Internal Storage Example in Android

We are able to save or read data from the device internal memory. FileInputStream and FileOutputStream classes are used to read and write data into the file.

Here, we are going to read and write data to the internal storage of the device.

 activity_main.xml

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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_main"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/editText"
        android:hint="enter file name"
        android:layout_marginTop="5dp" />

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/editText2"
        android:hint="enter text"
        android:layout_marginTop="5dp" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Create File and Save Text"
        android:id="@+id/button"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="10dp" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="View Text From Saved File"
        android:id="@+id/button2"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="10dp" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:id="@+id/textView"
        android:layout_marginTop="10dp"
        android:layout_gravity="center" />
</LinearLayout>

MainActivity.Java

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package com.android.anil.internalstorage;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class MainActivity extends AppCompatActivity {
    Button savebtn,showbtn;
    EditText e1,e2;
    TextView t1;
    String rec;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        savebtn=(Button)findViewById(R.id.button);
        showbtn=(Button)findViewById(R.id.button2);
        e1=(EditText)findViewById(R.id.editText);
        e2=(EditText)findViewById(R.id.editText2);
        t1=(TextView)findViewById(R.id.textView);
        savebtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String filename=e1.getText().toString();
                String text=e2.getText().toString();
                try {
                    FileOutputStream fileOutputStream=openFileOutput(filename+".txt",MODE_PRIVATE);
                    try {
                        fileOutputStream.write(text.getBytes());
                        fileOutputStream.close();
                        Toast.makeText(MainActivity.this, "File created and Text saved", Toast.LENGTH_SHORT).show();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }
            }
        });
        showbtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                 rec=e2.getText().toString();

                try {
                    FileInputStream fiso=openFileInput(rec+".txt");

                    StringBuffer stringbuffer=new StringBuffer();
                    int id1;
                    while ((id1=fiso.read())!=-1){

                        stringbuffer.append((char) id1);

                    }
                    fiso.close();
                    t1.setText(stringbuffer.toString());
                    Toast.makeText(MainActivity.this, "Data is : "+stringbuffer.toString(), Toast.LENGTH_SHORT).show();



                } catch (IOException e) {
                    e.printStackTrace();
                }


            }
        });
    }
}

Output is:

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