Null pointer exception in android sqlite
Question
I am new to android I am creating an android application that consists of a registration dialog and sqlite storage.But here i was getting null pointer exception.I didn't find any mistake but it was showing null pointer exception.I have been trying this code since 2 hours
Here i used custom buttons fin alert dialog downloaded from here This is my activity displays alert dialog and registers into database
package com.developer.milanandroid;
import java.io.File;
import java.util.ArrayList;
import com.milan.lib.progressgenarator.lib.ProgressGenerator;
import com.milan.lib.progressgenarator.lib.ProgressGenerator.OnCompleteListener;
import com.milan.paperbuttons.adminsettingsbuttons;
import com.milan.paperbuttons.ShowDatabase;
import com.milan.validation.lib.RegExpressionValueValidator;
import com.milan.validation.lib.ValidationManager;
import com.processbutton.lib.milan.ActionProcessButton;
import android.app.Activity;
import android.app.Dialog;
import android.content.Intent;
import android.database.Cursor;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.text.method.HideReturnsTransformationMethod;
import android.text.method.PasswordTransformationMethod;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.Window;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.CompoundButton.OnCheckedChangeListener;
public class AdminSettings extends Activity implements OnCompleteListener{
public LoginDataBaseAdapter logindatabase_adapter_child;
// public SQLiteDatabase db;
Button Review;
TextView text_fetched_database_results;
String username,password;
Cursor c;
adminsettingsbuttons review,fetch_database,adduser;
MediaPlayer media_player;
private ArrayList<String> USER_NAME = new ArrayList<String>();
private ArrayList<String> USER_PWD = new ArrayList<String>();
Dialog database_list;
DataBaseHelper database_helper_child;
File Milan,Sample;
//-----------------------RegistrationDialog variables--------------------------------//
com.milan.material.widgets.dialog.FloatingEditText username_dialog,password_dialog,confirm_password;
Dialog registration_dialog;
private ValidationManager validation_manager;
CheckBox show_password;
public ActionProcessButton Registerbutton,clear_Button;
LoginDataBaseAdapter logindatabaseadapter;
String dialog_user_name_string,dialog_pasword_string,dialog_confirm_string;
int username_length=5,password_length=5;
String stored_pass;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.admin_settings);
fetch_database = (adminsettingsbuttons)findViewById(R.id.Button_Fetch_from_Database);
fetch_database.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent database_list = new Intent(AdminSettings.this,DatabaseListView.class);
startActivity(database_list);
}
});
review = (adminsettingsbuttons)findViewById(R.id.button_review);
review.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
//Milan = new File(extStorageDirectory+"/Milan");
//if(!Milan.exists()){
// Milan.mkdir();
/*media_player = new MediaPlayer(AdminSettings.this,)
media_player.start();*/
//}
//Sample = new File(extStorageDirectory+"/Milan/Sample.txt");
// try {
// Sample.createNewFile();
// } catch (IOException e) {
// TODO Auto-generated catch block
// e.printStackTrace();
// }
Intent review = new Intent(getApplicationContext(),Review.class);
startActivity(review);
}
});
adduser= (adminsettingsbuttons)findViewById(R.id.button_Adduser);
adduser.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
registration_dialog = new Dialog(AdminSettings.this);
registration_dialog.requestWindowFeature(Window.FEATURE_LEFT_ICON);
registration_dialog.setContentView(R.layout.registrationdialog);
registration_dialog.setTitle("User Registration");
registration_dialog.setFeatureDrawableResource(Window.FEATURE_LEFT_ICON, R.drawable.user);
username_dialog = (com.milan.material.widgets.dialog.FloatingEditText)registration_dialog.findViewById(R.id.edt_dialog_username);
password_dialog = (com.milan.material.widgets.dialog.FloatingEditText)registration_dialog.findViewById(R.id.edt_dialog_password);
confirm_password = (com.milan.material.widgets.dialog.FloatingEditText)registration_dialog.findViewById(R.id.edt_dialog_confirm_password);
validation_manager = new ValidationManager(AdminSettings.this);
/*-----------------For validating each username and password fields in the registration dialog----------------------*/
