在android中执行PDF阅读器时出现错误

Question

我是一个新的android，我正在尝试从服务器读取pdf。我发现不同的方式，并尝试了其中的大部分。我尝试使用webview，使用谷歌文档，但没有适合我。我不喜欢使用另一个第三方或插件。

我发现这个代码工作完美，但它从assets文件夹中读取。

protected void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_books_view); 
CopyReadAssets(); 
} 

    private void CopyReadAssets() 
    { 

     AssetManager assetManager = getAssets(); 

     InputStream in = null; 
     OutputStream out = null; 
     File file = new File(getFilesDir(), "test.pdf"); 
     try 
     { 
      in = assetManager.open("test.pdf"); 
      out = openFileOutput(file.getName(), Context.MODE_WORLD_READABLE); 

      copyFile(in, out); 
      in.close(); 
      in = null; 
      out.flush(); 
      out.close(); 
      out = null; 
     } catch (Exception e) 
     { 
      Log.e("tag", e.getMessage()); 
     } 

     Intent intent = new Intent(Intent.ACTION_VIEW); 
     intent.setDataAndType(
       Uri.parse("file://" + getFilesDir() + "/test.pdf"), 
       "application/pdf"); 

     startActivity(intent); 
    } 


    private void copyFile(InputStream in, OutputStream out) throws IOException 
    { 
     byte[] buffer = new byte[1024]; 
     int read; 
     while ((read = in.read(buffer)) != -1) 
     { 
      out.write(buffer, 0, read); 
     } 
    } 

我试着将它修改为：

public class TestActivity extends Activity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_test); 
     //Call an AsycTask so you don't lock the main UI thread 
     new RequestTask().execute(); 

    }//end onCreate 

    private class RequestTask extends AsyncTask<String, String, String> 
    { 
     //Background task 
     protected String doInBackground(String... uri) 
     { 
      //Stuff you do in background goes here 
      HttpClient httpclient = new DefaultHttpClient(); 
      HttpResponse response; 
      String responseString = null; 
      //------- 
      String fileName="test"; 
      String fileExtension=".pdf"; 
      try 
      { 
      URL url = new URL("my url"); 
      HttpURLConnection c = (HttpURLConnection) url.openConnection(); 
      c.setRequestMethod("GET"); 
      c.setDoOutput(true); 
      c.connect(); 
      String PATH = Environment.getExternalStorageDirectory() + "/mydownload/"; 
      File file = new File(PATH); 
      file.mkdirs(); 
      File outputFile = new File(file, fileName+fileExtension); 
      FileOutputStream fos = new FileOutputStream(outputFile); 
      InputStream is = c.getInputStream(); 
      byte[] buffer = new byte[1024]; 
      int len1 = 0; 
      while ((len1 = is.read(buffer)) != -1) { 
       fos.write(buffer, 0, len1); 
      } 
      responseString = fos.toString(); 
      fos.flush(); 
      fos.close(); 
      is.close(); 
      } 
      catch (ClientProtocolException e) 
      { 
       //TODO Handle problems.. 
      } 
      catch (IOException e) 
      { 
       //TODO Handle problems.. 
      } 

      return responseString; 
     } 
     @Override 
     protected void onPostExecute(String result) 
     { 
      super.onPostExecute(result); 
      //Do anything with response.. 
      //Stuff you do after the asych task is done 

      Intent intent = new Intent(Intent.ACTION_VIEW); 
      intent.setDataAndType(
        Uri.parse(result), 
        "application/pdf"); 

      startActivity(intent); 
     } 
    } //end RequestTask class 

，但它给了我举杯消息： （（不支持的文件类型））

有人可以帮我请，我花了几乎整整一天的时间试图找出问题。

Answer 1

我更改使用整体更简单的方法这个代码

 //setContentView(R.layout.activity_main); 
     WebView webView=new WebView(GeneralHealthEducationArBooksViewActivity.this); 
     webView.getSettings().setJavaScriptEnabled(true); 
     webView.getSettings().setPluginState(PluginState.ON); 

     //---you need this to prevent the webview from 
     // launching another browser when a url 
     // redirection occurs--- 
     webView.setWebViewClient(new Callback()); 

     String pdfURL = "your link"; 
     webView.loadUrl(
"http://docs.google.com/gview?embedded=true&url=" + pdfURL); 

     setContentView(webView); 

xml文件

<?xml version="1.0" encoding="utf-8"?> 
<WebView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/webview" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" > 


</WebView> 

最后，pdf正在显示:)

Answer 2

您必须使用HttpClient执行您的pdf文件的GET请求。这是一个例子返回一个字符串缓冲区，你必须重新创建你的PDF远程文件读取

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

     @Override 
     protected String doInBackground(String... uri) { 
      HttpClient httpclient = new DefaultHttpClient(); 
      HttpResponse response; 
      String responseString = null; 
      try { 
       response = httpclient.execute(new HttpGet(uri[0])); 
       StatusLine statusLine = response.getStatusLine(); 
       if(statusLine.getStatusCode() == HttpStatus.SC_OK){ 
        ByteArrayOutputStream out = new ByteArrayOutputStream(); 
        response.getEntity().writeTo(out); 
        out.close(); 
        responseString = out.toString(); 
       } else{ 
        //Closes the connection. 
        response.getEntity().getContent().close(); 
        throw new IOException(statusLine.getReasonPhrase()); 
       } 
      } catch (ClientProtocolException e) { 
       //TODO Handle problems.. 
      } catch (IOException e) { 
       //TODO Handle problems.. 
      } 
      return responseString; 
     } 

     @Override 
     protected void onPostExecute(String result) { 
      super.onPostExecute(result); 
      //Do anything with response.. 
     } 
    } 

经过超过您可以拨打

new RequestTask().execute(url);