Android: SharedPreferences. How to implement them properly - java

I'm trying to store a user entry into an EditText field however when I exit the application it does not appear.
So for example a user types in his/her name and then exits the application. When the user returns and launches the Application the users name appears in the EditText field. However I can't get this to work. I believe its to do with sharedPreferences but I'm not sure where I'm going wrong.
I'm quite new to android and java so finding this quite difficult. Any help would be much appreciated.
public class MainActivity extends Activity {
public final static String EXTRA_FROM = "com.example.assignment1.FROM";
#Override
protected void onSaveInstanceState(Bundle outState)
{
super.onSaveInstanceState(outState);
EditText emailFrom =(EditText) findViewById(R.id.editEmailFrom);
String from = emailFrom.getText().toString();
outState.putString(EXTRA_FROM, from);
}
#Override
protected void onRestoreInstanceState(Bundle savedState)
{
EditText emailFrom =(EditText) findViewById(R.id.editEmailFrom);
String from = savedState.getString(EXTRA_FROM);
emailFrom.setText(from);
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
public void emailSend (View sendButton)
{
Intent intent = new Intent(this,DisplayEmailActivity.class);
EditText emailFrom =(EditText) findViewById(R.id.editEmailFrom);
String from = emailFrom.getText().toString();
intent.putExtra(EXTRA_FROM,from);
SharedPreferences saveFrom = getSharedPreferences(EXTRA_FROM, MODE_PRIVATE);
Editor editor = saveFrom.edit();
editor.putString(EXTRA_FROM, from);
editor.commit();
String storedfrom = saveFrom.getString(EXTRA_FROM, from);
emailFrom.setText(storedfrom);
startActivity(intent);
}
Second Activity
public class DisplayEmailActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display_email);
Intent intent = getIntent();
String from = intent.getStringExtra(MainActivity.EXTRA_FROM);
TextView textFrom =(TextView)findViewById(R.id.displayEmailFrom);
textFrom.setText(from);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_display_email, menu);
return true;
}

Ok, so after you store value in your EditText emailFrom, you have to save it in SharedPreferences like this:
String from = emailFrom.getText().toString(); // Getting String value from EditText and storing it in "from" String
SharedPreferences settings = getSharedPreferences("MyPreferencesFile", 0); // Opening SharedPreferences
SharedPreferences.Editor editor = settings.edit(); // Opening editor for SharedPreferences
editor.putString("exampleName", from); // You are putting here a String "from" and give it a "exampleName" name. Later you will use this name to restore data.
And then when you launch your application, you need to load data from SharedPreferences:
SharedPreferences settings = getSharedPreferences("MyPreferencesFile", 0); // Again opening SharedPreferences
String from = settings.getString("exampleName", ""); // The second argument is the default value. The default value will be set if there wasn't saved any data with "exampleName" name
if(from != "") // If "from" is not empty, it means that the data was stored in SharedPreferences
emailFrom.setText(from); // Setting text in your EditText

You are using onSaveInstanceState() and onRestoreInstanceState() to save and restore the content of the EditText. However, this methods are called only when the application is being terminated by the OS to be immediatlly recreated (i.e. device rotation).
If you want to preserve values when the application is terminated by the user, you need to store it somewhere, a file, a database or in your case I would suggest SharedPreferences.
I've posted an answer to a similar question in: SharePreferences
Good luck.

Related

How to save textview when application is closed?

I'm trying to save textview from getIntent String. When I close the application, then open again, textview is null. I have used many methods like onSaveInstance, SharedPreference but all failed.
Code :
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
jamShubuh = findViewById(R.id.jamShubuhTextView);
jamDzuhur = findViewById(R.id.jamDzuhurTextView);
jamAshar = findViewById(R.id.jamAsharTextView);
getShubuh = getIntent().getStringExtra("getShubuh");
getDzuhur = getIntent().getStringExtra("getDzuhur");
getAshar = getIntent().getStringExtra("getAshar");
jamShubuh.setText(getShubuh);
jamDzuhur.setText(getDzuhur);
jamAshar.setText(getAshar);
SharedPreferences sharedPreferences = getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("shubuh", getShubuh);
editor.putString("dzuhur", getDzuhur);
editor.putString("ashar", getAshar);
retriveData();
private void retriveData() {
SharedPreferences getData = getPreferences(Context.MODE_PRIVATE);
getData.getString("shubuh", null);
getData.getString("dzuhur", null);
getData.getString("ashar", null);
}
To use the shared preferences, I suggest you to make certain class to handle it. Maybe like this.
import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
public class MyPrefManager {
SharedPreferences sp;
SharedPreferences.Editor editor;
public void setPref(Context context, String key, String value){
sp = PreferenceManager.getDefaultSharedPreferences(context);
editor = sp.edit();
editor.putString(key, value);
editor.commit();
}
public String getPref(Context context, String key){
sp = PreferenceManager.getDefaultSharedPreferences(context);
value = null;
String X = sp.getString(key, value);
return X;
}
}
Then use setPref method to set the value and getPref method to get the value. Assume now you are in MainActivity and you want to save values of getShubuh, getDzuhur, and getAshar to Preference Manager, you can do something like this :
MyPrefManager MPM = new MyPrefManager();
MPM.setPref(MainActivity.this,"keyShubuh",getShubuh);
MPM.setPref(MainActivity.this,"keyDzuhur",getDzuhur);
MPM.setPref(MainActivity.this,"keyAshar",getAshar);
And to get the value of keyShubuh, keyDzuhur, and keyAshar wherever you want, you can do something like this.
MyPrefManager MPM = new MyPrefManager();
MPM.getPref(AnyActivity.this,"keyShubuh");
MPM.getPref(AnyActivity.this,"keyDzuhur");
MPM.getPref(AnyActivity.this,"keyAshar");
Hope it can help.
To save text state
//Saving The Text Entered by User
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
editText = findViewById(R.id.editText);// getting the reference of editext from xml
CharSequence text = editText.getText();// getting text u entered in edittext
outState.putCharSequence("savedText", text);// saved that text in bundle object i.e. outState
}
and restore saved text
//Restoring the State
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
editText = findViewById(R.id.editText);// getting the reference of textview from xml
CharSequence savedText =
savedInstanceState.getCharSequence("savedText");// getting the text of editext
editText.setText(savedText);// set the text that is retrieved from bundle object
}
instead of EditText you can use TextView.

Shared preferences? (Extremely simple issue!?)

