Reading files(.txt , .docx , .pdf) and view only this type of files from SD-card

 Main Activity class 

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.List;
import org.w3c.dom.Document;
import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.DialogInterface.OnClickListener;
import android.content.pm.PackageManager;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.GridView;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity
{
ImageButton text,word,pdf;
BufferedReader reader = null;
StringBuilder builder = null;

Button fileclick;
File file;
Document document;
String f1;
private static final int REQUEST_PICK_FILE = 1;

private TextView mFilePathTextView, ccc;
String str;
//   private Button mStartActivityButton;
private File selectedFile;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

Intent intent = new Intent(this, FilePickerActivity.class);

startActivityForResult(intent, REQUEST_PICK_FILE);
// str=(String) mFilePathTextView.getText();
// file = new File(str);




//      mFilePathTextView = (TextView)findViewById(R.id.file_path_text_view);

       
// fileclick=(Button)findViewById(R.id.search);
// ccc=(TextView)findViewById(R.id.showtext);
// mFilePathTextView=(TextView)findViewById(R.id.file_path_text_view);
// fileclick.setOnClickListener(this);

// fileopen.setOnClickListener(this);

}

// public void onClick(View v)
// {
//
//// Intent intent = new Intent(this, FilePickerActivity.class);
////
//// startActivityForResult(intent, REQUEST_PICK_FILE);
//// str=(String) mFilePathTextView.getText();
//// file = new File(str);
////
//
//    }


@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(resultCode == RESULT_OK) {
switch(requestCode) {
case REQUEST_PICK_FILE:
if(data.hasExtra(FilePickerActivity.EXTRA_FILE_PATH)) {
// Get the file path
selectedFile = new File(data.getStringExtra(FilePickerActivity.EXTRA_FILE_PATH));
// Set the file path text view
mFilePathTextView.setText(selectedFile.getPath());



//Now you have your selected file, You can do your additional requirement with file.              
}
}
}
}
}

file picker Activity Class 

import java.io.BufferedReader;

import java.io.DataInputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.FilenameFilter;

import java.io.IOException;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Comparator;

import java.util.List;

import java.util.Vector;

import android.app.ListActivity;

import android.content.Context;

import android.content.Intent;

import android.content.pm.PackageManager;

import android.net.Uri;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.ArrayAdapter;

import android.widget.ImageView;

import android.widget.ListView;

import android.widget.TextView;

import android.widget.Toast;

public class FilePickerActivity extends ListActivity 

{

BufferedReader reader;

FileInputStream fis=null;

final StringBuffer buffer= new StringBuffer();

static String text_word=null;

StringBuilder builder;

public final static String EXTRA_FILE_PATH = "file_path";

public final static String EXTRA_SHOW_HIDDEN_FILES = "show_hidden_files";

public final static String EXTRA_ACCEPTED_FILE_EXTENSIONS = "accepted_file_extensions";

private final static String DEFAULT_INITIAL_DIRECTORY = "/";

String txtPattern=".txt", docPattern=".doc",docxPattern=".docx",DocPattern=".DOC",DocxPattern=".DOCX",TxtPattern=".TXT",pdfPattern=".pdf",PdfPattern=".PDF"; 

Vector<String> mStrings =new Vector<String>();

protected File mDirectory;

protected ArrayList<File> mFiles;

protected FilePickerListAdapter mAdapter;

protected boolean mShowHiddenFiles = false;

protected String[] acceptedFileExtensions;

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

// Set the view to be shown if the list is empty

LayoutInflater inflator = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);

View emptyView = inflator.inflate(R.layout.file_picker_empty_view, null);

((ViewGroup)getListView().getParent()).addView(emptyView);

getListView().setEmptyView(emptyView);

// Set initial directory

mDirectory = new File(DEFAULT_INITIAL_DIRECTORY);

// Initialize the ArrayList

mFiles = new ArrayList<File>();

// Set the ListAdapter

mAdapter = new FilePickerListAdapter(this, mFiles);

setListAdapter(mAdapter);

// Initialize the extensions array to allow any file extensions

acceptedFileExtensions = new String[] {};

