Question

我已将pdf文件上传到firebase存储，在将pdf文件上传到firebase存储后，我收到了下载网址。现在我想在我的应用程序中从这个下载URL打开pdf文件。

以下是我将pdf文件上传到firebase存储后的网址。

https://firebasestorage.googleapis.com/v0/b/realtime-chat-46f4c.appspot.com/o/documents%2Fbf307aa5-79ae-4532-8128-ee394537b357.pdf?alt=media&token=2d0c5329-4717-4adc-9418-6614913e5bfa

现在我想打开一个查看这个pdf文件的意图，我已经使用了以下代码：

String url = "https://firebasestorage.googleapis.com/v0/b/realtime-chat-46f4c.appspot.com/o/documents%2Fbf307aa5-79ae-4532-8128-ee394537b357.pdf?alt=media&token=2d0c5329-4717-4adc-9418-6614913e5bfa";

Intent intent = new Intent(android.content.Intent.ACTION_VIEW);
intent.setDataAndType(Uri.parse(url), "application/pdf");
startActivity(Intent.createChooser(intent, "Choose an Application:"));

我的手机有应用程序可以打开此pdf文件，但仍然表示没有安装应用程序来查看此文件。

如果我在File中转换这个url并使用下面的代码，那么应用程序的选择器会被打开但是它会导致无法打开文件的错误。

Intent intent = new Intent(android.content.Intent.ACTION_VIEW);
File file = new File(name);
intent.setDataAndType(Uri.fromFile(file), "aplication/pdf");

我看到很多答案说首先下载文件然后打开它，但我不想下载文件，我只是想查看它。

如果有人对此有任何疑问，请帮助我。

非常感谢先进。

Answer 1

您应该使用Intent Chooser

Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.parse(url), "application/pdf");
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
Intent newIntent = Intent.createChooser(intent, "Open File");
try {
    startActivity(newIntent);
} catch (ActivityNotFoundException e) {
    // Instruct the user to install a PDF reader here, or something
}

Answer 2

请将以下文件/方法添加到您的项目中

PdfDownloader.java
PDFDownloaderAsyncTask.java

然后使用以下方法 handleViewPdf 来查看pdf：

private void handleViewPdf () {

    File folder = getAppDirectory(context);
    String fileName = "test.pdf";// getPdfFileName(pdfUrl);
    File pdfFile = new File(folder, fileName);

    if (pdfFile.exists () && pdfFile.length () > 0) {
        openPDFFile (context, Uri.fromFile(pdfFile));
    }
    else {
        if (pdfFile.length () == 0) {
            pdfFile.delete ();
        }
        try {
            pdfFile.createNewFile ();
        }
        catch (IOException e) {
            e.printStackTrace ();
        }
        ArrayList<String> fileNameAndURL = new ArrayList<> ();
        fileNameAndURL.add (pdfFile.toString ());
        fileNameAndURL.add (pdfUrl);
        fileNameAndURL.add (fileName);
        if (pdfDownloaderAsyncTask == null) {
            pdfDownloaderAsyncTask = new PDFDownloaderAsyncTask (context, pdfFile);
        }
        if (hasInternetConnection (context)) {
            if (!pdfDownloaderAsyncTask.isDownloadingPdf ()) {
                pdfDownloaderAsyncTask = new PDFDownloaderAsyncTask (context, pdfFile);
                pdfDownloaderAsyncTask.execute (fileNameAndURL);
            }
        }
        else {
            //show error
        }
    }
}

<强> PDFDownloaderAsyncTask.java

    import java.io.File;
    import java.util.ArrayList;

    import android.content.Context;
    import android.net.Uri;
    import android.os.AsyncTask;
    import android.os.Handler;
    import android.text.TextUtils;
    import android.widget.Toast;


    public class PDFDownloaderAsyncTask extends AsyncTask<ArrayList<String>, Void, String> {

        private boolean isDownloadingPdf = false;

        private File    file;
        private Context context;

        public PDFDownloaderAsyncTask (Context context, File file) {

            this.file = file;
            this.context = context;
            this.isDownloadingPdf = false;
        }

        public boolean isDownloadingPdf () {

            return this.isDownloadingPdf;
        }

        @Override
        protected void onPreExecute () {

            super.onPreExecute ();
            //show loader etc
        }

        @Override
        protected String doInBackground (ArrayList<String>... params) {

            isDownloadingPdf = true;
            File file = new File (params[0].get (0));
            String fileStatus = PdfDownloader.downloadFile (params[0].get (1), file);
            return fileStatus;
        }

