org.hd.d.pg2k.webSvr.util
Class XMLCompressionFilter

java.lang.Object
  org.hd.d.pg2k.webSvr.util.XMLCompressionFilter

All Implemented Interfaces:

javax.servlet.Filter

public final class XMLCompressionFilter
extends java.lang.Object
implements javax.servlet.Filter

Compresses XML by removing redundant whitespace (etc). Should quickly reduce the size of many XML documents on the fly without changing their semantics.

This will allow document streaming (ie incremental processing) and will support flush() to allow the push of partial documents, although this may not be able to push partial XML atoms (eg partial elements and entities).

To avoid upsetting some older consumers of XML, such as old mobile phones and PDAs, this may avoid some transformations such as <x></x> to <x/>.

To avoid upsetting older HTML consumers of XHTML this may avoid some transformations such as <br /> to <br/>.

logger

private final WebUtils.ServletLoggerWithFallback logger

Our logger which falls back to System.out if servlet log not available; never null.

config

private javax.servlet.FilterConfig config

The filter configuration object we are associated with. If this value is null, this filter instance is not currently configured.

XMLCompressionFilter

public XMLCompressionFilter()

getFilterConfig

public javax.servlet.FilterConfig getFilterConfig()

setFilterConfig

public void setFilterConfig(javax.servlet.FilterConfig c)

init

public void init(javax.servlet.FilterConfig filterConfig)

Place this filter into service.

Specified by:

init in interface javax.servlet.Filter

Parameters:

filterConfig - filter configuration object; null to unset

destroy

public void destroy()

Take this filter out of service.

Specified by:

destroy in interface javax.servlet.Filter

doFilter

public void doFilter(javax.servlet.ServletRequest request,
                     javax.servlet.ServletResponse response,
                     javax.servlet.FilterChain chain)
              throws java.io.IOException,
                     javax.servlet.ServletException

Compacts the (XML) reponse text when possible.

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

java.io.IOException

javax.servlet.ServletException