Develop Reference

Store and retrive Listview data using Shared Preferences

I have a listview of ringtones .. I feed the list via mysql database.. (such as song names,song urls ...).
I dynamically add products(ringtones) in my listview by adding new item in my database, so none of this data are inside my app except row icons.
This is the view
As you can see I have a bookmark border icon that when user clicks on it, it will turn into selected...This is how it works :
holder.favImage=(ImageView)v.findViewById(R.id.favImage);
holder.favImage.setImageResource(product.getFavId());
holder.favImage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Product product = (Product) mDataItems.get(position);
if(product.faved){
product.setFavId(R.mipmap.bookmarked);
sharedPreference.addFavorite(mContext,product);
product.faved=false;
}
else {
sharedPreference.removeFavorite(mContext,product);
product.setFavId(R.mipmap.bookmark_border);
product.faved = true;
}
notifyDataSetChanged();
}
});
but nothing will happen in my "FAVORITES" tab .. Even the state of bookmark icon when it is selected will not be saved..
Custom Adapter
public class FunDapter<T> extends BaseAdapter {
protected List<T> mDataItems;
protected List<T> mOrigDataItems;
protected final Context mContext;
private final int mLayoutResource;
private final BindDictionary<T> mBindDictionary;
SharedPreference sharedPreference;
public FunDapter(Context context, List<T> dataItems, int layoutResource,
BindDictionary<T> dictionary) {
this(context, dataItems, layoutResource, null, dictionary);
}
public FunDapter(Context context, List<T> dataItems, int layoutResource,
LongExtractor<T> idExtractor, BindDictionary<T> dictionary) {
this.mContext = context;
this.mDataItems = dataItems;
this.mOrigDataItems = dataItems;
this.mLayoutResource = layoutResource;
this.mBindDictionary = dictionary;
sharedPreference = new SharedPreference();
}
public void updateData(List<T> dataItems) {
this.mDataItems = dataItems;
this.mOrigDataItems = dataItems;
notifyDataSetChanged();
}
#Override
public int getCount() {
if (mDataItems == null || mBindDictionary == null) return 0;
return mDataItems.size();
}
#Override
public T getItem(int position) {
return mDataItems.get(position);
}
#Override
public long getItemId(int position) {
if(idExtractor == null) return position;
else return idExtractor.getLongValue(getItem(position), position);
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
View v = convertView;
final GenericViewHolder holder;
if (null == v) {
LayoutInflater vi =
(LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(mLayoutResource, null);
holder = new GenericViewHolder();
holder.root = v;
//init the sub views and put them in a holder instance
FunDapterUtils.initViews(v, holder, mBindDictionary);
v.setTag(holder);
}else {
holder = (GenericViewHolder) v.getTag();
}
final T item = getItem(position);
showData(item, holder, position);
final Product product = (Product) mDataItems.get(position);
holder.favImage=(ImageView)v.findViewById(R.id.favImage);
holder.favImage.setImageResource(product.getFavId());
holder.favImage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(product.faved){
product.setFavId(R.mipmap.bookmarked);
sharedPreference.addFavorite(mContext,product);
product.faved=false;
}
else {
sharedPreference.removeFavorite(mContext,product);
product.setFavId(R.mipmap.bookmark_border);
product.faved = true;
}
notifyDataSetChanged();
}
});
return v;
}
}
Product model class
#SuppressWarnings("serial")
public class Product implements Serializable {
#SerializedName("pid")
public int pid;
#SerializedName("name")
public String name;
#SerializedName("qty")
public int qty;
#SerializedName("price")
public String description;
#SerializedName("song_url")
public String song_url;
#SerializedName("date")
public String date;
public boolean paused = true;
public boolean faved = true;
private int favId;
public int getFavId() {
return favId;}
public void setFavId(int favId) {
this.favId = favId;}
}
SharedPreferences class
public class SharedPreference {
public static final String PREFS_NAME = "PRODUCT_APP";
public static final String FAVORITES = "Product_Favorite";
public SharedPreference() {
super();
}
// This four methods are used for maintaining favorites.
public void saveFavorites(Context context, List<Product> favorites) {
SharedPreferences settings;
Editor editor;
settings = context.getSharedPreferences(PREFS_NAME,Context.MODE_PRIVATE);
editor = settings.edit();
Gson gson = new Gson();
String jsonFavorites = gson.toJson(favorites);
editor.putString(FAVORITES, jsonFavorites);
editor.commit();
}
public void addFavorite(Context context, Product product) {
List<Product> favorites = getFavorites(context);
if (favorites == null)
favorites = new ArrayList<Product>();
favorites.add(product);
saveFavorites(context, favorites);
}
public void removeFavorite(Context context, Product product) {
ArrayList<Product> favorites = getFavorites(context);
if (favorites != null) {
favorites.remove(product);
saveFavorites(context, favorites);
}
}
public ArrayList<Product> getFavorites(Context context) {
SharedPreferences settings;
List<Product> favorites;
settings = context.getSharedPreferences(PREFS_NAME,Context.MODE_PRIVATE);
if (settings.contains(FAVORITES)) {
String jsonFavorites = settings.getString(FAVORITES, null);
Gson gson = new Gson();
Product[] favoriteItems = gson.fromJson(jsonFavorites,Product[].class);
favorites = Arrays.asList(favoriteItems);
favorites = new ArrayList<Product>(favorites);
} else
return null;
return (ArrayList<Product>) favorites;
}
}
I'm stuck here for a few days, Can you help me please !

Actually your implementation more complex for the favorite, I thing simply take one column into your database like name isFavorite and by default added zero into this column when you press button then change value zero to one but every time we are not connected with internet so use SQLite database reason behind that size and speed of the SQLite database is more compare to SharedPreferences.
But here you not want to use SQLite database so first download json from the your web service and only change made when user click on the favorite button like
Json format before click:
{unieq_id:”1”, isFavorite :”0”}
Json format after click:
{unieq_id:”1”, isFavorite :”1”}
If isFavourite 0 then your non favorite icon display else display your favorite icon.

Create favorite listview with shared preferences

I have a listview of ringtones .. I feed the list via mysql database.. (such as song names,song urls ...). I dynamically add products(ringtones) in my listview by adding new item in my database, so none of this data are inside my app except row icons.
This is the view
As you can see I have a bookmark border icon that when user clicks on it, it will turn into selected...This is how it works :
#Override
public void favOnClick(int position) {
Product product = productList.get(position);
if (product.faved) {
sharedPreference.addFavorite(activity,product);
product.setFavId(R.mipmap.bookmarked);
product.faved=false;
}else {
sharedPreference.removeFavorite(activity,product);
product.setFavId(R.mipmap.bookmark_border);
product.faved = true;
}
adapter.notifyDataSetChanged();
};
but nothing will happen in my "FAVORITES" tab .. Even the state of bookmark icon when it is selected will not be saved..
Custom Adapter
public class FunDapter<T> extends BaseAdapter {
public interface PlayPauseClick {
void favOnClick(int position);
}
private PlayPauseClick callback;
public void setPlayPauseClickListener(PlayPauseClick listener) {
this.callback = listener;
}
protected List<T> mDataItems;
protected List<T> mOrigDataItems;
protected final Context mContext;
private final int mLayoutResource;
private final BindDictionary<T> mBindDictionary;
public FunDapter(Context context, List<T> dataItems, int layoutResource,
BindDictionary<T> dictionary) {
this(context, dataItems, layoutResource, null, dictionary);
}
public FunDapter(Context context, List<T> dataItems, int layoutResource,
LongExtractor<T> idExtractor, BindDictionary<T> dictionary) {
this.mContext = context;
this.mDataItems = dataItems;
this.mOrigDataItems = dataItems;
this.mLayoutResource = layoutResource;
this.mBindDictionary = dictionary;
sharedPreference = new SharedPreference();
}
public void updateData(List<T> dataItems) {
this.mDataItems = dataItems;
this.mOrigDataItems = dataItems;
notifyDataSetChanged();
}
#Override
public int getCount() {
if (mDataItems == null || mBindDictionary == null) return 0;
return mDataItems.size();
}
#Override
public T getItem(int position) {
return mDataItems.get(position);
}
#Override
public long getItemId(int position) {
if(idExtractor == null) return position;
else return idExtractor.getLongValue(getItem(position), position);
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
View v = convertView;
final GenericViewHolder holder;
if (null == v) {
LayoutInflater vi =
(LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(mLayoutResource, null);
holder = new GenericViewHolder();
holder.root = v;
//init the sub views and put them in a holder instance
FunDapterUtils.initViews(v, holder, mBindDictionary);
v.setTag(holder);
}else {
holder = (GenericViewHolder) v.getTag();
}
final T item = getItem(position);
showData(item, holder, position);
Product product = (Product) mDataItems.get(position);
holder.favImage=(ImageView)v.findViewById(R.id.favImage);
holder.favImage.setImageResource(product.getFavId());
holder.favImage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (callback != null) {
callback.favOnClick(position);
}
}
});
return v;
}
}
Product model class
#SuppressWarnings("serial")
public class Product implements Serializable {
#SerializedName("pid")
public int pid;
#SerializedName("name")
public String name;
#SerializedName("qty")
public int qty;
#SerializedName("price")
public String description;
#SerializedName("song_url")
public String song_url;
#SerializedName("date")
public String date;
public boolean paused = true;
public boolean faved = true;
private int favId;
public int getFavId() {
return favId;}
public void setFavId(int favId) {
this.favId = favId;}
}
SharedPreferences class
public class SharedPreference {
public static final String PREFS_NAME = "PRODUCT_APP";
public static final String FAVORITES = "Product_Favorite";
public SharedPreference() {
super();
}
// This four methods are used for maintaining favorites.
public void saveFavorites(Context context, List<Product> favorites) {
SharedPreferences settings;
Editor editor;
settings = context.getSharedPreferences(PREFS_NAME,Context.MODE_PRIVATE);
editor = settings.edit();
Gson gson = new Gson();
String jsonFavorites = gson.toJson(favorites);
editor.putString(FAVORITES, jsonFavorites);
editor.commit();
}
public void addFavorite(Context context, Product product) {
List<Product> favorites = getFavorites(context);
if (favorites == null)
favorites = new ArrayList<Product>();
favorites.add(product);
saveFavorites(context, favorites);
}
public void removeFavorite(Context context, Product product) {
ArrayList<Product> favorites = getFavorites(context);
if (favorites != null) {
favorites.remove(product);
saveFavorites(context, favorites);
}
}
public ArrayList<Product> getFavorites(Context context) {
SharedPreferences settings;
List<Product> favorites;
settings = context.getSharedPreferences(PREFS_NAME,Context.MODE_PRIVATE);
if (settings.contains(FAVORITES)) {
String jsonFavorites = settings.getString(FAVORITES, null);
Gson gson = new Gson();
Product[] favoriteItems = gson.fromJson(jsonFavorites,Product[].class);
favorites = Arrays.asList(favoriteItems);
favorites = new ArrayList<Product>(favorites);
} else
return null;
return (ArrayList<Product>) favorites;
}
}
I'm stuck here for a few days, Can you help me please !
This is my project link if you would like to look into it for further info
http://symphonyrecords.ir/RingtoneApp.rar

There are two problems here (based on your project)
First (saving state of bookmark Imageview)
In adapter create a method that checks whether a particular product exists in SharedPreferences
public boolean checkFavoriteItem(Product checkProduct) {
boolean check = false;
List<Product> favorites = sharedPreference.getFavorites(null, mContext);
if (favorites != null) {
for (Product product : favorites) {
if (product.equals(checkProduct)) {
check = true;
break;
}
}
}
return check;
}
Inside adapter check if a product exists in shared preferences then set bookmarked drawable and set a tag
if (checkFavoriteItem(product)) {
holder.favoriteImg.setImageResource(R.mipmap.bookmarked);
holder.favoriteImg.setTag("bookmarked");
} else {
holder.favoriteImg.setImageResource(R.mipmap.bookmark_border);
holder.favoriteImg.setTag("bookmark_border");
}
Then inside favOnClick callback method
#Override
public boolean favOnClick(int position ,View v) {
Product product = (Product) productList.get(position);
ImageView button = (ImageView) v.findViewById(R.id.favImage);
String tag = button.getTag().toString();
if (tag.equalsIgnoreCase("bookmark_border")) {
sharedPreference.addFavorite(activity,product);
Toast.makeText(activity,"Added to Favorites",Toast.LENGTH_SHORT).show();
button.setTag("bookmarked");
button.setImageResource(R.mipmap.bookmarked);
} else {
sharedPreference.removeFavorite(activity,product);
button.setTag("bookmark_border");
button.setImageResource(R.mipmap.bookmark_border);
Toast.makeText(activity,"Removed from Favorites",Toast.LENGTH_SHORT).show();
}
return true;
}
Second (get favorite product and pass it to "FAVORITE" Fragment)
Inside getFavorite method add a String parameter
Then in your "FAVORITE" Fragment with processFinish(your AsyncResponse) call your getFavorite in order to get your Favorite product list then set your adapter :
Context mContext;
`mContext = getContext();`
#Override
public void processFinish(String s) {
productList = sharedPreference.getFavorites(s, mContext);
BindDictionary<Product> dict = new BindDictionary<Product>();
dict.addStringField(R.id.tvName, new StringExtractor<Product>() {
#Override
public String getStringValue(Product product, int position) {
return product.name;
}
});
dict.addStringField(R.id.tvDescription, new StringExtractor<Product>() {
#Override
public String getStringValue(Product product, int position) {
return product.description;
}
});
dict.addStringField(R.id.tvQty, new StringExtractor<Product>() {
#Override
public String getStringValue(Product product, int position) {
return "" + product.qty;
}
});
adapter = new FunDapter<>(getActivity(), productList, R.layout.d_layout_list_d, dict);
lvProduct.setAdapter(adapter);
}

Make sure favOnClick method change the object in FunDapter.mDataItems.
So, Change the callback method:
#Override
public void favOnClick(int position) {
Product product = adapter.get(position);
if (product.faved) {
sharedPreference.addFavorite(activity, product);
product.setFavId(R.mipmap.bookmarked);
product.faved=false;
}else {
sharedPreference.removeFavorite(activity, product);
product.setFavId(R.mipmap.bookmark_border);
product.faved = true;
}
adapter.notifyDataSetChanged();
};

Check this, 99% working code
On click Fav Btn
List< RvModel > favorites_list = storageFavorites.loadFavourite();
boolean exist = false;
if (favorites_list == null) {
favorites_list = new ArrayList<>();
}
for (int i = 0; i < favorites_list.size(); i++) {
if (favorites_list.get(i).getId().equals(rvModelArrayList.get(position).getId())) {
exist = true;
}
}
if (!exist) {
ArrayList< RvModel > audios = new ArrayList< RvModel >(favorites_list);
audios.add(rvModelArrayList.get(position));
storageFavorites.storeImage(audios);
holder.bookMarkBtn.setImageDrawable(activity.getResources().getDrawable(R.drawable.ic_bookmark_full));
} else {
ArrayList< RvModel > new_favorites = new ArrayList< RvModel >();
for (int i = 0; i < favorites_list.size(); i++) {
if (!favorites_list.get(i).getId().equals(rvModelArrayList.get(position).getId())) {
new_favorites.add(favorites_list.get(i));
}
}
if (favorites) {
Log.v("DOWNLOADED", "favorites==true");
rvModelArrayList.remove(position);
notifyDataSetChanged();
//holder.ripple_view_wallpaper_item.setVisibility(View.GONE);
}
storageFavorites.storeImage(new_favorites);
holder.bookMarkBtn.setImageDrawable(activity.getResources().getDrawable(R.drawable.ic_bookmark));
}
}

save positions of selected checkbox in sqlite db and restore state of checkbox

I want to save the positions of selected checkboxes on button click in database and close the app. And using these positions, restore the selected states of checkboxes when I open the app. Can anyone help me in this?
public class MainActivity extends AppCompatActivity {
MyCustomAdapter dataAdapter = null;
String str, str1;
SharedPreferences pref;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pref = getSharedPreferences("MYPref", Context.MODE_PRIVATE);
str1 = pref.getString("key","");
List<String> list = Arrays.asList(str1.split(","));
System.out.println(list);
displayListView();
checkButtonClick();
}
private void displayListView()
{
//HERE I WANT TO RETRIEVE THE POSITIONS TO SET EARLIER SELECTED CHECKOX AGAIN SELECTED
ArrayList<States> stateList = new ArrayList<States>();
States _states = new States("AP","Andhra Pradesh",false);
stateList.add(_states);
_states = new States("DL","Delhi",false);
stateList.add(_states);
_states = new States("GA","Goa",false);
stateList.add(_states);
_states = new States("JK","Jammu & Kashmir",false);
stateList.add(_states);
_states = new States("KA","Karnataka",false);
stateList.add(_states);
_states = new States("KL","Kerala",false);
stateList.add(_states);
_states = new States("RJ","Rajasthan",false);
stateList.add(_states);
_states = new States("WB","West Bengal",false);
stateList.add(_states);
dataAdapter = new MyCustomAdapter(this,R.layout.state_info, stateList);
ListView listView = (ListView) findViewById(R.id.listView1);
listView.setAdapter(dataAdapter);
}
private void checkButtonClick()
{
Button myButton = (Button) findViewById(R.id.findSelected);
myButton.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
StringBuffer responseText = new StringBuffer();
responseText.append("The following were selected...\n");
ArrayList<States> stateList = dataAdapter.stateList;
for(int i=0;i<stateList.size();i++)
{
States state = stateList.get(i);
if(state.isSelected())
{
responseText.append("\n" + state.getName());
// HERE I WANT TO SAVE POSITIONS
}
}
Toast.makeText(getApplicationContext(),
responseText, Toast.LENGTH_LONG).show();
}
});
}
}
public class MyCustomAdapter extends ArrayAdapter<States> {
public ArrayList<States> stateList;
public MyCustomAdapter(Context context, int textViewResourceId, ArrayList<States> stateList)
{
super(context, textViewResourceId, stateList);
this.stateList = new ArrayList<States>();
this.stateList.addAll(stateList);
}
private class ViewHolder
{
TextView code;
CheckBox name;
}
#Override
public View getView(int position, View convertView, ViewGroup parent)
{
ViewHolder holder = null;
Log.v("ConvertView", String.valueOf(position));
if (convertView == null)
{
LayoutInflater vi = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = vi.inflate(R.layout.state_info, null);
holder = new ViewHolder();
holder.code = (TextView) convertView.findViewById(R.id.code);
holder.name = (CheckBox) convertView.findViewById(R.id.checkBox1);
convertView.setTag(holder);
holder.name.setOnClickListener( new View.OnClickListener()
{
public void onClick(View v)
{
CheckBox cb = (CheckBox) v;
States _state = (States) cb.getTag();
/* Toast.makeText(getApplicationContext(), "Clicked on Checkbox: " + cb.getText() + " is " + cb.isChecked(),
Toast.LENGTH_LONG).show();*/
_state.setSelected(cb.isChecked());
}
});
}
else
{
holder = (ViewHolder) convertView.getTag();
}
States state = stateList.get(position);
holder.code.setText(" (" + state.getCode() + ")");
holder.name.setText(state.getName());
holder.name.setChecked(state.isSelected());
holder.name.setTag(state);
return convertView;
}
}
public class States {
String code = null;
String name = null;
boolean selected = false;
public States(String code, String name, boolean selected) {
this.code = code;
this.name = name;
this.selected = selected;
}
public String getCode() {
return code;
}
public void setCode(String code) {
this.code = code;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public boolean isSelected() {
return selected;
}
public void setSelected(boolean selected) {
this.selected = selected;
}
}

Is your data going to be huge? if Yes, use SQLlite. If only like what you stated, only for loading up app parameters, Share preference is better. Try below functions.
public static <T> T readPreference(Class<T> clazz, String key) {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(Application.getInstance());
if (clazz.equals(String.class)) {
return (T) preferences.getString(key, "");
} else if (clazz.equals(Integer.class)) {
return (T) (Integer) preferences.getInt(key, 0);
} else if (clazz.equals(Boolean.class)) {
return (T) (Boolean) preferences.getBoolean(key, false);
} else if (clazz.equals(Float.class)) {
return (T) (Float) preferences.getFloat(key, -0.0f);
}
return null;
}
public static void writePreference(String key, Object value) {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(Application.getInstance());
SharedPreferences.Editor edit = preferences.edit();
if (value instanceof Integer) {
edit.putInt(key, (Integer) value);
} else if (value instanceof Boolean) {
edit.putBoolean(key, (Boolean) value);
} else if (value instanceof Float) {
edit.putFloat(key, (Float) value);
} else if (value instanceof Long) {
edit.putLong(key, (Long) value);
} else if (value instanceof String) {
edit.putString(key, (String) value);
}
edit.apply();
}

Adding favorite button in list view

I have a listview which has a favorite button for every list item which when clicked should add the list item to another activity called my fav9rites. I am using a Baseadapter for the listview and Sharedpreference for adding favorites.
When I click the favorite button, the list view item is getting added in the my favorites activity but I am facing the following problems:
1)the favorite button when clicked should turn dark indicating that the list item is added to favorites. This happens but when I close the activity and come back again the button reverts back instead of being dark
2)on long press on list item in my favorites activity , the list item should be removed from the favorites but this is not happening.
Hope everyone understand my question
My code
my base adapter
public View getView(final int position, View view, ViewGroup parent)
{
final ViewHolder holder;
if(view == null){
holder = new ViewHolder();
view = inflater.inflate(R.layout.beg_list_item,null);
holder.listHeading = (TextView) view.findViewById(R.id.beg_list_itemTextView);
// holder.listHash = (TextView) view.findViewById(R.id.listview_hashtags);
holder.alphabetList = (ImageView) view.findViewById(R.id.beg_list_itemImageView);
holder.favoriteImg = (ImageView) view.findViewById(R.id.favbtn);
view.setTag(holder);
}else{
holder = (ViewHolder) view.getTag();
}
CodeList code = (CodeList) getItem(position);
holder.listHeading.setText(codeList.get(position).getListHeading());
imageLoader.DisplayImage(codeList.get(position).getAlphabetimg(),
holder.alphabetList);
// holder.listHash.setText(codeList.get(position).getListHashTags());
if (checkFavoriteItem(code)) {
holder.favoriteImg.setImageResource(R.drawable.favorite);
holder.favoriteImg.setTag("yes");
} else {
holder.favoriteImg.setImageResource(R.drawable.unfavorite);
holder.favoriteImg.setTag("no");
}
view.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View arg0){
Intent intent = new Intent(context, SingleItemView.class);
//intent.putExtra("listheading",
// (codeList.get(position).getListHeading()));
//intent.putExtra("alphabetimg",
// (codeList.get(position).getAlphabetimg()));
intent.putExtra("demovideo",
(codeList.get(position).getDailogdemovideo()));
intent.putExtra("download",
(codeList.get(position).getDownloadCode()));
// Start SingleItemView Class
context.startActivity(intent);
}
});
final ImageView favoritesbutton = (ImageView) view.findViewById(R.id.favbtn);
favoritesbutton.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v){
String tag = favoritesbutton.getTag().toString();
if(tag.equalsIgnoreCase("no")){
shrdPrefence.addFavorite(context, codeList.get(position));
Toast.makeText(context, R.string.fav_added, Toast.LENGTH_SHORT).show();
favoritesbutton.setTag("yes");
favoritesbutton.setImageResource(R.drawable.favorite);
}else{
shrdPrefence.removeFavorite(context, codeList.get(position));
favoritesbutton.setTag("no");
favoritesbutton.setImageResource(R.drawable.unfavorite);
Toast.makeText(context, R.string.fav_removed, Toast.LENGTH_SHORT).show();
}
}
});
return view;
}
//Checks whether a particular product exists in SharedPreferences*/
public boolean checkFavoriteItem(CodeList checkCode) {
boolean check = false;
List<CodeList> favorites = shrdPrefence.getFavorites(context);
if (favorites != null) {
for (CodeList code : favorites) {
if (code.equals(checkCode)) {
check = true;
break;
}
}
}
return check;
}
public void add(CodeList code) {
codeList.add(code);
notifyDataSetChanged();
}
public void remove(CodeList code) {
codeList.remove(code);
notifyDataSetChanged();
}
sharedpreference.java
public class SharedPreference
{
public static final String PREFS_NAME = "MY_APP";
public static final String FAVORITES = "code_Favorite";
public SharedPreference(){
super();
}
public void saveFavorites(Context context, List<CodeList> favorites){
SharedPreferences settings;
Editor editor;
settings = context.getSharedPreferences(PREFS_NAME,
Context.MODE_PRIVATE);
editor = settings.edit();
Gson gson = new Gson();
String jsonFavorites = gson.toJson(favorites);
editor.putString(FAVORITES, jsonFavorites);
editor.commit();
}
public void addFavorite(Context context, CodeList code){
List<CodeList> favorites = getFavorites(context);
if(favorites == null)
favorites = new ArrayList<CodeList>();
favorites.add(code);
saveFavorites(context,favorites);
}
public void removeFavorite(Context context, CodeList code) {
ArrayList<CodeList> favorites = getFavorites(context);
if (favorites != null) {
favorites.remove(code);
saveFavorites(context, favorites);
}
}
public ArrayList<CodeList> getFavorites(Context context) {
SharedPreferences settings;
List<CodeList> favorites;
settings = context.getSharedPreferences(PREFS_NAME,
Context.MODE_PRIVATE);
if (settings.contains(FAVORITES)) {
String jsonFavorites = settings.getString(FAVORITES, null);
Gson gson = new Gson();
CodeList[] favoriteItems = gson.fromJson(jsonFavorites,
CodeList[].class);
favorites = Arrays.asList(favoriteItems);
favorites = new ArrayList<CodeList>(favorites);
} else
return null;
return (ArrayList<CodeList>) favorites;
}
}
my favorite..java
public class MyFavActivity extends Activity
{
SharedPreference shrdPrfence;
List<CodeList> favorites;
FinalAdapter fnlAdpter;
Context context = this.context;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.fav_layout);
shrdPrfence = new SharedPreference();
favorites = shrdPrfence.getFavorites(MyFavActivity.this);
if(favorites == null){
Dialog dialog = new Dialog(MyFavActivity.this);
dialog.setTitle(R.string.nofav_title);
dialog.show();
}else{
if(favorites.size() == 0){
Dialog dialog = new Dialog(MyFavActivity.this);
dialog.setTitle(R.string.nofav_title);
dialog.show();
}
ListView favList = (ListView) findViewById(R.id.fav_layoutListView);
if(favorites != null){
fnlAdpter = new FinalAdapter(MyFavActivity.this, favorites);
favList.setAdapter(fnlAdpter);
favList.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View arg1,
int position, long arg3) {
}
});
favList.setOnItemLongClickListener(new OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> parent, View view,
int position, long id) {
ImageView button = (ImageView) view
.findViewById(R.id.favbtn);
String tag = button.getTag().toString();
if (tag.equalsIgnoreCase("no")) {
shrdPrfence.addFavorite(MyFavActivity.this,
favorites.get(position));
Toast.makeText(
MyFavActivity.this,
R.string.fav_added,
Toast.LENGTH_SHORT).show();
button.setTag("yes");
button.setImageResource(R.drawable.favorite);
} else {
shrdPrfence.removeFavorite(MyFavActivity.this,
favorites.get(position));
button.setTag("no");
button.setImageResource(R.drawable.unfavorite);
fnlAdpter.remove(favorites.get(position));
Toast.makeText(
MyFavActivity.this,
R.string.fav_removed,
Toast.LENGTH_SHORT).show();
}
return true;
}
});
}
}
}
}

Actually your saveFavorites() method works fine, becuse you just call gson.toJson() ( convert everything in json format)
You want to get saved data with SharedPreferences and you have used this line to retrieve your data
gson.fromJson(jsonFavorites, CodeList[].class);
you never get your saved data with this line, because you save a list and you want to retrieve an array (!)
If you saved a list you must retrive your data with a list token. And you need this line
gson.fromJson(jsonFavorites,new TypeToken<ArrayList<CodeList>>() {}.getType());
I think this will solve your question. Good luck.

Unable to use Shared Preferences for Arraylist

This is my list of songs from the NewList.class: http://postimg.org/image/uieab0wuv/ and i want in another activity to have a favorite list with the songs i get when the star button is long-pressed .
I used this tutorial(http://androidopentutorials.com/android-how-to-store-list-of-values-in-sharedpreferences/) to adapt my project but it doesn't work for an ArrayList
**the activity which generates the list **:
public class NewList extends Activity implements
AdapterView.OnItemClickListener, AdapterView.OnItemLongClickListener {
public static final String ARG_ITEM_ID = "product_list";
Activity activity;
ListView productListView;
ArrayList<Track> tracks;
SharedPreference sharedPreference;
private ListView newListView;
private EditText inputSearch;
private int TRACK_POSITION;
private AdapterExploreListView adapterExploreListView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_explore_music);
newListView = (ListView) findViewById(R.id.newListView);
Bundle extras = getIntent().getExtras();
int temp = extras.getInt("id");
TextView mTextView = (TextView) findViewById(R.id.title_genre);
mTextView.setText(Consts.genresArray[temp]);
fillListWithStyle(Consts.genresArray[temp]);
newListView.setOnItemClickListener(this);
newListView.setOnItemLongClickListener(this);
Toast.makeText(getApplicationContext(),
"Position :" + temp, Toast.LENGTH_LONG)
.show();
}
private void fillListWithStyle(final String style)
{
new AsyncTask<Void,Void,ArrayList<Track>>()
{
#Override
protected ArrayList<Track> doInBackground(Void... voids) {
JsonParser parser = new JsonParser();
String encodedURL="";
try {
encodedURL = URLEncoder.encode(style, "utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return parser.getTracksForUrl(Consts.url1 + encodedURL + Consts.url2, "tracks");
}
#Override
protected void onPostExecute(ArrayList<Track> tracks) {
super.onPostExecute(tracks);
DataHolder.getInstance().setTracks(tracks);
adapterExploreListView = new AdapterExploreListView(NewList.this, tracks);
newListView.setAdapter(adapterExploreListView);
}
}.execute();
}
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Intent intent = new Intent(this, PlayerActivity.class);
intent.putExtra(PlayerActivity.TRACK_POSITION, i);
startActivityForResult(intent, 1);
TRACK_POSITION=i;
}
#Override
public boolean onItemLongClick(AdapterView<?> arg0, View view,
int position, long arg3) {
ImageView button = (ImageView) view.findViewById(R.id.favbutton);
String tag = button.getTag().toString();
if (tag.equalsIgnoreCase("grey")) {
sharedPreference.addFavorite(activity, tracks.get(position));
Toast.makeText(activity,
activity.getResources().getString(R.string.add_favr),
Toast.LENGTH_SHORT).show();
button.setTag("red");
button.setImageResource(R.drawable.favoritespic);
} else {
sharedPreference.removeFavorite(activity, tracks.get(position));
button.setTag("grey");
button.setImageResource(R.drawable.favoritespicg);
Toast.makeText(activity,
activity.getResources().getString(R.string.remove_favr),
Toast.LENGTH_SHORT).show();
}
return true;
}
}
the adapter
public class AdapterExploreListView extends ArrayAdapter<Track> {
private Context context;
ArrayList<Track> tracks;
SharedPreference sharedPreference;
public AdapterExploreListView(Context context, ArrayList<Track> tracks) {
super(context, R.layout.row_list_explore, tracks);
this.context = context;
this.tracks = new ArrayList<>();
this.tracks = tracks;
sharedPreference = new SharedPreference();
}
#Override
public int getCount() {
return tracks.size();
}
#Override
public Track getItem(int position) {
return tracks.get(position);
}
#Override
public long getItemId(int position) {
return 0;
}
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
View rowView = view;
// reuse views
if (rowView == null) {
LayoutInflater inflater = LayoutInflater.from(context);
rowView = inflater.inflate(R.layout.row_list_explore, null);
// configure view holder
ViewHolder viewHolder = new ViewHolder();
viewHolder.title = (TextView) rowView.findViewById(R.id.titleTextView);
viewHolder.userName = (TextView) rowView.findViewById(R.id.userNameTextView);
viewHolder.favoriteImg = (ImageView) rowView.findViewById(R.id.favbutton);
rowView.setTag(viewHolder);
}
// fill data
final ViewHolder holder = (ViewHolder) rowView.getTag();
Track track = tracks.get(i);
holder.title.setText(track.getTitle());
holder.userName.setText(track.getUsername());
if (checkFavoriteItem(track)) {
holder.favoriteImg.setImageResource(R.drawable.favoritespic);
holder.favoriteImg.setTag("red");
} else {
holder.favoriteImg.setImageResource(R.drawable.favoritespicg);
holder.favoriteImg.setTag("grey");
}
return rowView;
}
static class ViewHolder {
TextView title;
TextView userName;
ImageView favoriteImg;
}
/*Checks whether a particular product exists in SharedPreferences*/
public boolean checkFavoriteItem(Track checkProduct) {
boolean check = false;
List<Track> favorites = sharedPreference.getFavorites(context);
if (favorites != null) {
for (Track track : favorites) {
if (track.equals(checkProduct)) {
check = true;
break;
}
}
}
return check;
}
#Override
public void add(Track track) {
super.add(track);
tracks.add(track);
notifyDataSetChanged();
}
#Override
public void remove(Track track) {
super.remove(track);
tracks.remove(track);
notifyDataSetChanged();
}
}
**the SharedPreference class **
public class SharedPreference {
public static final String PREFS_NAME = "PRODUCT_APP";
public static final String FAVORITES = "Product_Favorite";
public SharedPreference() {
super();
}
// This four methods are used for maintaining favorites.
public void saveFavorites(Context context, ArrayList<Track> favorites) {
SharedPreferences settings;
Editor editor;
settings = context.getSharedPreferences(PREFS_NAME,
Context.MODE_PRIVATE);
editor = settings.edit();
Gson gson = new Gson();
String jsonFavorites = gson.toJson(favorites);
editor.putString(FAVORITES, jsonFavorites);
editor.commit();
}
public void addFavorite(Context context, Track track) {
ArrayList<Track> favorites = getFavorites(context);
if (favorites == null)
favorites = new ArrayList<Track>();
favorites.add(track);
saveFavorites(context, favorites);
}
public void removeFavorite(Context context, Track track) {
ArrayList<Track> favorites = getFavorites(context);
if (favorites != null) {
favorites.remove(track);
saveFavorites(context, favorites);
}
}
public ArrayList<Track> getFavorites(Context context) {
SharedPreferences settings;
ArrayList<Track> favorites;
settings = context.getSharedPreferences(PREFS_NAME,
Context.MODE_PRIVATE);
if (settings.contains(FAVORITES)) {
String jsonFavorites = settings.getString(FAVORITES, null);
Gson gson = new Gson();
Track[] favoriteItems = gson.fromJson(jsonFavorites,
Track[].class);
favorites = (ArrayList<Track>) Arrays.asList(favoriteItems);
favorites = new ArrayList<Track>(favorites);
} else
return null;
return (ArrayList<Track>) favorites;
}
}
and the activity where i want to generate my list of favorites
public class ForthActivity extends Activity {
SharedPreference sharedPreference;
ArrayList<Track> favorites;
ListView favoriteList;
AdapterExploreListView adapterExploreListView;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.forthact);
// Get favorite items from SharedPreferences.
sharedPreference = new SharedPreference();
favorites = sharedPreference.getFavorites(ForthActivity.this);
if (favorites == null) {
} else {
if (favorites.size() == 0) {
}
favoriteList = (ListView) findViewById(R.id.forthlistview);
if (favorites != null) {
adapterExploreListView = new AdapterExploreListView(ForthActivity.this, favorites);
favoriteList.setAdapter(adapterExploreListView);
favoriteList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View arg1,
int position, long arg3) {
}
});
favoriteList
.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(
AdapterView<?> parent, View view,
int position, long id) {
ImageView button = (ImageView) view
.findViewById(R.id.favbutton);
String tag = button.getTag().toString();
if (tag.equalsIgnoreCase("grey")) {
sharedPreference.addFavorite(ForthActivity.this,
favorites.get(position));
Toast.makeText(
ForthActivity.this,
ForthActivity.this.getResources().getString(
R.string.add_favr),
Toast.LENGTH_SHORT).show();
button.setTag("red");
button.setImageResource(R.drawable.favoritespic);
} else {
sharedPreference.removeFavorite(ForthActivity.this,
favorites.get(position));
button.setTag("grey");
button.setImageResource(R.drawable.favoritespicg);
adapterExploreListView.remove(favorites
.get(position));
Toast.makeText(
ForthActivity.this,
ForthActivity.this.getResources().getString(
R.string.remove_favr),
Toast.LENGTH_SHORT).show();
}
return true;
}
});
}
}
}
}
Please help me .Thank you !

#Override
public boolean onItemLongClick(AdapterView<?> arg0, View view,
int position, long arg3) {
ImageView button = (ImageView) view.findViewById(R.id.favbutton);
sharedPreference = new SharedPreference();
String tag = button.getTag().toString();
if (tag.equalsIgnoreCase("grey")) {
sharedPreference.addFavorite(NewList.this, tracks.get(position));
Toast.makeText(NewList.this,
NewList.this.getResources().getString(R.string.add_favr),
Toast.LENGTH_SHORT).show();
button.setTag("red");
button.setImageResource(R.drawable.favoritespic);
} else {
sharedPreference.removeFavorite(NewList.this, tracks.get(position));
button.setTag("grey");
button.setImageResource(R.drawable.favoritespicg);
Toast.makeText(NewList.this,
NewList.this.getResources().getString(R.string.remove_favr),
Toast.LENGTH_SHORT).show();
}
return true;
}
and this code
private void fillListWithStyle(final String style)
{
new AsyncTask<Void,Void,ArrayList<Track>>()
{
#Override
protected ArrayList<Track> doInBackground(Void... voids) {
JsonParser parser = new JsonParser();
String encodedURL="";
try {
encodedURL = URLEncoder.encode(style, "utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return parser.getTracksForUrl(Consts.url1 + encodedURL + Consts.url2, "tracks");
}
#Override
protected void onPostExecute(ArrayList<Track> trackss) {
super.onPostExecute(trackss);
DataHolder.getInstance().setTracks(trackss);
adapterExploreListView = new AdapterExploreListView(NewList.this, trackss);
tracks = trackss;
newListView.setAdapter(adapterExploreListView);
}
}.execute();
}

I solved my problem ,these are the edits .I hope it will help someone else !
on the new list .class
#Override
public boolean onItemLongClick(AdapterView<?> arg0, View view,
int position, long arg3) {
TextView textView4 = (TextView)view.findViewById(R.id.titleTextView);
TextView textView5 = (TextView)view.findViewById(R.id.userNameTextView);
n =textView4.getText().toString();
m=textView5.getText().toString();
MyObject=new CustomObject(n,m);
sharedPreference = new SharedPreference();
sharedPreference.addFavorite(NewList.this, MyObject);
Toast.makeText(NewList.this,
NewList.this.getResources().getString(R.string.add_favr),
Toast.LENGTH_SHORT).show();
return true;
}
}
the favorites activity *
public class FavActivity extends Activity {
ListView lv;
SharedPreference sharedPreference;
List<CustomObject> favorites;
ProductListAdapter productListAdapter;
Activity context = this;
public static final String FAVORITES = "Favorite";
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.forthact);
sharedPreference = new SharedPreference();
favorites = sharedPreference.getFavorites(context);
lv = (ListView) findViewById(R.id.forthlistview);
fillFavoriteList();
}
private void fillFavoriteList() {
if (favorites != null) {
productListAdapter = new ProductListAdapter(ForthActivity.this, favorites);
lv.setAdapter(productListAdapter);
productListAdapter.notifyDataSetChanged();
}
}
}
the SharedPreferences class
public class SharedPreference {
public static final String PREFS_NAME = "PRODUCT_APP";
public static final String FAVORITES = "Product_Favorite";
public SharedPreference() {
super();
}
// This four methods are used for maintaining favorites.
public void saveFavorites(Context context, List<CustomObject> favorites) {
SharedPreferences settings;
SharedPreferences.Editor editor;
settings = context.getSharedPreferences(PREFS_NAME,
Context.MODE_PRIVATE);
editor = settings.edit();
Gson gson = new Gson();
String jsonFavorites = gson.toJson(favorites);
editor.putString(FAVORITES, jsonFavorites);
editor.commit();
}
public void addFavorite(Context context, CustomObject product) {
List<CustomObject> favorites = getFavorites(context);
String s=product.getProp1();
if (favorites == null)
favorites = new ArrayList<CustomObject>();
favorites.add(product);
saveFavorites(context, favorites);
}
public void removeFavorite(Context context, CustomObject product) {
ArrayList<CustomObject> favorites = getFavorites(context);
if (favorites != null) {
favorites.remove(product);
saveFavorites(context, favorites);
}
}
public ArrayList<CustomObject> getFavorites(Context context) {
SharedPreferences settings;
List<CustomObject> favorites;
settings = context.getSharedPreferences(PREFS_NAME,
Context.MODE_PRIVATE);
if (settings.contains(FAVORITES)) {
String jsonFavorites = settings.getString(FAVORITES, null);
Gson gson = new Gson();
CustomObject[] favoriteItems = gson.fromJson(jsonFavorites,
CustomObject[].class);
favorites = Arrays.asList(favoriteItems);
favorites = new ArrayList<CustomObject>(favorites);
} else
return null;
return (ArrayList<CustomObject>) favorites;
}
}