Code of a simple android app which can browse and open a text file

Here I provide the codes of a simple android app which can be used to browse and open a text file from device.

Codes in main.xml

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

<LinearLayout

xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:gravity="center"

android:orientation="vertical">

<Button

android:layout_height="wrap_content"

android:layout_width="wrap_content"

android:text="Button"

android:id="@+id/select"/>

<EditText

android:layout_height="wrap_content"

android:layout_width="match_parent"

android:ems="10"

android:id="@+id/edittext1"/>

<EditText

android:layout_height="match_parent"

android:layout_width="match_parent"

android:ems="10"

android:id="@+id/edittext2"/>

</LinearLayout>

Codes in MainActivity.java

package com.myfile.open;

import android.app.*;

import android.os.*;

import android.widget.*;

import android.view.*;

import android.view.View;

import android.content.*;

import java.io.*;

public class MainActivity extends Activity 

{

private Button btn;

private EditText edittext1;

private EditText edittext2;

private static final int PICKFILE_RESULT_CODE = 1;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

btn = (Button) findViewById(R.id.select);

edittext1 = (EditText) findViewById(R.id.edittext1);

edittext2 = (EditText) findViewById(R.id.edittext2);

btn.setOnClickListener(new View.OnClickListener(){

@Override

public void onClick(View v){

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);

intent.setType("text/*");

startActivityForResult(intent,PICKFILE_RESULT_CODE);}

});

}

@Override

protected void onActivityResult(int requestCode, int resultCode, Intent data) {

if(resultCode == RESULT_OK) {

switch(requestCode) {

case PICKFILE_RESULT_CODE:

String selectedFile = data.getData().getPath();

String filename= selectedFile.substring(selectedFile.lastIndexOf("/")+1);

edittext1.setText(filename);

selectedFile = selectedFile.substring(selectedFile.lastIndexOf(":")+1);

try {

File myFile = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/" + selectedFile);

FileInputStream fIn = new FileInputStream( myFile );

BufferedReader myReader = new BufferedReader( new InputStreamReader(fIn));

String aDataRow = "";

String aBuffer = "";

while ((aDataRow = myReader.readLine()) != null) { aBuffer+= aDataRow + "\n";}

edittext2.setText(aBuffer);

myReader.close();

Toast.makeText(getBaseContext(),"Done reading file "+filename+" from sdcard",Toast.LENGTH_SHORT).show();}

catch (Exception e) {

Toast.makeText(getBaseContext(), e.getMessage(),Toast.LENGTH_SHORT).show();}

break;

         }

      }

   }

}

Codes in AndroidManifest.xml

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

<manifest xmlns:android= "http://schemas.android.com/apk/res/android"

package= "com.myfile.open" >

<uses-permission android:name= "android.permission.WRITE_EXTERNAL_STORAGE" />

<application

     android:allowBackup="true"

     android:icon="@drawable/ic_launcher"

     android:label="@string/app_name"

     android:theme="@style/AppTheme"

     android:resizeableActivity = "true">

     <activity

         android:name=".MainActivity"

         android:label="@string/app_name" >

         <intent-filter>

             <action android:name= "android.intent.action.MAIN" />

             <category android:name= "android.intent.category.LAUNCHER" />

         </intent-filter>

     </activity>

</application>

</manifest>

Note that this app requires permissions to WRITE EXTERNAL STORAGE.

The code has been described in this video: