I am trying to pass through a username (EMAIL) into the createLoginSession within my SharedPreferencesManagement class. When I try to execute this on the login i'm getting an error which states that "createLoginSession(java.lang.String) on a null object reference".
public class SessionManagement {
// Shared Preferences
SharedPreferences pref;
// Editor for Shared preferences
Editor editor;
// Context
Context _context;
// Shared pref mode
int PRIVATE_MODE = 0;
// Sharedpref file name
private static final String PREF_NAME = "AndroidHivePref";
// All Shared Preferences Keys
private static final String IS_LOGIN = "IsLoggedIn";
// Email address (make variable public to access from outside)
public static final String KEY_EMAIL = "email";
// Constructor
public SessionManagement(Context context){
this._context = context;
pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
editor = pref.edit();
}
/**
* Create login session
* */
public void createLoginSession(String email){
// Storing login value as TRUE
editor.putBoolean(IS_LOGIN, true);
// Storing email in pref
editor.putString(KEY_EMAIL, email);
// commit changes
editor.commit();
}
/**
* Check login method wil check user login status
* If false it will redirect user to login page
* Else won't do anything
* */
public void checkLogin(){
// Check login status
if(!this.isLoggedIn()){
// user is not logged in redirect him to Login Activity
Intent i = new Intent(_context, ActivityLogin.class);
// Closing all the Activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
// Add new Flag to start new Activity
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// Staring Login Activity
_context.startActivity(i);
}
}
/**
* Get stored session data
* */
public HashMap<String, String> getUserDetails(){
HashMap<String, String> user = new HashMap<String, String>();
// user email id
user.put(KEY_EMAIL, pref.getString(KEY_EMAIL, null));
// return user
return user;
}
/**
* Clear session details
* */
public void logoutUser(){
// Clearing all data from Shared Preferences
editor.clear();
editor.commit();
// After logout redirect user to Loing Activity
Intent i = new Intent(_context, ActivityLogin.class);
// Closing all the Activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
// Add new Flag to start new Activity
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// Staring Login Activity
_context.startActivity(i);
}
/**
* Quick check for login
* **/
// Get Login State
public boolean isLoggedIn(){
return pref.getBoolean(IS_LOGIN, false);
}
The code for the Activity Login is as follows:
package com.example.myapplication;
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TextInputEditText;
import android.support.design.widget.TextInputLayout;
import android.support.v4.widget.NestedScrollView;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.AppCompatButton;
import android.support.v7.widget.AppCompatTextView;
import android.util.Log;
import android.view.View;
import com.example.myapplication.R;
import com.example.myapplication.InputValidation;
import com.example.myapplication.DatabaseHelper;
public class ActivityLogin extends AppCompatActivity implements
View.OnClickListener {
private final AppCompatActivity activity = ActivityLogin.this;
private NestedScrollView nestedScrollView;
private TextInputLayout textInputLayoutEmail;
private TextInputLayout textInputLayoutPassword;
private TextInputEditText textInputEditTextEmail;
private TextInputEditText textInputEditTextPassword;
private AppCompatButton appCompatButtonLogin;
private AppCompatTextView textViewLinkRegister;
private InputValidation inputValidation;
private DatabaseHelper databaseHelper;
public String email;
//Session Manager Class
SessionManagement session;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
getSupportActionBar().hide();
initViews();
initListeners();
initObjects();
}
/**
* This method is to initialize views
*/
private void initViews() {
nestedScrollView = (NestedScrollView) findViewById(R.id.nestedScrollView);
textInputLayoutEmail = (TextInputLayout)
findViewById(R.id.textInputLayoutEmail);
textInputLayoutPassword = (TextInputLayout)
findViewById(R.id.textInputLayoutPassword);
textInputEditTextEmail = (TextInputEditText)
findViewById(R.id.textInputEditTextEmail);
textInputEditTextPassword = (TextInputEditText)
findViewById(R.id.textInputEditTextPassword);
appCompatButtonLogin = (AppCompatButton)
findViewById(R.id.appCompatButtonLogin);
textViewLinkRegister = (AppCompatTextView)
findViewById(R.id.textViewLinkRegister);
;
}
/**
* This method is to initialize listeners
*/
private void initListeners() {
appCompatButtonLogin.setOnClickListener(this);
textViewLinkRegister.setOnClickListener(this);
}
/**
* This method is to initialize objects to be used
*/
private void initObjects() {
databaseHelper = new DatabaseHelper(activity);
inputValidation = new InputValidation(activity);
}
/**
* This implemented method is to listen the click on view
*
* @param v
*/
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.appCompatButtonLogin:
verifyFromSQLite();
break;
case R.id.textViewLinkRegister:
// Navigate to RegisterActivity
Intent intentRegister = new Intent(getApplicationContext(),
RegisterActivity.class);
startActivity(intentRegister);
break;
}
}
/**
* This method is to validate the input text fields and verify login
credentials from SQLite
*/
private void verifyFromSQLite() {
if (!inputValidation.isInputEditTextFilled(textInputEditTextEmail,
textInputLayoutEmail, getString(R.string.error_message_email))) {
return;
}
if (!inputValidation.isInputEditTextEmail(textInputEditTextEmail,
textInputLayoutEmail, getString(R.string.error_message_email))) {
return;
}
if (!inputValidation.isInputEditTextFilled(textInputEditTextPassword,
textInputLayoutPassword, getString(R.string.error_message_email))) {
return;
}
if
(databaseHelper.checkUser(textInputEditTextEmail.getText().toString().trim()
, textInputEditTextPassword.getText().toString().trim())) {
email = textInputEditTextEmail.getText().toString().trim();
Intent accountsIntent = new Intent(activity, MainMenuActivity.class);
accountsIntent.putExtra("EMAIL",
textInputEditTextEmail.getText().toString().trim());
session.createLoginSession(email);
emptyInputEditText();
startActivity(accountsIntent);
} else {
// Snack Bar to show success message that record is wrong
Snackbar.make(nestedScrollView,
getString(R.string.error_valid_email_password), Snackbar.LENGTH_LONG).show();
}
}
/**
* This method is to empty all input edit text
*/
private void emptyInputEditText() {
textInputEditTextEmail.setText(null);
textInputEditTextPassword.setText(null);
}
}
The error is on the line "session.createLoginSession("EMAIL");" as this is being passed in as a null value.
