Develop Reference

Where to put file for storing sharedpreferences

I want to utilize the sharedpreferences in my app, but in all of the tutorials and documentation in the internet I can not find out where to put the file that I am suppose to use.
What I mean is, when trying to access it as so:
public static final String PREFS_NAME = "AOP_PREFS";
SharedPreferences settings = getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
I don't know where to put the file AOP_PREFS.xml so that my class can use it. Am I missing something and I'm not suppose to be creating a file?

I don't quite understand what you are trying to do here. If your code is in an activity class, you just need to call getSharedPreferences(int) instead of getSharedPreferences(String, int). You get the preferences like this:
SharedPreferences prefs = getSharedPreferences (Context.MODE_PRIVATE);
Or you can use the PreferenceManager class to get the shared preferences as well:
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
where this is a Context object.
You can retrieve a string from the preferences using a key (In this case, myString).
prefs.getString ("myString", "");
If you have not saved a string with the myString key, the second parameter will be returned.
This is how you can save a string into the preferences:
prefs.edit().putString ("myString", "Some String value");
The first parameter is the key, and the second is the value. Self-explanatory!
NOW REMEMBER! Every time you save something, call apply()!
prefs.edit().putString ("myString", "Some String value").apply();
*******
And that's all you have to know about shared preferences!

Using SharedPreferences, the file is automatically created in the files folder in internal storage of your app, so you don't need to explicitly do anything to create the file.
The file in this case will be AOP_PREFS.xml.
You can also just use "default" SharedPreferences, which will be stored in an xml file with the package name of your app.
Example of Writing to Default SharedPreferences:
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor editor = sp.edit();
editor.putLong("some_value", someValue);
editor.commit();
Reading:
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
Long someVal = sp.getLong("some_value", 0);
Note that unless you have a rooted device, you won't be able to view files in internal storage.

Trying to edit specific sharedpreferences from different activity

So I have an application and i am trying to get one activity's shared preferences from a different activity. I cant use defaultSharedPreferences. Here is my code:
thisd = ma.
getSharedPreferences(
user, Context.MODE_PRIVATE);
Where thisd is the shared preferences, user is the specific sharedpreferences, and ma is the instance of the activity that has the shared preferences. Right now in activity called AddNameActivity.

Shared Preferences are not specific to any activity. It is common across application.
In the File where you add a value to Shared Prefernces, add this code sample.
SharedPreferences prefs = getSharedPreferences("your_file_name", MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
editor.putString("yourStringName", "this_is_the_saved_value");
editor.commit();
In the file where you want to read the value (may be second activity), add this code sample.
SharedPreferences prefs = getSharedPreferences("your_file_name",MODE_PRIVATE);
String string = prefs.getString("yourStringName","default_value");
You can use a default file to save/ read your preferences.
In that case, Just replace the first line of the two code snippets above by this:
SharedPreferences prefs = getDefaultSharedPreferences(getApplicationContext());

How to store strings in Shared Preferences

I would like the user to be able to create a nickname for a string that shows up in their textview. The app will feed a string into the activity through a service and display it in a textview. I would then like the user to be able to nickname that string, so that every time the string is displayed again the nickname will show up instead of the original string.
My question is, can I use shared preferences to do this? What would be the logic behind the user being able to assign nicknames? If you could point out any literature or sample code that would be greatly appreciated as well. Thank you for any help.

