I am currently trying to save and retrieve array of string into the shared preference in my android apps. The problem is, I haven't add any string into my "set of string", so basically when I tried to retrieve it, it will return null. The problem is, after I get the Set of string, I want to add a string to the set. But it shows error that I can't add a string to a null object. Can someone help me? thanks..
pref = getSharedPreferences("save", MODE_PRIVATE);
Set<String> setId = pref.getStringSet("id", null);
setId.add("admin");
Editor editor = pref.edit();
editor.putStringSet("id", setId);
editor.commit();
You should just return an empty implementation of Set as your default value. For example, an empty ArraySet should work fine:
Set<String> setId = pref.getStringSet("id", new ArraySet<>());
SharedPreferences pref = getSharedPreferences("save", MODE_PRIVATE);
Set<String> setId = pref.getStringSet("id", null);
//The second argument 'null' means if there is no value for key "id", it will return null
if(setId == null){
setId = new HashSet<String>();
}
setId.add("admin");
SharedPreferences.Editor editor = pref.edit();
editor.putStringSet("id", setId);
editor.commit();
Related
I aaded three shared preferences as below code. And I am able to retrieve onl n shared preference value.
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor editor = preferences.edit();
editor.putBoolean("Loggedin",true);
editor.putString("userId",userid);
editor.putString("pwd",password);
editor.apply();
editor.commit();
I used the following code for retrieving from another activity. I am able to retrieve only the boolean value. Other values are not there. getting the default value for the string values. please help me.
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
Boolean loggedin=preferences.getBoolean("Loggedin", false);
String userId=preferences.getString("userId", "0");
String pwd=preferences.getString("pwd", "0");
check first the value u store in preferences are stored or not
using this code
Boolean loggedin=preferences.getBoolean("Loggedin", false);
String userId=preferences.getString("userId", null);
String pwd=preferences.getString("pwd", null);
if(userId==null || pwd==null)
{
//data not therer
}
else
{
//do something with data
}
and let me know if any error occured..
I think you're not getting the SharedPreferences in a correct way.
See the doc for ex: https://developer.android.com/training/basics/data-storage/shared-preferences.html
Context context = getActivity();
SharedPreferences sharedPref = context.getSharedPreferences(
getString(R.string.preference_file_key), Context.MODE_PRIVATE);
Also, you don't need to call apply() AND commit(). Just one of those is enough. See the javadoc for the differences btw them.
Use this code
String userId=preferences.getString("userId", null);
String pwd=preferences.getString("pwd", null);
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
Boolean loggedin=preferences.getBoolean("Loggedin", false);
String userId=preferences.getString("userId", "");
String pwd=preferences.getString("pwd", "");
if(userId==null || userId==""||pwd==null ||pwd=="")
{
}
else
{
}
Try code in this way.
Set values in First Activity
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor editor = preferences.edit();
editor.putBoolean("Loggedin",true);
editor.putString("userId",userid);
editor.putString("pwd",password);
editor.apply();
Retrieve value in Second Activity
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
Boolean loggedin=preferences.getBoolean("Loggedin", false);
String userId=preferences.getString("userId", "");
String pwd=preferences.getString("pwd", "");
Used in that way for retrieve values from shared preferences for your code.
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
Boolean loggedin=preferences.getBoolean("Loggedin", false);
//Checking the value of userId and pwd,if they are null then there is no values of userId and pwd other than default.
if (userId != null && pwd != null) {
String userId = preferences.getString("userId", "0");
String pwd = preferences.getString("pwd", "0");
} else {
String userId = "0";
String pwd = "0";
}
I'm newbie for Android Studio & Java, i'm PHP user.
Just want to know how to do like PHP session in Android Studio.
No matter which Activity i go to, i can easily get the session value example like the User ID. (session["USERID"])
now the method i using is putting extra everytime i call for another activity.
i'm sure there will be a better way to do this.
anyone have any good suggestion?
PS: I google around and it keep return me PHP session tutorial/example/etc but not for Android Studio....(may be i enter work #keyword or sentence)
Thank You Very Much
Thanks to fillobotto & Arshid KV
here is my code
first_main activity
sharedpreference = getSharedPreferences(BIZInfo, Context.MODE_PRIVATE);
sharedpreference.edit().putString(userid, "12345");
sharedpreference.edit().commit();
second_main activity
sharedpreference = PreferenceManager.getDefaultSharedPreferences(this);
String restoredText = sharedpreference.getString("text", null);
if (restoredText != null) {
sp_name = sharedpreference.getString("userid", "No name defined");
}
Log.i("TAG", "onCreate: [" + sp_name + "]");
log show empty value/nothing...
what went wrong!?
You can use SharedPreferences as session in php
Demo code :-
Setting values in Preference:
SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE).edit();
editor.putString("name", "Arshid");
editor.putInt("Age", 22);
editor.commit();
Retrieve data from preference:
SharedPreferences prefs = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE);
String restoredText = prefs.getString("text", null);
if (restoredText != null) {
String name = prefs.getString("name", "No name defined");//"No name defined" is the default value.
int Age = prefs.getInt("Age", 0); //0 is the default value.
}
You were really near to the solution. This is what I use:
public static String getSession(Activity context) {
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
return sharedPreferences.getString("session", null);
}
public static void setSession(Activity context, String session) {
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("session", session);
editor.apply();
}
I'm actually passing the Activityto get SharedPreferences, but in this way you will obtain an instance of the object which is not activity-related.
I am using this code for string array of string values in shared preferences.
