See what's new in Android & IOS & Hybrid development … explore and learn in site

Shared Preference[Local Storage]

Shared Preferences are XML files to store private primitive data in key-value pairs. Data Types include Booleans, floats, ints, longs, and strings.

When we want to save some data which is accessible throughout the application, one way to do is to save it in global variable. But it will vanish once the application is closed. Another and recommended way is to save in SharedPreference

SharedPreferences saves the data in key-value pair and can be accessed in same.

we can create Object of SharedPreferences using two methods,

1).getSharedPreferences() : Using this methods you can create Multiple SharedPreferences.and its first parameters in name of SharedPreferences.

2).getPreferences() : Using this method you can create Single SharedPreferences.

package com.androidfeeders.sharedpreferencesexample;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    EditText editText;
    EditText editText1;
    Button button;
    String string,string1;
    TextView textView;
    SqliteDBHelper dbHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        editText=(EditText)findViewById(R.id.input);
        editText1=(EditText)findViewById(R.id.input1);
        textView=(TextView) findViewById(R.id.getString);
        button=(Button) findViewById(R.id.buttonClick);
        button.setOnClickListener(this);


        //Sqlite database
        dbHelper= new SqliteDBHelper(getApplicationContext());
    }

    @Override
    public void onClick(View view) {
        string= editText.getText().toString();
        string1= editText1.getText().toString();

        //Sqlite database
        dbHelper.insertData(string,string1);

        //Shared Preferences
        SharedPreferenceHelper.getInstance(this).saveStringData("keystring",string); //get data
        textView.setText(SharedPreferenceHelper.getInstance(this).getStringData("keystring")); //set data

    }

}

package com.androidfeeders.sharedpreferencesexample;

import android.content.Context;
import android.content.SharedPreferences;




public class SharedPreferenceHelper {

    private static SharedPreferenceHelper sharedPreferenceHelper;
    private SharedPreferences sharedPreferences;

    //Singleton method for create single instance in application
    public static SharedPreferenceHelper getInstance(Context context) {
        if (sharedPreferenceHelper == null) {
            sharedPreferenceHelper = new SharedPreferenceHelper(context);
        }
        return sharedPreferenceHelper;
    }

    // SharedPreferenceHelper class Constuctor
    // @param context
    private SharedPreferenceHelper(Context context) {
        //context mode private only access in applicaion itself
        sharedPreferences = context.getSharedPreferences("pref", Context.MODE_PRIVATE);
    }

    /**
     * Get String value for a particular key.
     *
     * @param key   The string resource Id of the key
     * @param value The default value to return
     */
    public void saveStringData(String key, String value) {
        SharedPreferences.Editor prefsEditor = sharedPreferences.edit();
        prefsEditor.putString(key, value);
        prefsEditor.commit();
    }

    /**
     * Set String value for a particular key.
     *
     * @param key The string resource Id of the key
     */

    public String getStringData(String key) {
        if (sharedPreferences != null) {
            return sharedPreferences.getString(key, "");
        }
        return "";
    }
}

package com.androidfeeders.sharedpreferencesexample;

import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;


public class SqliteDBHelper extends SQLiteOpenHelper {
    public static final String TABLENAME = "";
    public static final String COL1 = "ID";
    public static final String COL2 = "NAME";
    public static final String COL3 = "PLACE";


    public SqliteDBHelper(Context context) {
        super(context, "Student.db", null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
        sqLiteDatabase.execSQL("CREATE TABLE" + TABLENAME + "(ID INTEGER PRIMARY KEY  AUTOINCREMENT ,NAME TEXT, PLACE TEXT)");

    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
        sqLiteDatabase.execSQL("DROP TABLE IF EXISTS" + TABLENAME);
    }

    public boolean insertData(String name,String place)
    {
        SQLiteDatabase sqLiteDatabase= this.getWritableDatabase();

        ContentValues contentValues= new ContentValues();
        contentValues.put(COL2,name);
        contentValues.put(COL3,place);
        sqLiteDatabase.insert(TABLENAME,null,contentValues);

        return true;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <EditText
        android:layout_width="160dp"
        android:id="@+id/input"
        android:layout_height="wrap_content"
        android:hint="name"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.318"
        app:layout_constraintHorizontal_bias="0.446" />
    <EditText
        android:layout_width="160dp"
        android:id="@+id/input1"
        android:layout_height="wrap_content"
        android:hint="place"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.44"
        app:layout_constraintHorizontal_bias="0.446" />


    <Button
        android:layout_width="160dp"
        android:id="@+id/buttonClick"
        android:layout_height="wrap_content"
        android:text="save"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.65" />


    <TextView
        android:layout_width="160dp"
        android:id="@+id/getString"
        android:layout_height="wrap_content"
        android:text="Type something"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.805"
        app:layout_constraintHorizontal_bias="0.566" />

</android.support.constraint.ConstraintLayout>

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.androidfeeders.sharedpreferencesexample"
        minSdkVersion 15
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0-alpha3'
    implementation 'com.android.support.constraint:constraint-layout:1.1.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.1'
        

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

<resources>
    <string name="app_name">SharedPreferencesExample</string>
</resources>

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".sharedpreferencesexample">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

I started to learn android and Kotlin and iOS and Hybrid application and i cant code IOS very well. But i love more interesting to code and finding new developer minds who are join to me You're welcome to keep on using my website.Instead, you can join our FB page for developer comments and post there: https://www.facebook.com/ramasamy.m.779 Best wishes :) Ramasamy(Software Developer)

Android Development and IOS Development & React Native Application

See what's new in Android & IOS & Hybrid development … explore and learn in site