IllegalStateException: PWC3990: getWriter() has already been called for this response

Question

java.lang.IllegalStateException: PWC3990: getWriter() has already been called for this response

How to solve this error? I run a simple servlet code to display the bar graph.

Aftershock

unless you show us some relevant code, how do you think we can guess how to fix your problem? – Amalburga

Answer 1

You cannot call both getOutputStream() and getWriter() on the same response. Keep in mind that JSP implicitly uses getWriter().

Anastasius

but how to use getoutputstream in jfreecharts at the same time how to disply the string using getwriter??? – Aftershock

In theory, you need to write the string to getOutputStream() instead. You can use OutputStreamWriter for this. Since I don't use JFreeChart, I only don't know if it's allowed by JFreeChart to mix the response like that. – Anastasius

Answer 2

Also make sure that the request is not being redirected to current servlet from some place else. If it is, then there is a high probability that one of getOutputStream() or getWriter() has already been called on it.

Sorrell