Android SharedPreferences

Apr 24, 2015 By: Dr. Droid Android Basics Comments: 0

Android provides many ways of storing data of an application. One of this way is called Shared Preferences. Shared Preferences allow you to save and retrieve data in the form of key,value pair.

In order to use shared preferences , you have to call a method getSharedPreferences() that returns a SharedPreference instance poiting to the file that contains the values of preferences.

SharedPreferences sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);

1	SharedPreferences sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);

The first parameter is the key and the second parameter is the MODE. Apart from private there are other modes availaible that are listed below:

Mode	Description
MODE_APPEND	This will append the new preferences with the already existing preferences.
MODE_ENABLE_WRITE_AHEAD_LOGGING	Database open flag. When it is set , it would enable write ahead logging by default.
MODE_MULTI_PROCESS	This method will check for modification of preferences even if the sharedpreference instance has already been loaded.
MODE_PRIVATE	By setting this mode , the file can only be accessed using calling application.
MODE_WORLD_READABLE	This mode allow other application to read the preferences.
MODE_WORLD_WRITEABL	This mode allow other application to write the preferences.

You can save something in the sharedpreferences by using SharedPreferences.Editor class. You will call the edit method of SharedPreference instance and will recieve it in an editor object. Its syntax is:

Editor editor = sharedpreferences.edit();
editor.putString("key", "value");
editor.commit();

Editor editor = sharedpreferences.edit();

editor.putString("key", "value");

editor.commit();

Apart from the putString method , there are methods availaible in the editor class that allows manipulation of data inside shared preferences. They are listed as follows:

Method	Description
apply()	It is an abstract method. It will commit your changes back from editor to the sharedPreference object you are calling.
clear()	It will remove all values from the editor.
remove(String key)	It will remove the value whose key has been passed as a parameter.
putLong(String key, long value)	It will save a long value in a preference editor.
putInt(String key, int value)	It will save a integer value in a preference editor.
putFloat(String key, float value)	It will save a float value in a preference editor.

Example

In this example i will be demonstrating how to work on SharedPreferences for storing values in it and fetching again the values.

VIDEO DEMO

Let’s get start by creating a project in Eclipse IDE.

1. Create a new project in Eclipse by navigating to File ⇒ New Android ⇒ Application Project and fill required details. (I kept my main activity name as MainActivity.java)

2. Open your your AndroidManifest.xml file and make your “MainActivity” as Launcher activity.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.sharedpreference_demo"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="22" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="com.sharedpreference_demo"

android:versionCode="1"

android:versionName="1.0" >

<uses-sdk

android:minSdkVersion="8"

android:targetSdkVersion="22" />

<application

android:allowBackup="true"

android:icon="@drawable/ic_launcher"

android:label="@string/app_name"

android:theme="@style/AppTheme" >

<activity

android:name=".MainActivity"

android:label="@string/app_name" >

<intent-filter>

</intent-filter>

</activity>

</application>

</manifest>

3. Create a layout file for MainActivtiy.java under res ⇒ layout folder. I named the layout file as activity_main.xml.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#ffffff"
    android:orientation="vertical"
    android:padding="5dp" >

    <EditText
        android:id="@+id/username"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:hint="@string/name"
        android:inputType="text"
        android:padding="10dp"
        android:singleLine="true" />

    <EditText
        android:id="@+id/emailid"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:hint="@string/email"
        android:inputType="textEmailAddress"
        android:padding="10dp"
        android:singleLine="true" />

    <EditText
        android:id="@+id/phoneno"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:hint="@string/phone"
        android:inputType="phone"
        android:padding="10dp"
        android:singleLine="true" />

    <Button
        android:id="@+id/save"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:background="#ff6600"
        android:padding="10dp"
        android:text="@string/save"
        android:textColor="#ffffff"
        android:textSize="18sp" />

    <Button
        android:id="@+id/show"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:background="#ff6600"
        android:padding="10dp"
        android:text="@string/show"
        android:textColor="#ffffff"
        android:textSize="18sp"
        />

    <TextView
        android:id="@+id/saved_data"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:padding="10dp"
        android:textSize="18sp"
        android:visibility="gone" />

    <Button
        android:id="@+id/delete"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:background="#ff6600"
        android:padding="10dp"
        android:text="@string/delete"
        android:textColor="#ffffff"
        android:textSize="18sp"
        android:visibility="gone" />

</LinearLayout>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:background="#ffffff"

android:orientation="vertical"

android:padding="5dp" >

<EditText

android:id="@+id/username"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:layout_margin="5dp"

android:hint="@string/name"

android:inputType="text"

android:padding="10dp"

android:singleLine="true" />

<EditText

android:id="@+id/emailid"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:layout_margin="5dp"

android:hint="@string/email"

android:inputType="textEmailAddress"

android:padding="10dp"

android:singleLine="true" />

<EditText

android:id="@+id/phoneno"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:layout_margin="5dp"

android:hint="@string/phone"

android:inputType="phone"

android:padding="10dp"

android:singleLine="true" />

<Button

android:id="@+id/save"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:layout_margin="5dp"

android:background="#ff6600"

android:padding="10dp"

android:text="@string/save"

android:textColor="#ffffff"

android:textSize="18sp" />

<Button

android:id="@+id/show"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:layout_margin="5dp"

android:background="#ff6600"

android:padding="10dp"

android:text="@string/show"

android:textColor="#ffffff"

android:textSize="18sp"

<TextView

android:id="@+id/saved_data"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:layout_margin="5dp"

android:padding="10dp"

android:textSize="18sp"

android:visibility="gone" />

<Button

android:id="@+id/delete"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:layout_margin="5dp"

android:background="#ff6600"

android:padding="10dp"

android:text="@string/delete"

android:textColor="#ffffff"

android:textSize="18sp"

android:visibility="gone" />

</LinearLayout>

4. Add the following code in MainActivity.java activity. In this following code we use editor to store data in shared preferences on button click and fetch data from shared preferences and finally deleting/clearing shared preferences.

package com.sharedpreference_demo;

import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.text.TextUtils;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends ActionBarActivity implements OnClickListener {

	EditText name, email, phone;
	Button save, show, delete;
	TextView show_saved_data;

	//Shared Preference for storing data
	SharedPreferences preferences;
	
	//Editor to edit shared preference
	Editor editor;

	//String variables for shared preference
	private static final String shared_preferences = "shared_preferences";
	private static final String stored_name = "name";
	private static final String stored_email = "email";
	private static final String stored_phone = "phone";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		//Finding all views id
		name = (EditText) findViewById(R.id.username);
		email = (EditText) findViewById(R.id.emailid);
		phone = (EditText) findViewById(R.id.phoneno);

		save = (Button) findViewById(R.id.save);
		show = (Button) findViewById(R.id.show);
		delete = (Button) findViewById(R.id.delete);

		show_saved_data = (TextView) findViewById(R.id.saved_data);

		//Getting shared preference
		preferences = getSharedPreferences(shared_preferences,
				Context.MODE_PRIVATE);
		
		//Initializing editor to edit preference
		editor = preferences.edit();

		//Implementing click listener on all buttons that are used
		save.setOnClickListener(this);
		show.setOnClickListener(this);
		delete.setOnClickListener(this);

	}

	@Override
	public void onClick(View v) {
		switch (v.getId()) {
		case R.id.save:

			//Getting edittext texts into string variables
			String getName = name.getText().toString();
			String getEmail = email.getText().toString();
			String getPhone = phone.getText().toString();

			//Checking if all text fields are filled or empty 
			if (TextUtils.isEmpty(getName) || TextUtils.isEmpty(getEmail)
					|| TextUtils.isEmpty(getPhone)) {
				
				//If all text fields are not filled an toast is shown
				Toast.makeText(MainActivity.this, "Please Fill all Fields.",
						Toast.LENGTH_SHORT).show();
			} else {
				
				//else text fields data is stored in shared preference
				editor.putString(stored_name, getName);
				editor.putString(stored_email, getEmail);
				editor.putString(stored_phone, getPhone);
				
				//After storing data commit the editor to save data
				editor.commit();

				//And clear the edittext fields
				name.setText("");
				email.setText("");
				phone.setText("");

				//Toast is shown to show that data is saved
				Toast.makeText(MainActivity.this, "Data Saved Successfully.",
						Toast.LENGTH_SHORT).show();
			}

			break;

		case R.id.show:

			//Check if preference contains stored data or not
			if (preferences.contains(stored_name)
					&& preferences.contains(stored_email)
					&& preferences.contains(stored_phone)) {

				//If data is stored get the data and display on textView
				String getSavedName = preferences.getString(stored_name, null);
				String getSavedEmail = preferences
						.getString(stored_email, null);
				String getSavedPhone = preferences
						.getString(stored_phone, null);

				show_saved_data.setText("Full Name : " + getSavedName + "n"
						+ "Email Id : " + getSavedEmail + "n" + "Phone No. : "
						+ getSavedPhone);

				//Showing delete button that is invisible till
				delete.setVisibility(View.VISIBLE);

			} else {

				//Display the data if data is not saved
				show_saved_data
						.setText("There is no data in Shared Prefrences.");

			}
			
			//Showing textView on show button click
			show_saved_data.setVisibility(View.VISIBLE);
			break;
			
		case R.id.delete:
			
			//Check if data contains in shared preference
			if (preferences.contains(stored_name)
					&& preferences.contains(stored_email)
					&& preferences.contains(stored_phone)) {

				//If contains clear the editor and commit it
				editor.clear();
				editor.commit();
			} else {
				
				//If not present any data then toast is displayed
				Toast.makeText(MainActivity.this, "Already Cleared.",
						Toast.LENGTH_SHORT).show();
			}

			// Both textView and delete button is visible
			show_saved_data.setVisibility(View.GONE);
			delete.setVisibility(View.GONE);

			break;
		}

	}

}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

package com.sharedpreference_demo;

import android.content.Context;

import android.content.SharedPreferences;

import android.content.SharedPreferences.Editor;

import android.os.Bundle;

import android.support.v7.app.ActionBarActivity;

import android.text.TextUtils;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

import android.widget.Toast;

public class MainActivity extends ActionBarActivity implements OnClickListener {

EditText name, email, phone;

Button save, show, delete;

TextView show_saved_data;

//Shared Preference for storing data

SharedPreferences preferences;

//Editor to edit shared preference

Editor editor;

//String variables for shared preference

private static final String shared_preferences = "shared_preferences";

private static final String stored_name = "name";

private static final String stored_email = "email";

private static final String stored_phone = "phone";

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

//Finding all views id

name = (EditText) findViewById(R.id.username);

email = (EditText) findViewById(R.id.emailid);

phone = (EditText) findViewById(R.id.phoneno);

save = (Button) findViewById(R.id.save);

show = (Button) findViewById(R.id.show);

delete = (Button) findViewById(R.id.delete);

show_saved_data = (TextView) findViewById(R.id.saved_data);

//Getting shared preference

preferences = getSharedPreferences(shared_preferences,

Context.MODE_PRIVATE);

//Initializing editor to edit preference

editor = preferences.edit();

//Implementing click listener on all buttons that are used

save.setOnClickListener(this);

show.setOnClickListener(this);

delete.setOnClickListener(this);

}

@Override

public void onClick(View v) {

switch (v.getId()) {

case R.id.save:

//Getting edittext texts into string variables

String getName = name.getText().toString();

String getEmail = email.getText().toString();

String getPhone = phone.getText().toString();

//Checking if all text fields are filled or empty

if (TextUtils.isEmpty(getName) || TextUtils.isEmpty(getEmail)

|| TextUtils.isEmpty(getPhone)) {

//If all text fields are not filled an toast is shown

Toast.makeText(MainActivity.this, "Please Fill all Fields.",

Toast.LENGTH_SHORT).show();

} else {

//else text fields data is stored in shared preference

editor.putString(stored_name, getName);

editor.putString(stored_email, getEmail);

editor.putString(stored_phone, getPhone);

//After storing data commit the editor to save data

editor.commit();

//And clear the edittext fields

name.setText("");

email.setText("");

phone.setText("");

//Toast is shown to show that data is saved

Toast.makeText(MainActivity.this, "Data Saved Successfully.",

Toast.LENGTH_SHORT).show();

}

break;

case R.id.show:

//Check if preference contains stored data or not

if (preferences.contains(stored_name)

&& preferences.contains(stored_email)

&& preferences.contains(stored_phone)) {

//If data is stored get the data and display on textView

String getSavedName = preferences.getString(stored_name, null);

String getSavedEmail = preferences

.getString(stored_email, null);

String getSavedPhone = preferences

.getString(stored_phone, null);

show_saved_data.setText("Full Name : " + getSavedName + "n"

+ "Email Id : " + getSavedEmail + "n" + "Phone No. : "

+ getSavedPhone);

//Showing delete button that is invisible till

delete.setVisibility(View.VISIBLE);

} else {

//Display the data if data is not saved

show_saved_data

.setText("There is no data in Shared Prefrences.");

}

//Showing textView on show button click

show_saved_data.setVisibility(View.VISIBLE);

break;

case R.id.delete:

//Check if data contains in shared preference

if (preferences.contains(stored_name)

&& preferences.contains(stored_email)

&& preferences.contains(stored_phone)) {

//If contains clear the editor and commit it

editor.clear();

editor.commit();

} else {

//If not present any data then toast is displayed

Toast.makeText(MainActivity.this, "Already Cleared.",

Toast.LENGTH_SHORT).show();

}

// Both textView and delete button is visible

show_saved_data.setVisibility(View.GONE);

delete.setVisibility(View.GONE);

break;

}

5. Now, run the application and you will get the output as shown in video.

Thanks. 🙂