
private void setListViewHandler(ListView listView1, boolean b) {
listView1.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
if (fav_id == 1) {
Intent intent = new Intent(cc.this, tc.class);
startActivity(intent);
}
if (fav_id == 2) {
Intent intent = new Intent(cc.this, vc.class);
startActivity(intent);
}
}
});
}
}
public class StringResourcesHandling {
private static final String[] allowedStringResourcePrefixes = new String[]{"db_"};
private static boolean loaded = false;
private static Field[] fields = R.string.class.getFields();
private static ArrayList<String> allowedStringResourceNames = new ArrayList<>();
private static void loadStringResources() {
if (loaded) return;
for (Field f: fields) {
if (isResourceNameAllowedPrefix(f.getName())) {
allowedStringResourceNames.add(f.getName());
}
}
loaded = true;
}
private static boolean isResourceNameAllowedPrefix(String resourceName) {
if (allowedStringResourcePrefixes.length < 1) return true;
for (String s: allowedStringResourcePrefixes) {
if (resourceName.substring(0,s.length()).equals(s)) return true;
}
return false;
}
public static String getStringByName(Context context, String name) {
String rv = "";
boolean nameFound = false;
if (!loaded) {
loadStringResources();
}
for (String s: allowedStringResourceNames) {
if (s.equals(name)) {
nameFound = true;
break;
}
}
if (!nameFound) return rv;
return context.getString(context.getResources().getIdentifier(name,"string",context.getPackageName()));
}
public static List<String> getAllStringResourceNames() {
if (!loaded) {
loadStringResources();
}
return allowedStringResourceNames;
}
}
note: i get the data in 1st listview from strings.xml
please help me thank u in advance

You can add a column say 'isFavourite' in your db table which has list vew data. When user mark listitem as favourite, save the change in db table . When user navigates to favourite list populate the list from. db table with favourite filter in select query.

I suggest using SharedPreferences. You stated that your value gets overwritten. That won't be the case if you create multiple keys.
Example:
Say you have an ArrayList of String you want to pass from ClassA to ClassB:
ClassA:
for (int i = 0; i < list.size(); i++) {
sharedPref.edit().putString("text" + i, "abcde").apply();
}
ClassB:
for (int i = 0; i < list.size(); i++) {
sharedPref.getString("text" + i, null);
}
If you have problems with the listsize, you can also pass the listsize to sharedpref and retrieve it again.

Database refusing to delete item

I was working on an app where the user will input text through an editText, and it will be stored into listView and DataBase.
But when I ran the code, the Item refused to delete.
InputContract.java
public class InputContract {
public static final String DB_NAME = "com.dobleu.peek.db";
public static final int DB_VERSION = 1;
public class TaskEntry implements BaseColumns {
public static final String TABLE = "tasks";
public static final String COL_TASK_TITLE = "title";
}
}
InputDbHelper.java
public class InputDbHelper extends SQLiteOpenHelper {
public InputDbHelper(Context context) {
super(context, InputContract.DB_NAME, null, InputContract.DB_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
String createTable = "CREATE TABLE " + InputContract.TaskEntry.TABLE + " ( " +
InputContract.TaskEntry._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
InputContract.TaskEntry.COL_TASK_TITLE + " TEXT NOT NULL);";
db.execSQL(createTable);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + InputContract.TaskEntry.TABLE);
onCreate(db);
}
}
MainActivity.java
public class MainActivity extends AppCompatActivity {
ListView list;
private ArrayList<String> items;
private ArrayAdapter<String> itemsAdapter;
ConstraintLayout l1;
ConstraintLayout l2;
TextView displayText;
TextView amt;
TextView itms;
private static int TIME = 1000;
private InputDbHelper mHelper;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams. FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
init();
mHelper = new InputDbHelper(this);
updateUI();
int no = list.getAdapter().getCount();
amt.setText("" + no);
setupListViewListener();
}
private void setupListViewListener() {
list.setOnItemLongClickListener(
new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> adapter,
View item, int pos, long id) {
// Remove the item within array at position
items.remove(pos);
// Refresh the adapter
SQLiteDatabase db = mHelper.getWritableDatabase();
db.delete(InputContract.TaskEntry.TABLE,
InputContract.TaskEntry.COL_TASK_TITLE + " = ?",
new String[]{"Name of entry you want deleted"});
db.close();
updateUI();
itemsAdapter.notifyDataSetChanged();
// Return true consumes the long click event (marks it handled)
return true;
}
});
}
public void init(){
ActionBar ab = getSupportActionBar();
assert ab != null;
ab.hide();
list = (ListView)findViewById(R.id.list);
displayText = (TextView)findViewById(R.id.displayText);
amt = (TextView)findViewById(R.id.amt);
itms = (TextView)findViewById(R.id.itms);
items = new ArrayList<String>();
itemsAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, items);
list.setAdapter(itemsAdapter);
l1 = (ConstraintLayout)findViewById(R.id.one);
l2 = (ConstraintLayout)findViewById(R.id.two);
Typeface regular = Typeface.createFromAsset(getAssets(), "fonts/regular.ttf");
Typeface bold = Typeface.createFromAsset(getAssets(), "fonts/bold.ttf");
amt.setTypeface(bold);
itms.setTypeface(regular);
displayText.setTypeface(regular);
}
public void add(View v){
AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
LayoutInflater inflater = this.getLayoutInflater();
final View dialogView = inflater.inflate(R.layout.dialog, null);
dialogBuilder.setView(dialogView);
final EditText edt = (EditText) dialogView.findViewById(R.id.edit1);
dialogBuilder.setTitle("Add Item");
dialogBuilder.setMessage("Enter text below");
dialogBuilder.setPositiveButton("Done", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
String txt = edt.getText().toString();
items.add(txt);
SQLiteDatabase db = mHelper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(InputContract.TaskEntry.COL_TASK_TITLE, txt);
db.insertWithOnConflict(InputContract.TaskEntry.TABLE, null, values, SQLiteDatabase.CONFLICT_REPLACE);
db.close();
updateUI();
int no = list.getAdapter().getCount();
amt.setText("" + no);
}
});
dialogBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
//pass
}
});
AlertDialog b = dialogBuilder.create();
b.show();
}
public void play(View v){
Animation fadeOut = AnimationUtils.loadAnimation(this, abc_fade_out);
Animation fadeIn = AnimationUtils.loadAnimation(this, abc_fade_in);
l1.startAnimation(fadeOut);
l1.setVisibility(View.GONE);
l2.setVisibility(View.VISIBLE);
l2.startAnimation(fadeIn);
String[] array = new String[items.size()];
final String[] mStringArray = items.toArray(array);
final android.os.Handler handler = new android.os.Handler();
handler.post(new Runnable() {
int i = 0;
#Override
public void run() {
displayText.setText(mStringArray[i]);
i++;
if (i == mStringArray.length) {
handler.removeCallbacks(this);
} else {
handler.postDelayed(this, TIME);
}
}
});
}
public void one(View v){TIME = 1000;}
public void three(View v){TIME = 3000;}
public void five(View v){TIME = 5000;}
public void seven(View v){TIME = 7000;}
public void ten(View v){TIME = 10000;}
private void updateUI() {
ArrayList<String> taskList = new ArrayList<>();
SQLiteDatabase db = mHelper.getReadableDatabase();
Cursor cursor = db.query(InputContract.TaskEntry.TABLE,
new String[]{InputContract.TaskEntry._ID, InputContract.TaskEntry.COL_TASK_TITLE},
null, null, null, null, null);
while (cursor.moveToNext()) {
int idx = cursor.getColumnIndex(InputContract.TaskEntry.COL_TASK_TITLE);
taskList.add(cursor.getString(idx));
}
if (itemsAdapter== null) {
itemsAdapter= new ArrayAdapter<>(this, android.R.layout.simple_list_item_1,
taskList);
list.setAdapter(itemsAdapter);
} else {
itemsAdapter.clear();
itemsAdapter.addAll(taskList);
itemsAdapter.notifyDataSetChanged();
}
cursor.close();
db.close();
}
}
In MainActivity.java, specifically in setupListViewListener(), when the listView is held, it is supposed to delete the item that is being held. But the list only vibrates and remains the same. How can I fix this?

