Is it possible to save string array in preference while iterating its values in loop? Say for example :
String[] arrayvalue = new String[5];
for (int i = 0; i <= number; i++) {
Log.d(TAG, "ArrayValue" == " + arrayvalue[i]);
String abcd = arrayvalue[i].toString();
prefs.setData(context, abcd);
Log.d("Prefs", "Saving in Preference");
}
There are actually 5 values, so while saving I will see "Log" is executed 5 times, but while retrieving I am only seeing the last 5th value in preference, why is that so ?
//Retrieving
String converteddata = prefs.getData(context);
Log.d("Prefs", "Retreiving from Preference : " + converteddata);
Save
public synchronized String getData(Context context) {
Log.d(TAG, "getData");
SharedPreferences prefs = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
return prefs.getString(DATA, DEFAULT_DATA);
}
//Retrieve
public synchronized void setData(Context context, String data) {
Log.d(TAG, "setData");
SharedPreferences prefs = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
prefs.edit().putString(DATA, data).commit();
}
You can create your own String representation of the array like this:
StringBuilder sb = new StringBuilder();
for (int i = 0; i < playlists.length; i++) {
sb.append(playlists[i]).append(",");
//here you save the string each eteration
prefsEditor.putString(PLAYLISTS, sb.toString());
}
Then when you get the String from SharedPreferences simply parse it like this:
String[] playlists = playlist.split(",");
I hope its the answer you look for.
Related
I have been working on this problem for about five hours, implementing many different ways to achieve this goal, but nothing seems to be working. I am at the point to where I can't even think straight any more, so I am posting this here.
I have a shared preference which retrieves a string. that string is converted into a string array. I have a 2d array with four arrays set to the index. I want to loop through the 2d array and compare my string array to it. If the contents of each 2d array index are found in my string array, print true, else, false.
final SharedPreferences sharedPref = CocktailsFrag.this.getActivity().getPreferences(Activity.MODE_PRIVATE);
//recall stored ingredients
String arrayString = sharedPref.getString("myIngredients", null);
if(arrayString ==null) {
//do nothing
} else {
String str1 = arrayString.replace("[", "");
String str2 = str1.replace("]", "");
String[] strValues = str2.split(",");
String drink1[] = {"Ale", "Brandy"};
String drink2[] = {"Vodka", "Tobasco Sauce"};
String drink3[] = {"Lager", "Stout"};
String drink4[] = {"Guiness", "Champagne"};
String[][] arrays = {drink1, drink2, drink3, drink4};
for(int i=0; i<arrays.length-1;i++) {
String[] indexValue = arrays[i];
if(strValues[i].contains(indexValue[i])) {
Toast.makeText(getActivity().getApplicationContext(), indexValue[i]+ "", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getActivity().getApplicationContext(), "false", Toast.LENGTH_LONG).show();
}
}
}
Any thoughts on how to achieve this?
This code is not as efficient as simply iterating over the arrays but it doesn't matter with the number of elements and it is easier to read.
final SharedPreferences sharedPref = CocktailsFrag.this.getActivity().getPreferences(Activity.MODE_PRIVATE);
//recall stored ingredients
String arrayString = sharedPref.getString("myIngredients", null);
if(arrayString ==null) {
//do nothing
} else {
String str1 = arrayString.replace("[", "").replace("]", "");
List<String> strValues2 = Arrays.asList(str1.split(","));
String drink1[] = {"Ale", "Brandy"};
String drink2[] = {"Vodka", "Tobasco Sauce"};
String drink3[] = {"Lager", "Stout"};
String drink4[] = {"Guiness", "Champagne"};
String[][] arrays = {drink1, drink2, drink3, drink4};
for(String[] drinkArr : arrays){
if(strValues2.containsAll(Arrays.asList(drinkArr))) {
Toast.makeText(getActivity().getApplicationContext(), "true", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getActivity().getApplicationContext(), "false", Toast.LENGTH_LONG).show();
}
}
}
If you wanted to do this using arrays only one option is the following.
for(String[] drinkArr : arrays) {
boolean allDrinksFound = true;
for(int i = 0; i < drinkArr.length; i++) {
boolean drinkFound = false;
for(int j = 0; j < strValues.length; j++) {
if(drinkArr[i].equals(strValues[j])) {
drinkFound = true;
break;
}
}
allDrinksFound = allDrinksFound && drinkFound;
}
if(allDrinksFound) {
Toast.makeText(getActivity().getApplicationContext(), "true", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getActivity().getApplicationContext(), "false", Toast.LENGTH_LONG).show();
}
}
For my app, I need to save a simple SparseBooleanArray to memory and read it later.
Is there any way to save it using SharedPreferences?
I considered using an SQLite database but it seemed overkill for something as simple as this. Some other answers I found on StackOverflow suggested using GSON for saving it as a String but I need to keep this app very light and fast in file size. Is there any way of achieving this without relying on a third party library and while maintaining good performance?
You can use the power of JSON to save in the shared preferences for any type of object
For example SparseIntArray
Save items like Json string
public static void saveArrayPref(Context context, String prefKey, SparseIntArray intDict) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = prefs.edit();
JSONArray json = new JSONArray();
StringBuffer data = new StringBuffer().append("[");
for(int i = 0; i < intDict.size(); i++) {
data.append("{")
.append("\"key\": ")
.append(intDict.keyAt(i)).append(",")
.append("\"order\": ")
.append(intDict.valueAt(i))
.append("},");
json.put(data);
}
data.append("]");
editor.putString(prefKey, intDict.size() == 0 ? null : data.toString());
editor.commit();
}
and read json string
public static SparseIntArray getArrayPref(Context context, String prefKey) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
String json = prefs.getString(prefKey, null);
SparseIntArray intDict = new SparseIntArray();
if (json != null) {
try {
JSONArray jsonArray = new JSONArray(json);
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject item = jsonArray.getJSONObject(i);
intDict.put(item.getInt("key"), item.getInt("order"));
}
} catch (JSONException e) {
e.printStackTrace();
}
}
return intDict;
}
and use like this:
SparseIntArray myKeyList = new SparseIntArray();
...
//write list
saveArrayPref(getApplicationContext(),"MyList", myKeyList);
...
//read list
myKeyList = getArrayPref(getApplicationContext(), "MyList");
Write the values separately, and keep a list of the names of the values you write:
SparseBooleanArray array = //your array;
SharedPreferences prefs = //your preferences
//write
SharedPreferences.Editor edit = prefs.edit();
Set<String> keys = new HashSet<String>(array.size());
for(int i = 0, z = array.size(); i < z; ++i) {
int key = array.keyAt(i);
keys.add(String.valueOf(key));
edit.putBoolean("key_" + key, array.valueAt(i));
}
edit.putStringSet("keys", keys);
edit.commit();
//read
Set<String> set = prefs.getStringSet("keys", null);
if(set != null && !set.isEmpty()) {
for (String key : set) {
int k = Integer.parseInt(key);
array.put(k, prefs.getBoolean("key_"+key, false));
}
}
String sets are supported since API 11.
You could instead build a single csv string and split that rather than storing the set.
You can serialize the object to a byte array and then probably base64 the byte array before saving to SharedPreferences. Object serialization is really easy, you don't need a third party library for that.
public static byte[] serialize(Object obj) {
ByteArrayOutputStream byteArrayOS = new ByteArrayOutputStream();
ObjectOutputStream objectOS = new ObjectOutputStream(byteArrayOS);
objectOS.writeObject(obj);
objectOS.flush();
return byteArrayOS.toByteArray();
}
public static Object deserialize(byte[] data) {
ByteArrayInputStream byteArrayIS = new ByteArrayInputStream(data);
ObjectInputStream objectIS = new ObjectInputStream(byteArrayIS);
return objectIS.readObject();
}
The code above doesn't have try catch block for simplicity. You can add it on your own.
I have been doing this as the following by using Gson
To save sparseboolean array in SharedPreference:
public void SaveSparseBoolean() {
SparseBooleanArray booleanArray = new SparseBooleanArray();
SharedPreferences sP;
sP=context.getSharedPreferences("MY_APPS_PREF",Context.MODE_PRIVATE)
SharedPreferences.Editor editor=sP.edit();
Gson gson=new Gson();
editor.putString("Sparse_Array",gson.toJson(booleanArray));
editor.commit();
}
To get the SparsebooleanArray from SharedPreferences
public SparseBooleanArray getSparseArray() {
SparseBooleanArray booleanArray;
SharedPreferences sP;
sP = context.getSharedPreferences("MY_APPS_PREF", Context.MODE_PRIVATE);
Gson gson=new Gson();
booleanArray=gson.fromJson(sP.getString("Sparse_Array",""),SparseBooleanArray.class);
return booleanArray;
}
Hi guys I have got a String I am trying to store in to SharedPreferences:
here is the method I am using to store the string:
global vars:
private ArrayList<String> mListEmailAddresses;
method:
public void setEmailAddressList(String emailAddress){
emailAddress.replaceAll(",", "");
mListEmailAddresses.add(emailAddress);
SharedPreferences prefs = getSharedPreferences("invitefriends", 0);
StringBuilder str = new StringBuilder();
for (int i = 0; i < mListEmailAddresses.size(); i++) {
str.append(mListEmailAddresses.get(i).toString()).append(",");
}
LogUtils.log("emails: " + str.toString());
String theString = str.toString();
prefs.edit().putString("emails", theString);
prefs.edit().commit();
}
everytime this method is called the str.toString method is updated with a new email added to the list. for example "email1#gmail.com,email2#yahoo.co.uk,email3#hotmail.co.uk" would be the string that gets formed. the Log shows this string correctly. I then go to put theString under the key "emails" and whenever the view is restarted it is refreshed like so:
SharedPreferences prefs = getSharedPreferences("invitefriends", 0);
String savedString = prefs.getString("emails", "");
LogUtils.log("saved emails: " + savedString);
StringTokenizer st = new StringTokenizer(savedString, ",");
mListEmailAddresses = new ArrayList<String>();
for (int i = 0; i < st.countTokens(); i++) {
String strEmail = st.nextToken().toString();
mListEmailAddresses.add(strEmail);
}
The problem is that the Log here shows the saved emails is an empty string. What am I doing wrong? Thanks guys.
You are making the commit on an other instance of the editor. Try the following code
SharedPreferences.Editor editor = prefs.edit();
editor.putString("emails", theString);
editor.commit();
how to get value from shared preferences and save it array list
I want to get the string from shared preferences so that i want save that string to array list
SharedPreferences keyValues = context.getSharedPreferences("name_icons_list", context.MODE_PRIVATE);
if(keyValues.getString(""+str,"").equals("true"))
{
holder.tb1.setChecked(true);
onApps.add(str);
System.out.println("Block appp+++++"+onApps);
System.out.println("******************************************");
System.out.println("data retrive from database"+ position);
System.out.println("******************************************");
}
You may use this code to save preference in arraylist and vice versa
public String[] getApplicationList() { Log.i("test","prefrence getapplist");
return mApplicationList;
}
public void saveApplicationList(String[] applicationList) { Log.i("test","prefrence saveapplist");
mApplicationList = applicationList;
String combined = "";
for (int i=0; i<mApplicationList.length; i++){
combined = combined + mApplicationList[i] + ";";
}
mPref.edit().putString(PREF_APPLICATION_LIST, combined).commit();
}
I believe this should do the trick:
String savedString = context.getSharedPreferences(FILE_NAME, Context.MODE_PRIVATE)
.getString("name_icons_list", "");
StringTokenizer st = new StringTokenizer(savedString, ",");
int numberOfToken = st.countTokens();
ArrayList<String> arraylist = new ArrayList<String>();
for (int i = 0; i < numberOfToken; i++) {
arraylist.add(st.nextToken());
}
I want to save/recall an integer array using SharedPreferences. Is this possible?
You can try to do it this way:
Put your integers into a string, delimiting every int by a character, for example a comma, and then save them as a string:
SharedPreferences prefs = getPreferences(MODE_PRIVATE);
int[] list = new int[10];
StringBuilder str = new StringBuilder();
for (int i = 0; i < list.length; i++) {
str.append(list[i]).append(",");
}
prefs.edit().putString("string", str.toString());
Get the string and parse it using StringTokenizer:
String savedString = prefs.getString("string", "");
StringTokenizer st = new StringTokenizer(savedString, ",");
int[] savedList = new int[10];
for (int i = 0; i < 10; i++) {
savedList[i] = Integer.parseInt(st.nextToken());
}
You can't put Arrays in SharedPreferences, but you can workaround:
private static final String LEN_PREFIX = "Count_";
private static final String VAL_PREFIX = "IntValue_";
public void storeIntArray(String name, int[] array){
SharedPreferences.Editor edit= mContext.getSharedPreferences("NAME", Context.MODE_PRIVATE).edit();
edit.putInt(LEN_PREFIX + name, array.length);
int count = 0;
for (int i: array){
edit.putInt(VAL_PREFIX + name + count++, i);
}
edit.commit();
}
public int[] getFromPrefs(String name){
int[] ret;
SharedPreferences prefs = mContext.getSharedPreferences("NAME", Context.MODE_PRIVATE);
int count = prefs.getInt(LEN_PREFIX + name, 0);
ret = new int[count];
for (int i = 0; i < count; i++){
ret[i] = prefs.getInt(VAL_PREFIX+ name + i, i);
}
return ret;
}
Here's my version, based on Egor's answer. I prefer not to use StringBuilder unless I'm building an enourmous string, but thanks to Egor for using StringTokenizer -- haven't made much use of this in the past, but it's very handy! FYI, this went in my Utility class:
public static void saveIntListPrefs(
String name, Activity activity, List<Integer> list)
{
String s = "";
for (Integer i : list) {
s += i + ",";
}
Editor editor = activity.getPreferences(Context.MODE_PRIVATE).edit();
editor.putString(name, s);
editor.commit();
}
public static ArrayList<Integer> readIntArrayPrefs(String name, Activity activity)
{
SharedPreferences prefs = activity.getPreferences(Context.MODE_PRIVATE);
String s = prefs.getString(name, "");
StringTokenizer st = new StringTokenizer(s, ",");
ArrayList<Integer> result = new ArrayList<Integer>();
while (st.hasMoreTokens()) {
result.add(Integer.parseInt(st.nextToken()));
}
return result;
}
I like to use JSON, which can be stored and retrieved as a string, to represent any complex data in SharedPreferences.
So, in the case of an int array:
public void setPrefIntArray(String tag, int[] value)
{
SharedPreferences.Editor prefEditor = PreferenceManager.getDefaultSharedPreferences(context)
.edit();
String s;
try
{
JSONArray jsonArr = new JSONArray();
for (int i : value)
jsonArr.put(i);
JSONObject json = new JSONObject();
json.put(tag, jsonArr);
s = json.toString();
}
catch(JSONException excp)
{
s = "";
}
prefEditor.putString(tag, s);
prefEditor.commit();
}
public int[] getPrefIntArray(String tag, int[] defaultValue)
{
SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(context);
String s = pref.getString(tag, "");
try
{
JSONObject json = new JSONObject(new JSONTokener(s));
JSONArray jsonArr = json.getJSONArray(tag);
int[] result = new int[jsonArr.length()];
for (int i = 0; i < jsonArr.length(); i++)
result[i] = jsonArr.getInt(i);
return result;
}
catch(JSONException excp)
{
return defaultValue;
}
}
The beauty is that the same idea can be applied to any other complex data representable as a JSON.
Two solutions:
(1) Use http://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/StringUtils.html
It has split/join functions that let you join and split the integers in one liners:
StringUtils.join([1, 2, 3], ';') = "1;2;3"
StringUtils.split("1;2;3", ';') = ["1", "2", "3"]
You'd still have to convert the strings back to integers, though.
Actually, for splitting java.lang.String.split() will work just as fine:
http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#split(java.lang.String)
(2) Use the SharedPreferences.putStringSet() (API 11):
SharedPreferences.Editor editor = preferences.edit();
int count = this.intSet.size();
if (count > 0) {
Set<String> theSet = new HashSet<String>();
for (Long l : this.intSet) {
theSet.add(String.valueOf(l));
}
editor.putStringSet(PREFS_KEY, theSet);
} else {
editor.remove(PREFS_KEY);
}
editor.commit();
And to get it back:
Set<String> theSet = this.preferences.getStringSet(PREFS_KEY, null);
if (theSet != null && !theSet.isEmpty()) {
this.intSet.clear();
for (String s : theSet) {
this.intSet.add(Integer.valueOf(s));
}
}
This code does not catch the NPEs or NumberFormatExceptions because the intSet is otherwise assured to not contain any nulls. But of course, if you cannot assure that in your code you should surround this with a try/catch.
Here is how the "convert to comma-separated String" solution could look in Kotlin, implemented as extension functions:
fun SharedPreferences.Editor.putIntArray(key: String, value: IntArray): SharedPreferences.Editor {
return putString(key, value.joinToString(
separator = ",",
transform = { it.toString() }))
}
fun SharedPreferences.getIntArray(key: String): IntArray {
with(getString(key, "")) {
with(if(isNotEmpty()) split(',') else return intArrayOf()) {
return IntArray(count(), { this[it].toInt() })
}
}
}
That way you can use putIntArray(String, IntArray) and getIntArray(String) just like the other put and set methods:
val prefs = getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
prefs.edit().putIntArray(INT_ARRAY_TEST_KEY, intArrayOf(1, 2, 3)).apply()
val intArray = prefs.getIntArray(INT_ARRAY_TEST_KEY)
I went for the below solution, it's the least verbose of what I could see in this thread (in my case I wanted to have a set as a collection). "value" is the of type Set<Int>.
Save:
sharedPreferences.edit {
if (value.isNotEmpty()) {
putStringSet(key, hashSetOf(*value.map { it.toString() }.toTypedArray()))
} else {
remove(key)
}
}
Retrieve:
val stringSet = sharedPreferences.getStringSet(key, null)
if (stringSet.isNullOrEmpty()) return emptySet()
return setOf<Int>(*stringSet.map { Integer.valueOf(it) }.toTypedArray())
You can only save primitive values in sharedPreference. Use Sqlite instead.