validation_manager.add("", new RegExpressionValueValidator(username_dialog, "^[a-zA-Z0-9\\-'\\s]{3,}$", "Please enter your user name"));
validation_manager.add("", new RegExpressionValueValidator(password_dialog, "^[a-zA-Z0-9\\-'\\s]{3,}$", "Please enter your password"));
validation_manager.add("", new RegExpressionValueValidator(confirm_password, "^[a-zA-Z0-9\\-'\\s]{3,}$","Please enter confirm password"));
/*-------------------For viewing passwords on clicking show passwords checkbox-------------------------------------------*/
show_password = (CheckBox)registration_dialog.findViewById(R.id.show_password);
show_password.setOnCheckedChangeListener(new OnCheckedChangeListener()
{
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if(!isChecked)
{
password_dialog.setTransformationMethod(PasswordTransformationMethod.getInstance());
confirm_password.setTransformationMethod(PasswordTransformationMethod.getInstance());
}
else
{
password_dialog.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
confirm_password.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
}
}
});
/*-----------------------Progress generator of register button------------------------------------*/
final ProgressGenerator progressGenerator = new ProgressGenerator(AdminSettings.this);
Registerbutton = (ActionProcessButton)registration_dialog.findViewById(R.id.Btn_Register);
Registerbutton.setMode(ActionProcessButton.Mode.ENDLESS);
Registerbutton.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
int a,b,c;
dialog_user_name_string = username_dialog.getText().toString();
dialog_pasword_string = password_dialog.getText().toString();
dialog_confirm_string = confirm_password.getText().toString();
//dialog_seq_answer = seq_answer.getText().toString();
if((!dialog_user_name_string.equals("")) &&(!dialog_pasword_string.equals("")) && (!dialog_confirm_string.equals(""))){
a= dialog_user_name_string.length();
b= dialog_pasword_string.length();
c= dialog_confirm_string.length();
if((a<=username_length) && (b<=password_length) && (c<=password_length)){
Toast.makeText(AdminSettings.this, "Sorry,Username and password length must be greater than 5 characters", Toast.LENGTH_LONG).show();
media_player = MediaPlayer.create(AdminSettings.this, R.raw.usernameandpasswordlength);
media_player.start();
}
else{
stored_pass = logindatabaseadapter.checkSinlgeEntry(dialog_user_name_string);
if(!stored_pass.equals("NOT EXIST")){
if(dialog_pasword_string.equals(dialog_confirm_string)){
logindatabaseadapter.insertEntry(dialog_user_name_string, dialog_pasword_string); //Inserting username and password into the database
progressGenerator.start(Registerbutton);
Registerbutton.setEnabled(false);
media_player= MediaPlayer.create(AdminSettings.this, R.raw.regesteringintodatabase);
media_player.start();
username_dialog.setEnabled(false);
password_dialog.setEnabled(false);
confirm_password.setEnabled(false);
//registration_dialog.setCancelable(false);
}
else{
media_player= MediaPlayer.create(AdminSettings.this, R.raw.databasepasswordsnotmatched);
media_player.start();
Toast.makeText(AdminSettings.this, "Passwords did not matched please try again", Toast.LENGTH_LONG).show();
}
}
}
}
else {
/*------------------Calling for validation---------------------------*/
validation_manager.validateAllAndSetError();
Toast.makeText(AdminSettings.this, "please fill all the fields", Toast.LENGTH_LONG).show();
media_player= MediaPlayer.create(AdminSettings.this, R.raw.pleasefilallthedetails);
media_player.start();
}
}
});
clear_Button = (ActionProcessButton)registration_dialog.findViewById(R.id.Btn_Clear);
clear_Button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
username_dialog.setText("");
password_dialog.setText("");
confirm_password.setText("");
}
});
registration_dialog.show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.admin_settings, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onComplete() {
Toast.makeText(AdminSettings.this, "Account created succesfully"+" "+dialog_user_name_string,Toast.LENGTH_LONG).show();
media_player= MediaPlayer.create(AdminSettings.this, R.raw.congratulationsdb);
media_player.start();
}
}
Logindatabase Adapter:
package com.developer.milanandroid;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.view.View;
public class LoginDataBaseAdapter
{
//Database name
static final String DATABASE_NAME = "MilanloginRegistration.db";
static final int DATABASE_VERSION = 1;
public static final int NAME_COLUMN = 1;
// TODO: Create public field for each column in your table.
