Read Text file from SD Card : Android Programming


To read a text file from SD Card (External Memory) in Android one has to make use of Environment.getExternalStorageDirectory() to get access to the external Storage. We make use of the File Class from java.io package as we usually use.

Example :

We will create an Android Project with an Activity that has a Button and TextView. When the button is clicked we will read a text file from the SD card location "/Dir/data.txt" and display the data from the file to the TextView.

Note : Do not forget to place the text file in External Storage /Dir/data.txt. Also do not forget to add user permission : <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/> in AndroidManifest.xml file.

File : activity_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: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.code2care.readtextfile.MainActivity" >

    <TextView
        android:id="@+id/text_file_data"
        android:layout_width="fill_parent"
        android:layout_height="200dp"
        android:layout_alignParentRight="true"
        android:padding="10dp"
        android:text="@string/text_file_data" />

    <Button
        android:id="@+id/read_text_file"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="127dp"
        android:onClick="getTextFile"
        android:text="@string/btn" />

</RelativeLayout>
File : strings.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">ReadTextFile</string>
    <string name="hello_world">Hello world!</string>
    <string name="action_settings">Settings</string>
    <string name="text_file_data"></string>
    <string name="btn">Open Text File</string>

</resources>
<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">ReadTextFile</string>
    <string name="hello_world">Hello world!</string>
    <string name="action_settings">Settings</string>
    <string name="text_file_data"></string>
    <string name="btn">Open Text File</string>

</resources>
package com.code2care.readtextfile;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;

import android.os.Bundle;
import android.os.Environment;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

	TextView dispText;

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

		dispText = (TextView) findViewById(R.id.text_file_data);
	}

	public void getTextFile(View v) {

		// You can provide the dir location from SD card root
		String data = getTextFileData("/Dir/data.txt");

		// Display the text conetents on a TextView
		dispText.setText(data);

	}

	public String getTextFileData(String fileName) {

		// Get the dir of SD Card
		File sdCardDir = Environment.getExternalStorageDirectory();

		// Get The Text file
		File txtFile = new File(sdCardDir, fileName);

		// Read the file Contents in a StringBuilder Object
		StringBuilder text = new StringBuilder();

		try {
			BufferedReader reader = new BufferedReader(new FileReader(txtFile));

			String line;

			while ((line = reader.readLine()) != null) {
				text.append(line + '\n');
			}
			reader.close();
		} catch (IOException e) {
			Log.e("C2c", "Error occured while reading text file!!");
		}
		return text.toString();
	}
}
Output :
Read-Text-File-SD-Card
Read-Text-File-SD-Card
Text-Contents-displayed-on-TextView
Text-Contents-displayed-on-TextView

If you are testing this Scenario on Emulator device, do not forget to create an SD Card with some memory while creating the Emulator from Android Virtual Device Manager.

Related Questions :

How to read a file from Android External Storage ?

How to get a text from Android SD Card ?

How to display text in TextView from a file read from SD Card?

HashTags : #Android #AndroidTutorial #SDCard #FileOperations #SecondaryStorage #FileRead