I suspect that your issue is that you have hard coded the TASK_TITLE to be deleted as "Name of entry you want deleted" as opposed to getting the TASK_TITLE from the item that was long clicked.
So try using :-
private void setupListViewListener() {
list.setOnItemLongClickListener(
new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> adapter,
View item, int pos, long id) {
String title_of_row_to_delete = list.getItemAtPosition(i).toString(); //<<<<<<<<
// Remove the item within array at position
items.remove(pos);
// Refresh the adapter
SQLiteDatabase db = mHelper.getWritableDatabase();
db.delete(InputContract.TaskEntry.TABLE,
InputContract.TaskEntry.COL_TASK_TITLE + " = ?",
new String[]{title_of_row_to_delete}); //<<<<<<<<
db.close();
updateUI();
itemsAdapter.notifyDataSetChanged();
// Return true consumes the long click event (marks it handled)
return true;
}
});
}
This will extract the TASK_TITLE from the list and then use that as the argument to find the row to be deleted.
//<<<<<<<< indicates changed lines.

Any Idea on how I can stop adding multiple entry's of ID's into a database with this code?

I'm trying to figure a way of allowing users NOT to be able to add the same ID twice as if I wanted to delete one of the users and he shared the ID with another it would delete both.
So far I have found no help doing so does anyone have an idea?
public class MainActivity extends AppCompatActivity {
private Button button;
private EditText IdText;
private EditText NameText;
private EditText AgeText;
private EditText WeightText;
private EditText HeightText;
private EditText ReachText;
MyDBHandler dbHandler;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
IdText = (EditText) findViewById(R.id.IdText);
NameText = (EditText) findViewById(R.id.NameText);
HeightText = (EditText) findViewById(R.id.HeightText);
AgeText = (EditText) findViewById(R.id.AgeText);
WeightText = (EditText) findViewById(R.id.WeightText);
ReachText = (EditText) findViewById(R.id.ReachText);
button = (Button) findViewById(R.id.button);
dbHandler = new MyDBHandler(this);
AddData();
}
public void AddData() {
button.setOnClickListener(
new View.OnClickListener() {
#Override
public void onClick(View v) {
if ((IdText.getText().toString()).isEmpty()) {
IdText.setError("Please fill out your name");
return;
} else if ((NameText.getText().toString()).isEmpty()) {
NameText.setError("Please fill out your ID");
return;
} else if ((AgeText.getText().toString()).isEmpty()) {
AgeText.setError("Please fill out your Age");
return;
} else if ((HeightText.getText().toString()).isEmpty()) {
HeightText.setError("Please fill out your Height in centimeters");
return;
} else if ((WeightText.getText().toString()).isEmpty()) {
WeightText.setError("Please fill out your weight in kilos");
return;
} else if ((ReachText.getText().toString()).isEmpty()) {
ReachText.setError("Please fill out your reach in inches");
return;
} else {
boolean isInserted = dbHandler.insertData(IdText.getText().toString(),
NameText.getText().toString(),
AgeText.getText().toString(),
HeightText.getText().toString(),
WeightText.getText().toString(),
ReachText.getText().toString());
if (isInserted == true)
Toast.makeText(MainActivity.this, "Fighter added", Toast.LENGTH_LONG).show();
else
Toast.makeText(MainActivity.this, "Data not inserted", Toast.LENGTH_LONG).show();
}
}
}
);
}
public class MyDBHandler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "Fighters.db";
public static final String TABLE_PRODUCTS = "Fighter";
public static final String COLUMN_ID = "ID1";
public static final String COLUMN_NAME = "Name";
public static final String COLUMN_AGE = "Age";
public static final String COLUMN_WEIGHT = "Weight";
public static final String COLUMN_HEIGHT = "Height";
public static final String COLUMN_REACH = "Reach";
SQLiteDatabase db;
public MyDBHandler(Context context) {
super(context, DATABASE_NAME, null, 1);
SQLiteDatabase db = this.getWritableDatabase();
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE " + TABLE_PRODUCTS + " (ID INTEGER PRIMARY KEY AUTOINCREMENT,ID1 TEXT,Name TEXT,Age INTEGER,Weight INTEGER,Height TEXT,Reach TEXT)");
}
#Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
db.execSQL("DROP TABLE IF EXISTS" + TABLE_PRODUCTS);
this.onCreate(db);
}
//Add new row to the database
public boolean insertData(String id1, String name, String age, String weight, String height, String reach) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(COLUMN_ID, id1);
contentValues.put(COLUMN_NAME, name);
contentValues.put(COLUMN_AGE, age);
contentValues.put(COLUMN_WEIGHT, weight);
contentValues.put(COLUMN_HEIGHT, height);
contentValues.put(COLUMN_REACH, reach);
long result = db.insert(TABLE_PRODUCTS, null, contentValues);
if (result == -1)
return false;
else
return true;
}
public Cursor getAllData() {
SQLiteDatabase db = this.getWritableDatabase();
Cursor res = db.rawQuery("select * from " + TABLE_PRODUCTS, null);
return res;
}
public boolean updateData(String id1,String name, String age, String weight, String height, String reach) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(COLUMN_ID, id1);
contentValues.put(COLUMN_NAME, name);
contentValues.put(COLUMN_AGE, age);
contentValues.put(COLUMN_WEIGHT, weight);
contentValues.put(COLUMN_HEIGHT, height);
contentValues.put(COLUMN_REACH, reach);
db.update(TABLE_PRODUCTS, contentValues, "ID1 = ?", new String[] {id1 });
return true;
}
public Integer deleteData (String id) {
SQLiteDatabase db = this.getWritableDatabase();
return db.delete(TABLE_PRODUCTS, "ID1 = ?", new String[] {id});
}

