SharedPreferences Android

Interface for accessing and modifying preference data returned by getSharedPreferences(String, int). For any particular set of preferences, there is a single instance of this class that all clients share. Modifications to the preferences must go through an SharedPreferences.Editor object to ensure the preference values remain in a consistent state and control when they are committed to storage. Objects that are returned from the various get methods must be treated as immutable by the application.


MainActivity.java

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    EditText user, pass;

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

        user = (EditText) findViewById(R.id.editText);
        pass = (EditText) findViewById(R.id.editText2);

    }

    public void save(View view) {

        SharedPreferences sharedPreferences =getSharedPreferences("MyData",MODE_PRIVATE);
        SharedPreferences.Editor editor=sharedPreferences.edit();
        editor.putString("name",user.getText().toString());
        editor.putString("pass",pass.getText().toString());

        editor.commit();

        Toast.makeText(this, "Data was Saved successfully", Toast.LENGTH_SHORT).show();

    }

    public void next(View view) {

        Toast.makeText(this, "Next", Toast.LENGTH_SHORT).show();
        Intent in = new Intent(getApplicationContext(), Another.class);
        startActivity(in);


    }
}

Another.java

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class Another extends AppCompatActivity {
 
    public static final String DEFAULT="N/A";
      EditText user, passTv;

    @Override    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_another);
        user = (EditText) findViewById(R.id.editText3);
        passTv = (EditText) findViewById(R.id.editText4);
    }

    public void load(View view) {

        SharedPreferences sharedPreferences=getSharedPreferences("MyData",
                                                         Context.MODE_PRIVATE);

        String name =sharedPreferences.getString("name", DEFAULT);
        String pass =sharedPreferences.getString("pass", DEFAULT);

        if(name.equals(DEFAULT) || pass.equals(DEFAULT)) {

            Toast.makeText(this, "No Data was Found", Toast.LENGTH_SHORT).show();

        }

        else {

            Toast.makeText(this, "Data Loaded successfully", Toast.LENGTH_SHORT).show();

            user.setText(name);
            passTv.setText(pass);

        }

    }

    public void back(View view) {

        Toast.makeText(this, "Back", Toast.LENGTH_SHORT).show();

        Intent in = new Intent(getApplicationContext(), MainActivity.class);

        startActivity(in);
    }

}

main.xml

<RelativeLayout 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:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">



    <EditText

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/editText"

        android:layout_alignParentTop="true"

        android:layout_marginTop="63dp"

        android:layout_alignParentRight="true"

        android:layout_alignParentEnd="true"

        android:layout_alignParentLeft="true"

        android:layout_alignParentStart="true"

        android:hint="Username" />



    <EditText

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:inputType="textPassword"

        android:ems="10"

        android:id="@+id/editText2"

        android:layout_below="@+id/editText"

        android:layout_alignParentLeft="true"

        android:layout_alignParentStart="true"

        android:layout_alignRight="@+id/editText"

        android:layout_alignEnd="@+id/editText"

        android:hint="Password" />



    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="save"

        android:id="@+id/saveBtn"

        android:onClick="save"

        android:layout_centerVertical="true"

        android:layout_alignParentLeft="true"

        android:layout_alignParentStart="true" />



    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="Another"

        android:id="@+id/button"

        android:layout_centerVertical="true"

        android:onClick="next"

        android:layout_alignRight="@+id/editText2"

        android:layout_alignEnd="@+id/editText2" />

</RelativeLayout>

activity_another.xml

 <relativelayout 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:paddingbottom="@dimen/activity_vertical_margin"
        android:paddingleft="@dimen/activity_horizontal_margin"
        android:paddingright="@dimen/activity_horizontal_margin"
        android:paddingtop="@dimen/activity_vertical_margin"
        tools:context="com.blogspot.help2computer.shared.Another">

        <button
            android:id="@+id/loadBtn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignparentleft="true"
            android:layout_alignparentstart="true"
            android:layout_alignparenttop="true"
            android:layout_margintop="73dp"
            android:onclick="load"
            android:text="Load">

        </button>

        <button
            android:id="@+id/backBtn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignbottom="@+id/loadBtn"
            android:layout_alignparentend="true"
            android:layout_alignparentright="true"
            android:onclick="back"
            android:text="back">

            <edittext
                android:id="@+id/editText3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignend="@+id/backBtn"
                android:layout_alignparentleft="true"
                android:layout_alignparentstart="true"
                android:layout_alignright="@+id/backBtn"
                android:layout_below="@+id/loadBtn"
                android:layout_margintop="46dp"
                android:hint="Username">

                <edittext
                    android:id="@+id/editText4"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_alignend="@+id/editText3"
                    android:layout_alignparentleft="true"
                    android:layout_alignparentstart="true"
                    android:layout_alignright="@+id/editText3"
                    android:layout_below="@+id/editText3"
                    android:ems="10"
                    android:hint="Password"
                    android:inputtype="textPassword"></edittext>
            </edittext>
        </button>
    </relativelayout>