        @Override
        protected void onPostExecute (String result) {

            super.onPostExecute (result);
            Loader.hideLoader ();
            if (!TextUtils.isEmpty (result) && result.equalsIgnoreCase (context.getString (R.string.txt_success))) {
                showPdf ();
            }
            else {
                isDownloadingPdf = false;
                Toast.makeText (context, context.getString (R.string.error_could_not_download_pdf), Toast.LENGTH_LONG).show ();
                file.delete ();
            }
        }

        @Override
        protected void onCancelled () {

            isDownloadingPdf = false;
            super.onCancelled ();
            //Loader.hideLoader ();
        }

        @Override
        protected void onCancelled (String s) {

            isDownloadingPdf = false;
            super.onCancelled (s);
            //Loader.hideLoader ();
        }

        private void showPdf () {

            new Handler ().postDelayed (new Runnable () {
                @Override
                public void run () {

                    isDownloadingPdf = false;
                    openPDFFile (context, Uri.fromFile (file));
                }
            }, 1000);
        }
    }

<强> PdfDownloader.java

package com.pdf;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class PdfDownloader {
    private static final int MEGABYTE = 1024 * 1024;

    public static String downloadFile (String fileUrl, File directory) {

        String downloadStatus;
        try {

            URL url = new URL (fileUrl);
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection ();
            urlConnection.connect ();

            InputStream inputStream = urlConnection.getInputStream ();
            FileOutputStream fileOutputStream = new FileOutputStream (directory);
            int totalSize = urlConnection.getContentLength ();

            Log.d ("PDF", "Total size: " + totalSize);
            byte[] buffer = new byte[MEGABYTE];
            int bufferLength = 0;
            while ((bufferLength = inputStream.read (buffer)) > 0) {
                fileOutputStream.write (buffer, 0, bufferLength);
            }
            downloadStatus = "success";
            fileOutputStream.close ();
        }
        catch (FileNotFoundException e) {
            downloadStatus = "FileNotFoundException";
            e.printStackTrace ();
        }
        catch (MalformedURLException e) {
            downloadStatus = "MalformedURLException";
            e.printStackTrace ();
        }
        catch (IOException e) {
            downloadStatus = "IOException";
            e.printStackTrace ();
        }
        Log.d ("PDF", "Download Status: " + downloadStatus);
        return downloadStatus;
    }


    public static void openPDFFile (Context context, Uri path) {

        Intent intent = new Intent (Intent.ACTION_VIEW);
        intent.setDataAndType (path, "application/pdf");
        intent.setFlags (Intent.FLAG_ACTIVITY_CLEAR_TOP);
        try {
            context.startActivity (intent);
        }
        catch (ActivityNotFoundException e) {
            Toast.makeText (context, context.getString (R.string.txt_no_pdf_available), Toast.LENGTH_SHORT).show ();
        }
        Loader.hideLoader ();
    }

    public static File getAppDirectory (Context context) {

        String extStorageDirectory = Environment.getExternalStorageDirectory ().toString ();
        File folder = new File (extStorageDirectory, context.getString (R.string.app_folder_name).trim ());
        if (!folder.exists ()) {
            boolean success = folder.mkdirs();
            Log.d ("Directory", "mkdirs():" + success);
        }
        return folder;
    }

}

Answer 3

您的手机未检测到PDF，因为您使用的网址是String对象而不是PDF对象。从技术上讲，除非您下载PDF，否则不应以PDF格式打开手机。只有当Android操作系统告诉他们有一个有效的PDF文件时，手机上的PDF查看器才会被激活。请查看任何PDF库的源代码以更好地理解这一点 - ＆gt; https://android-arsenal.com/tag/72?sort=created

但是，要解决您的问题，您应该尝试将网址作为网址打开。它将激活手机上的浏览器，进而检测到它需要PDF阅读器并激活相应的阅读器。

像

这样的东西

String url = "https://firebasestorage.googleapis.com/v0/b/realtime-chat-46f4c.appspot.com/o/documents%2Fbf307aa5-79ae-4532-8128-ee394537b357.pdf?alt=media&token=2d0c5329-4717-4adc-9418-6614913e5bfa";


public void openWebPage(String url) {
    Uri webpage = Uri.parse(url);
    Intent intent = new Intent(Intent.ACTION_VIEW, webpage);
    if (intent.resolveActivity(getPackageManager()) != null) {
        startActivity(intent);
    }
}

但是，我想您只想验证文件是否已成功上传。如果手机上有本地副本，则只需打开本地副本，而不是下载另一份副本。如果是这种情况，那么我建议使用文件元数据来实现这一点。类似的东西：

 // Create file metadata including the content type
StorageMetadata metadata = new StorageMetadata.Builder()
        .setCustomMetadata("myPDFfile", "localPDFfileName")
        .build();

// Upload the file and metadata
uploadTask = storageRef.child("pdf/localPDFfileName.pdf").putFile(file, metadata);

在您的成功侦听器上，检索文件元数据。如果已下载并看起来完整，则从本地手机存储打开PDF。如果没有，那么请尝试从我在帖子开头提到的downloadURL下载。这应该涵盖您尝试进行的验证。

如果我没有正确理解你的问题，请详细说明。我会捡起来并相应地修改我的回复。

Answer 4

如果要在应用程序中打开保存的pdf文件，而不是创建在其他应用程序中打开的意图，则可以使用以下库在Xml文件中创建PdfView。 AndroidPdfViewer（此库还提供了放大功能）

之后，如Firebase Document中所述，使用firebase存储中文件位置的已保存路径引用以字节为单位获取文件，并将其添加为您的PdfView。

例如，您的文件路径将类似于：“ / folder1 / yourfile.pdf”

pdfView = (PDFView) findViewById(R.id.pdfView);
mFirebaseStorage=FirebaseStorage.getInstance().getReference();

final long ONE_MEGABYTE = 1024 * 1024;

mFirebaseStorage.child("YourSavedFilePathRef").getBytes(ONE_MEGABYTE).addOnSuccessListener(new OnSuccessListener<byte[]>() {
    @Override
    public void onSuccess(byte[] bytes) {
 pdfView.fromBytes(bytes).load();
    }
}).addOnFailureListener(new OnFailureListener() {
    @Override
    public void onFailure(@NonNull Exception e) {
        Toast.makeText(MainActivity.this,"download unsuccessful",Toast.LENGTH_LONG).show();
    }
});

Answer 5

简单代码：）

<body>


  <h1> Welcome to the Ancient game of Lapis, Papyrus, Scalpellus!</h1>

  <div class="c">
    <button id="lbutton"><b>Lapis<b></button>
    <button id="pbutton"><b>Papyrus<b></button>
    <button id="sbutton"><b>Scalpellus<b></button>
  </div>

  <h2> The results are in...</h2>


</body>

希望它能起作用：）

Answer 6

尝试对您的Firebase数据库文件URL进行编码。它可以和我一起工作

Answer 7

使用Webview查看pdf文件 -

 WebView webview = (WebView) findViewById(R.id.webview);
    webview.getSettings().setJavaScriptEnabled(true);
    String pdf = "https://firebasestorage.googleapis.com/v0/b/realtime-chat-46f4c.appspot.com/o/documents%2Fbf307aa5-79ae-4532-8128-ee394537b357.pdf?alt=media&token=2d0c5329-4717-4adc-9418-6614913e5bfa";
    webview.loadUrl("http://drive.google.com/viewerng/viewer?embedded=true&url=" + pdf);

打开存储在Firebase存储中的pdf文件网址

7 个答案: