Append more values to Shared Preferences rather than overwriting the existing values

Question

In my app, I need the values to be saved in to Sharedpreferences file RKs_Data without overwriting the existing data. Every time, I click \'Yes\' in my app, I require all the va

Answer 1

Follow these steps:

Extract the value stored in SharedPreferences

String value = prefs.getString(<Key>, <DefaultValue>);

Append to the extracted value

String appendedValue = append(value, newValue);

Write the result back to SharedPreferences

editor.putString(<Key>, appendedValue).commit();

Answer 2

you could CSV format your shared preference data. For example, Get CSV string from shared preference and add it to a list. Append to your list then put it back into your sharedpreferance. Code example

// init List of strings somewhere before

List<String>  listOfFavoritePhrases = new ArrayList<String>();

// append data into list

listOfFavoritePhrases.add("Brian|99999299999");
listOfFavoritePhrases.add("Monet|00010000000");

// Put list of strings after you have made changes back, in CSV format

SharedPreferences prefs = getSharedPreferences("PACKAGE", Context.MODE_PRIVATE);
            SharedPreferences.Editor   editor = prefs.edit();
            editor.putString("phrases",TextUtils.join(",", listOfFavoritePhrases));
            editor.commit();

// get data

     SharedPreferences prefs = getSharedPreferences("PACKAGE", Context.MODE_PRIVATE);
    String serialized = prefs.getString("phrases", "Brian");
     listOfFavoritePhrases = new ArrayList<String>(Arrays.asList(TextUtils.split(serialized, ",")));

and then

String CurrentString = listOfFavoritePhrases.get(0); // first element
String[] separated = CurrentString.split("|");
Toast.makeText(this, separated[0], Toast.LENGTH_LONG).show(); // brian
Toast.makeText(this, separated[1], Toast.LENGTH_LONG).show(); // 99999299999

Hope this Helps.

Answer 3

Finally my code looks like this: Sharing the final code as it can be useful to others who are newbies like me :)

---

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.rks_contactslist_main);
        ListView listview = getListView();

        sp = getSharedPreferences("PACKAGE", Context.MODE_PRIVATE);
        String str = sp.getString("FAV_CONTACS",
                "NO fav contacts are saved as of now");
---------

protected void onListItemClick(ListView listview, View view, int position,
            long id) {
        // TODO Auto-generated method stub
        super.onListItemClick(listview, view, position, id);
        ContactBean bean = (ContactBean) listview.getItemAtPosition(position);

        showCallDialog(bean.getName(), bean.getPhoneNo());
    }


---------

    public void onClick(DialogInterface dialog, int which) {
                Fav_Contacts_file = getFilesDir();
                    if (count <5) {
                        SharedPreferences.Editor editor = sp.edit();

                        String new_contact = name + " " + phoneNo;


                        String existing_contact = sp.getString("CONTACTS", "");
                        /*String existing_phone = sp.getString("phoneNo", "");
                        String existing_contact = existing_name + " " +existing_phone ;*/


                        String latestfavContacts = append(existing_contact, new_contact);


                        editor.putString("CONTACTS", latestfavContacts);
                        editor.commit();
                        count++;
                        Toast.makeText(
                                getApplicationContext(),
                                "The data saved successfully to ........ : "
                                        + Fav_Contacts_file + "/PACKAGE",
                                Toast.LENGTH_SHORT).show();
                        Toast.makeText(
                                getApplicationContext(),
                                "Name : " + name + " and Phone : "
                                        + phoneNo, Toast.LENGTH_SHORT)
                                .show();
                    }
                    else {
                        Toast.makeText(
                                getApplicationContext(),
                                "More than 5 Fav Contacts are NOT allowed",                                     
                                Toast.LENGTH_SHORT).show();
                    }

                }
            });
            alert.show();
        }

        protected String append(String existing_contact, String new_contact) {
            String latestfavContacts = existing_contact + " | "+ new_contact ;
            return latestfavContacts;
        }

and the data stored in SharedPreference file 'PACAKAGE' looks like this:

<?xml version="1.0" encoding="UTF-8" standalone="true"?>
-<map>
<string name="CONTACTS"> | Alen 1 231-231-231 | Alex Zun 1 234-321-231 | Dr. S.K. Taher Ali 040-7265587 | Gazer 1 312-345-452 | Helen (432) 341-1343</string>
</map>

I'm yet to work on the formatting and present it to the UI friendly mode as per my application needs.