使用java servlet在瀏覽器中顯示PDF

Question

我在我的應用程序中有pdf文件。我需要在瀏覽器中顯示PDF。我正在讀取文件作爲fileInputStream，我需要在瀏覽器中顯示PDF在我的應用程序。但我沒有pdf路徑，我有文件流。

請給我一些建議和例子

---

我已經使用AJAX來顯示PDF，我現在用的是call_method（）JavaScript的Ajax請求方法調用showPdf行動，在showpdf行動只是轉換pdf文件作爲ByteArrayOutputStream並將結果寫入輸出流。但它顯示了以下提到的結果。

結果在JSP：

％PDF-1.4％1個endstream endobj 4 0 OBJ < >>> /多媒體[0 0 595 842] >> endobj 1 0 OBJ <> endobj 3 0 OBJ <> endobj 5 0 OBJ <> endobj 6 0 OBJ <> endobj外部參照0 7 0000000000 65535˚F0000000389 00000ñ0000000015 00000ñ0000000477 00000ñ0000000232 00000ñ0000000540 00000ñ0000000585 00000ñ拖車< < 142354f5ebefd65d6aacd33a7cb2b4ab>] /信息6 0 R /大小7 >> startxref 707 %% EOF

P租約給一些建議。

的Javascript AJAX：

call_method(); <br/> 
function call_method(){ 

    Ext.Ajax.request({ 
      waitMsg: 'Saving changes...', 
      url:'test.action?method=showPdf', 
      params : { },  
      failure:function(response,options){ 

      }, 
      success:function(response,options){ 
       $("#pdf_content").show();    
       $("#pdf_content").html(response.responseText); 
       $("#pdf_content").show('slow'); 
      } 
    }); 
} 

Java方法：

public String showPdf() throws IOException { 

    getResponse().setContentType("application/pdf"); 

    getResponse().setHeader("Content-disposition","inline; filename=automatic_start.pdf"); 


    ByteArrayOutputStream baos = getByteArrayOutputStream(); 

    getResponse().setContentLength(baos.size()); 

    ServletOutputStream sos; 

    sos = getResponse().getOutputStream(); 

    baos.writeTo(sos); 

    sos.flush(); 

    return null; 
} 


private ByteArrayOutputStream getByteArrayOutputStream() throws IOException { 

    String filePath = "/homefolder/"; 

    String folderPath=filePath+"1122/automatic_start.pdf"; 

    File file = new File(folderPath); 

    FileInputStream fis = new FileInputStream(file); 



    ByteArrayOutputStream bos = new ByteArrayOutputStream(); 
    byte[] buf = new byte[256]; 
    try { 
      for (int readNum; (readNum = fis.read(buf)) != -1;) { 
       bos.write(buf, 0, readNum); //no doubt here is 0 
       //Writes len bytes from the specified byte array starting at offset off to this byte array output stream. 
       System.out.println("read " + readNum + " bytes,"); 
      } 

     } catch (IOException ex) { 
      ex.printStackTrace(); 
     } 


    return bos; 
} 

Answer 1

在你的servlet，設置MIME類型正確的一個PDF：application/pdf

見http://www.iana.org/assignments/media-types/

Answer 2

你必須寫InputStream您的回覆OutputStream如下：

• 你Content-Disposition將不得不inline。
• 您的Content-Type必須是application/pdf。
• 您的Content-Length將是InputStream中總數據的長度（以字節爲單位）。

設置後，將輸入流數據寫入輸出響應流。

東西的這種效果：

/* (non-Javadoc) 
* @see org.bfs.bayweb.util.renderer.ServletViewRenderer#render(javax.servlet.ServletRequest, javax.servlet.ServletResponse) 
*/ 
public void render(ServletRequest request, ServletResponse response) throws IOException { 
    // TODO Auto-generated method stub 
    try { 
     ByteArrayOutputStream baos = new ByteArrayOutputStream(); 
     byte[] buffer = new byte[DEFAULT_BUFFER_SIZE]; 
     int inputStreamLength = 0; 
     int length = 0; 
     while ((length = getInputStream().read(buffer)) > 0) { 
      inputStreamLength += length; 
      baos.write(buffer, 0, length); 
     } 

     if (inputStreamLength > getContentLength()) { 
      setContentLength(inputStreamLength); 
     } 

     if (response instanceof HttpServletResponse) { 
      HttpServletResponse httpResponse = (HttpServletResponse) response; 
      httpResponse.reset(); 
      httpResponse.setHeader("Content-Type", getContentType()); 
      httpResponse.setHeader("Content-Length", String.valueOf(getContentLength())); 
      httpResponse.setHeader("Content-Disposition", "\"" + getContentDisposition() + "\"" + ((getFileName() != null && !getFileName().isEmpty()) ? "; filename=\"" + getFileName() + "\"": "")); 
     } 

     response.getOutputStream().write(baos.toByteArray(), 0, (int)getContentLength()); 

     //finally 
     response.getOutputStream().flush(); 

     //clear 
     baos = null; 
    } finally { 
     // TODO Auto-generated catch block 
     close(response.getOutputStream()); 
     close(getInputStream()); 
    } 
} 

private void close(Closeable resource) throws IOException { 
    if (resource != null) { 
     resource.close(); 
    } 
}