Question

我试图通过调用amazon url在android webview中显示pdf文件。但它只显示白屏。无法加载。

当我使用其他网址时，亚马逊会在网页浏览中显示pdf文件。我也试过这个： http://docs.google.com/gview?embedded=true&url=“+ MYURL

我也尝试过写url：并且效果很好。 http://www.durgasoft.com/Android%20Interview%20Questions.pdf

如果有人有任何建议，请指导我。

以下是我的代码供您参考：

 webView.getSettings().setJavaScriptEnabled(true);
 webView.getSettings().setPluginState(PluginState.ON);
 String url = Common.getPdfFromAmazon("52f3761d290c4.pdf");   
 webView.loadUrl(url);

Android Menifest.xml also give Internet Permission:
**<uses-permission android:name="android.permission.INTERNET" />**

i can also try this "http://docs.google.com/gview?embedded=true&url=" + url ;

Here is my logcat image.

谢谢。

Answer 1

要从亚马逊网络服务中显示PDF，您需要先将PDF下载并存储到您的设备，然后通过您设备上提供的PDF阅读器/查看器应用程序打开它。

1＆GT;＆GT;致电DownloadFileAsync()调用下载流程并传递您的亚马逊网络服务网址。

new DownloadFileAsync().execute(url);

2 - ;＆GT;在AsyncTask中下载PDF过程。

class DownloadFileAsync extends AsyncTask<String, String, String> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(final String... aurl) {

        try {
            String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
            File dir = new File(extStorageDirectory, "pdf");
            if(dir.exists()==false) {
                dir.mkdirs();
            }
            File directory = new File(dir, "original.pdf");
            try {
                if(!directory.exists())
                    directory.createNewFile();
            } catch (IOException e1) {
                e1.printStackTrace();
            }

            URL url = new URL(aurl[0]);
            URLConnection conexion = url.openConnection();
            int lenghtOfFile = conexion.getContentLength();
            conexion.connect();
            conexion.setReadTimeout(10000);
            conexion.setConnectTimeout(15000); // millis

            FileOutputStream f = new FileOutputStream(directory);

            InputStream in = conexion.getInputStream();

            byte[] buffer = new byte[1024];
            int len1 = 0;
            while ((len1 = in.read(buffer)) > 0) {
                f.write(buffer, 0, len1);
            }
            f.flush();
            f.close();
            in.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;

    }

    @Override
    protected void onPostExecute(String unused) {
    }
}

3＆GT;＆GT;下载pdf后致电showPdfFromSdCard()。

public static  void showPdfFromSdCard(Context ctx) {
    File file = new File(Environment.getExternalStorageDirectory() + "/pdf/original.pdf");
    PackageManager packageManager = ctx.getPackageManager();
    Intent testIntent = new Intent(Intent.ACTION_VIEW);
    testIntent.setType("application/pdf");
    List list = packageManager.queryIntentActivities(testIntent, PackageManager.MATCH_DEFAULT_ONLY);
    Intent intent = new Intent();
    intent.setAction(Intent.ACTION_VIEW);
    Uri uri = Uri.fromFile(file);
    intent.setDataAndType(uri, "application/pdf");
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    try {
        ctx.startActivity(intent);
    } catch (ActivityNotFoundException e) {
        Toast.makeText(ctx,
                "No Application Available to View PDF",
                Toast.LENGTH_SHORT).show();
    }
}

4＆GT;＆GT;在deletePdfFromSdcard()

中致电onResume()

public static void deletePdfFromSdcard(){
    File file = new    File(Environment.getExternalStorageDirectory()+"/pdf/original.pdf");
    boolean pdfDelete = file.delete();
}

Answer 2

您需要在应用程序标记之外的清单文件中添加Internet权限。

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

Answer 3

经过2天的研究没有找到解决方案，所以我尝试首先从亚马逊网络服务下载PDF文件并存储到SD卡中然后打开PDF文件在这里我的代码

注意： - 此解决方案仅适用于在Web视图中显示PDF来自Amazon Web Service。从其他网络服务尝试此代码： -

   WebView webview=(WebView)findviewbyid(R.id.Webview);
   String MyURL= "this is your PDF URL";
   String url = "http://docs.google.com/gview?embedded=true&url=" + MyURL;
   Log.i(TAG, "Opening PDF: " + url);
   webView.getSettings().setJavaScriptEnabled(true); 
   webView.loadUrl(url);

----------------------------------------------- -----------------------------------------------＆GT;对于Amazon Web Service请尝试此代码

   1>> Download PDF from Amazon WebService

public static void DownloadFile(String fileURL, File directory) {
    try {

        FileOutputStream f = new FileOutputStream(directory);
        URL u = new URL(fileURL);
        HttpURLConnection c = (HttpURLConnection) u.openConnection();
        c.setRequestMethod("GET");
        c.connect();

        InputStream in = c.getInputStream();

        byte[] buffer = new byte[1024];
        int len1 = 0;
        while ((len1 = in.read(buffer)) > 0) {
            f.write(buffer, 0, len1);
        }
        f.close();
    } catch (Exception e) {
        e.printStackTrace();
    }

}

2 - ;＆GT;从SD卡显示PDF

public static  void showPdfFromSdCard(Context ctx)
{
    File file = new File(Environment.getExternalStorageDirectory()+"/pdf/MyPdf.pdf");
    PackageManager packageManager = ctx.getPackageManager();
    Intent testIntent = new Intent(Intent.ACTION_VIEW);
    testIntent.setType("application/pdf");
    List list = packageManager.queryIntentActivities(testIntent, PackageManager.MATCH_DEFAULT_ONLY);
    Intent intent = new Intent();
    intent.setAction(Intent.ACTION_VIEW);
    Uri uri = Uri.fromFile(file);
    intent.setDataAndType(uri, "application/pdf");
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    try {
         ctx.startActivity(intent);
    } 
    catch (ActivityNotFoundException e) {
        Toast.makeText(ctx, 
            "No Application Available to View PDF", 
            Toast.LENGTH_SHORT).show();
    }

下载PDF showPdfFromSdCard方法后调用。

显示PDF后，您从SD卡中删除PDF文件这里是从SD卡中删除PDF的代码

public static void deletePdfFromSdcard(){
    File file = new    File(Environment.getExternalStorageDirectory()+"/pdf/MyPdf.pdf");
    boolean pdfDelete = file.delete();


}

Answer 4

I will do some modification in @Monika Moon code,

if you don't want to save the File in the device, the process explained above is too long as well as required FileProvider to open the pdf in external pdf viewer.

so for the better solution please follow the below steps.
Step 1:

please add this library to your gradle file. AndroidPdfViewer

Step 2:

add this in your XML view->

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

Step 3:

PDFView pdfView;

InputStream inputStream;

pdfView=findViewById(R.id.pdfView);

        class DownloadFileAsync extends AsyncTask<String, String, String> {

        @Override
        protected void onPreExecute() {
            if (mProgressDialog!=null)
            {
                Utils.cancelProgressDialog(mProgressDialog);
            }
            mProgressDialog = Utils.showProgressDialog(DocumentViewActivity.this);

            super.onPreExecute();
        }

        @Override
        protected String doInBackground(final String... aurl) {

            try {

                URL url = new URL(aurl[0]);
                URLConnection conexion = url.openConnection();
                conexion.connect();
                conexion.setReadTimeout(20000);
                conexion.setConnectTimeout(25000); // millis


                 inputStream = conexion.getInputStream();

            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;

        }

        @Override
        protected void onPostExecute(String unused) {


            if (inputStream != null) {
                pdfView.fromStream(inputStream)
                        .defaultPage(0)
                        .password(null)
                        .scrollHandle(null)
                        .enableAntialiasing(true)
                        .scrollHandle(new DefaultScrollHandle(DocumentViewActivity.this))
                        .spacing(0)
                        .onLoad(new OnLoadCompleteListener() {
                            @Override
                            public void loadComplete(int nbPages) {
                                Utils.cancelProgressDialog(mProgressDialog);

                            }
                        })
                        .load();
            }else {
                Utils.cancelProgressDialog(mProgressDialog);
            }
        }
    }
@Override
protected void onDestroy() {
    if (inputStream!=null)
    {
        try {
            inputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    super.onDestroy();
}

Final Step : call new DownloadFileAsync().execute(url);

Android Web View无法从Amazon Service Url查看PDF

4 个答案: