Asked by: Giulietta Gilperezasked in category: General Last Updated: 17th May, 2020
What is doFilter () method in Java?
Similarly one may ask, what is servlet filter and how does it work?
Servlet Filter. A filter is an object that is invoked at the preprocessing and postprocessing of a request. It is mainly used to perform filtering tasks such as conversion, logging, compression, encryption and decryption, input validation etc. The servlet filter is pluggable, i.e. its entry is defined in the web.
Furthermore, when destroy () method of filter gets called? destroy. Called by the web container to indicate to a filter that it is being taken out of service. This method is only called once all threads within the filter's doFilter method have exited or after a timeout period has passed.
In this way, what is doFilter called?
For each request, the method doFilter is called once. The statements in doFilter are executed until "chain.doFilter(req, resp)" is reached. " chain.doFilter(req, resp)" causes the execution to be continued in the next filter in chain or in the servlet.
How do you create a filter in Java?
Basically, there are 3 steps to create a filter: - Write a Java class that implements the Filter interface and override filter's life cycle methods. - Specify initialization parameters for the filter (optional). - Specify filter mapping, either to Java servlets or URL patterns.