I have a problem to getting retrieve values from sharedPreferences that stored as a String Set.
Set<String> set = new HashSet<String>();
set.add("Price: " + String.valueOf(item.getItemPrice()));
set.add("Quantity: " + String.valueOf(QuantityofItem));
set.add("Total: " + String.valueOf(BillValue));
set.add(customizeMsg);
set.add("Image: " + item.getItemImage());
editor.putStringSet(item.getItemName(), set);
my StringSet contains these 5 values and i want to retrieve that stored data and retrieve as a list view . any method how it can be perform?
i have a problem to getting retrieve values from sharedPrefrences that stored as a String Set.
Unless you commit() or apply() that editor, your data will not be saved.
i want to retrieve that stored data
Call getStringSet() on the SharedPreferences, passing in whatever key you are using (here, item.getItemName()).
retrieve as a list view
You are welcome to create an ArrayList out of the Set<String> elements, then wrap that in an ArrayAdapter, then put the ArrayAdapter into a ListView.
I want to retrieve that stored data and retrieve as a list view.
#. I guess you are trying to retrieve stored Set data as ArrayList. Use below code to retrieve Set as ArrayList :
SharedPreferences sharedPreferences = context.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
// Set
Set<String> set = sharedPreferences.getStringSet(KEY_ITEM_NAME, new HashSet<String>());
// List
ArrayList<String> list = new ArrayList<String>(set);
#. If you have stored multiple Set in SharedPreferences then do the same for others. Get Set by using KEY_ITEM_NAME value as item.getItemName().
#. If you want to show it on ListView then follow the steps described by #CommonsWare
Related
i create app where when user added new data , there is new label
I have tried and it worked, but I wonder how can I make the json that I store in SharedPreferences
do not over write
so I can add 2 or more user json to adapter
Here is my put string file the json variable contain user that added
SharedPreferences sharedPreferences = getSharedPreferences("newUser", MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("listNewUser",json)
editor.apply();
Here is how I can get json from shared preference
try{
String listNewUserAdd = sh.getString("listNewUser","");
JSONObject object = new JSONObject(listNewUserAdd);
for (int i=0; i<object.length(); i++) {
CustomerNew customer = new CustomerNew();
customer.setCustomerName(object.getString("receiverName"));
customer.setAccountId(object.getString("customerReference"));
customer.setId(object.getLong("customerId"));
System.out.println("### GET CUSTOMER NAME "+customer.getCustomerName());
listSortNew.add(customer);
if (listSortNew == null) {
// if the array list is empty
// creating a new array list.
listSortNew = new ArrayList<>();
}
}
I think there are two ways to realize it. One way is when you put data you have to check if it exists.
SharedPreferences sharedPreferences = getSharedPreferences("newUser", MODE_PRIVATE);
String listNewUser = sharedPreferences.getString("listNewUser","");
if(!TextUtils.isEmpty(listNewUser)){
//covert it the list object
//then add the all new item to it
//finally convert it to json string
}
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("listNewUser",json)
editor.apply();
the other way is to change the SharedPreferences MODE_APPEND
but you must know, it doesn't mean that you add multiple values for each key. It means that if the file already exists it is appended to and not erased. We usually used MODE_PRIVATE
In the end I suggest you firstly get the data from it, then check if you need change, you can change the data, then save it again.
Please be patient while I explain my issue:
1) I am storing my preferences via a StringSet as follows:
SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE).edit();
// Create a new Arraylist with the details of our details
ArrayList <String> newCityFareDetails = new ArrayList<String>();
// Store various values
newCityFareDetails.add(0, String.valueOf(cloneFare.value1()));
newCityFareDetails.add(1, String.valueOf(cloneFare.value2()));
newCityFareDetails.add(2, String.valueOf(cloneFare.value3()));
newCityFareDetails.add(3, String.valueOf(cloneFare.value4()));
newCityFareDetails.add(4, cloneFare.value5());
// Only value 5 is a string, rest are all floats
// Convert to a hashstring, give it the name of our value
Set<String> set = new HashSet<String>();
set.addAll(newCityFareDetails);
editor.putStringSet(extras.getString("startCity"), set);
// And write it to storage
editor.commit();
Now, I'm trying to read it as follows:
SharedPreferences prefs = getSharedPreferences(MY_PREFS_NAME, Context.MODE_PRIVATE);
Set<String> tryCityFromPrefs = prefs.getStringSet(currentCity, null);
if (tryCityFromPrefs!=null){
// Crude code, but we convert the preferences into a String array
String[] values = tryCityFromPrefs.toArray(new String[tryCityFromPrefs.size()]);
myFare = new Fare(Float.parseFloat(values[0]), Float.parseFloat(values[1]),
Float.parseFloat(values[2]), Float.parseFloat(values[3]), values[4]);
}
Now, problem is that the myFare is not getting initialized properly because the values in the array are scrambled. i.e. the String value that was at the last position when we save is now in the 2nd position. Is this something to do with Sets to String conversion? Or am I missing something obvious?
A Set does not guarantee order. While there are specific Set implementations (e.g., LinkedHashSet) that are ordered, that's not what SharedPreferences uses.
Your options are:
Change your app to not care about the order.
Save the data in SharedPreferences some other way. In this app, for example, I use JsonReader/JsonWriter to save an ArrayList into a single String value.
Save the data in some other fashion (e.g., JSON file, SQLite database with a sequence number to maintain order).
I want to store an ArrayList<class> in shared preference. But the error showed up in editor3.putString("Array", nama);. I guess the error caused by putString. What sould i do?
Should I used another method to storing arraylist ?
ArrayList<Class> nama = new ArrayList<Class>(9);
nama.add(dragsandal.class);nama.add(Terimakasih.class);
nama.add(Ludah.class);
nama.add(Permisi.class);
nama.add(Tolong.class);
nama.add(Maaf.class);
SharedPreferences pref3 = getApplicationContext().getSharedPreferences("Array", MODE_PRIVATE);
SharedPreferences.Editor editor3 = pref3.edit();
editor3.putString("Array", nama);
editor3.apply();
You should use putStringSet(Set<String>) to store sets (Lists with unique elements). SharedPreferences do not provide a method to store lists directly.
You can easily convert your list to a set using e.g. new HashSet<String>(yourList);
If you need to store a list, you can serialize your list to a String, e.g. by using Gson and storing the json value. Then putString(json) would be correct.
First I don't think there is a way to store lists in Shared preferences. Second it is not a good idea. In your case,I would consider using Sqlite database. It would make things easier.
You can't store a Class type object in SharedPreferences. Also you can't store Lists. If you really need to, you can store the full name of the class object as a String. Then when you read the value back you, you can use Class.forName() to convert that string back to a class. It seems weird, but you can do it.
You could try this to save and restore a set of class names:
Set<String> set = new HashSet<String>();
set.put(Terimakasih.class.getName());
set.put(Ludah.class.getName());
set.put(Permisi.class.getName());
set.put(Tolong.class.getName());
set.put(Maaf.class.getName());
SharedPreferences pref3 = getApplicationContext().getSharedPreferences("set", MODE_PRIVATE);
SharedPreferences.Editor editor3 = pref3.edit();
editor3.putStringSet("set", set);
editor3.apply();
Set<String> strings = pref3.getStringSet("set", Collections.emptySet());
Set<Class> classes = new HashSet<Class>();
for (String s : strings) {
classes.put(Class.forName(s));
}
In my app, the user can add a name and an age for multiple people. Most likely it will only be around 2 or 3. I want to store these in shared preferences. I set a counter to keep track of how many people have been stored as well as to manage which key goes with which value. I took the edittext input and put it in a string and then put it into the shared preferences like so, adding on the counter so I know that is the first person and would access the person with "name1".
//this is in the class
public int count = 1;
//this is in the main
SharedPreferences sharedPreferences = getSharedPreferences("registerData", Context.MODE_PRIVATE);
SharedPreferences.Editor myEditor = sharedPreferences.edit();
myEditor.putString("Name"+count, name);
myEditor.putString("Age"+count, age);
Unless I am mistaken, that should put the string "name" into "Name1".
Then I go and try to access it in another activity with...
SharedPreferences sharedPreferences = getSharedPreferences("registerData", Context.MODE_PRIVATE);
String name = sharedPreferences.getString("Name"+count,"");
String age = sharedPreferences.getString("Age"+count,"");
Then i would update the counter before the next person would be added to change the key to "Name2" "Age2", and so on.
Whenever I try to set the strings to a textview, they show up blank. Which means its not the same String to access the key. The putString has to get the "Name1", because even when I try to access the getString("Name",""), it's still blank. Is there something I'm doing wrong or missing. Or there is a better way of doing this? Thanks.
SharedPreferences sharedPreferences = getSharedPreferences("registerData",Context.MODE_PRIVATE);
SharedPreferences.Editor myEditor = sharedPreferences.edit();
myEditor.putString("Name"+count, name);
myEditor.putString("Age"+count, age);
myEditor.apply();//returns nothing,don't forgot to commit changes
also you can use
myEditor.commit() //returns true if the save works, false otherwise.
Is there something I'm doing wrong or missing. Or there is a better
way of doing this?
If SharedPreferences key names are dynamic then you should use SharedPreferences.getAll() which return all keys available in selected preference:
Map<String, ?> allKeys = sharedPreferences.getAll();
Now iterate through allKeys to check key names and get values from Map.Entry related to key like:
for (Map.Entry<String, ?> entry : allKeys.entrySet()) {
Log.v("TAG","Key Name :" entry.getKey());
Log.v("TAG","Key Value :" entry.getValue());
}
You have to call apply() on the shared preference editor after making changes.
...
myEditor.apply();
Shared preferences however, are not meant to store content related data. Consider using more appropriate solutions like a database.
I created a simple game. At the end the user's name and score is supposed to get into a highscore list. For this i would like to store these data in sharedpreferences. I saw a post and i am trying to apply it to my app but it force closes. I don't even know if this is the right thing i am doing. So i put these keypairs (player, score) into an arraylist. From there i can get the values out into a listview.
This is just an example.
SharedPreferences.Editor scoreEditor = myScores.edit();
scoreEditor.putString("PLAYER", "Thomas");
scoreEditor.putString("SCORE", "5");
scoreEditor.commit();
final ArrayList<HashMap<String,String>> LIST = new ArrayList<HashMap<String,String>>();
Map<String, ?> items = myScores.getAll();
for(String s : items.keySet()){
HashMap<String,String> hmap = new HashMap<String,String>();
hmap.put("PLAYER", s);
hmap.put("SCORE", items.get(s).toString());
LIST.add(hmap);
}
Toast.makeText(Start.this, "LIST size: "+LIST.size(), Toast.LENGTH_LONG).show();
For me it would also be okay if i store these data like this:
scoreEditor.putString("DATA", "Thomas" + "-" + "5");
and put that into ArrayList<String> LIST = new ArrayList<String>();
but i don't know how to do it.
Could you guys help me with this?
Edit: So i could go another way as Haphazard suggested. I put together this code, but i don't know if this is the way to do it. I haven't tested it yet, as sg is wrong with the sharedpreferences and i am still trying to figure it out.
SharedPreferences.Editor scoreEditor = myScores.edit();
scoreEditor.putString("DATA", "Thomas" + "-" + "5");
scoreEditor.commit();
HashSet<String> hset=new HashSet<String>();
hset.addAll((Collection<? extends String>) myScores.getAll());
ArrayList<String> LIST = new ArrayList<String>(hset);
The SharedPreferences Editor does not accept Lists but it does accept Sets. You could convert your List into a HashSet or something similar and store it like that. When your read it back, convert it into an ArrayList, sort it if needed and you're good to go.
Please note that the Set has to be a set of Strings so you will have to stick with your "Thomas" + "-" + "5" setup.
Edit: To your new update, I was thinking more of something like
//Retrieve the values
Set<String> set = new HashSet<String>();
set = myScores.getStringSet("key", null);
//Set the values
Set<String> set = new HashSet<String>();
set.addAll(listOfExistingScores);
scoreEditor.putStringSet("key", set);
scoreEditor.commit();
That code is untested, but it should work
EDIT: If your API level is below the get/setStringSet() level then you can try this:
1) Turn your list of high scores into a delimited string. That means if you had ["Tom, 1", "Ed, 5"] you could loop through it and turn it into a String like "Tom, 1|Ed, 5". You can easily store that using setString(..).
2) When you want to read the values back, perform a getString(..) and then String.split("|") to get the original list back. Well, it returns an array but that can be converted to a list easily enough.