How to load attachment file from JSP
I want to know how to download any file from JSP page based on posting content as attachment from mail server.
I want to create a link in a JSP page, and by clicking on that link, the user can download the file from the mail server. The link must be for the attachment type . How can I do this in JSP?
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Don't use JSP for this, this is a recipe for a problem when using it to stream binary files as all spaces outside the tags <% %>
will be printed and on the response, which will only corrupt the binary content. All you have to do is just place the HTML link, for example <a href="fileservlet/file.ext">
in a JSP, and use the servlet class to do the whole processing and streaming task. To set the response header, just use HttpServletResponse#setHeader()
.
response.setHeader("Content-Disposition", "attachment;filename=name.ext");
Here you can find a basic example of a servlet that does just this: FileServlet
.
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I suggest you break this question down a bit.
Do you know how to access attachments from a regular Java program? How to interact with the mail server, etc.? If you know this, it should be a simple exercise to provide downloadable format nesting via jsp. Although, I would highly recommend that you make a regular servlet, since you probably wouldn't use the additional technique around jsp very much.
Just make sure you set the content type to match what you downloaded:
In jsp: <%@page contentType="image/png" %>
In a servlet: response.setContentType("image/png");
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URL url = new URL("http://localhost:8080/Works/images/abt.jpg");
//for image
response.setContentType("image/jpeg");
response.setHeader("Content-Disposition", "attachment; filename=icon" + ".jpg");
//for pdf
//response.setContentType("application/pdf");
//response.setHeader("Content-Disposition", "attachment; filename=report" + ".pdf");
//for excel sheet
// URL url = new URL("http://localhost:8080/Works/images/address.xls");
//response.setContentType("application/vnd.ms-excel");
//response.setHeader("Content-disposition", "attachment;filename=myExcel.xls");
URLConnection connection = url.openConnection();
InputStream stream = connection.getInputStream();
BufferedOutputStream outs = new BufferedOutputStream(response.getOutputStream());
int len;
byte[] buf = new byte[1024];
while ((len = stream.read(buf)) > 0) {
outs.write(buf, 0, len);
}
outs.close();
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