// SQL Statement to create a new database.
public static final String TABLE_NAME="MilanLoginregistration";
public static final String ID="_id";
public static final String USER_NAME="USERNAME";
public static final String USER_PASSWORD ="PASSWORD";
static final String DATABASE_CREATE = "create table "+ TABLE_NAME +
"( " +ID+" integer primary key autoincrement,"+"USERNAME text not null,"+USER_PASSWORD+" text not null); ";
// Variable to hold the database instance
public SQLiteDatabase db;
// Context of the application using the database.
private final Context context;
// Database open/upgrade helper
private DataBaseHelper dbHelper;
public LoginDataBaseAdapter(Context _context)
{
context = _context;
dbHelper = new DataBaseHelper(context, DATABASE_NAME, null, DATABASE_VERSION);
}
public LoginDataBaseAdapter open() throws SQLException
{
db = dbHelper.getWritableDatabase();
return this;
}
public void close()
{
db.close();
}
public SQLiteDatabase getDatabaseInstance()
{
return db;
}
public LoginDataBaseAdapter opentoRead() throws android.database.SQLException{
dbHelper = new DataBaseHelper(context, DATABASE_NAME, null, DATABASE_VERSION);
db = dbHelper.getReadableDatabase();
return this;
}
public LoginDataBaseAdapter opentoWrite() throws android.database.SQLException{
dbHelper = new DataBaseHelper(context, DATABASE_NAME, null, DATABASE_VERSION);
db = dbHelper.getWritableDatabase();
return this;
}
public void Close(){
dbHelper.close();
}
public void insertEntry(String username,String password)
{
ContentValues newValues = new ContentValues();
newValues.put("USERNAME",username);
newValues.put("PASSWORD",password);
// Insert the row into your table
db.insert("MilanLoginregistration",null,newValues);
///Toast.makeText(context, "Reminder Is Successfully Saved", Toast.LENGTH_LONG).show();
}
public int deleteAll(){
return db.delete(TABLE_NAME, null, null);
}
public void deleteEntry(int id){
//String id=String.valueOf(ID);
db.delete(TABLE_NAME, ID+"="+id, null);
// Toast.makeText(context, "Number fo Entry Deleted Successfully : "+numberOFEntriesDeleted, Toast.LENGTH_LONG).show();
}
public Cursor queue_all(){
String[] columns = new String[]{ID,"USERNAME","PASSWORD"};
Cursor cursor_queue_all =db.query(TABLE_NAME, columns, null, null, null, null, null);
return cursor_queue_all;
}
public Cursor feching_Data(){
String[] columns = {ID,USER_NAME,USER_PASSWORD};
db = dbHelper.getWritableDatabase();
Cursor cursor = db.query(TABLE_NAME, columns,null,null,null,null,null);
return cursor;
}
public String getSinlgeEntry(String userName)
{
Cursor cursor=db.query("MilanLoginregistration", null, " USERNAME=?", new String[]{userName}, null, null, null);
if(cursor.getCount()<1) // UserName Not Exist
{
cursor.close();
return "NOT EXIST";
}
cursor.moveToFirst();
String password= cursor.getString(cursor.getColumnIndex("PASSWORD"));
//cursor.close();
return password;
}
public String checkSinlgeEntry(String userName)
{
Cursor cursor=db.query("MilanLoginregistration", null, " USERNAME=?", new String[]{userName}, null, null, null);
if(cursor.getCount()>=1) // UserName Exist
{
cursor.close();
return "EXIST";
}
// cursor.close();
return "";
}
public void updateEntry(String user_name,String pasword)
{
// Define the updated row content.
