store and retrieve a class object in shared preference

Yes we can do this using Gson

Download Working code from GitHub

SharedPreferences mPrefs = getPreferences(MODE_PRIVATE);

For save

Editor prefsEditor = mPrefs.edit();
Gson gson = new Gson();
String json = gson.toJson(myObject); // myObject - instance of MyObject
prefsEditor.putString("MyObject", json);
prefsEditor.commit();

For get

Gson gson = new Gson();
String json = mPrefs.getString("MyObject", "");
MyObject obj = gson.fromJson(json, MyObject.class);

Update1

The latest version of GSON can be downloaded from github.com/google/gson.

Update2

If you are using Gradle/Android Studio just put following in build.gradle dependencies section -

implementation 'com.google.code.gson:gson:2.6.2'

we can use Outputstream to output our Object to internal memory. And convert to string then save in preference. For example:

    mPrefs = getPreferences(MODE_PRIVATE);
    SharedPreferences.Editor ed = mPrefs.edit();
    ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream();

    ObjectOutputStream objectOutput;
    try {
        objectOutput = new ObjectOutputStream(arrayOutputStream);
        objectOutput.writeObject(object);
        byte[] data = arrayOutputStream.toByteArray();
        objectOutput.close();
        arrayOutputStream.close();

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        Base64OutputStream b64 = new Base64OutputStream(out, Base64.DEFAULT);
        b64.write(data);
        b64.close();
        out.close();

        ed.putString(key, new String(out.toByteArray()));

        ed.commit();
    } catch (IOException e) {
        e.printStackTrace();
    }

when we need to extract Object from Preference. Use the code as below

    byte[] bytes = mPrefs.getString(indexName, "{}").getBytes();
    if (bytes.length == 0) {
        return null;
    }
    ByteArrayInputStream byteArray = new ByteArrayInputStream(bytes);
    Base64InputStream base64InputStream = new Base64InputStream(byteArray, Base64.DEFAULT);
    ObjectInputStream in;
    in = new ObjectInputStream(base64InputStream);
    MyObject myObject = (MyObject) in.readObject();

Not possible.

You can only store, simple values in SharedPrefences SharePreferences.Editor

What particularly about the class do you need to save?

I had the same problem, here's my solution:

I have class MyClass and ArrayList<MyClass> that I want to save to Shared Preferences. At first I've added a method to MyClass that converts it to JSON object:

public JSONObject getJSONObject() {
    JSONObject obj = new JSONObject();
    try {
        obj.put("id", this.id);
        obj.put("name", this.name);
    } catch (JSONException e) {
        e.printStackTrace();
    }
    return obj;
}

Then here's the method for saving object ArrayList<MyClass> items:

SharedPreferences mPrefs = context.getSharedPreferences("some_name", 0);
SharedPreferences.Editor editor = mPrefs.edit();

Set<String> set= new HashSet<String>();
for (int i = 0; i < items.size(); i++) {
    set.add(items.get(i).getJSONObject().toString());
}

editor.putStringSet("some_name", set);
editor.commit();

And here's the method for retrieving the object:

public static ArrayList<MyClass> loadFromStorage() {
    SharedPreferences mPrefs = context.getSharedPreferences("some_name", 0);

    ArrayList<MyClass> items = new ArrayList<MyClass>();

    Set<String> set = mPrefs.getStringSet("some_name", null);
    if (set != null) {
        for (String s : set) {
            try {
                JSONObject jsonObject = new JSONObject(s);
                Long id = jsonObject.getLong("id"));
                String name = jsonObject.getString("name");
                MyClass myclass = new MyClass(id, name);

                items.add(myclass);

            } catch (JSONException e) {
                e.printStackTrace();
         }
    }
    return items;
}

Note that StringSet in Shared Preferences is available since API 11.

Using Gson Library:

dependencies {
compile 'com.google.code.gson:gson:2.8.2'
}

Store:

Gson gson = new Gson();
//Your json response object value store in json object
JSONObject jsonObject = response.getJSONObject();
//Convert json object to string
String json = gson.toJson(jsonObject);
//Store in the sharedpreference
getPrefs().setUserJson(json);

Retrieve:

String json = getPrefs().getUserJson();