Size of the response sent by the server.

[Robin Sharma]

Hi!

How do i calculate the size of the response sent by the server for a request? I am using a servlet filter which just prints the size of the request/response. Now, I can get the size of the request using the request.getContentLength() method. But, how do i get the size of the response?

Thanks.

[Bear Bibeault]

Why do you feel you need it?

[dema rogatkin]

It's quite simple. You need to wrap a response object in your object which plays a role of proxy. You should care only about two methods: getOutputStream and getWriter. Return your own implementation wrapping objects returned by original response for these methods. Your implementation is also a proxy which counts a number of processed bytes. You can use Java proxy capabilities or HttpServletResponseWrapper to simplify your implementation.

[William Brogden]

If, on the other hand, he needs the size to set the response content-length header, this size is needed before anything is written to the response. In that case all output should be to a local buffer - see java.io CharArrayWriter or ByteArrayOutputStream - finish the output, use the size to set the header, write the whole buffer at one go.
Bill