ContentValues updatedValues = new ContentValues();
// Assign values for each row.
updatedValues.put("USERNAME", user_name);
updatedValues.put("PASSWORD",pasword);
String where="USERNAME = ?";
db.update("MilanLoginregistration",updatedValues, where, new String[]{user_name});
}
/*public void Display(View v){
Cursor c = db.rawQuery("select * from MilanloginRegistration", null);
admin_settings_child.text_fetched_database_results.setText("");
c.moveToFirst();
do{
String username = c.getString(c.getColumnIndex("USERNAME"));
String password = c.getString(1);
admin_settings_child.text_fetched_database_results.append("USERNAME::-->"+username+"PASSWORD::-->"+password+"\n");
}while(c.moveToNext());
}*/
}
This is my logcat
01-02 05:05:03.100: E/AndroidRuntime(18345): FATAL EXCEPTION: main
01-02 05:05:03.100: E/AndroidRuntime(18345): Process: com.developer.milanandroid, PID: 18345
01-02 05:05:03.100: E/AndroidRuntime(18345): java.lang.NullPointerException
01-02 05:05:03.100: E/AndroidRuntime(18345): at com.developer.milanandroid.AdminSettings$3$2.onClick(AdminSettings.java:187)
01-02 05:05:03.100: E/AndroidRuntime(18345): at android.view.View.performClick(View.java:4438)
01-02 05:05:03.100: E/AndroidRuntime(18345): at android.view.View$PerformClick.run(View.java:18422)
01-02 05:05:03.100: E/AndroidRuntime(18345): at android.os.Handler.handleCallback(Handler.java:733)
01-02 05:05:03.100: E/AndroidRuntime(18345): at android.os.Handler.dispatchMessage(Handler.java:95)
01-02 05:05:03.100: E/AndroidRuntime(18345): at android.os.Looper.loop(Looper.java:136)
01-02 05:05:03.100: E/AndroidRuntime(18345): at android.app.ActivityThread.main(ActivityThread.java:5017)
01-02 05:05:03.100: E/AndroidRuntime(18345): at java.lang.reflect.Method.invokeNative(Native Method)
01-02 05:05:03.100: E/AndroidRuntime(18345): at java.lang.reflect.Method.invoke(Method.java:515)
01-02 05:05:03.100: E/AndroidRuntime(18345): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
01-02 05:05:03.100: E/AndroidRuntime(18345): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
01-02 05:05:03.100: E/AndroidRuntime(18345): at dalvik.system.NativeStart.main(Native Method)
3 answers
solution1
0 2015-05-20 12:56:01
You are trying to get the following from the dialog before showing the dialog:
username_dialog = (com.milan.material.widgets.dialog.FloatingEditText)registration_dialog.findViewById(R.id.edt_dialog_username);
password_dialog = (com.milan.material.widgets.dialog.FloatingEditText)registration_dialog.findViewById(R.id.edt_dialog_password);
confirm_password = (com.milan.material.widgets.dialog.FloatingEditText)registration_dialog.findViewById(R.id.edt_dialog_confirm_password);
Try to get these views after showing the dialog or just inflate the R.layout.registrationdialog to a view object and then use the view object instead of registration_dialog .
solution2
0 ACCPTED 2015-05-20 12:56:36
You haven't defined the logindatabaseadapter variable.
When you call logindatabaseadapter.checkSinlgeEntry(...) you will get a NullPointerException as at that point, logindatabaseadapter = null .
You will need to add logindatabaseadapter = new LoginDataBaseAdapter(this) to your onCreate
solution3
0 2015-05-22 11:51:02
Thanks @Ed George for posting answer i found answer by initialising database and open it
logindatabaseadapter = new Logindatabaseadapter();
logindatabaseadapter.open();
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.
Related Question
Android SQLite Null Pointer Exception
Android Null Pointer Exception SQLite
Android SQLite null pointer exception on opening database
Android sqlite database null pointer exception
Android sqlite database null pointer exception on Insert
null pointer exception on inserting values in sqlite datatable - Android
Null Pointer Exception when inserting to sqlite database - Android
Android: Null Pointer Exception on Updating the values for SQLite Database
null pointer exception while creating sqlite database android
Null pointer exception for on Click Android (Button saves to SQLite Database)
Related Tags