Android Internal Storage

 

Android Internal Storage Example

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.

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Example of reading and writing data to the android internal storage

activity_main.xml

Drag the 2 edittexts, 2 textviews and 2 buttons from the pallete, now the activity_main.xml file will like this:

File: activity_main.xml

1. <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  
2.     xmlns:tools="http://schemas.android.com/tools"  
3.     android:layout_width="match_parent"  
4.     android:layout_height="match_parent"  
5.     tools:context=".MainActivity" >  
6.   
7.     <EditText  
8.         android:id="@+id/editText1"  
9.         android:layout_width="wrap_content"  
10.         android:layout_height="wrap_content"  
11.         android:layout_alignParentRight="true"  
12.         android:layout_alignParentTop="true"  
13.         android:layout_marginRight="20dp"  
14.         android:layout_marginTop="24dp"  
15.         android:ems="10" >  
16.   
17.         <requestFocus />  
18.     </EditText>  
19.   
20.     <EditText  
21.         android:id="@+id/editText2"  
22.         android:layout_width="wrap_content"  
23.         android:layout_height="wrap_content"  
24.         android:layout_alignRight="@+id/editText1"  
25.         android:layout_below="@+id/editText1"  
26.         android:layout_marginTop="24dp"  
27.         android:ems="10" />  
28.   
29.     <TextView  
30.         android:id="@+id/textView1"  
31.         android:layout_width="wrap_content"  
32.         android:layout_height="wrap_content"  
33.         android:layout_alignBaseline="@+id/editText1"  
34.         android:layout_alignBottom="@+id/editText1"  
35.         android:layout_alignParentLeft="true"  
36.         android:text="File Name:" />  
37.   
38.     <TextView  
39.         android:id="@+id/textView2"  
40.         android:layout_width="wrap_content"  
41.         android:layout_height="wrap_content"  
42.         android:layout_alignBaseline="@+id/editText2"  
43.         android:layout_alignBottom="@+id/editText2"  
44.         android:layout_alignParentLeft="true"  
45.         android:text="Data:" />  
46.   
47.     <Button  
48.         android:id="@+id/button1"  
49.         android:layout_width="wrap_content"  
50.         android:layout_height="wrap_content"  
51.         android:layout_alignLeft="@+id/editText2"  
52.         android:layout_below="@+id/editText2"  
53.         android:layout_marginLeft="70dp"  
54.         android:layout_marginTop="16dp"  
55.         android:text="save" />  
56.   
57.     <Button  
58.         android:id="@+id/button2"  
59.         android:layout_width="wrap_content"  
60.         android:layout_height="wrap_content"  
61.         android:layout_alignBaseline="@+id/button1"  
62.         android:layout_alignBottom="@+id/button1"  
63.         android:layout_toRightOf="@+id/button1"  
64.         android:text="read" />  
65.   
66. </RelativeLayout>  

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Activity class

Let's write the code to write and read data from the internal storage.

File: MainActivity.java

1. package example.javatpoint.com.internalstorage;  
2.   
3. import android.content.Context;  
4. import android.support.v7.app.AppCompatActivity;  
5. import android.os.Bundle;  
6. import android.view.View;  
7. import android.widget.Button;  
8. import android.widget.EditText;  
9. import android.widget.Toast;  
10.   
11. import java.io.BufferedReader;  
12. import java.io.FileNotFoundException;  
13. import java.io.FileOutputStream;  
14. import java.io.IOException;  
15. import java.io.InputStreamReader;  
16.   
17. public class MainActivity extends AppCompatActivity {  
18.     EditText editTextFileName,editTextData;  
19.     Button saveButton,readButton;  
20.     @Override  
21.     protected void onCreate(Bundle savedInstanceState) {  
22.         super.onCreate(savedInstanceState);  
23.         setContentView(R.layout.activity_main);  
24.   
25.         editTextFileName=findViewById(R.id.editText1);  
26.         editTextData=findViewById(R.id.editText2);  
27.         saveButton=findViewById(R.id.button1);  
28.         readButton=findViewById(R.id.button2);  
29.   
30.         //Performing Action on Read Button  
31.         saveButton.setOnClickListener(new View.OnClickListener(){  
32.   
33.             @Override  
34.             public void onClick(View arg0) {  
35.                 String filename=editTextFileName.getText().toString();  
36.                 String data=editTextData.getText().toString();  
37.   
38.                 FileOutputStream fos;  
39.                 try {  
40.                     fos = openFileOutput(filename, Context.MODE_PRIVATE);  
41.                     //default mode is PRIVATE, can be APPEND etc.  
42.                     fos.write(data.getBytes());  
43.                     fos.close();  
44.   
45.                     Toast.makeText(getApplicationContext(),filename + " saved",  
46.                             Toast.LENGTH_LONG).show();  
47.   
48.   
49.                 } catch (FileNotFoundException e) {e.printStackTrace();}  
50.                 catch (IOException e) {e.printStackTrace();}  
51.   
52.             }  
53.   
54.         });  
55.   
56.         //Performing Action on Read Button  
57.         readButton.setOnClickListener(new View.OnClickListener(){  
58.   
59.             @Override  
60.             public void onClick(View arg0) {  
61.                 String filename=editTextFileName.getText().toString();  
62.                 StringBuffer stringBuffer = new StringBuffer();  
63.                 try {  
64.                     //Attaching BufferedReader to the FileInputStream by the help of InputStreamReader  
65.                     BufferedReader inputReader = new BufferedReader(new InputStreamReader(  
66.                             openFileInput(filename)));  
67.                     String inputString;  
68.                     //Reading data line by line and storing it into the stringbuffer  
69.                     while ((inputString = inputReader.readLine()) != null) {  
70.                         stringBuffer.append(inputString + "\n");  
71.                     }  
72.   
73.                 } catch (IOException e) {  
74.                     e.printStackTrace();  
75.                 }  
76.                 //Displaying data on the toast  
77.             Toast.makeText(getApplicationContext(),stringBuffer.toString(),Toast.LENGTH_LONG).show();  
78.   
79.             }  
80.   
81.         });  
82.     }  
83. }  

Output: