Develop Reference

getResources on a null object in an android project

I have a method in a library I am creating for a series of apps I am doing. This method will display an input dialog for the user to input a string entry. I am writing this project for android using android studio, and I am writing it in Java.
Here is the Logcat:
2020-11-17 00:44:23.819 6758-6758/com.phoenixhosman.launcher E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.phoenixhosman.launcher, PID: 6758
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
at android.content.ContextWrapper.getResources(ContextWrapper.java:91)
at android.view.ContextThemeWrapper.getResourcesInternal(ContextThemeWrapper.java:127)
at android.view.ContextThemeWrapper.getResources(ContextThemeWrapper.java:121)
at android.content.Context.getString(Context.java:594)
at com.phoenixhosman.phoenixlib.ActivityPhoenixLib.InputDialog(ActivityPhoenixLib.java:97)
at com.phoenixhosman.launcher.ActivityHome.onClick(ActivityHome.java:151)
at android.view.View.performClick(View.java:6603)
at android.view.View.performClickInternal(View.java:6576)
at android.view.View.access$3100(View.java:780)
at android.view.View$PerformClick.run(View.java:26090)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6714)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:503)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:911)
Here in my ActivityHome.java file:
/*
The Phoenix Hospitality Management System
Launcher App Source Code
Main Activity Code File
Copyright (c) 2020 By Troy Marker Enterprises
All Rights Under Copyright Reserved
The code in this file was created for use with the Phoenix Hospitality Management System (PHMS).
Use of this code outside the PHMS is strictly prohibited.
*/
package com.phoenixhosman.launcher;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import androidx.annotation.NonNull;
import com.phoenixhosman.phoenixapi.*;
import com.phoenixhosman.phoenixlib.ProviderUser;
import com.phoenixhosman.phoenixlib.ActivityPhoenixLib;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.concurrent.atomic.AtomicInteger;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import static com.phoenixhosman.phoenixapi.ManagerSecurityApi.*;
/**
* This activity display links to the other apps in the Phoenix Hospitality
* system, and use authentication to only show those that the user has
* permission to use.
* #author Troy L. Marker
* #version 1.0.0
* #since 0.5.0
*/
public class ActivityHome extends Activity implements View.OnClickListener
{
private String strCoName;
private String strApiUrl;
private String strLockPass;
private EditText etUsername;
private EditText etPassword;
final private static int REQUEST_CODE_1 = 1;
final ActivityPhoenixLib Phoenix = new ActivityPhoenixLib();
/**
* This method will create the activity, read content to display, and show the main activity screen
* Used when the activity is (re)created.
* #param savedInstanceState current saved instance state
*/
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
View decorView = getWindow().getDecorView();
decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_FULLSCREEN);
setContentView(R.layout.activity_home);
etUsername = findViewById(R.id.etUsername);
etPassword = findViewById(R.id.etPassword);
TextView tvWarning = findViewById(R.id.tvWarning);
Button btnLogon = findViewById(R.id.btnLogon);
Button btnLockPass = findViewById(R.id.btnLockPass);
btnLogon.setOnClickListener(this);
btnLockPass.setOnClickListener(this);
#SuppressLint("Recycle") Cursor cursor = getContentResolver().query(Uri.parse("content://com.phoenixhosman.installer.ProviderSettings/settings"), null, null, null, null, null);
assert cursor != null;
if(cursor.moveToFirst()) {
while(!cursor.isAfterLast()) {
strCoName = cursor.getString(cursor.getColumnIndex("coname"));
strApiUrl = cursor.getString(cursor.getColumnIndex("apiurl"));
strLockPass = cursor.getString(cursor.getColumnIndex("lockpass"));
cursor.moveToNext();
}
new ManagerSecurityApi(strApiUrl);
tvWarning.setText(getString(R.string.warning, rtrim(strCoName)));
} else {
Phoenix.Error(getApplicationContext(),getString(R.string.required), false);
}
}
/**
* Override of the onBackPress method from the parent class
* This disables the back button on the device.
*/
#Override
public void onBackPressed() {
Phoenix.Error(ActivityHome.this, getString(R.string.disabled, getString(R.string.back)),false);
}
/**
* This method overrides the parents click listner.
* #param v the view clicked.
*/
#Override
public void onClick(View v) {
Button button = (Button)v;
String buttonText = button.getText().toString();
if (buttonText.equals(getString(R.string.login))) {
if (etUsername.getText().toString().isEmpty() || etPassword.getText().toString().isEmpty()) {
Phoenix.Error(ActivityHome.this, getString(R.string.both_required,getString(R.string.username_password)), false);
} else {
Call<String> call = getInstance().getApi().login(etUsername.getText().toString(), etPassword.getText().toString());
call.enqueue(new Callback<String>() {
#Override
public void onResponse(#NonNull Call<String> call, #NonNull Response<String> response) {
String body = response.body();
try {
assert body != null;
JSONObject obj = new JSONObject(body);
if (obj.optBoolean("success")) {
etUsername.setText("");
etPassword.setText("");
etUsername.requestFocus();
getContentResolver().delete(ProviderUser.CONTENT_URI, null, null);
ContentValues values = new ContentValues();
values.put(ProviderUser.name, obj.optString("username"));
values.put(ProviderUser.grade, obj.optInt("grade"));
values.put(ProviderUser.gradename, obj.optString("gradename"));
values.put(ProviderUser.department, obj.optInt("department"));
values.put(ProviderUser.departmentname, obj.optString("departmentname"));
getContentResolver().insert(ProviderUser.CONTENT_URI, values);
Phoenix.Success(ActivityHome.this, obj.optString("message"), 5);
showApps(obj.optString("username"), obj.optInt("grade"), obj.optString("gradename"), obj.optInt("department"), obj.optString("departmentname"));
} else {
Phoenix.Error(getApplicationContext(), getString(R.string.user_not), false);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
#Override
public void onFailure(#NonNull Call<String> call, #NonNull Throwable t) {
}
});
}
} else if (buttonText.equals(getString(R.string.admin_access))) {
String LockPass = Phoenix.InputDialog(ActivityHome.this.getApplicationContext(), getString(R.string.input_prompt, getString(R.string.enter_lock_pass)));
if (LockPass.equals(strLockPass)) {
this.getPackageManager().clearPackagePreferredActivities(this.getPackageName());
finish();
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
}
} else {
throw new IllegalStateException(getString(R.string.unexpected) + v.getId());
}
}
/**
* This method will call the App Display Activity
*/
private void showApps(String username, Integer grade, String gradename, Integer department, String departmentname){
Intent intent = new Intent(ActivityHome.this.getApplicationContext(), ActivityApp.class);
intent.putExtra("username", username);
intent.putExtra("grade", String.valueOf(grade));
intent.putExtra("gradename", gradename);
intent.putExtra("department", String.valueOf(department));
intent.putExtra("departmentname", departmentname);
startActivityForResult(intent, REQUEST_CODE_1);
}
/**
* Function to trim whitespace from the end of a string.
* #param s the string to trim
* #return the trimmed string
*/
#NonNull
public static String rtrim(String s) {
AtomicInteger i;
i = new AtomicInteger(s.length() - 1);
while (i.get() >= 0 && Character.isWhitespace(s.charAt(i.get()))) {
i.getAndDecrement();
}
return s.substring(0, i.get() +1);
}
}
And finially, here is my ActivityPhoenixLib.java file:
package com.phoenixhosman.phoenixlib;
import android.app.Activity;
import android.content.Context;
import android.os.Handler;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import static android.view.View.inflate;
public class ActivityPhoenixLib extends Activity {
/**
* While not needed, this constructor makes calls to the member method of the class
* to clear errors in the editor.
*/
public ActivityPhoenixLib() {
Error(this, "", false);
Success(this,"",0);
String dummy = InputDialog(this, "");
if (dummy.equals("test")) {
}
}
/**
* This method displays a dialog box with an error message and a close button.
* #param strError the error message to display
*/
public void Error(Context context, #NonNull String strError, Boolean exit) {
if (strError.equals("")) {
return;
}
AlertDialog.Builder mBuilder = new AlertDialog.Builder(context);
View view = inflate(context, R.layout.dialog_error, null);
Button btnExit = view.findViewById(R.id.btnExitButton);
Button btnError = view.findViewById(R.id.btnErrorMessage);
btnError.setText(strError);
mBuilder.setView(view);
AlertDialog dialog = mBuilder.create();
dialog.setCanceledOnTouchOutside(false);
dialog.setCancelable(false);
dialog.show();
btnExit.setOnClickListener(v -> {
dialog.dismiss();
if (exit) System.exit(0);
});
}
/**
* This method displays a dialog box with a message and a close button.
* It also has an auto close function to auto close after a specified number of seconds.
* #param strMessage the message to display
*/
public void Success(Context context, #NonNull String strMessage, Integer autoclose) {
if (strMessage.equals("")) {
return;
}
AlertDialog.Builder mBuilder = new AlertDialog.Builder(context);
View view = inflate(context, R.layout.dialog_success, null);
Button btnExit = view.findViewById(R.id.btnButton);
Button btnError = view.findViewById(R.id.btnMessage);
btnError.setText(strMessage);
mBuilder.setView(view);
AlertDialog dialog = mBuilder.create();
dialog.setCanceledOnTouchOutside(false);
dialog.setCancelable(false);
dialog.show();
btnExit.setOnClickListener(v -> dialog.dismiss());
new Handler().postDelayed(dialog::dismiss, autoclose * 1000);
}
/**
* This method show an input box to get string input from the user.
* #param strPrompt - the dialog prompt
*/
public String InputDialog(Context context, String strPrompt) {
if (strPrompt.equals("")) {
return "";
}
AlertDialog.Builder mBuilder = new AlertDialog.Builder(context);
final String[] retval = new String[1];
View view = inflate(context, R.layout.dialog_input, null);
TextView txtPrompt = view.findViewById(R.id.txtPrompt);
EditText edtLockPass = view.findViewById(R.id.edtLockPass);
Button btnEnter = view.findViewById(R.id.btnEnter);
--> Line 97 <-- txtPrompt.setText(getString(R.string.input_prompt, strPrompt));
mBuilder.setView(view);
AlertDialog dialog = mBuilder.create();
dialog.setCanceledOnTouchOutside(false);
dialog.setCancelable(false);
dialog.show();
btnEnter.setOnClickListener(v -> {
if (edtLockPass.getText().toString().equals("")) {
retval[0] = "";
} else {
retval[0] = edtLockPass.getText().toString();
}
});
dialog.dismiss();
return retval[0];
}
}
I have tried several different things. I am going on the assumption that the context is not being passed to the InputDialog function, and I have tried different way of pass the context to the function: this. ActivityHome.this, getApplicationContext, and none of them seemed to work. Is there something I have nbot considered? Any help would be appreciated. Thanks.
Edit-In responce to one of the comments about my getString usage, on the page linked here my usage is documented, the second string is is the argument object for the formatting string.
Edit 2: I also tried to use a single parameter getSting on the line in question, and got the smae error.

My app keeps crashing when I go to another activity

I am trying to make an app named 'moviesinfo', in which I have a login page, with sign up and forgot password option. When I try to log in, the app crashes. I also don't know if the data entered on the sign-up page is being stored in the database or not.
This is my mainactivity.java
package com.example.moviesinfo;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
SQLiteDatabase db;
SQLiteOpenHelper openHelper;
private EditText user;
private EditText password;
private Button btn;
private Button btn2;
private Button forgot;
Cursor cursor;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
forgot=findViewById(R.id.forgot);
btn2=(Button) findViewById(R.id.signup);
user= (EditText) findViewById(R.id.username);
password = (EditText) findViewById(R.id.password);
btn = (Button) findViewById(R.id.login);
openHelper= new DatabaseHelper(this);
db=openHelper.getReadableDatabase();
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String username1= user.getText().toString();
String password1= password.getText().toString();
cursor = db.rawQuery("SELECT * FROM " +DatabaseHelper.TABLENAME + " WHERE " + DatabaseHelper.COL2 + "=? AND " + DatabaseHelper.COL3+"=?", new String[]{username1,password1});
if (cursor!=null){
if (cursor.getCount()>0){
cursor.moveToNext();
Intent intent = new Intent(MainActivity.this,listmenu.class);
startActivity(intent);
//Toast.makeText(getApplicationContext(),"Login Successful", Toast.LENGTH_SHORT).show();//
}else{
Toast.makeText(getApplicationContext(),"Error" , Toast.LENGTH_SHORT).show();
}
}
}
});
btn2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
sign_up();
}
});
forgot.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
forgot();
}
});
}
private void sign_up()
{
Intent intent= new Intent(MainActivity.this, signup.class);
startActivity(intent);
}
private void forgot()
{
Intent intent= new Intent(MainActivity.this, forgot.class);
startActivity(intent);
}
}
This is the signup.java class
package com.example.moviesinfo;
import android.content.ContentValues;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import java.lang.String;
import java.util.ArrayList;
public class signup extends AppCompatActivity {
SQLiteOpenHelper openHelper;
DatabaseHelper db;
SQLiteDatabase db1;
public String uname = "";
public String pwd = "";
public ArrayList<String> cpwd = new ArrayList<String>();
EditText e1, e2, e3;
Button b1,b2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_signup);
openHelper= new DatabaseHelper(this);
e1 = (EditText) findViewById(R.id.username);
e2 = (EditText) findViewById(R.id.password);
e3 = (EditText) findViewById(R.id.cpwd);
b1 = (Button) findViewById(R.id.save);
b2 = (Button) findViewById(R.id.login2);
b1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
db1=openHelper.getWritableDatabase();
String username =e1.getText().toString();
String password =e2.getText().toString();
String confirm_password =e3.getText().toString();
insert_data(username,password,confirm_password);
}
});
b2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(signup.this,MainActivity.class);
startActivity(intent);
}
});
}
public void insert_data(String username, String password, String confirm_password)
{
ContentValues contentValues = new ContentValues();
contentValues.put(DatabaseHelper.COL2, username);
contentValues.put(DatabaseHelper.COL3, password);
contentValues.put(DatabaseHelper.COL4, confirm_password);
long id=db1.insert(DatabaseHelper.TABLENAME, null, contentValues);
}
}
This is the DatabseHelper.java class
package com.example.moviesinfo;
import com.example.moviesinfo.signup;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME="userdetails.db";
public static final String TABLENAME="user details";
public static final String COL1="id";
public static final String COL2="username";
public static final String COL3="password";
public static final String COL4="confirmpassword";
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null,1);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE " + "TABLENAME(ID INTEGER PRIMARY KEY AUTOINCREMENT,USERNAME TEXT,PASSWORD TEXT,CONFIRMPASSWORD TEXT)");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " +TABLENAME);
onCreate(db);
}
}
I expect that when I click the login button it should jump to the next activity with checking the login details from the database.