// Get intent extras

if(getIntent().hasExtra(EXTRA_FILE_PATH)) {

mDirectory = new File(getIntent().getStringExtra(EXTRA_FILE_PATH));

}

if(getIntent().hasExtra(EXTRA_SHOW_HIDDEN_FILES)) {

mShowHiddenFiles = getIntent().getBooleanExtra(EXTRA_SHOW_HIDDEN_FILES, false);

}

if(getIntent().hasExtra(EXTRA_ACCEPTED_FILE_EXTENSIONS)) {

ArrayList<String> collection = getIntent().getStringArrayListExtra(EXTRA_ACCEPTED_FILE_EXTENSIONS);

acceptedFileExtensions = (String[]) collection.toArray(new String[collection.size()]);

}

}

protected void onResume() {

refreshFilesList();

super.onResume();

}

/**

* Updates the list view to the current directory

*/

protected void refreshFilesList() {

// Clear the files ArrayList

mFiles.clear();

// Set the extension file filter

ExtensionFilenameFilter filter = new ExtensionFilenameFilter(acceptedFileExtensions);

// Get the files in the directory

File[] files = mDirectory.listFiles(filter);

if(files != null && files.length > 0) 

{

for (int i = 0; i < files.length; i++) 

{

String mCheck=files[i].getAbsoluteFile().toString();

mCheck=mCheck.substring(mCheck.lastIndexOf("/")+1);

// System.out.println("listFile[i].getAbsoluteFile().toString()"+files[i].getAbsoluteFile().toString());

// System.out.println("mCheck..."+mCheck);

if (files[i].isDirectory() && !(mCheck.startsWith(".")) ) 

{

System.out.println(files[i].toString()+" "+"created by amit singh tomar");

// if(files[i].getName().equals("/sdcard"));

// {

// mFiles.add(files[i]);

// }

if (files[i].toString().equals("/sdcard")) 

{

mFiles.add(files[i]);

   

System.out.println("dinesh +amit ........");

} 

}

else 

{

if (files[i].getName().endsWith(txtPattern) ||files[i].getName().endsWith(DocPattern)||files[i].getName().endsWith(docPattern) ||files[i].getName().endsWith(docxPattern) ||files[i].getName().endsWith(DocxPattern) ||files[i].getName().endsWith(TxtPattern) ||files[i].getName().endsWith(pdfPattern) ||files[i].getName().endsWith(PdfPattern))

{

mFiles.add(files[i]);

}

}

}

//           for(File f : files) 

//           {

//            

//            

//                if(f.isHidden() && !mShowHiddenFiles) {

//                    // Don't add the file

//                    continue;

//                }

//                 mFiles.add(f);

}

Collections.sort(mFiles, new FileComparator());

//     }

mAdapter.notifyDataSetChanged();

}

public void onBackPressed() {

if(mDirectory.getParentFile() != null) {

// Go to parent directory

mDirectory = mDirectory.getParentFile();

refreshFilesList();

return;

}

super.onBackPressed();

}

protected void onListItemClick(ListView l, View v, int position, long id) 

{

//Toast.makeText(getApplicationContext(), "pos"+" "+position, Toast.LENGTH_LONG).show();

File newFile = (File)l.getItemAtPosition(position);

if(newFile.isFile()) 

{

// Set result

Intent extra = new Intent();

extra.putExtra(EXTRA_FILE_PATH, newFile.getAbsolutePath());

setResult(RESULT_OK, extra);

 if(newFile.getName().endsWith(".doc")||newFile.getName().endsWith(".docx") ||newFile.getName().endsWith(".DOCX") ||newFile.getName().endsWith(".DOC"))

 {

 Uri path = Uri.fromFile(newFile);

 Intent objIntent = new Intent(Intent.ACTION_VIEW);

objIntent.setDataAndType(path,"application/vnd.openxmlformats-officedocument.wordprocessingml.document");

objIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

startActivity(objIntent);

 }

 else if(newFile.getName().endsWith(".pdf") ||newFile.getName().endsWith(".PDF"))

 {

 PackageManager packageManager = getPackageManager();

Intent testIntent = new Intent(Intent.ACTION_VIEW);

testIntent.setType("application/pdf");

List list = packageManager.queryIntentActivities(testIntent, PackageManager.MATCH_DEFAULT_ONLY);

if (list.size() > 0 && newFile.isFile())

{

Intent intent1 = new Intent();

intent1.setAction(Intent.ACTION_VIEW);

Uri uri = Uri.fromFile(newFile);

intent1.setDataAndType(uri,"application/pdf");

startActivity(intent1);

       }

 }

 else

 {

 try {

 fis = openFileInput(newFile.toString());

 DataInputStream dataIO = new DataInputStream(fis);

   String strLine = null;

   if ((strLine = reader.readLine()) != null) 

   {

   

       buffer.append(strLine);

       text_word= buffer.toString();

       

   }

   dataIO.close();

   fis.close();

// reader = new BufferedReader(new FileReader(newFile));

// builder = new StringBuilder();

// String line;

// while ((line = reader.readLine()) != null) 

// {

// builder.append(line);

//

//

// }

}

catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

 }

// Finish the activity

finish();

}

else

{

mDirectory = newFile;

// Update the files list

refreshFilesList();

}

super.onListItemClick(l, v, position, id);

}

private class FilePickerListAdapter extends ArrayAdapter<File> {

private List<File> mObjects;

public FilePickerListAdapter(Context context, List<File> objects) {

super(context, R.layout.file_picker_list_item, android.R.id.text1, objects);

mObjects = objects;

}

public View getView(int position, View convertView, ViewGroup parent) {

View row = null;

if(convertView == null) { 

LayoutInflater inflater = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

row = inflater.inflate(R.layout.file_picker_list_item, parent, false);

} else {

row = convertView;

}

File object = mObjects.get(position);

ImageView imageView = (ImageView)row.findViewById(R.id.file_picker_image);

TextView textView = (TextView)row.findViewById(R.id.file_picker_text);

// Set single line

textView.setSingleLine(true);

textView.setText(object.getName());

if(object.isFile()) {

// Show the file icon

imageView.setImageResource(R.drawable.fileimg);

} else {

// Show the folder icon

imageView.setImageResource(R.drawable.folderimg);

}

return row;

}

}

private class FileComparator implements Comparator<File> {

public int compare(File f1, File f2) {

if(f1 == f2) {

return 0;

}

if(f1.isDirectory() && f2.isFile()) {

// Show directories above files

return -1;

}

if(f1.isFile() && f2.isDirectory()) {

// Show files below directories

return 1;

}

// Sort the directories alphabetically

return f1.getName().compareToIgnoreCase(f2.getName());

}

}

private class ExtensionFilenameFilter implements FilenameFilter 

{

private String[] mExtensions;

public ExtensionFilenameFilter(String[] extensions) 

{

super();

mExtensions = extensions;

}

public boolean accept(File dir, String filename)

{

if(new File(dir, filename).isDirectory()) 

{

// Accept all directory names

return true;

}

if(mExtensions != null && mExtensions.length > 0) 

{

for(int i = 0; i < mExtensions.length; i++) 

{

if(mExtensions[i].endsWith(".txt")) 

{

// The filename ends with the extension

return true;

}

}

// The filename did not match any of the extensions

return false;

}

// No extensions has been set. Accept all file extensions.

return true;

}

}

}

Manifest File 

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

    package="com.example.practise_pdf_word_docx_file"

    android:versionCode="1"

    android:versionName="1.0" >

    <uses-sdk

        android:minSdkVersion="8"

        android:targetSdkVersion="15" />

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

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

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

    <application

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <activity

            android:name=".MainActivity"

            android:label="@string/title_activity_main" >

            <intent-filter>

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

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

            </intent-filter>

        </activity>

           <activity android:name=".FilePickerActivity"

                  android:label="@string/app_name">

        </activity>

    </application>

</manifest>

Permission : 

READ_CONTACTS

WRITE_CONTACTS

WRITE_EXTERNAL_STORAGE