You have to make sure that your asset folder contains sample_pdf.pdf (Library also support opening pdf from Uri and SDCard)
After going through several posts I came across this simple answer on Quora which pretty much do the work. Following are steps:-
Add this dependency in your gradle file:
compile 'com.github.barteksc:android-pdf-viewer:2.0.3' activity_main.xml
<com.github.barteksc.pdfviewer.PDFView android:id="@+id/pdfView" android:layout_width="match_parent" android:layout_height="match_parent" /> MainActivity.java
package pdfviewer.pdfviewer; import android.app.Activity; import android.os.Bundle; import android.util.Log; import com.github.barteksc.pdfviewer.PDFView; import com.github.barteksc.pdfviewer.listener.OnLoadCompleteListener; import com.github.barteksc.pdfviewer.listener.OnPageChangeListener; import com.github.barteksc.pdfviewer.scroll.DefaultScrollHandle; import com.shockwave.pdfium.PdfDocument; import java.util.List; public class MainActivity extends Activity implements OnPageChangeListener,OnLoadCompleteListener{ private static final String TAG = MainActivity.class.getSimpleName(); public static final String SAMPLE_FILE = "sample_pdf.pdf"; PDFView pdfView; Integer pageNumber = 0; String pdfFileName; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); pdfView= (PDFView)findViewById(R.id.pdfView); displayFromAsset(SAMPLE_FILE); } private void displayFromAsset(String assetFileName) { pdfFileName = assetFileName; pdfView.fromAsset(SAMPLE_FILE) .defaultPage(pageNumber) .enableSwipe(true) .swipeHorizontal(false) .onPageChange(this) .enableAnnotationRendering(true) .onLoad(this) .scrollHandle(new DefaultScrollHandle(this)) .load(); } @Override public void onPageChanged(int page, int pageCount) { pageNumber = page; setTitle(String.format("%s %s / %s", pdfFileName, page + 1, pageCount)); } @Override public void loadComplete(int nbPages) { PdfDocument.Meta meta = pdfView.getDocumentMeta(); printBookmarksTree(pdfView.getTableOfContents(), "-"); } public void printBookmarksTree(List<PdfDocument.Bookmark> tree, String sep) { for (PdfDocument.Bookmark b : tree) { Log.e(TAG, String.format("%s %s, p %d", sep, b.getTitle(), b.getPageIdx())); if (b.hasChildren()) { printBookmarksTree(b.getChildren(), sep + "-"); } } } } You have to make sure that your asset folder contains sample_pdf.pdf (Library also support opening pdf from Uri and SDCard) 
Happy coding :)
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