Issue 1
The first issue you will encounter is that the table name user details has a space. user will be extracted as the identifier but then the SQL parser is not expecting details, it is not a keyword or clause and thus a syntax error as per the following which would be found in the log :-
5-19 14:09:14.335 26779-26779/s.e.so56180693anotheractivity E/AndroidRuntime: FATAL EXCEPTION: main
Process: s.e.so56180693anotheractivity, PID: 26779
java.lang.RuntimeException: Unable to start activity ComponentInfo{s.e.so56180693anotheractivity/s.e.so56180693anotheractivity.MainActivity}: android.database.sqlite.SQLiteException: near "details": syntax error (code 1 SQLITE_ERROR): , while compiling: CREATE TABLE IF NOT EXISTS user details(_id INTEGER PRIMARY KEY,username TEXT,password TEXT, confirmpassword TEXT)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: android.database.sqlite.SQLiteException: near "details": syntax error (code 1 SQLITE_ERROR): , while compiling: CREATE TABLE IF NOT EXISTS user details(_id INTEGER PRIMARY KEY,username TEXT,password TEXT, confirmpassword TEXT)
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:903)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:514)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1769)
at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1698)
at s.e.so56180693anotheractivity.DatabaseHelper.onCreate(DatabaseHelper.java:33)
at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:393)
at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:322)
at s.e.so56180693anotheractivity.MainActivity.onCreate(MainActivity.java:35)
at android.app.Activity.performCreate(Activity.java:7136)
see Debug your app
An identifier can have normally unacceptable characters, such as a space, start with a number, if it is enclosed in specific characters as per :-
If you want to use a keyword as a name, you need to quote it. There are four ways of quoting keywords in SQLite:
'keyword' A keyword in single quotes is a string literal.
"keyword" A keyword in double-quotes is an identifier.
[keyword] A keyword enclosed in square brackets is an identifier. This is not
standard SQL. This quoting mechanism is used by MS Access and SQL
Server and is included in SQLite for compatibility.
keyword A keyword enclosed in grave accents (ASCII code 96) is an identifier.
This is not standard SQL. This quoting mechanism is used by MySQL and is included in SQLite for compatibility.
e.g. you could have :-
public static final String TABLENAME="user details"; //<<<<<<<<<< cannot have spaces in a name unless enclosed
//!!!!NOTE!!!! ONLY 1 of the below would be allowed
public static final String TABLENAME="`user details`"; //<<<<<<<<<< e.g (with space)
public static final String TABLENAME= "[user details]";
public static final String TABLENAME = "\"user details\"";
public static final String TABLENAME = "'user details'";
public static final String TABLENAME="user_details"; //<<<<<<<<<< changed to this for testing.
Read the comments
Fix for Issue 1
public static final String TABLENAME="user details";
was changed to :-
public static final String TABLENAME="user_details";
The App was uninstalled and rerun.
Issue 2
The next issue is that the SQL to create the table will not create a table named according to the value that the constant TABLENAME (user_details after applying the Fix 1) has. The table is named TABLENAME as the word TABLENAME is in quotes.
It results in the exception :-
2019-05-19 13:56:15.118 26443-26443/s.e.so56180693anotheractivity E/SQLiteLog: (1) no such table: user_details
Fix for Issue 2
The following is how it would be suggested that the CREATE TABLE sql is setup:-
//Uses the identifiers (names) as per the variables
db.execSQL("CREATE TABLE IF NOT EXISTS " + TABLENAME + "(" +
COL1 + " INTEGER PRIMARY KEY," + // NO NEED FOR INEFFICIENT AUTOINCREMENT
COL2 + " TEXT UNIQUE," + //ADDED UNIQUE so that user names are not duplicated
COL3 + " TEXT, " +
COL4 + " TEXT" +
")"
);
That is constants are used for the names.
IMPORTANT as this is a change to the database schema and that the database exists you MUST delete the database so that the DatabaseHelper onCreate method will run.
The keyword UNIQUE has been added, otherwise the same user could be added multiple times
Question
I also don't know if the data entered on the sign-up page is being
stored in the database or not.
To enable you to know or not and as you should now be aware of looking in the log then amending the insert_data method as follows will enable you to see if the data is being stored.
public long insert_data(String username, String password, String confirm_password) // Signature changed to return long (id)
{
ContentValues contentValues = new ContentValues();
contentValues.put(DatabaseHelper.COL2, username);
contentValues.put(DatabaseHelper.COL3, password);
contentValues.put(DatabaseHelper.COL4, confirm_password);
long id=db1.insert(DatabaseHelper.TABLENAME, null, contentValues);
//TODO REMOVE LOGGING BEFORE PUBLISHING THE APP
if (id > 0) {
Log.d("INSERTUSERDETAILSROW","The row was successfully inserted into the " + DatabaseHelper.TABLENAME + " table.");
} else {
Log.d("INSERTUSERDETAILSROW","Row not inserted!!!!!!!!!!");
}
return id; // Can be useful to have access to the id that was generated. Note method signature change
}
Example output :-
in the log :-
D/INSERTUSERDETAILSROW: The row was successfully inserted into the user_details table.
Issue 4
If the password and confirm_password values do not match, the row is still added i.e. the confirm_password values serves no purpose.
Fix for Issue 4
A check is added to only add data if the password and confirm_password values match. If they do not then a Toast is issued.
b1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
db1=openHelper.getWritableDatabase();
String username =e1.getText().toString();
String password =e2.getText().toString();
String confirm_password =e3.getText().toString();
if (password.equals(confirm_password)) {
insert_data(username, password, confirm_password);
} else {
Toast.makeText(v.getContext(),"Password and Confirm Password do not match. Data not added.",Toast.LENGTH_LONG).show();
}
}
});
Issue 5
Although it won't appear to be a problem your should not start the activity when you want to return from an activity as that will destroy the initial activity and start another. The correct way is to finish the activity and it will then return to the actual activity from which it is was started from.
Fix for Issue 5
b2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//Intent intent = new Intent(signup.this,MainActivity.class);
//startActivity(intent);
finish(); //<<<<<<<<<< Proper way to return
}
});
Done
That's it. The App should now be relatively functional as far as logging in and signing up is concerned.

I want to save user profile in local sqlite database and the user information

I've done firebase authentication for login and sign up and now i want
to save user profile in local sqlite database. I've fetched the user
information from firebase and storing them in a string variable and
passing these variables to the Adduser function to save this data in
the local database.But data is not getting stored and showing "Error
with saving user" ,that is rowid is "-1" always. i'm new to android.
please help me to solve this issue. thanks in advance
java file
package com.example.mansi.busezon;
import android.app.Application;
import android.content.ContentValues;
mport android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import com.example.mansi.busezon.data.dbContract;
import com.example.mansi.busezon.data.dbHelper;
import com.google.firebase.FirebaseApp;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
i
public class SELL_BUY extends AppCompatActivity {
// private dbHelper mDbHelper;
String name;
String email ;
String address ;
String phoneno ;
String password ;
//String userId;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Set the content of the activity to use the activity_main.xml layout file
setContentView(R.layout.activity_sell__buy);
check();
TextView BUY= (TextView) findViewById(R.id.buy);
BUY.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//create intent to open the activity
Intent BUYintent= new Intent(SELL_BUY.this,HomeActivity.class);
//start the new activity
startActivity(BUYintent);
}
});
TextView SELL= (TextView) findViewById(R.id.sell);
SELL.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//create intent to open the activity
Intent SELLintent= new Intent(SELL_BUY.this,SellHomepage.class);
//start the new activity
startActivity(SELLintent);
}
});
}
public void sendMessage(View view)
{
Intent intent = new Intent(SELL_BUY.this, profile_page.class);
startActivity(intent);
}
private void check()
{
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
//database reference pointing to demo node
// DatabaseReference demoRef = rootRef.child("CI8hvEW0sfZ0oU1GziTpGYPJv2z2");
// String value = "User22";
// //push creates a unique id in database
// demoRef.push().setValue(value);
rootRef.addListenerForSingleValueEvent(new ValueEventListener()
{
String userId=getIntent().getStringExtra("Id");
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren())
{
if(ds.getKey().equals(userId))
{
//name1="aakritijohar";
name = ds.child("name").getValue(String.class);
email = ds.child("email").getValue(String.class);
address = ds.child("addres").getValue(String.class);
phoneno = ds.child("phoneno").getValue(String.class);
TextView textView = (TextView) findViewById(R.id.test);
textView.setText(phoneno);
password = ds.child("password").getValue(String.class);
Toast.makeText(SELL_BUY.this, email + " " + ds.getKey(), Toast.LENGTH_SHORT).show();
insertUser(name,email,address,phoneno,password);
}
}
Bundle extras=getIntent().getExtras();
if(extras!=null) {
String name = extras.getString("name");
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
});
}
private void insertUser(String nameString,String EMAILString,String addressString,String numbertString,String pass) {
// Create database helper
dbHelper mDbHelper = new dbHelper(this);
// Gets the database in write mode
SQLiteDatabase db = mDbHelper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(dbContract.userEntry.COLUMN_USER_NAME, nameString);
values.put(dbContract.userEntry.COLUMN_EMAIL, EMAILString);
values.put(dbContract.userEntry.COLUMN_number, numbertString);
values.put(dbContract.userEntry.COLUMN_address, addressString);
values.put(dbContract.userEntry.COLUMN_password, pass);
// Insert a new row for user in the database, returning the ID of that new row.
long newRowId = db.insert(dbContract.userEntry.TABLE_NAME, null, values);
// Show a toast message depending on whether or not the insertion was successful
if (newRowId == -1) {
// If the row ID is -1, then there was an error with insertion.
Toast.makeText(this, "Error with saving user", Toast.LENGTH_SHORT).show();
} else {
// Otherwise, the insertion was successful and we can display a toast with the row ID.
Toast.makeText(this, "user saved " + newRowId, Toast.LENGTH_SHORT).show();
}
}
}
database helper class
package com.example.mansi.busezon.data;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
/**
* Database helper for Pets app. Manages database creation and version management.
*/
public class dbHelper extends SQLiteOpenHelper {
public static final String LOG_TAG = dbHelper.class.getSimpleName();
/** Name of the database file */
private static final String DATABASE_NAME = "user.db";
/**
* Database version. If you change the database schema, you must increment the database version.
*/
private static final int DATABASE_VERSION = 1;
/**
* Constructs a new instance of {#link dbHelper}.
*
* #param context of the app
*/
public dbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
/**
* This is called when the database is created for the first time.
*/
#Override
public void onCreate(SQLiteDatabase db) {
// Create a String that contains the SQL statement to create the pets table
String SQL_CREATE_USER_TABLE = "CREATE TABLE " + dbContract.userEntry.TABLE_NAME + " ("
+ dbContract.userEntry._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ dbContract.userEntry.COLUMN_USER_NAME + " TEXT NOT NULL, "
+ dbContract.userEntry.COLUMN_address + " VARCHAR, "
+ dbContract.userEntry.COLUMN_number + " VARCHAR NOT NULL, "
+ dbContract.userEntry.COLUMN_EMAIL + " VARCHAR NOT NULL, "
+ dbContract.userEntry.COLUMN_password + " VARCHAR NOT NULL );";
// Execute the SQL statement
db.execSQL(SQL_CREATE_USER_TABLE);
}
/**
* This is called when the database needs to be upgraded.
*/
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// The database is still at version 1, so there's nothing to do be done here.
}
}

There doesn't appear to be anything wrong with the code as it is.
As such I suspect that your issue may be that you have changed the table structure since running the App.
e.g. by adding a new column and then changing the code accordingly
However, that you have then not taken into consideration that the onCreate method only gets automatically invoked when the database is created.
That is the 'onCreate' method does not run every time the App is started.
I'd suggest that deleting the App's data or uninstalling the App and then rerunning the App will resolve the issue.
If that doesn't resolve the issue then please check the log as that should contain a stack-trace for when the insert comes across the issue even though the App doesn't itself crash (you could use the insertOrThrow method instead of insert which would then result in an exception/crash).
If you then still have issues, please update the question to include the stack-trace.

Accessing data from barcode scanner app to use in SQLite query

This is my first question here on stack overflow, so please forgive me for any oversight or formatting errors. This issue seems simple enough, but I am not able to "put the pieces together" for some reason. I am also learning java and android studio as I go, so please forgive and educate on any bad code.
I need to gather data from my barcode scanning app, submit it to a variable, and then pass that variable through my database to fetch information based on the UPC code. I am using the ZXing library for the barcode scanner, with the handleResult method to capture the initial data.
I have the data collected within the SimpleScanner activity, but I can't figure out how to use that variable in a SQlite query. Below are the main classes I am using.
Any help would be appreciated. I can query the entire database just fine, but I need to look up the rows that match the actual item I am scanning. Thanks again!
SimpleScannerActivity.java
package com.example.android.dropr;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.database.Cursor;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.widget.Toast;
import com.google.zxing.Result;
import java.util.ArrayList;
import java.util.List;
import me.dm7.barcodescanner.zxing.ZXingScannerView;
public class SimpleScannerActivity extends MainActivity implements ZXingScannerView.ResultHandler {
private ZXingScannerView mScannerView;
#Override
public void onCreate(Bundle state) {
super.onCreate(state);
mScannerView = new ZXingScannerView(this); // Programmatically initialize the scanner view
setContentView(mScannerView); // Set the scanner view as the content view
}
#Override
public void onResume() {
super.onResume();
mScannerView.setResultHandler(this); // Register ourselves as a handler for scan results.
mScannerView.startCamera(); // Start camera on resume
}
#Override
public void onPause () {
super.onPause();
mScannerView.stopCamera(); // Stop the camera on pause
}
#Override
public void handleResult(Result rawResult) {
String TAG = "Dropr";
/**
* Create Alert Dialog, so that user has time to read the information within.
*/
AlertDialog.Builder scanInfo = new AlertDialog.Builder(this);
String messageContent = "Content - " + rawResult.getText();
String messageFormat = "Format - " + rawResult.getBarcodeFormat().toString() + ".";
scanInfo.setTitle("Scan Information:");
scanInfo.setMessage(messageContent + "\n" + messageFormat);
scanInfo.setCancelable(true);
scanInfo.setPositiveButton(
"OK",
new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
// IF you would like to resume scanning, call this method below:
// Handle the data
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
mScannerView.resumeCameraPreview(SimpleScannerActivity.this);
}
}, 1000);
}
});
AlertDialog showInfo = scanInfo.create();
showInfo.show();
// Do something with the result here
Log.v(TAG, rawResult.getText());
Log.v(TAG, rawResult.getBarcodeFormat().toString());
}
}
DatabaseAccess.java
package com.example.android.dropr;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import java.util.ArrayList;
import java.util.List;
public class DatabaseAccess {
private SQLiteOpenHelper openHelper;
private SQLiteDatabase database;
private static DatabaseAccess instance;
private SimpleScannerActivity scannerActivity = new SimpleScannerActivity();
/**
* Private constructor to avoid object creation from outside classes.
*
* #param context
*/
protected DatabaseAccess(Context context) {
this.openHelper = new DatabaseOpenHelper(context);
}
/**
* Return a singleton instance of DatabaseAccess.
*
* #param context
* #return the instance of DatabaseAccess
*/
public static DatabaseAccess getInstance(Context context) {
if (instance == null) {
instance = new DatabaseAccess(context);
}
return instance;
}
/**
* Open the database connection
*/
public void open() {
this.database = openHelper.getWritableDatabase();
}
/**
* Close the database connection
*/
public void close() {
if (database != null) {
this.database.close();
}
}
/**
* Read all quotes from the database.
*
* #return a list of quotes
*/
public List<String> getCodes() {
List<String> list = new ArrayList<>();
Cursor cursor = database.rawQuery("SELECT name, upc14 FROM Barcodes", null);
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
list.add(cursor.getString(0));
list.add(cursor.getString(1));
cursor.moveToNext();
}
cursor.close();
return list;
}
}

I finally came up with a solution, thanks to #muratgu! I created another method that creates and stores a variable for the scanned data, and passes the variable through a query.
/**
* read a single record from the database the matches the UPC-A code scanned.
* if there is no match, do nothing.
* #param rawContent
* #return a brand name based on the matching UPC-A code that was scanned.
*/
public String getInfo(String rawContent) {
String TAG = "Getinfo():";
String content = "00" + rawContent;
String brandName = "";
Cursor cursor = database.rawQuery("SELECT name, upc12 from Barcodes WHERE '" + content + "' = upc12", null);
if(cursor.getCount() > 0) {
cursor.moveToFirst();
brandName = cursor.getString(cursor.getColumnIndex("name"));
cursor.close();
} else {
Log.v(TAG, "uh oh, something went wrong in the if loop! ");
}
return brandName;
}
This method gets called in the SimpleScannerActivity.java file, where the scanned data can be passed through the variable. The method returns the name of the item, which is then placed in the dialog box. Exactly what I needed.
Thanks again, #muratgu! you gave me enough information that I could solve the problem myself. I just had to think on it for a bit!