I am just trying to store the users input from an editText in a Shared Preference, but it is not working:
editText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView v, int keycode, KeyEvent event) {
Log.v(TAG, keyword.getString("keyword", "mDefault")); //IT LOGS OUT THE DEFAULT STRING EVEN **AFTER** STORING THE PREFERENCES BEFORE
if (keycode == EditorInfo.IME_ACTION_SEND) {
editText.setText(editText.getText().toString());
keywordEditor.putString("keyword", editText.getText().toString());
keywordEditor.commit();
Log.v(TAG, keyword.getString("keyword", "default")); //CORRECT! THIS LINE WORKS
}
}
return true;
});
When I first edit the text, I will first get a log of "mDefault" which is normal, since nothing is stored in the shared preference.
Then, I store something in the shared preference, and to make sure it stored, I log and I get a log of what I typed. Which means the shared preference data WAS stored.
Heres the problem: After I have stored something in the shared preference, I go to a different activity, and I come back, and all the data stored in the shared preference is GONE!
The very first log still says mDefault after navigating through activities.
What could the problem be?
EDIT:
Here is my instantiation:
onCreate:
keyword = PreferenceManager.getDefaultSharedPreferences(this); //Making a shared preferences
keywordEditor = keyword.edit();
Maybe you don't save on setOnEditorActionListener. Save when you go to a different activity. Because when it goes to different activity the setOnEditorActionListener editText.getText().toString() it returns null.
STORING PREFERENCES:
SharedPreferences pref = getSharedPreferences("MyPrefs",Context.MODE_PRIVATE);
// We need an editor object to make changes
SharedPreferences.Editor edit = pref.edit();
// Set/Store data
edit.putString("username", "Rishabh");
edit.putString("password", "rishabh123");
// Commit the changes
edit.commit();
RETRIEVING PREFERENCES:
SharedPreferences pref = getSharedPreferences("MyPrefs", Context.MODE_PRIVATE);
String username = pref.getString("username", "");
String password= pref.getString("password", "");
Log.d(TAG, username);
Log.d(TAG, password);
Adding this as an example in case you missed a key components. This is currently working for me:
public class Main2Activity extends ActionBarActivity {
private SharedPreferences keyword;
private SharedPreferences.Editor keywordEditor;
private String TAG = "TAG";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
keyword = PreferenceManager.getDefaultSharedPreferences(this); //Making a shared preferences
keywordEditor = keyword.edit();
final EditText editText = (EditText) findViewById(R.id.et_text);
findViewById(R.id.btn_launch).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(Main2Activity.this, Main22Activity.class);
startActivity(intent);
}
});
editText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView v, int keycode, KeyEvent event) {
Log.v(TAG, "Initial: " + keyword.getString("keyword", "mDefault")); //IT LOGS OUT THE DEFAULT STRING EVEN **AFTER** STORING THE PREFERENCES BEFORE
if (keycode == EditorInfo.IME_ACTION_SEND) {
editText.setText(editText.getText().toString());
keywordEditor.putString("keyword", editText.getText().toString());
keywordEditor.commit();
Log.v(TAG, "Saving in prefs: " + keyword.getString("keyword", "default")); //CORRECT! THIS LINE WORKS
}
return true;
}
});
}
}
From a fresh install:
I typed in "test" and hit the send button on keyboard therefore invoked the onEditorAction
Then clicked on launch new activity -> hit back button and typed in "test2" and hit send button.
The following is the log out put:
02-29 23:26:42.068 18105-18105/com.example.naveed.myapplication V/TAG: Initial: mDefault
02-29 23:26:42.136 18105-18105/com.example.naveed.myapplication V/TAG: Saving in prefs: test
02-29 23:26:53.281 18105-18105/com.example.naveed.myapplication V/TAG: Initial: test
02-29 23:26:53.338 18105-18105/com.example.naveed.myapplication V/TAG: Saving in prefs: test2
As you can see initially it was "mDefault" then "test" was saved. I launched a new activity and came back. Next time the initial was "test" since it was saved last time and "test2" was the new value saved.
Create SharedPreferences class
public class SharedPreferenceClass
{
// Shared Preferences
SharedPreferences pref;
// Editor for Shared preferences
SharedPreferences.Editor editor;
// Context
Context _context;
// Shared pref mode
int PRIVATE_MODE = 0;
// Sharedpref file name
private static final String PREF_NAME = "INTELLIJ_AMIYO";
public static final String KEY_SET_VALUE= "KEY_SET_VALUE";
public SharedPreferenceClass(Context context){
this._context = context;
pref = _context.getSharedPreferences(PREF_NAME, 0);
editor = pref.edit();
}
public void setUserDATA(String data)
{
editor.remove(KEY_SET_VALUE);
editor.putString(KEY_SET_VALUE, data);
editor.commit();
}
public String getUserDATA()
{
String getData= pref.getString(KEY_SET_VALUE, null);
return getData;
}
}
Now call this in your Activity section globally
SharedPreferenceClass sharedPrefClassObj;
& call onCreate(Bundle savedInstanceState) section
sharedPrefClassObj = new SharedPreferenceClass(getApplicationContext());
Now add this
editText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView v, int keycode, KeyEvent event) {
if (keycode == EditorInfo.IME_ACTION_SEND) {
editText.setText(editText.getText().toString());
sharedPrefClassObj.setUserDATA(editText.getText().toString()); // Set data
// Get data sharedPrefClassObj.getUserDATA();
}
}
return true;
});
Very important: you need a Preference name (for example: "MY_PREFS_NAME") to set and retrieve the values:
SharedPreferences.Editor keywordEditor = context.getSharedPreferences("MY_PREFS_NAME", MODE_PRIVATE).edit();
Use the same constant Preference name and it will give you the same preferences in any point of your app.

Load strings from sharedpreferences in EditText (two classes)

I have two different activity's. First one only showed to the user first time - to store phonenumber inside sharedprefs. I think the problem is my load from prefs method but just in case I will leave everything here to make it more relevant to future users. It looks like in both activitys the "mobilnummer" is saved - but I am having problem to display them.
The idea is it to be overwritten if user updates it - I think the method will do that?
OnStartUp.java
public static final String PREFS_NAME = "MobileNumberSaved";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mobilnummer = (EditText) findViewById(R.id.mobilnummer);
final Button button = (Button) findViewById(R.id.ntonboarding);}
public void SaveToMobile(View v) {
if (mobilnummer.getText().toString().length() >= 8) {
FragmentedUser.SaveMobile(mobilnummer.getText().toString()); // just saves to Parse.com (This works)
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("mobilnummer", mobilnummer.toString());
editor.commit();
}
}
Profile
EditText mobilnummer;
public static final String PREFS_NAME = "MobileNumberSaved";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mobilnummer = (EditText) findViewById(R.id.mobilnummer);
This is the issue/problem i think! (Code below)
SharedPreferences MobileNumberSaved = this.getSharedPreferences("mobilnummer", Context.MODE_PRIVATE);
String tempMobilnummer = mobilnummer.getText().toString();
mobilnummer.setText(tempMobilnummer);
// IF user wants to change mobilenumber
mobilnummer.setOnEditorActionListener(new TextView.OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
boolean handled = false;
if (actionId == EditorInfo.IME_ACTION_SEND) {
if (mobilnummer.getText().toString().length() >= 8)
FragmentedUser.SaveMobile(mobilnummer.getText().toString());
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("mobilnummer", mobilnummer.toString());
editor.commit();
tlfstatus.setImageResource(R.drawable.ok);
handled = true;
}
return handled;
}
});
I think here is your error:
SharedPreferences MobileNumberSaved = this.getSharedPreferences("mobilnummer", Context.MODE_PRIVATE);
//here it should be MobileNumberSaved instead of mobilnummer, because tehre is no sense to set the same text to the textView again after you got it from there
String tempMobilnummer = MobileNumberSaved.getText().toString();
mobilnummer.setText(tempMobilnummer);
But the correct way to get a value from shared preferences is something like this:
SharedPreferences prefs = getSharedPreferences(PREFS_NAME, MODE_PRIVATE);
String savedMobileNumber = prefs.getString("mobilnummer", "");
mobilnummer.setText(savedMobileNumber);
Update: when you save the value in the shared preferences, you save only the editText, not it's value, so do something like this when saving:
SharedPreferences.Editor editor = settings.edit();
//mobilnumber is your EditText, so get it's text like this
editor.putString("mobilnummer", mobilnummer.getText().toString());
editor.commit();
And everything else is still the same that I wrote above

