Desenhar um ficheiro PDF com o Java no Android

// create a new renderer
 PdfRenderer renderer = new PdfRenderer(getSeekableFileDescriptor());

 // let us just render all pages
 final int pageCount = renderer.getPageCount();
 for (int i = 0; i < pageCount; i++) {
     Page page = renderer.openPage(i);

     // say we render for showing on the screen
     page.render(mBitmap, null, null, Page.RENDER_MODE_FOR_DISPLAY);

     // do stuff with the bitmap

     // close the page
     page.close();
 }

 // close the renderer
 renderer.close();

Para mais informações, ver o Aplicação de amostras .

Para APIs mais antigos eu recomendo Android PdfViewer library , é muito rápido e fácil de usar, licenciado sob a Licença Apache 2.0:

pdfView.fromAsset(String)
  .pages(0, 2, 1, 3, 3, 3) // all pages are displayed by default
  .enableSwipe(true)
  .swipeHorizontal(false)
  .enableDoubletap(true)
  .defaultPage(0)
  .onDraw(onDrawListener)
  .onLoad(onLoadCompleteListener)
  .onPageChange(onPageChangeListener)
  .onPageScroll(onPageScrollListener)
  .onError(onErrorListener)
  .enableAnnotationRendering(false)
  .password(null)
  .scrollHandle(null)
  .load();

Tirado do meu blog:

public class MyPdfViewActivity extends Activity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    WebView mWebView=new WebView(MyPdfViewActivity.this);
    mWebView.getSettings().setJavaScriptEnabled(true);
    mWebView.getSettings().setPluginsEnabled(true);
    mWebView.loadUrl("https://docs.google.com/gview?embedded=true&url="+LinkTo);
    setContentView(mWebView);
  }
}

Esta solução verifica se está instalado um aplicativo leitor de PDF e faz o seguinte: - Se um leitor estiver instalado, baixar o arquivo PDF para o dispositivo e iniciar um aplicativo leitor de PDF - Se nenhum leitor estiver instalado, pergunte ao usuário se ele quer ver o arquivo PDF online através do Google Drive

Nota!Esta solução usa o Android.DownloadManager classe, que foi introduzida em API9 (Android 2.3 ou pão de gengibre). Isto significa que não funciona no Android 2.2 ou antes.

Eu escrevi um post no blog sobre isso Aqui, Mas eu forneci o código completo abaixo para completar:

public class PDFTools {
    private static final String GOOGLE_DRIVE_PDF_READER_PREFIX = "http://drive.google.com/viewer?url=";
    private static final String PDF_MIME_TYPE = "application/pdf";
    private static final String HTML_MIME_TYPE = "text/html";

    /**
     * If a PDF reader is installed, download the PDF file and open it in a reader. 
     * Otherwise ask the user if he/she wants to view it in the Google Drive online PDF reader.<br />
     * <br />
     * <b>BEWARE:</b> This method
     * @param context
     * @param pdfUrl
     * @return
     */
    public static void showPDFUrl( final Context context, final String pdfUrl ) {
        if ( isPDFSupported( context ) ) {
            downloadAndOpenPDF(context, pdfUrl);
        } else {
            askToOpenPDFThroughGoogleDrive( context, pdfUrl );
        }
    }

    /**
     * Downloads a PDF with the Android DownloadManager and opens it with an installed PDF reader app.
     * @param context
     * @param pdfUrl
     */
    @TargetApi(Build.VERSION_CODES.GINGERBREAD)
    public static void downloadAndOpenPDF(final Context context, final String pdfUrl) {
        // Get filename
        final String filename = pdfUrl.substring( pdfUrl.lastIndexOf( "/" ) + 1 );
        // The place where the downloaded PDF file will be put
        final File tempFile = new File( context.getExternalFilesDir( Environment.DIRECTORY_DOWNLOADS ), filename );
        if ( tempFile.exists() ) {
            // If we have downloaded the file before, just go ahead and show it.
            openPDF( context, Uri.fromFile( tempFile ) );
            return;
        }

        // Show progress dialog while downloading
        final ProgressDialog progress = ProgressDialog.show( context, context.getString( R.string.pdf_show_local_progress_title ), context.getString( R.string.pdf_show_local_progress_content ), true );

        // Create the download request
        DownloadManager.Request r = new DownloadManager.Request( Uri.parse( pdfUrl ) );
        r.setDestinationInExternalFilesDir( context, Environment.DIRECTORY_DOWNLOADS, filename );
        final DownloadManager dm = (DownloadManager) context.getSystemService( Context.DOWNLOAD_SERVICE );
        BroadcastReceiver onComplete = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                if ( !progress.isShowing() ) {
                    return;
                }
                context.unregisterReceiver( this );

                progress.dismiss();
                long downloadId = intent.getLongExtra( DownloadManager.EXTRA_DOWNLOAD_ID, -1 );
                Cursor c = dm.query( new DownloadManager.Query().setFilterById( downloadId ) );

                if ( c.moveToFirst() ) {
                    int status = c.getInt( c.getColumnIndex( DownloadManager.COLUMN_STATUS ) );
                    if ( status == DownloadManager.STATUS_SUCCESSFUL ) {
                        openPDF( context, Uri.fromFile( tempFile ) );
                    }
                }
                c.close();
            }
        };
        context.registerReceiver( onComplete, new IntentFilter( DownloadManager.ACTION_DOWNLOAD_COMPLETE ) );

        // Enqueue the request
        dm.enqueue( r );
    }

    /**
     * Show a dialog asking the user if he wants to open the PDF through Google Drive
     * @param context
     * @param pdfUrl
     */
    public static void askToOpenPDFThroughGoogleDrive( final Context context, final String pdfUrl ) {
        new AlertDialog.Builder( context )
            .setTitle( R.string.pdf_show_online_dialog_title )
            .setMessage( R.string.pdf_show_online_dialog_question )
            .setNegativeButton( R.string.pdf_show_online_dialog_button_no, null )
            .setPositiveButton( R.string.pdf_show_online_dialog_button_yes, new OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    openPDFThroughGoogleDrive(context, pdfUrl); 
                }
            })
            .show();
    }

    /**
     * Launches a browser to view the PDF through Google Drive
     * @param context
     * @param pdfUrl
     */
    public static void openPDFThroughGoogleDrive(final Context context, final String pdfUrl) {
        Intent i = new Intent( Intent.ACTION_VIEW );
        i.setDataAndType(Uri.parse(GOOGLE_DRIVE_PDF_READER_PREFIX + pdfUrl ), HTML_MIME_TYPE );
        context.startActivity( i );
    }
    /**
     * Open a local PDF file with an installed reader
     * @param context
     * @param localUri
     */
    public static final void openPDF(Context context, Uri localUri ) {
        Intent i = new Intent( Intent.ACTION_VIEW );
        i.setDataAndType( localUri, PDF_MIME_TYPE );
        context.startActivity( i );
    }
    /**
     * Checks if any apps are installed that supports reading of PDF files.
     * @param context
     * @return
     */
    public static boolean isPDFSupported( Context context ) {
        Intent i = new Intent( Intent.ACTION_VIEW );
        final File tempFile = new File( context.getExternalFilesDir( Environment.DIRECTORY_DOWNLOADS ), "test.pdf" );
        i.setDataAndType( Uri.fromFile( tempFile ), PDF_MIME_TYPE );
        return context.getPackageManager().queryIntentActivities( i, PackageManager.MATCH_DEFAULT_ONLY ).size() > 0;
    }

}

Finalmente consegui modificar o código do butelo para abrir QUALQUER ficheiro PDF no sistema de ficheiros Android usando pdf.js. O código pode ser encontrado no meu GitHub

O que eu fiz foi modificado o pdffile.js para ler o argumento HTML file assim:

var url = getURLParameter('file');

function getURLParameter(name) {
return decodeURIComponent((new RegExp('[?|&]' + name + '=' + '([^&;]+?)(&|#|;|$)').exec(location.search)||[,""])[1].replace(/\+/g, '%20'))||null}

Então o que você precisa fazer é apenas adicionar o caminho do arquivo depois do index.html Assim:

Uri path = Uri.parse(Environment.getExternalStorageDirectory().toString() + "/data/test.pdf");
webView.loadUrl("file:///android_asset/pdfviewer/index.html?file=" + path);

Actualiza a variável path para apontar para um PDF válido no sistema de ficheiros Adroid.

Faça o Download do código fonte aqui ( mostre o ficheiro PDF dentro da minha aplicação android)

Adicione esta dependência ao seu grau: compile ' com.github.barteksc: android-pdf-viewer: 2.0.3 '

Activity_main.xml

<RelativeLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ffffff"
    xmlns:android="http://schemas.android.com/apk/res/android" >

    <TextView
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:background="@color/colorPrimaryDark"
        android:text="View PDF"
        android:textColor="#ffffff"
        android:id="@+id/tv_header"
        android:textSize="18dp"
        android:gravity="center"></TextView>

    <com.github.barteksc.pdfviewer.PDFView
        android:id="@+id/pdfView"
        android:layout_below="@+id/tv_header"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>


    </RelativeLayout>

MainActivity.java

import android.app.Activity;
import android.database.Cursor;
import android.net.Uri;
import android.provider.OpenableColumns;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.RelativeLayout;

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 = "android_tutorial.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 + "-");
            }
        }
    }

}

Para adicionar um pouco de luz a isto, eu teria que ir com o pdf.solução js de Mozilla. Aqui está o link para uma implementação já bem escrita deste: https://bitbucket.org/butelo/pdfviewer/.

private String getInternalPDFURL(String interalPDFName){
    return "file:///android_asset/pdfviewer/index.html?pdf=" + interalPDFName + ".pdf";
}

var url = '../' + getPDFURL();

function getPDFURL(){
    var query = window.location.search.substring(1);
    var vars = query.split("=");
    var pdfPage = vars[1];
    return pdfPage;
}

Usei o código abaixo para abrir e imprimir o PDF usando Wi-Fi. Estou a enviar todo o meu código, e espero que seja útil.

public class MainActivity extends Activity {

    int Result_code = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button mButton = (Button)findViewById(R.id.button1);

        mButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                 PrintManager printManager = (PrintManager)getSystemService(Context.PRINT_SERVICE);
                String jobName =  " Document";
                printManager.print(jobName, pda, null);
            }
        });
    }


    public void openDocument(String name) {

        Intent intent = new Intent(android.content.Intent.ACTION_VIEW);
        File file = new File(name);
        String extension = android.webkit.MimeTypeMap.getFileExtensionFromUrl(Uri.fromFile(file).toString());
        String mimetype = android.webkit.MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

        if (extension.equalsIgnoreCase("") || mimetype == null) {
            // if there is no extension or there is no definite mimetype, still try to open the file
            intent.setDataAndType(Uri.fromFile(file), "text/*");
        }
        else {
            intent.setDataAndType(Uri.fromFile(file), mimetype);
        }

        // custom message for the intent
        startActivityForResult((Intent.createChooser(intent, "Choose an Application:")), Result_code);
        //startActivityForResult(intent, Result_code);
        //Toast.makeText(getApplicationContext(),"There are no email clients installed.", Toast.LENGTH_SHORT).show();
    }


    @SuppressLint("NewApi")
    PrintDocumentAdapter pda = new PrintDocumentAdapter(){

        @Override
        public void onWrite(PageRange[] pages, ParcelFileDescriptor destination, CancellationSignal cancellationSignal, WriteResultCallback callback){
            InputStream input = null;
            OutputStream output = null;

            try {
                String filename = Environment.getExternalStorageDirectory()    + "/" + "Holiday.pdf";
                File file = new File(filename);
                input = new FileInputStream(file);
                output = new FileOutputStream(destination.getFileDescriptor());

                byte[] buf = new byte[1024];
                int bytesRead;

                while ((bytesRead = input.read(buf)) > 0) {
                     output.write(buf, 0, bytesRead);
                }

                callback.onWriteFinished(new PageRange[]{PageRange.ALL_PAGES});
            }
            catch (FileNotFoundException ee){
                //Catch exception
            }
            catch (Exception e) {
                //Catch exception
            }
            finally {
                try {
                    input.close();
                    output.close();
                }
                catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        @Override
        public void onLayout(PrintAttributes oldAttributes, PrintAttributes newAttributes, CancellationSignal cancellationSignal, LayoutResultCallback callback, Bundle extras){

            if (cancellationSignal.isCanceled()) {
                callback.onLayoutCancelled();
                return;
            }

           // int pages = computePageCount(newAttributes);

            PrintDocumentInfo pdi = new PrintDocumentInfo.Builder("Name of file").setContentType(PrintDocumentInfo.CONTENT_TYPE_DOCUMENT).build();

            callback.onLayoutFinished(pdi, true);
        }
    };
}

De qualquer forma não existe nenhuma antevisão do documento pdf no Android webview.Se quiser antever o base64 pdf. Requer uma biblioteca de terceiros.

Construir.Gradle

compile 'com.github.barteksc:android-pdf-viewer:2.7.0'

Dialog_ PDF_ Viewer

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

<!--
  ~ Copyright (c) 2017.
  ~ Samet Öztoprak
  ~ All rights reserved.
  -->

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/dialog_pdf_viewer_close"
        style="@style/ExitButtonImageViewStyle"
        android:src="@drawable/popup_exit" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:background="@color/white"
        android:orientation="vertical">

        <com.github.barteksc.pdfviewer.PDFView
            android:id="@+id/pdfView"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

    </LinearLayout>

    <View style="@style/HorizontalLine" />

    <com.pozitron.commons.customviews.ButtonFont
        android:id="@+id/dialog_pdf_viewer_button"
        style="@style/ButtonPrimary2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="15dp"
        android:text="@string/agreed" />

</LinearLayout>

DailogPDFViewer.java

public class DialogPdfViewer extends Dialog {
    PDFView pdfView;
    byte[] decodedString;

    public interface OnDialogPdfViewerListener {
        void onAgreeClick(DialogPdfViewer dialogFullEula);

        void onCloseClick(DialogPdfViewer dialogFullEula);
    }

    public DialogPdfViewer(Context context, String base64, final DialogPdfViewer.OnDialogPdfViewerListener onDialogPdfViewerListener) {
        super(context);

        setContentView(R.layout.dialog_pdf_viewer);
        findViewById(R.id.dialog_pdf_viewer_close).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                onDialogPdfViewerListener.onCloseClick(DialogPdfViewer.this);
            }
        });

        findViewById(R.id.dialog_pdf_viewer_button).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                onDialogPdfViewerListener.onAgreeClick(DialogPdfViewer.this);
            }
        });

        decodedString = Base64.decode(base64.toString(), Base64.DEFAULT);

        pdfView = ((PDFView) findViewById(R.id.pdfView));
        pdfView.fromBytes(decodedString).load();

        setOnKeyListener(new OnKeyListener() {
            @Override
            public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
                if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN) {
                    onDialogPdfViewerListener.onCloseClick(DialogPdfViewer.this);
                }
                return true;
            }
        });

    }
}