Problem with ArrayList

I am fairly new to Java programming and was following a tutorial located here: http://coenraets.org/blog/android-samples/androidtutorial/
Where I copied the code I am having a problem with here: http://code.google.com/p/androidtutorial/source/browse/trunk/%20androidtutorial/EmployeeDirectory6/src/samples/employeedirectory/EmployeeDetails.java
EDIT: Thank You all. Thanks to #adamcodes for pointing out I totally missed that link where he put out the source code. It looks like he forgot to include that link in the step by step tutorial.
At about 25 lines down I'm getting an error at
protected ArrayList<EmployeeAction> actions;
which says "EmployeeAction cannot be resolved to a type" My question is does the class EmployeeAction have to be created
actions = new ArrayList<EmployeeAction>();
Even if I put "actions = new ArrayList();" in my code? If so what should the class contain?
package samples.employeedirectory;
import java.util.ArrayList;
import java.util.List;
import android.app.ListActivity;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class EmployeeDetails extends ListActivity {
protected TextView employeeNameText;
protected TextView titleText;
protected ArrayList<EmployeeAction> actions;
protected EmployeeActionAdapter adapter;
protected int employeeId;
protected int managerId;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.employee_details);
employeeId = getIntent().getIntExtra("EMPLOYEE_ID", 0);
SQLiteDatabase db = (new DatabaseHelper(this)).getWritableDatabase();
Cursor cursor = db.rawQuery("SELECT emp._id, emp.firstName, emp.lastName, emp.title, emp.officePhone, emp.cellPhone, emp.email, emp.managerId, mgr.firstName managerFirstName, mgr.lastName managerLastName FROM employee emp LEFT OUTER JOIN employee mgr ON emp.managerId = mgr._id WHERE emp._id = ?",
new String[]{""+employeeId});
if (cursor.getCount() == 1)
{
cursor.moveToFirst();
employeeNameText = (TextView) findViewById(R.id.employeeName);
employeeNameText.setText(cursor.getString(cursor.getColumnIndex("firstName")) + " " + cursor.getString(cursor.getColumnIndex("lastName")));
titleText = (TextView) findViewById(R.id.title);
titleText.setText(cursor.getString(cursor.getColumnIndex("title")));
actions = new ArrayList<EmployeeAction>();
String officePhone = cursor.getString(cursor.getColumnIndex("officePhone"));
if (officePhone != null) {
actions.add(new EmployeeAction("Call office", officePhone, EmployeeAction.ACTION_CALL));
}
String cellPhone = cursor.getString(cursor.getColumnIndex("cellPhone"));
if (cellPhone != null) {
actions.add(new EmployeeAction("Call mobile", cellPhone, EmployeeAction.ACTION_CALL));
actions.add(new EmployeeAction("SMS", cellPhone, EmployeeAction.ACTION_SMS));
}
String email = cursor.getString(cursor.getColumnIndex("email"));
if (email != null) {
actions.add(new EmployeeAction("Email", email, EmployeeAction.ACTION_EMAIL));
}
managerId = cursor.getInt(cursor.getColumnIndex("managerId"));
if (managerId>0) {
actions.add(new EmployeeAction("View manager", cursor.getString(cursor.getColumnIndex("managerFirstName")) + " " + cursor.getString(cursor.getColumnIndex("managerLastName")), EmployeeAction.ACTION_VIEW));
}
cursor = db.rawQuery("SELECT count(*) FROM employee WHERE managerId = ?",
