Using PdfViewerActivity in my app

Question

I have to open a .PDF in my app for which I'm using the below code:

Activity1.java

package com.example.vinita.pdfdictionary;
import android.app.ListActivity;
import android.content.Intent;
import android.os.Environment;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.io.File;
import java.io.FilenameFilter;
import java.util.Arrays;
import net.sf.andpdf.pdfviewer.PdfViewerActivity;

public class Activity1 extends ListActivity {
    private File[] imagelist;
    String[] pdflist;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_activity1);
        File images = Environment.getExternalStorageDirectory();
        imagelist = images.listFiles(new FilenameFilter() {
            @Override
            public boolean accept(File dir, String name) {
                return ((name.endsWith(".pdf")));
            }
        });
        pdflist = new String[imagelist.length];
        for (int i = 0; i < imagelist.length; i++) {
            pdflist[i] = imagelist[i].getName();
        }
        Arrays.sort(imagelist);
        Arrays.sort(pdflist);
        this.setListAdapter(new ArrayAdapter(this,android.R.layout.simple_list_item_1,pdflist));
    }
    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);
        Intent intent=new Intent(this,Activity2.class);
        intent.putExtra(PdfViewerActivity.EXTRA_PDFFILENAME,"mnt/sdcard/sample.pdf");
        startActivity(intent);

    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_activity1, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

Activity2.java

package com.example.vinita.pdfdictionary;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import net.sf.andpdf.pdfviewer.PdfViewerActivity;


public class Activity2 extends PdfViewerActivity {


    public int getPreviousPageImageResource() {
        return R.drawable.left_arrow;
    }

    public int getNextPageImageResource() {
        return R.drawable.right_arrow;
    }

    public int getZoomInImageResource() {
        return R.drawable.zoom_in;
    }

    public int getZoomOutImageResource() {
        return R.drawable.zoom_out;
    }

    public int getPdfPasswordLayoutResource() {
        return R.layout.pdf_file_password;
    }

    public int getPdfPageNumberResource() {
        return R.layout.dialog_pagenumber;
    }

    public int getPdfPasswordEditField() {
        return R.id.etPassword;
    }

    public int getPdfPasswordOkButton() {
        return R.id.btOK;
    }

    public int getPdfPasswordExitButton() {
        return R.id.btExit;
    }

    public int getPdfPageNumberEditField() {
        return R.id.pagenum_edit;
    }
}

It is showing error as in the log cat below.

I am using Android Studio.

Please any one tell me what's this.

Error:Execution failed for task ':app:dexDebug'. com.android.ide.common.internal.LoggedErrorException: Failed to run command: C:\Users\Vinita\AppData\Local\Android\sdk\build-tools\22.0.1\dx.bat --dex --no-optimize --output F:\PDFVIEWERPROJECTRELATEDALLDATA\PDFDICTIONARY\app\build\intermediates\dex\debug --input-list=F:\PDFVIEWERPROJECTRELATEDALLDATA\PDFDICTIONARY\app\build\intermediates\tmp\dex\debug\inputList.txt Error Code: 2 Output: UNEXPECTED TOP-LEVEL EXCEPTION: com.android.dex.DexException: Multiple dex files define Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompatIcs; at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:596) at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:554) at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:535) at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:171) at com.android.dx.merge.DexMerger.merge(DexMerger.java:189) at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:454) at com.android.dx.command.dexer.Main.runMonoDex(Main.java:303) at com.android.dx.command.dexer.Main.run(Main.java:246) at com.android.dx.command.dexer.Main.main(Main.java:215) at com.android.dx.command.Main.main(Main.java:106)

build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.0.0'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }

}

allprojects {
    repositories {
        jcenter()
    }
}