I use Shared Preferences to fetch and store a variable, I then fetch that variable across a different class. After I restart the app, the initial variable stored is to be updated by the new one. What I can see is that on quitting the application, I should set my shared preference to be cleared and then again fetch the fetch value.
However, the problem is that even on restart, the shared preference still store the older value and do not update themselves.
Here is the code where I initially save the value
protected void onLoginSuccess(String cookieString, String userName) {
// set cookie and initialize data center.
mCookieString = cookieString;
SharedPreferences settings =getSharedPreferences("cookie",MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putString("cookie", cookieString);
editor.commit();
//editor.apply();
mDataCenter = new LsApiDataCenter(this, userName);
mCachedUserData.clear();
System.out.println("shhhhhhhhhhhh iis original : "+cookieString);
mSendersObservers.clear();
mMessageObservers.clear();
mNotificationObservers.clear();
Later, Upon exit I want the shared preference to be cleared and this is how I do it
protected void onLogoutSuccess() {
// clear cookie and data center.
SharedPreferences settings =getSharedPreferences("cookie",MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.clear().commit();
mCookieString = null;
mDataCenter = null;
mCachedUserData.clear();
mSendersObservers.clear();
mMessageObservers.clear();
mNotificationObservers.clear();
Finally, this is how I fetch them in a completely different class
SharedPreferences settings = mMainActivity.getSharedPreferences("cookie", Context.MODE_PRIVATE);
count = settings.getString("cookie","");
The problem is that the value which I get upon fetching is the old value and not the latest value since i am fetching a value provided by a server via api used when the user logs in. However, I get the old value and the latest value is not fetched.
Thanks
If you want to clear the value of cookie variable you can do like this
SharedPreferences settings =getSharedPreferences("cookie",MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putString("cookie", null);
editor.commit();
Related
I am using static session_counter to store the data,
yes the data I want to retrieve when app is opened is a INTEGER
private static int session_counter = 0;
MY app state
AFTER USER PERFORMED AN ACTION THE SESSION COUNTER SHOWS 1,
BUT WHEN THE APPLICATION IS CLOSED AND RE-OPENED AGAIN THE COUNTER IS SET TO 0
I WANT THAT SESSION COUNTER TO BE THE SAME AS PREVIOUS STATE TILL THE SPECIFIC CONDITION IS MET
For applications such as this you need a way where you can persist the data between each session.
as a previous answer mentioned shared preferences is the most effective way to do it.
Other alternatives exist as
Room
A remote database (Firebase) etc.
The structure will be somewhat like this
```
// Create object of SharedPreferences.
SharedPreferences sharedPref = getSharedPreferences("mypref", 0);
//now get Editor
SharedPreferences.Editor editor = sharedPref.edit();
//put your value
editor.putString("session_value", required_Text);
//commits your edits
editor.commit();
// Its used to retrieve data
SharedPreferences sharedPref = getSharedPreferences("mypref", 0);
String name = sharedPref.getString("session_value", "")
```
In your case it will be like
textView.text= sharedPref.getString("session_value", "")
if(condition){
editor.putString("session_value", required_Text);
}
You might want to use shared-preferences to save your value. This answer might be useful
I'm working on a practise 7 days exercise app. I set a progree bar on the main activity and want to change progress after days. Means if i complete exercise of day 1 ,progress bar set 15% . and when i complete day2 , progress set 30%. I can do it without shared preference , it working correctlt but when after day1 complete i closed the app it again set progress from 0 . So i want to use shared preferences for this reason . Kindly someone guide me regarding this issue;
For Set Value to Shared Prefrence
SharedPreferences.Editor editor = getSharedPreferences("ProgressBarData",
MODE_PRIVATE).edit();
editor.putInt("progress", 15);
editor.apply();
for get value From Shared Prefrence
SharedPreferences prefs = getSharedPreferences(ProgressBarData,
MODE_PRIVATE);
int progress = prefs.getInt("progress", 0);
1st ur know ur mistake
u can't store ur data in local variable because at the end of the activity it destroyed every things and when u come back to android activity it will be started all thing once again and every thing is restarted
[https://developer.android.com/guide/components/activities/activity-lifecycle
read this u have better understanding
Now ur solution
if u want to store the data and process every day better to use local storage like
Sqlite ,room or shared preference.
Step to do the task
There is three step to store, get and remove data into share preference
For storing , getting deleting data
//storing
SharedPreferences.Editor editor = context.getSharedPreferences(name,Context.MODE_PRIVATE).edit();
editor.putString(key, data);
editor.apply();
//getting
SharedPreferences getSharedPrefrence = context.getSharedPreferences(name, Context.MODE_PRIVATE);
int data = getSharedPrefrence.getInt(key, IntegerValuesAndStringValues.REGISTER_BEFORE_LOGIN);
return data;
BasicFunctions.removeSharedPrefrences(getContext(),"Name of the preference");
I have a variable and I want to change it only the first time that I start my app. For example:
I open the app: Variable is not initialized. Variable changes to 4.
I close the app
I open the app Variable is 4.
And so on.
How can I do this?
I guess you are new to Android. You can save the values using "SharedPreferences".
Check this link : https://developer.android.com/training/basics/data-storage/shared-preferences.html
Also check out this example :
https://www.tutorialspoint.com/android/android_shared_preferences.htm
You can use this code :
SharedPreferences sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);
Editor editor = sharedpreferences.edit();
editor.putString("key", "value");
editor.commit();
Here, MyPREFERENCES is the file name. Replace the "value" with the variable name.
Again, if you want to retrieve the value, then use:
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
prefs.getBoolean("key", true);
//There are other methods like getInt(),getDouoble().getString() depending on the type of value
You can also write to a local file and use SQLite for that purposes if you would like to persist big object's data.
I am working on a small project that requires a details screen where the user inputs his details and they are permanently stored. The user must have the option to change the details as well if he needs to do so. I looked into the saved preferences library however it does not seem to offer such functionality.
To give a visual idea of what is required, something like this screen should be fine:
http://www.google.com.mt/imgres?start=97&num=10&hl=en&tbo=d&biw=1366&bih=643&tbm=isch&tbnid=aQSZz782gIfOeM:&imgrefurl=http://andrejusb.blogspot.com/2011/10/iphone-web-application-development-with.html&docid=YpPF3-T8zLGOAM&imgurl=http://2.bp.blogspot.com/-YRISJXXajD0/Tq2KTpcqWiI/AAAAAAAAFiE/-aJen8IuVRM/s1600/7.png&w=365&h=712&ei=rbX6ULTDCOfV4gTroIDoCg&zoom=1&iact=hc&vpx=834&vpy=218&dur=2075&hovh=314&hovw=161&tx=80&ty=216&sig=108811856681773622351&page=4&tbnh=155&tbnw=79&ndsp=35&ved=1t:429,r:4,s:100,i:16
Any help is much appreciated. Thanks in advance
You could easily use Shared Preferences to store user's details. Everytime the Preference screen is opened the stored data can then be extracted from the Shared Preferences and presented to the user for edit. ONce the edit is done the new data can be updated back in the the Shared Preferences.
Also look at this thread to see how this can be done.
Using SharedPreferences would be perfect for this kind of small amount of data which you want to store persistently.
// 'this' is simply your Application Context, so you can access this nearly anywhere
SharedPreferences prefs = this.getSharedPreferences(
"com.example.app", Context.MODE_PRIVATE);
To obtain from the preferences:
// You can equally use KEY_LAST_NAME to get the last name, etc. They are just key/value pairs
// Note that the 2nd arg is simply the default value if there is no key/value mapping
String firstName = prefs.getString(KEY_FIRST_NAME_CONSTANT, "");
Or to save:
Editor editor = prefs.edit();
// firstName being the text they entered in the EditText
editor.putString(KEY_FIRST_NAME_CONSTANT, firstName);
editor.commit();
You can achieve such functionality using SharedPreferences Class in android.
public void onCreate(Bundle object){
super.onCreate(object);
// Initialize UI and link xml data to java view objects
......
SharedPreferences myPref = getPreferences(MODE_PRIVATE);
nameView.setText(myPref.getString("USER_NAME", null));
passView.setText(myPref.getString("PASSWORD", null));
}
public void onStop(){
super.onStop();
if (isFinishing()) {
getPreferences(MODE_PRIVATE).edit()
.putString("USER_NAME", nameView.getText().toString())
.putString("PASSWORD", passView.getText().toString())
.commit()
}
}
I am trying to save the date of file parsing, so that when next time user, opens the application, the date can be checked against the last parsing date.
I am using shared preference to save the data and retrieve it, but getting error. Here is the code :
SharedPreferences settings = getPreferences(0);
String today = new Date(System.currentTimeMillis()).toString();
SharedPreferences.Editor edit = settings.edit();
System.out.println("******** Today : " + today);
edit.putString("lastdate", today);
String fetch = settings.getString("lastdate", "0");
System.out.println("******** Fetch : " + fetch);
txtTest.setText(fetch);
But I am getting null pointer error, am I missing something?
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.
To see some more examples check Android's Data Storage post on developers site.
You need to change how you get the object
SharedPreferences settings = PreferenceManager
.getDefaultSharedPreferences(context);