How to insert and retrieve data display button using sqlite

I cant't get all data to display in button when click on button get. please help me.
public class DBHelper extends SQLiteOpenHelper {
private static final int VERSION = 1;
private static final String DATABASE = "Test";
private static final String TABLE_NAME = "savedata";
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_SEX = "sex";
public DBHelper(Context context) {
super(context, DATABASE, null,VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
String sql = "CREATE TABLE IF NOT EXISTS " +TABLE_NAME + "("
+ KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
+ KEY_NAME + " TEXT,"
+ KEY_SEX + " TEXT)";
db.execSQL(sql);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS" +TABLE_NAME);
onCreate(db);
}
public void Insertdata(Data data){
SQLiteDatabase db = getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, data.getName());
values.put(KEY_SEX, data.getSex());
db.insert(TABLE_NAME, null, values);
}
public List<Data> getAllData(){
List<Data> listData = new ArrayList<Data>();
SQLiteDatabase db = this.getWritableDatabase();
Cursor c = db.rawQuery("SELECT * FROM " +TABLE_NAME, null);
if (c.moveToFirst()){
do {
Data data = new Data();
data.setId(c.getInt(0));
data.setName(c.getString(1));
data.setSex(c.getString(2));
listData.add(data);
}while (c.moveToNext());
}
return listData;
}
}
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
name = (EditText)findViewById(R.id.edit_name);
sex = (EditText)findViewById(R.id.edit_sex);
btn_get = (Button)findViewById(R.id.btn_get);
btn_name = (Button)findViewById(R.id.btn_name);
btn_sex = (Button)findViewById(R.id.btn_sex);
btn_id = (Button)findViewById(R.id.btn_id);
db = new DBHelper(this);
_name = name.getText().toString();
_sex = sex.getText().toString();
data = new Data(_name,_sex);
btn_save =( Button)findViewById(R.id.btn_save);
SaveData();
getData();
}
public void SaveData(){
btn_save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try{
db.Insertdata(data);
Toast.makeText(getApplicationContext(), "SuccessFull",Toast.LENGTH_SHORT).show();
}catch (Exception e){
Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_SHORT).show();
}
}
});
}
public void getData(){
btn_get.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
if (currentData == null){
Toast.makeText(getApplicationContext(),"Null", Toast.LENGTH_SHORT).show();
}else {
currentData = db.getAllData();
btn_id.setText(String.valueOf(data.getId()));
btn_name.setText(data.getName());
btn_sex.setText(data.getSex());
}
}catch (Exception e){
Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_SHORT).show();
}
}
});
}

You've messed up badly. That's all I can suggest-
1. Create a class (for example "MyClass") that will extend AppCompatActivity and contains the view.
2. You've already created a class named DBHelper for your Database manipulation. It extends SQLiteOpenHelper.
3. Create object of DBHelper class inside the onCreate method of MyClass and access your database. onCreate method in MyClass will be looking similar to this-
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
name = (EditText)findViewById(R.id.edit_name);
sex = (EditText)findViewById(R.id.edit_sex);
btn_get = (Button)findViewById(R.id.btn_get);
btn_name = (Button)findViewById(R.id.btn_name);
btn_sex = (Button)findViewById(R.id.btn_sex);
btn_id = (Button)findViewById(R.id.btn_id);
db = new DBHelper(this);
_name = name.getText().toString();
_sex = sex.getText().toString();
data = new Data(_name,_sex);
btn_save =( Button)findViewById(R.id.btn_save);
btn_save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try{
db.Insertdata(data);
Toast.makeText(getApplicationContext(), "SuccessFull",Toast.LENGTH_SHORT).show();
}catch (Exception e){
Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_SHORT).show();
}
}
});
btn_get.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
if (currentData == null){
Toast.makeText(getApplicationContext(),"Null", Toast.LENGTH_SHORT).show();
}else {
currentData = db.getAllData();
btn_id.setText(String.valueOf(data.getId()));
btn_name.setText(data.getName());
btn_sex.setText(data.getSex());
}
}catch (Exception e){
Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_SHORT).show();
}
}
});
}
Hope that, this might help.

Android SQL query nullpointer can't get the data from database

here is the LogCat
I can't post image so i put it in google drive
link here
////////And here is the DB///////
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class UserDB {
public static final String TABLE_USER = "User";
public static final String ID = "ID";
public static final String USERNAME = "USERNAME";
public static final String PASSWORD = "PASSWORD";
public static final String CHKPASSWORD = "CHKPASSWORD";
public static final String SEX = "SEX";
public static final String eat = "eat";
public static final String drink = "drink";
public static final String smoke = "smoke";
public static final String conctrolweigh = "conctrolweigh";
public static final String blosuger = "blosuger";
public static final String hospital = "hospital";
private Context Context = null;
public static final String Education = "Education";
public static class DatabaseHelper extends SQLiteOpenHelper{
public static final String DATABASE_NAME = "diabetes.db";
private static final int DATABASE_VERSION = 1;
//usertable
public DatabaseHelper(Context context, CursorFactory factory) {
super(context, DATABASE_NAME, factory, DATABASE_VERSION);
}
public static final String TABLE_USER_CREATE =
"CREATE TABLE " + TABLE_USER
+ "("
+ ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ USERNAME + " text , "
+ PASSWORD+ " text ,"
+ CHKPASSWORD+ " text ,"
+ SEX+ " text ,"
+ eat + " text , "
+ drink + " text, "
+ smoke + " text, "
+ conctrolweigh + " text, "
+ blosuger + " text, "
+ hospital + " text, "
+ Education + " text);";
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, 1);
}
#Override
public void onOpen(SQLiteDatabase db) {
super.onOpen(db);
// 每次成功打開資料庫後首先被執行
}
#Override
public synchronized void close() {
super.close();
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(TABLE_USER_CREATE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROPB TABLE IF EXISTS " + TABLE_USER);
onCreate(db);
}
}
public DatabaseHelper dbHelper;
public SQLiteDatabase db;
public UserDB(Context context){
this.Context = context;
DatabaseHelper openHelper = new DatabaseHelper(this.Context);
this.db = openHelper.getWritableDatabase();
}
public UserDB open() throws SQLException{
dbHelper = new DatabaseHelper(Context);
db = dbHelper.getWritableDatabase();
return this;
}
public void close(){
dbHelper.close();
}
//add user
public void insertEntry(String ID, String PWD,String CHPW,String SEX,String eat,String drink,String smoke,String conctrolweigh,String blosuger,String hospital,String Education){
if (PWD.equals(CHPW)){
ContentValues newValues = new ContentValues();
newValues.put("USERNAME", ID);
newValues.put("PASSWORD", PWD);
newValues.put("CHKPASSWORD", CHPW);
newValues.put("SEX", SEX);
newValues.put("eat", eat);
newValues.put("drink", drink);
newValues.put("smoke", smoke);
newValues.put("conctrolweigh", conctrolweigh);
newValues.put("blosuger", blosuger);
newValues.put("hospital", hospital);
newValues.put("Education", Education);
db.insert(TABLE_USER, null, newValues);
}else{
}
}
public String getSinlgeEntry(String userName) {
Cursor cursor = db.query("User", null, " USERNAME=?",
new String[] { userName }, null, null, null);
if (cursor.getCount() < 1) // UserName Not Exist
return "Not Exist";
cursor.moveToFirst();
String password = cursor.getString(cursor.getColumnIndex("PASSWORD"));
return password;
}
public SQLiteDatabase getReadableDatabase() {
// TODO Auto-generated method stub
return null;
}
}
//////here is the Activity//////////
public class SelfteachingActivity extends Activity {
Button btnselback,tvartical ,tvfood,tvhealth,tvexcise;
TextView tvid,tvstore,tveat,tvhospital,tvblosuger,tvconctrolweigh,tvdrink,tvsmoke,tvSEX,tvEducation;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_selfteaching);
findViews();
setListeners();
//openDatabase();
String username= (this.getIntent().getExtras().getString("username"));
tvstore.setText(username);
tvid.setText(tvstore.getText().toString());
query();
}
private void query() {
UserDB helper = new UserDB(this);
SQLiteDatabase db = helper.getReadableDatabase();
helper.open();
if(helper.getReadableDatabase() == null){
Log.i("Log Activity Test", "helper is null!!!!!!!!!");
}
String user = tvstore.getText().toString();
try {
Log.i("Log Activity Test", "start db!!");
Cursor cursor = db.rawQuery("SELECT SEX,hospital,blosuger,drink,conctrolweigh,smoke,Education,eat FROM User Where USERNAME ='"+user+"'", null);
if(cursor!=null){
int rows_num = cursor.getCount();
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
Integer Id = cursor.getInt(cursor.getColumnIndex("id"));
tvSEX.setText(cursor.getString(cursor.getColumnIndex("SEX")));
tvhospital.setText(cursor.getString(cursor.getColumnIndex("hospital")));
tvblosuger.setText(cursor.getString(cursor.getColumnIndex("blosuger")));
tvdrink.setText(cursor.getString(cursor.getColumnIndex("drink")));
tvconctrolweigh.setText(cursor.getString(cursor.getColumnIndex("conctrolweigh")));
tvsmoke.setText(cursor.getString(cursor.getColumnIndex("smoke")));
tvEducation.setText(cursor.getString(cursor.getColumnIndex("Education")));
tveat.setText(cursor.getString(cursor.getColumnIndex("eat")));
cursor.moveToNext();
}
}
} catch (Exception ex) {
ex.printStackTrace();
} finally {
}
}
private long exitTime = 0;
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN){
if((System.currentTimeMillis()-exitTime) > 2000){
Toast.makeText(getApplicationContext(), "再按一次返回鍵退出", Toast.LENGTH_SHORT).show();
exitTime = System.currentTimeMillis();
} else {
finish();
System.exit(0);
}
return true;
}
return super.onKeyDown(keyCode, event);
}
private void findViews(){
btnselback = (Button)findViewById(R.id.buttonselback);
tvartical = (Button)findViewById(R.id.buttonartical);
tvfood = (Button)findViewById(R.id.buttonfood);
tvhealth = (Button)findViewById(R.id.buttonhealth);
tvexcise = (Button)findViewById(R.id.buttonescise);
tvid = (TextView)findViewById(R.id.tVsid);
tvstore = (TextView)findViewById(R.id.tvstore);
tveat = (TextView)findViewById(R.id.tveat);
tvhospital= (TextView)findViewById(R.id.tvhospital);
tvblosuger= (TextView)findViewById(R.id.tvblosuger);
tvconctrolweigh= (TextView)findViewById(R.id.tvconctrolweigh);
tvdrink= (TextView)findViewById(R.id.tvdrink);
tvsmoke= (TextView)findViewById(R.id.tvsmoke);
tvSEX= (TextView)findViewById(R.id.tvSEX);
tvEducation= (TextView)findViewById(R.id.tvEducation);
}
private void setListeners(){
//回上一頁
btnselback.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
String username = tvstore.getText().toString();
Intent intent = new Intent();
intent.setClass(SelfteachingActivity.this, LoginActivity.class);
intent.putExtra("username", username );
startActivity(intent);
SelfteachingActivity.this.finish();
}
});
//衛教文章
tvartical.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
String username = tvstore.getText().toString();
Intent intent = new Intent();
intent.setClass(SelfteachingActivity.this, ArticalActivity.class);
intent.putExtra("SEX", tvSEX.getText().toString() );
intent.putExtra("username", username );
intent.putExtra("hospital", tvhospital.getText().toString());
intent.putExtra("blosuger", tvblosuger.getText().toString() );
intent.putExtra("drink", tvdrink.getText().toString() );
intent.putExtra("conctrolweigh", tvconctrolweigh.getText().toString());
intent.putExtra("smoke", tvsmoke.getText().toString());
intent.putExtra("Education", tvEducation.getText().toString());
intent.putExtra("eat", tveat.getText().toString());
startActivity(intent);
SelfteachingActivity.this.finish();
}
});
//食物衛教
tvfood.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
String username = tvstore.getText().toString();
Intent intent = new Intent();
intent.setClass(SelfteachingActivity.this, FoodActivity.class);
intent.putExtra("username", username );
intent.putExtra("SEX", tvSEX.getText().toString() );
intent.putExtra("hospital", tvhospital.getText().toString());
intent.putExtra("blosuger", tvblosuger.getText().toString() );
intent.putExtra("drink", tvdrink.getText().toString() );
intent.putExtra("conctrolweigh", tvconctrolweigh.getText().toString());
intent.putExtra("smoke", tvsmoke.getText().toString());
intent.putExtra("Education", tvEducation.getText().toString());
intent.putExtra("eat", tveat.getText().toString());
startActivity(intent);
SelfteachingActivity.this.finish();
}
});
//健康衛教
tvhealth.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
String username = tvstore.getText().toString();
Intent intent = new Intent();
intent.setClass(SelfteachingActivity.this, HealthActivity.class);
intent.putExtra("username", username );
intent.putExtra("SEX", tvSEX.getText().toString() );
intent.putExtra("hospital", tvhospital.getText().toString());
intent.putExtra("blosuger", tvblosuger.getText().toString() );
intent.putExtra("drink", tvdrink.getText().toString() );
intent.putExtra("conctrolweigh", tvconctrolweigh.getText().toString());
intent.putExtra("smoke", tvsmoke.getText().toString());
intent.putExtra("Education", tvEducation.getText().toString());
intent.putExtra("eat", tveat.getText().toString());
startActivity(intent);
SelfteachingActivity.this.finish();
}
});
//運動衛教
tvexcise.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
String username = tvstore.getText().toString();
Intent intent = new Intent();
intent.setClass(SelfteachingActivity.this, ExciseActivity.class);
intent.putExtra("username", username );
intent.putExtra("SEX", tvSEX.getText().toString() );
intent.putExtra("hospital", tvhospital.getText().toString());
intent.putExtra("blosuger", tvblosuger.getText().toString() );
intent.putExtra("drink", tvdrink.getText().toString() );
intent.putExtra("conctrolweigh", tvconctrolweigh.getText().toString());
intent.putExtra("smoke", tvsmoke.getText().toString());
intent.putExtra("Education", tvEducation.getText().toString());
intent.putExtra("eat", tveat.getText().toString());
startActivity(intent);
SelfteachingActivity.this.finish();
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.selfteaching, menu);
return true;
}
}
Problem:
1.i don't get any data from SQL but no crash
what is the problem with my code?
the program stop in here
Cursor cursor = db.rawQuery("SELECT SEX,hospital,blosuger,drink,conctrolweigh,smoke,Education,eat FROM User Where USERNAME ='"+user+"'", null);
and say null pointer , i check the db and is null , i don't know how this happen.
plz help me

Method that you call
SQLiteDatabase db = helper.getReadableDatabase();
returns your null due to your code:
public SQLiteDatabase getReadableDatabase() {
// TODO Auto-generated method stub
return null;
}