SharedPreferences preferences = context.getSharedPreferences(
"browser_opened_urls", 0);
Set<String> urls = new HashSet<String>();
for (int i = 0; i < Browser.mainWebViewFlipper.getChildCount(); i++) {
WebView webview = (WebView) Browser.mainWebViewFlipper
.getChildAt(i);
urls.add(webview.getUrl());
}
preferences.edit().putStringSet("URLs", urls).commit();
But i am not getting how to get the values when retrieving set from shared preferences. Can anyone help ?
This is my code when i am getting set.
SharedPreferences preferences = getSharedPreferences("browser_opened_urls", 0);
Set<String> urls = preferences.getStringSet("URLs", null);
Now can anyone tell me how to get each stored value from "urls" ?
Ok i found answer myself.
SharedPreferences preferences = getSharedPreferences("browser_opened_urls", 0);
Set<String> urls = preferences.getStringSet("URLs", null);
if (urls != null) {
Iterator<String> iterator = urls.iterator();
while (iterator.hasNext()) {
String url = iterator.next();
}
Use getString method to retrieve the data from sharedPreferences
As mentioned in the android api reference.
Use method:-
getStringSet(String key, Set<String> defValues)
The solution to your question is SharedPreferences prefs=preferences.getStringSet(String URLs, Set<String> urls);
This is assuming you want to store in a new object for retrieving the old set
I have a sharedpreference var with values like these:
key0,value
key1,value
key3,value
key5,value
key6,value
key7,value
key10,value
What I want to do is to get a new sharedpreference value with items sorted sequentially like these:
key0,value
key1,value
key2,value
key3,value
key4,value
key5,value
key6,value
How do I do this?
Thank you in advanced.
You can use a workaround like this:
SharedPreferences shp = context.getSharedPreferences("yourSHP", MODE_PRIVATE);
//begin & end are to integers. For your case: 0 and 6 to get form key0 to key6
for(int i=begin;i<=end;i++){
String value = shp.getString("key"+i, "defaultValue");
//.....Here you can do whatever you want with your values
}
I hope this would help!!
SharedPreferences.Editor editor = getSharedPreferences(PREFS_NAME, 0).edit();
for( Entry<String, String> entry : testMap.entrySet() )
editor.putString( entry.getKey(), entry.getValue() );
editor.commit();
I did the following workaround. I don't know if there is another faster way to do it:
SharedPreferences shpTH = mContext.getSharedPreferences("PrefsTH", ListadoImagenesSubidasMain.MODE_PRIVATE);
Map<String,?> keysTH = shpTH.getAll();
List<String> imgTH = new ArrayList<String>();
for(Map.Entry<String,?> entry : keysTH.entrySet()){
imgTH.add(entry.getValue().toString());
}
SharedPreferences newPrefsTH = mContext.getSharedPreferences("PrefsTH", ListadoImagenesSubidasMain.MODE_PRIVATE);
newPrefsTH.edit().clear().commit();
int contTH = 0;
for(String item : imgTH){
SharedPreferences.Editor editorTH = newPrefsTH.edit();
editorTH.putString("urlTH" + contTH, item);
editorTH.commit();
contTH++;
}
Firstly I copy all the values to a list. Then I empty the sharedpreferences var and finally I put all the values got from the list filled previously in the empty sharedpreferences.
I'm creating Shared Preferences as follows
preferences = getSharedPreferences("text", 0);
final Editor editor = preferences.edit();
String s1 = serverIP.getText().toString();
String s2 = serverPort.getText().toString();
String s3 = syncPass.getText().toString();
String s4 = proxyServer.getText().toString();
String s5 = proxyPort.getText().toString();
editor.putString("SERVERIP", s1);
editor.putString("SERVERPORT", s2);
editor.putString("SYNCPASS", s3);
editor.putString("PROXYSERVER", s3);
editor.putString("PROXYPORT", s3);
and onCreate I want to display the values in a new set of TextViews, but the first time I don't have any values stored in the shared preferences and will get a NULL Pointer exception.
I want to know if there is any built-in method which can check if the SharedPreferences contains any value or not, so that I can check if the key exists and if not, then replace the new set of TextViews with the preferences value.
Try contains(String key) Accorting to the Javadocs,
Checks whether the preferences contains a preference. Returns true if
the preference exists in the preferences, otherwise false.
Every method for fetching values from SharedPreferences has default value which is returned in case the key does not exist
preferences = getSharedPreferences("text", 0);
String value = preferences.getString("unknown_key",null);
if (value == null) {
// the key does not exist
} else {
// handle the value
}
Try out
SharedPreferences shf = getSharedPreferences("NAME_SharedPref", MODE_WORLD_READABLE);
String strPref = shf.getString("SERVERIP", null);
if(strPref != null) {
// do some thing
}
I know this is a late answer but for those who want to know if a shared preference is either empty or zero size, you can check it two ways.
preferences = getSharedPreferences("text", 0);
Map<String, ?> entries = preferences.getAll();//get all entries from shared preference
Set<String> keys = entries.keySet();//set all key entries into an array of string type
//first option
if(keys.isEmpty()){
//do your staff here
}
//second option
if(keys.size()==0){
//this shows that it is empty as well
//do your staff here
}
//Below is extra
//If you want to get the names of each keys also, you can use
//For each loop as well
//Go through the set of keys
for (String key : keys) {
String keyName = key;//get each key name
}
LoadRuns();
if (loadedruns == 1) {
Toast.makeText(MainActivity.this, "First run", Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(MainActivity.this, "No. runs: " + loadedruns,
Toast.LENGTH_SHORT).show();
}
loadedruns++;
SaveRuns("runs", loadedruns);
public void SaveRuns(String key, int value){
sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putInt(key, value);
editor.commit();
}
public void LoadRuns(){
sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
loadedruns = sharedPreferences.getInt("runs", 1);
}