How do i store a textview using Shared Preferences

So my question might have been asked many times but i couldnt find an answer anywhere on the internet to it .
. What i want to do is store a textview using sharedprefeences .
In my first class (xp) i,m sending the textview to another class (feedback)
Now the feedback is reciving the textview with no single problem , but never saves it. How can i store that textview in the (feedback) class even after closing the app ??
Here's the class which is intenting the textview
public class Xp extends Activity {
Button accept;
TextView textV;
TextView xbnum;
public static final String PREFS_NAME = "MyPrefsFile";
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.xp);
accept = (Button) findViewById(R.id.accept);
textV = (TextView) findViewById(R.id.textV);
xbnum = (TextView) findViewById(R.id.xpnum);
Bundle extras = getIntent().getExtras();
if (extras != null) {
String value1 = extras.getString("intent_xp");
final String value = extras.getString("intent_extra");
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor edit = settings.edit();
edit.putString(PREFS_NAME, value);
edit.putString(PREFS_NAME,value1);
textV.setText(value);
xbnum.setText(value1);
edit.commit();
accept.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i = new Intent(Xp.this, feedback.class);
i.putExtra("intent_extra", textV.getText().toString());
startActivity(i);
finish();
}
});
}
}
}
And here is the class which will recive the intent and save the textview (As supposed )
public class feedback extends Activity {
TextView test1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.feedback);
test1 = (TextView) findViewById(R.id.test1);
Bundle extras = getIntent().getExtras();
if (extras != null) {
String value = extras.getString("intent_extra");
SharedPreferences settings = getSharedPreferences("intent_pref", 0);
SharedPreferences.Editor edit = settings.edit();
edit.putString("intent_pref",value);
test1.setText(value);
edit.apply();
}
}
}
The class is reciving the text , and everything is okay . Only when i close the app and open it , everything is cleared out ..
May be I'm wrong but it seems that you missunderstood how shared preferences works.
If you want to store several values in a preferences file an access it in others classes you have to create one instance of a SharedPreferences.
In your case it means create in both "feedback" and "Xp" a SharedPreferences instance like this :
SharedPreferences settings = getSharedPreferences("MyPrefsFile", SharedPreferences.MODE_PRIVATE);
and then use this instance to store your datas with an editor.
Be careful if you can't store several value for the same key.
You can also store your value in several files as you are actually doing. But if you want to set your textview with the value of your preferences file you have to get it with the getString("key_of_your_value") method on your shared preferences instance.

Android - Change class variable before onCreate

I am new to Android development. I am trying to call a method of one of my classes when a button on my main activity is pressed.
On my Main Activity I have this button:
public void buttonTest(){
Button b = (Button) findViewById(R.id.test);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
String s = "changeText:myText";
Intent in = new Intent(PlusActivity.this, Test.class);
in.putExtra("method",s);
startActivity(in);
}
});
}
And here is is the class (without imports) which that intent above is calling to.
public class Test extends Activity {
static String text = "test";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test);
TextView mTextView = (TextView) findViewById(R.id.textView);
mTextView.setText(text);
}
public void changeText(String s){
this.text = s;
}
#Override
protected void onNewIntent(Intent intent) {
super.onNewIntent(intent);
String[] array = intent.getStringExtra("method").split(":");
if(array[0].equals("changeText")){
changeText(array[1]);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.test, menu);
return true;
}
}
Basically I want to know if it is possible to change the value of that String text, before onCreate(). Basically each button will have a correspondent text, and I want to be able to modify that text based on which button.
If it is, what should I do/change?
Thanks in advance.
The right way to do it is to send the string you want it to be as an extra in the intent, and to read the extra from the intent and assign it to that variable in the onCreate function.
Use SharedPreference. Save in OnCLick of first class and retrieve in OnCreate of second class.
Initialization
SharedPreferences pref = getApplicationContext().getSharedPreferences("MyPref", 0); // 0 - for private mode
Editor editor = pref.edit();
Storing Data
editor.putBoolean("key_name", true); // Storing boolean - true/false
editor.putString("key_name", "string value"); // Storing string
editor.putInt("key_name", "int value"); // Storing integer
editor.putFloat("key_name", "float value"); // Storing float
editor.putLong("key_name", "long value"); // Storing long
editor.commit(); // commit changes
Retrieving Data
// returns stored preference value
// If value is not present return second param value - In this case null
pref.getString("key_name", null); // getting String
pref.getInt("key_name", null); // getting Integer
pref.getFloat("key_name", null); // getting Float
pref.getLong("key_name", null); // getting Long
pref.getBoolean("key_name", null); // getting boolean
Deleting Data
editor.remove("name"); // will delete key name
editor.remove("email"); // will delete key email
editor.commit(); // commit changes
Clearing Storage
editor.clear();
editor.commit(); // commit changes
String text;
if (savedInstanceState == null) {
extras = getIntent().getExtras();
if(extras == null) {
text= null;
} else {
text= extras.getString("your default string message");
}
} else {
String s = "your default string message";
text= (String) savedInstanceState.getSerializable(s);
}

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