如何将页面调用的内容保存到jsp / java中的文件中？

Question

In jsp/java how can you call a page that outputs a xml file as a result and save its result (xml type) into a xml file on server. Both files (the file that produces the xml and the file that we want to save/overwrite) live on the same server.

Basically I want to update my test.xml every now and then by calling generate.jsp that outputs a xml type result.

Thank you.

Answer 1

1. Register a filter that adds a wrapper to your response. That is, it returns to the chain a new HttpServletResponse objects, extending the original HttpServletResponse , and returning your custom OutputStream and PrintWriter instead of the original ones.
2. Your OutputStream and PrintWriter calls the original OutputStream and PrintWriter , but also write to a your file (using a new FileOutputStream )

Answer 2

If the request is idempotent, then just use java.net.URL to get an InputStream of the JSP output. Eg

InputStream input = new URL("http://example.com/context/page.jsp").openStream();

If the request is not idempotent, then you need to replace the PrintWriter of the response with a custom implementation which copies the output into some buffer/builder. I've posted a code example here before: Capture generated dynamic content at server side

Once having the output, just write it to disk the usual java.io way, assuming that JSP's are already in XHTML format.

Answer 3

Why don't you use a real template engine like FreeMarker? That would be easier.