Algorhithm:
At a certain point in your app lifecycle, write a preference using a "name" and a value.
Retrieve the value when the app starts and compare it to something.
Act consequently.
From the reference site: http://developer.android.com/guide/topics/data/data-storage.html#pref
Using Shared Preferences
The SharedPreferences class provides a general framework that allows you to save and retrieve persistent key-value pairs of primitive data types. You can use SharedPreferences to save any primitive data: booleans, floats, ints, longs, and strings. This data will persist across user sessions (even if your application is killed).
User Preferences
Shared preferences are not strictly for saving "user preferences," such as what ringtone a user has chosen. If you're interested in creating user preferences for your application, see PreferenceActivity, which provides an Activity framework for you to create user preferences, which will be automatically persisted (using shared preferences).
To get a SharedPreferences object for your application, use one of two methods:
getSharedPreferences() - Use this if you need multiple preferences files identified by name, which you specify with the first parameter.
getPreferences() - Use this if you need only one preferences file for your Activity. Because this will be the only preferences file for your Activity, you don't supply a name.
To write values:
Call edit() to get a SharedPreferences.Editor.
Add values with methods such as putBoolean() and putString().
Commit the new values with commit()
To read values, use SharedPreferences methods such as getBoolean() and getString().
Here is an example that saves a preference for silent keypress mode in a calculator:
public class Calc extends Activity
{
public static final String PREFS_NAME = "MyPrefsFile";
#Override
protected void onCreate(Bundle state){
super.onCreate(state);
//...
// Restore preferences
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
boolean silent = settings.getBoolean("silentMode", false);
setSilent(silent);
}
#Override
protected void onStop()
{
super.onStop();
// We need an Editor object to make preference changes.
// All objects are from android.context.Context
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putBoolean("silentMode", mSilentMode);
// Commit the edits!
editor.commit();
}
}

How to keep the project always be open using login page on android/eclipse

I have one log in page for the project 'x'.My need is if at first i entered into the project by providing proper values in to the log in page of the project.The project always want to be signed-in, whenever i try to open the project.How to achieve this concept?
Thanks for your precious time!..

Many applications may provide a way to capture user preferences on the settings of a specific application or an activity. For supporting this, Android provides a simple set of APIs.
Preferences are typically name value pairs. They can be stored as “Shared Preferences” across various activities in an application (note currently it cannot be shared across processes). Or it can be something that needs to be stored specific to an activity.
Shared Preferences: The shared preferences can be used by all the components (activities, services etc) off the applications.
Activity handled preferences: These preferences can only be used with in the activity and can not be used by other components of the application.
Shared Preferences:
The shared preferences are managed with the help of the getSharedPreferences method of the Context class. The preferences are stored in a default file(1) or you can specify a file name(2) to be used to refer to the preferences.
(1) Here is how you get the instance when you specify the file name
public static final String PREF_FILE_NAME = "PrefFile";
SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
MODE_PRIVATE is the operating mode for the preferences. It is the default mode and means the created file will be accessed by only the calling application. Other two mode supported are MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE. In MODE_WORLD_READABLE other application can read the created file but can not modify it. In case of MODE_WORLD_WRITEABLE other applications also have write permissions for the created file.
(2) The recommended way is to use by the default mode, without specifying the file name:
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
Finally, once you have the preferences instance, here is how you can retrieve the stored values from the preferences:
int storedPreference = preferences.getInt("storedInt", 0);
To store values in the preference file SharedPreference.Editor object has to be used. Editor is the nested interface of the SharedPreference class.
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("storedInt", storedPreference); // value to store
editor.commit();
Editor also support methods like remove() and clear() to delete the preference value from the file.
Activity Preferences:
The shared preferences can be used by other application components. But if you do not need to share the preferences with other components and want to have activities private preferences. You can do that with the help of getPreferences() method of the activity. The getPreference method uses the getSharedPreferences() method with the name of the activity class for the preference file name.
Following is the code to get preferences:
SharedPreferences preferences = getPreferences(MODE_PRIVATE);
int storedPreference = preferences.getInt("storedInt", 0);
The code to store values is also same as in case of shared preferences.
SharedPreferences preferences = getPreference(MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("storedInt", storedPreference); // value to store
editor.commit();
You can also use other methods like storing the activity state in database. Note Android also contains a package called android.preference. The package defines classes to implement application preferences UI.
To see some more examples check Android's Data Storage post on developers site.
For more info, check this link:
Making data persistent in android

Whenever you login set the user inside the preference file. Then in your main activity give a check whether you have value for this preference or not. If present, goto the landing page. Otherwise show the login page.
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
getLandingPage();
}
private void getLandingPage() {
if (isLoggedIn()) {
//goto login page
} else {
//goto landing page
}
}
/**
* Checks whether preference contains any value
*
* #return
*/
private boolean isLoggedIn() {
return ProjectPreferences.getUserName() == ProjectPreferences.NULL_STRING
? true
: false;
}
}
Also don't forget to set username while you login.

