使用android intent从服务器打开pdf文件

时间：2013-12-16 04:54:05

标签： java android pdf android-intent

我正在网上搜索如何在android上使用默认的pdf viewer从服务器打开pdf文件。我找到的是首先下载文件然后在意图中启动它或使用谷歌文档加载它。我不想做所有这些。我只是想从手机的默认pdf查看器直接从服务器加载它。我已经尝试打开视频网址并且有效。但是故意打开pdf网址是行不通的。以下是我的代码; 

private void openFilePDF(){
        try{
            Toast.makeText(getBaseContext(), "Opening PDF... ", Toast.LENGTH_SHORT).show();
            Intent inte = new Intent(Intent.ACTION_VIEW);
            inte.setDataAndType(
                    Uri.parse("http://122.248.233.68/pvfiles/Guide-2.pdf"),
                    "application/pdf");

            startActivity(inte);
            }catch(ActivityNotFoundException e){
                Log.e("Viewer not installed on your device.", e.getMessage());
            }
    }

我有什么方法可以加载pdf网址吗？

4 个答案:

答案 0 :(得分：16)

首先创建一个下载程序类

public class Downloader {

    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.setDoOutput(true);
            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();
        }

    }
}

之后创建一个从互联网下载PDF文件的活动

public class MainActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        String extStorageDirectory = Environment.getExternalStorageDirectory()
        .toString();
        File folder = new File(extStorageDirectory, "pdf");
        folder.mkdir();
        File file = new File(folder, "Read.pdf");
        try {
            file.createNewFile();
        } catch (IOException e1) {
            e1.printStackTrace();
        }
        Downloader.DownloadFile("http://122.248.233.68/pvfiles/Guide-2.pdf", file);

        showPdf();
    }
    public void showPdf()
        {
            File file = new File(Environment.getExternalStorageDirectory()+"/Mypdf/Read.pdf");
            PackageManager packageManager = 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");
            startActivity(intent);
        }
}

最后终于在AndroidManifest.xml

中声明了持久性 
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

答案 1 :(得分：8)

您可以使用WebView尝试此操作：

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);
  }
}

答案 2 :(得分：0)

据我所知，无法在设备上直接打开您的PDF文件。由于Android设备的浏览器属性，当我们尝试打开PDF文件时，它会下载到设备。打开PDF文件只有两种方法。

  1. 您可以使用PDF应用程序Intent选择应用程序来打开文件。

  2. 您可以使用Google文档网址附加您的服务器网址，并可以在浏览器中打开，以便您的PDF文件将在浏览器中打开

答案 3 :(得分：0)

从服务器下载Pdf文件，下载完成后，您可以使用挂起的意图打开此pdf文件。

在开始编写代码之前，请先查看下图，该图显示了我的附加代码的功能。

enter image description here enter image description here enter image description here enter image description here

步骤-1：您需要在异步任务上创建以从服务器url下载文件。 参见下面的代码：

public class DownloadFileFromURL extends AsyncTask<String, Integer, String> {

private NotificationManager mNotifyManager;
private NotificationCompat.Builder build;
private File fileurl;
int id = 123;
OutputStream output;
private Context context;
private String selectedDate;
private String ts = "";

public DownloadFileFromURL(Context context, String selectedDate) {
    this.context = context;
    this.selectedDate = selectedDate;

}

protected void onPreExecute() {
    super.onPreExecute();

    mNotifyManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    build = new NotificationCompat.Builder(context);
    build.setContentTitle("Download")
            .setContentText("Download in progress")
            .setChannelId(id + "")
            .setAutoCancel(false)
            .setDefaults(0)
            .setSmallIcon(R.drawable.ic_menu_download);

    // Since android Oreo notification channel is needed.
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        NotificationChannel channel = new NotificationChannel(id + "",
                "Social Media Downloader",
                NotificationManager.IMPORTANCE_HIGH);
        channel.setDescription("no sound");
        channel.setSound(null, null);
        channel.enableLights(false);
        channel.setLightColor(Color.BLUE);
        channel.enableVibration(false);
        mNotifyManager.createNotificationChannel(channel);

    }
    build.setProgress(100, 0, false);
    mNotifyManager.notify(id, build.build());
    String msg = "Download started";
    //CustomToast.showToast(context,msg);
}

@Override
protected String doInBackground(String... f_url) {
    int count;
    ts = selectedDate.split("T")[0];
    try {
        URL url = new URL(f_url[0]);
        URLConnection conection = url.openConnection();
        conection.connect();
        int lenghtOfFile = conection.getContentLength();

        InputStream input = new BufferedInputStream(url.openStream(),
                8192);
        // Output stream
        output = new FileOutputStream(Environment
                .getExternalStorageDirectory().toString()
                + Const.DownloadPath + ts + ".pdf");
        fileurl = new File(Environment.getExternalStorageDirectory()
                + Const.DownloadPath + ts + ".pdf");
        byte[] data = new byte[1024];

        long total = 0;

        while ((count = input.read(data)) != -1) {
            total += count;
            int cur = (int) ((total * 100) / lenghtOfFile);

            publishProgress(Math.min(cur, 100));
            if (Math.min(cur, 100) > 98) {
                try {
                    Thread.sleep(500);
                } catch (InterruptedException e) {
                    Log.d("Failure", "sleeping failure");
                }
            }
            Log.i("currentProgress", "currentProgress: " + Math.min(cur, 100) + "\n " + cur);

            output.write(data, 0, count);
        }

        output.flush();

        output.close();
        input.close();

    } catch (Exception e) {
        Log.e("Error: ", e.getMessage());
    }

    return null;
}

protected void onProgressUpdate(Integer... progress) {
    build.setProgress(100, progress[0], false);
    mNotifyManager.notify(id, build.build());
    super.onProgressUpdate(progress);
}

@Override
protected void onPostExecute(String file_url) {
    build.setContentText("Download complete");
    Intent intent = new Intent(context, DownloadBroadcastReceiver.class);
    Uri finalurl = FileProvider.getUriForFile(context, BuildConfig.APPLICATION_ID + ".provider", fileurl);
    intent.putExtra("currenturl", finalurl.toString());
    intent.putExtra("selectedfilename", ts);
    context.sendBroadcast(intent);
    build.setProgress(0, 0, false);
    mNotifyManager.notify(id, build.build());
} }

在上面的代码中，我使用 DownloadFileFromURL.java 类文件创建asynctask。在此类文件中的此处，编写代码以在android O及更早版本中显示通知。

步骤-2：：下载完成后，我会将其发送到广播接收器。借助广播接收器，您可以轻松地以待定意向打开PDF文件。您可以看到异步任务的广播接收器代码 onPostExecute 方法。

请参见下面的代码，以处理广播接收器中的未决意图。

public class DownloadBroadcastReceiver extends BroadcastReceiver {
private NotificationManager mNotifyManager;
private NotificationCompat.Builder build;
private int rId=123;
private String localuri="";
private String selectedfilename="";

@Override
public void onReceive(Context context, Intent intent) {
    localuri=intent.getStringExtra("currenturl");
    selectedfilename=intent.getStringExtra("selectedfilename");
    startNotification(context,intent);
}

private void startNotification(Context context, Intent intent) {
    Log.e("fat", "startNotification: "+localuri );

    File fileurl = new File(Environment.getExternalStorageDirectory()
            + Const.DownloadPath + selectedfilename+".pdf");
    Uri finalurl = FileProvider.getUriForFile(context, BuildConfig.APPLICATION_ID+".provider", fileurl);
    Intent downloadintent = new Intent(Intent.ACTION_VIEW);
    downloadintent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_ACTIVITY_CLEAR_TOP);
    downloadintent.setDataAndType(finalurl, "application/pdf");
    grantAllUriPermissions(context, downloadintent, finalurl);
    PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, downloadintent,
            PendingIntent.FLAG_UPDATE_CURRENT);

    mNotifyManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    build = new NotificationCompat.Builder(context);
    build.setContentTitle("Download Completed")
            .setContentText("Open Downloaded FIle")
            .setChannelId(rId+"")
            .setAutoCancel(true)
            .setContentIntent(pendingIntent)
            .setStyle(new NotificationCompat.DecoratedCustomViewStyle())
            .setSmallIcon(R.drawable.ic_menu_download);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        NotificationChannel channel = new NotificationChannel(rId+"" ,
                "Call Reminder",
                NotificationManager.IMPORTANCE_HIGH);
        channel.setDescription("With sound");
        channel.setSound(null,null);
        channel.enableLights(false);
        channel.setLightColor(Color.BLUE);
        channel.enableVibration(true);
        mNotifyManager.createNotificationChannel(channel);

    }


    mNotifyManager.notify(rId, build.build());

}

private void grantAllUriPermissions(Context context, Intent downloadintent, Uri finalurl) {
    List<ResolveInfo> resInfoList = context.getPackageManager().queryIntentActivities(downloadintent, PackageManager.MATCH_DEFAULT_ONLY);
    for (ResolveInfo resolveInfo : resInfoList) {
        String packageName = resolveInfo.activityInfo.packageName;
        context.grantUriPermission(packageName, finalurl, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
    }
} }

在上面的代码中，您看到我在通知压缩构建器中添加了挂起的意图。

注意：：当您添加待处理的意图时，您必须使用下面已经添加的代码分配访问权限。

 downloadintent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_ACTIVITY_CLEAR_TOP);
 grantAllUriPermissions(context, downloadintent, finalurl);

此处创建了GrantAllpermission方法，该方法在所有设备中均受支持。

 private void grantAllUriPermissions(Context context, Intent downloadintent, Uri finalurl) {
    List<ResolveInfo> resInfoList = context.getPackageManager().queryIntentActivities(downloadintent, PackageManager.MATCH_DEFAULT_ONLY);
    for (ResolveInfo resolveInfo : resInfoList) {
        String packageName = resolveInfo.activityInfo.packageName;
        context.grantUriPermission(packageName, finalurl, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
    }
}

步骤-3：使用以下代码将您的Broadcast接收器添加到android Manifest文件中。

 <receiver android:name=".services.DownloadBroadcastReceiver">
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED" />
        </intent-filter>
    </receiver>

步骤-4：还要在Android清单文件中添加文件提供程序。借助文件提供商，您可以从设备存储中打开文件。

  <provider
        android:name="androidx.core.content.FileProvider"
        android:authorities="${applicationId}.provider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_provider_path" />
    </provider>

注意：如果您在Andorid 10（O）设备中遇到问题，而不是在Android清单文件的应用程序中添加以下代码。

android:requestLegacyExternalStorage="true"

借助 requestLegacyExternalStorage ，您可以轻松获取已下载文件的列表。

步骤-5：现在，“最后一步”是在您的点击事件中调用您的异步类文件。在这里，我在pdf图片点击上写代码。要调用异步任务，请使用以下代码。

 new DownloadFileFromURL(fContext,selectedDate).execute(currentResponse.getData());

您可以从下面的链接下载上述代码的整个文件：

DownloadFileFromURL.java class file

DownloadBroadcastReceiver.java class file

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