SharedPreferences | Android Studio | Java

SharedPreferences | Android Studio | Java

SharedPreferences is one of the types of saving data in Android Devices. You can save String, int, boolean, long, float, and Set<String>  types of data in SharedPreferences. In SharedPreferences data is saved in the key-value form. If you have a relatively small collection of key-values that you'd like to save, then you should use the SharedPreferences APIs. You can Add, Edit/Modify and Remove data from the SharedPreferences easily.

To get the access to the preferences, we have the three APIs to choose from:

getPreferences() : used from within your Activity, to access the activity-specific preferences.

getSharedPreferences() : used from within your Activity (or other application Context), to access the application-level preferences.

getDefaultSharedPreferences() : used on the PreferenceManager, to get the shared preferences that work in concert with Android’s overall preference framework.

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SharedPreferences | Android Studio | Java

Step 1: Create a new project OR Open your existing project

Step 2: Code

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    android:padding="10dp"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/nameEt"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Name"
        android:inputType="textPersonName|textCapWords" />

    <EditText
        android:id="@+id/ageEt"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Age"
        android:inputType="date" />

    <EditText
        android:id="@+id/emailEt"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Email"
        android:inputType="textEmailAddress" />

    <EditText
        android:id="@+id/passwordEt"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Password"
        android:inputType="textPassword" />

    <CheckBox
        android:id="@+id/rememberCb"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Remember" />

    <Button
        android:id="@+id/saveBtn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:text="Save" />

</LinearLayout>

MainActivity.java

package com.blogspot.atifsoftwares.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    //declare views
    private EditText nameEt, ageEt, emailEt, passwordEt;
    private CheckBox rememberCb;
    private Button saveBtn;

    //variables
    String name, email, password;
    int age;
    boolean isRemembered;

    //shared pref
    SharedPreferences sharedPreferences;
    SharedPreferences.Editor spEditor;

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

        //init views
        nameEt = findViewById(R.id.nameEt);
        ageEt = findViewById(R.id.ageEt);
        emailEt = findViewById(R.id.emailEt);
        passwordEt = findViewById(R.id.passwordEt);
        rememberCb = findViewById(R.id.rememberCb);
        saveBtn = findViewById(R.id.saveBtn);

        //init share pref
        sharedPreferences = getSharedPreferences("USER_INFO_SP", MODE_PRIVATE);

        //get data from shared preferences
        name = sharedPreferences.getString("NAME", "");
        age = sharedPreferences.getInt("AGE", 0);
        email = sharedPreferences.getString("EMAIL", "");
        password = sharedPreferences.getString("PASSWORD", "");
        isRemembered = sharedPreferences.getBoolean("REMEMBER", false);

        //set data to views
        nameEt.setText(name);
        ageEt.setText("" + age);
        emailEt.setText(email);
        passwordEt.setText(password);
        rememberCb.setChecked(isRemembered);

        //click to input data from views
        saveBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //get data from views
                name = "" + nameEt.getText().toString().trim();
                age = Integer.parseInt(ageEt.getText().toString().trim());
                email = "" + emailEt.getText().toString().trim();
                password = "" + passwordEt.getText().toString().trim();
                if (rememberCb.isChecked()) {
                    isRemembered = true;

                    //save data to shared preferences
                    spEditor = sharedPreferences.edit();
                    spEditor.putString("NAME", name);
                    spEditor.putInt("AGE", age);
                    spEditor.putString("EMAIL", email);
                    spEditor.putString("PASSWORD", password);
                    spEditor.putBoolean("REMEMBER", true);
                    spEditor.apply();

                    Toast.makeText(MainActivity.this, "Info is remembered...", Toast.LENGTH_SHORT).show();
                } else {
                    isRemembered = false;

                    //don't save | remove data from shared preferences
                    spEditor = sharedPreferences.edit();
                    spEditor.clear();
                    spEditor.apply();

                    Toast.makeText(MainActivity.this, "Info is not remembered...", Toast.LENGTH_SHORT).show();
                }

            }
        });

    }
}

Step 3: Run Project

Output