extension

[Optional][Default: html]

It specifies how to process the response generated by other servlets.

If html or zhtml, XHTML is assumed to be the default namespace. If xul or zul, XUL is assumed to be the default namespace.

charset

[Optional][Default: UTF-8]

It specifies the default charset for the output of this filter.

If an empty string is specified as follows, the container's default is used. In other words, the setCharacterEncoding method of javax.servlet.ServletResponse is not called.

<param-value></param-value>

compress

[Optional][Default: true]

It specifies whether to compress the output if the browser supports the compression (Accept-Encoding) and this filter is not included by other Servlets.