Saving facebook login details locally in android app

I am developing an Android app where the user has the facility of Facebook sharing. I have the login details of the user for the Facebook, now what I am trying to do is these login details should be saved until the application is not deleted.
When I tried to find the answer for this, I got some answers stating about shared preferences. But I am not cleared exactly how it works.
Here is what I am trying to do,
Username = username.getText().toString();
PassWord = password.getText().toString();
where username and password are 2 edittext fields. When the user enters for the first time into Facebook, I should save these data somewhere for my future reference so that he need not login again.
Can any one let me know how to achieve this?

// Save your info
SharedPreferences settings = getSharedPreferences("my_file_name", 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("username", username.getText().toString());
editor.putString("password", password.getText().toString());
editor.commit();
// Obtain your info
SharedPreferences settings = getSharedPreferences("my_file_name", 0);
String username = settings.getString("username", "");
String password = settings.getString("password", "");
A file will be created in:
data/data/[your.package.path]/shared_prefs/[your.package.path]_preferences.xml

You can use sharedPreference for this.
Many applications may provide a way to capture user preferences on the settings of a specific application or an activity. For supporting this, Android provides a simple set of APIs.
Preferences are typically name value pairs. They can be stored as “Shared Preferences” across various activities in an application (note currently it cannot be shared across processes). Or it can be something that needs to be stored specific to an activity.
Shared Preferences: The shared preferences can be used by all the components (activities, services etc) off the applications.
Activity handled preferences: These preferences can only be used with in the activity and can not be used by other components of the application.
Shared Preferences:
The shared preferences are managed with the help of getSharedPreferences method of the Context class. The preferences are stored in a default file(1) or you can specify a file name(2) to be used to refer to the preferences.
(1) Here is how you get the instance when you specify the file name
public static final String PREF_FILE_NAME = "PrefFile";
SharedPreferences preferences = getSharedPreferences(PREF_FILE_NAME, MODE_PRIVATE);
MODE_PRIVATE is the operating mode for the preferences. It is the default mode and means the created file will be accessed by only the calling application. Other two mode supported are MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE. In MODE_WORLD_READABLE other application can read the created file but can not modify it. In case of MODE_WORLD_WRITEABLE other applications also have write permissions for the created file.
(2) The recommended way is to use by the default mode, without specifying the file name
SharedPreferences preferences = PreferencesManager.getDefaultSharedPreferences(context);
Finally, once you have the preferences instance, here is how you can retrieve the stored values from the preferences:
int storedPreference = preferences.getInt("storedInt", 0);
To store values in the preference file SharedPreference.Editor object has to be used. Editor is the nested interface of the SharedPreference class.
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("storedInt", storedPreference); // value to store
editor.commit();
Editor also support methods like remove() and clear() to delete the preference value from the file.
Activity Preferences:
The shared preferences can be used by other application components. But if you do not need to share the preferences with other components and want to have activities private preferences. You can do that with the help of getPreferences() method of the activity. The getPreference method uses the getSharedPreferences() method with the name of the activity class for the preference file name.
Following is the code to get preferences
SharedPreferences preferences = getPreferences(MODE_PRIVATE);
int storedPreference = preferences.getInt("storedInt", 0);
The code to store values is also same as in case of shared preferences.
SharedPreferences preferences = getPreference(MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
editor.putInt("storedInt", storedPreference); // value to store
editor.commit();
You can also use other methods like storing the activity state in database. Note Android also contains a package called android.preference. The package defines classes to implement application preferences UI.

Don't Use preferences to save facebook data:
Please use this code in Oncreate method:
if (isLoggedIn()) {
layout_after_fb_login.setVisibility(View.VISIBLE);
updateUI();
} else {
layout_after_fb_login.setVisibility(View.GONE);
}
////
private boolean isLoggedIn() {
AccessToken accesstoken = AccessToken.getCurrentAccessToken();
return !(accesstoken == null || accesstoken.getPermissions().isEmpty());
}
private void updateUI() {
Profile profile = Profile.getCurrentProfile();
if (null != profile) {
profilePictureView.setProfileId(profile.getId());
userNameView.setText(String.format("%s %s", profile.getFirstName(), profile.getLastName()));
layout_after_fb_login.setVisibility(View.VISIBLE);
} else {
layout_after_fb_login.setVisibility(View.GONE);
}
}