new String[]{""+employeeId});
cursor.moveToFirst();
int count = cursor.getInt(0);
if (count>0) {
actions.add(new EmployeeAction("View direct reports", "(" + count + ")", EmployeeAction.ACTION_REPORTS));
}
adapter = new EmployeeActionAdapter();
setListAdapter(adapter);
}
}
public void onListItemClick(ListView parent, View view, int position, long id) {
EmployeeAction action = actions.get(position);
Intent intent;
switch (action.getType()) {
case EmployeeAction.ACTION_CALL:
Uri callUri = Uri.parse("tel:" + action.getData());
intent = new Intent(Intent.ACTION_CALL, callUri);
startActivity(intent);
break;
case EmployeeAction.ACTION_EMAIL:
intent = new Intent(Intent.ACTION_SEND);
intent.setType("plain/text");
intent.putExtra(Intent.EXTRA_EMAIL, new String[]{action.getData()});
startActivity(intent);
break;
case EmployeeAction.ACTION_SMS:
Uri smsUri = Uri.parse("sms:" + action.getData());
intent = new Intent(Intent.ACTION_VIEW, smsUri);
startActivity(intent);
break;
case EmployeeAction.ACTION_REPORTS:
intent = new Intent(this, DirectReports.class);
intent.putExtra("EMPLOYEE_ID", employeeId);
startActivity(intent);
break;
case EmployeeAction.ACTION_VIEW:
intent = new Intent(this, EmployeeDetails.class);
intent.putExtra("EMPLOYEE_ID", managerId);
startActivity(intent);
break;
}
}
class EmployeeActionAdapter extends ArrayAdapter<EmployeeAction> {
EmployeeActionAdapter() {
super(EmployeeDetails.this, R.layout.action_list_item, actions);
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
EmployeeAction action = actions.get(position);
LayoutInflater inflater = getLayoutInflater();
View view = inflater.inflate(R.layout.action_list_item, parent, false);
TextView label = (TextView) view.findViewById(R.id.label);
label.setText(action.getLabel());
TextView data = (TextView) view.findViewById(R.id.data);
data.setText(action.getData());
return view;
}
}
}

Java is statically typed, and everything you want to refer to at compile time needs to exist. So yes - you have to create the EmployeeAction, if you need it. (And you need to import it with import yourpackage.EmployeeAction; at the top of the class)
The type definition if the list <EmployeeAction> is there to enforce compile time safety for the elements of the list. It means "you can only put instances of EmployeeAction in this collection". This is useful when later you access the collection - the compiler can guarantee that the list contains only EmployeeAction instances

Yes it definitly have to exists (EmployeeAction class). For what it should contains, I'd say probably a constructor that take parameters like these : (String location, String phone, EmployeeAction.ACTION*) and then setters and getters for these values.

EmplyeeAction is a not Java known class. Then, it could be imported (if it exists) or created.

The list is irrelevant here. A few lines down, your code says:
actions.add(new EmployeeAction("Call office", officePhone, EmployeeAction.ACTION_CALL));
Yes, you do need a class EmployeeAction to compile that code. It's probably introduced in a part of the tutorial you overlooked or skipped.

you have to have a EmployeeAction class.
since you say that you are new to java it will be good if go through this tutorial