Android SharedPreferences Example

Nikos MaravitsasMay 19th, 2013Last Updated: May 19th, 2013

1 452 3 minutes read

In this example we are going to see how to use Android SharedPreferences. You can permanently store preferences using SharedPreferences with the form of a pair : key and a value. Basically there are some ways you can store data in Android :

Shared Preferences: Prrimitive data storage (boolean Strings, ints etc..).
Internal Storage: Device memory storage.
External Storage: Store public data on storage media, like SD cards.
SQLite Database.

With SharedPreferences we talk about permanent storage about the application. That means that if you uninstall the application, all your data will be lost, so this is application specific. In contrast , SQLite stores structured data in a database, so even when you delete the application the data won’t be lost.

For this tutorial, we will use the following tools in a Windows 64-bit platform:

JDK 1.7
Eclipse 4.2 Juno
Android SKD 4.2

1. Create a new Android Project

Open Eclipse IDE and go to File -> New -> Project -> Android -> Android Application Project. You have to specify the Application Name, the Project Name and the Package name in the appropriate text fields and then click Next.

In the next window make sure the “Create activity” option is selected in order to create a new activity for your project, and click Next. This is optional as you can create a new activity after creating the project, but you can do it all in one step.

Select “BlankActivity” and click Next.

You will be asked to specify some information about the new activity. In the Layout Name text field you have to specify the name of the file that will contain the layout description of your app. In our case the file res/layout/main.xml will be created. Then, click Finish.

2. Create the main layout of the Application

Open res/layout/main.xml file :

And paste the following code :

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <CheckBox
        android:id="@+id/checkBox1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Check Box" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Enter Your Name...">

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Save" />

</LinearLayout>

Now you may open the Graphical layout editor to preview the User Interface you created:

3. Code

Now we have to write the code of the application. Use the Package Explorer to navigate to the Java file of the Activity you’ve created:

The code of this tutorial is very simple. Basically there are two main operations one can perform when using SharedPreferences in Android. That is store data and load data. You should:

Create a new SharedPreferences object.
Then get an Editor instance from that object. The Editor object will help you manipulate the data that you’ve stored.
Use putString, putBoolean methods to store a pair key/value
Use getBoolean, getString to get the values you want.

package com.javacodegeeks.android.androidsharedpreferences;

import android.app.Activity;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;

public class MainActivity extends Activity implements OnClickListener {

	CheckBox checkBox;
	EditText editText;
	Button button;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		checkBox = (CheckBox) findViewById(R.id.checkBox1);
		editText = (EditText) findViewById(R.id.editText1);
		button = (Button) findViewById(R.id.button1);
		button.setOnClickListener(this);
		loadSavedPreferences();
	}

	private void loadSavedPreferences() {
		SharedPreferences sharedPreferences = PreferenceManager
				.getDefaultSharedPreferences(this);
		boolean checkBoxValue = sharedPreferences.getBoolean("CheckBox_Value", false);
		String name = sharedPreferences.getString("storedName", "YourName");
		if (checkBoxValue) {
			checkBox.setChecked(true);
		} else {
			checkBox.setChecked(false);
		}

		editText.setText(name);
	}

	private void savePreferences(String key, boolean value) {
		SharedPreferences sharedPreferences = PreferenceManager
				.getDefaultSharedPreferences(this);
		Editor editor = sharedPreferences.edit();
		editor.putBoolean(key, value);
		editor.commit();
	}

	private void savePreferences(String key, String value) {
		SharedPreferences sharedPreferences = PreferenceManager
				.getDefaultSharedPreferences(this);
		Editor editor = sharedPreferences.edit();
		editor.putString(key, value);
		editor.commit();
	}

	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
		savePreferences("CheckBox_Value", checkBox.isChecked());
		if (checkBox.isChecked())
			savePreferences("storedName", editText.getText().toString());

		finish();
	}

}