Jsp Configuration

Jsp 2.1

init param	Description	Default	webdefault.xml
development	If `development=true`, recompilation checks are made on each request. See also `modificationTestInterval`	TRUE	-
fork	Should Ant fork its java compiles of JSP pages.	TRUE	FALSE
keepGenerated	Do you want to keep the generated Java files around?	FALSE	-
saveByteCode	If class files are generated as byte arrays, should they be saved to disk at the end of compilations?	FALSE	-
trimSpaces	Should white spaces between directives or actions be trimmed?	FALSE	-
isPoolingEnabled	Determines whether tag handler pooling is enabled	TRUE	-
mappedFile	Support for mapped Files. Generates a servlet that has a print statement per line of the jsp file.	TRUE	-
sendErrorToClient	If false, stack traces etc are sent to std error instead of the clients browser	FALSE	-
classDebugInfo	Include debugging info in class file	TRUE	-
checkInterval	Interval in seconds between background recompile checks. Only relevant if `development=false`	0	-
isSmapSuppressed	Generation of SMAP info for JSR45 debugging	FALSE	-
isSmapDumped	Dump SMAP JSR45 info to a file	FALSE	-
genStringAsCharArray	Option for generating Strings.	FALSE	-
genStringAsByteArray	Option for generating Strings	TRUE	-
defaultBufferNone		FALSE	-
errorOnUseBeanInvalidClassAttribute		FALSE	-
scratchDir	Directory where servlets are generated. Set by Jetty according to the work dir settings for the webapp.	-	-
compiler	Determined at runtime. For Jetty is the eclipse jdt compiler.
compilerTargetVM	Target vm to compile for.	1.5	-
compilerSourceVM	Sets source compliance level for the jdt compiler.	1.5	-
javaEncoding	Pass through the encoding to use for the compilation	UTF8	-
modificationTestInterval	If `development=true`, interval between recompilation checks, triggered by a request	0	-
xpoweredBy	Generate an X-Powered-By response header	FALSE	FALSE
usePrecompiled/use-precompiled		FALSE	-
isValidationEnabled/validating/enableTldValidation
reload-interval	If `reload-interval=0`, then no runtime checking of jsps, otherwise sets the checking interval for both `development=true` and `development=false`

Much confusion generally ensues about the development, checkInterval and modificationTestInterval parameters and jsp runtime recompilation. Here is a factoring out of the various options:

Check the jsp files for possible recompilation on every request:
Only check approximately every N seconds, where a request will trigger the time-lapse calculation. This example checks every 60 seconds:
Do no checking whatsoever, but still compile the jsp on the very first hit. (Note: this "reload-interval" parameter is a short hand for a "development=false" and "checkInterval=0" combination):
Don't do any request-time checking, but instead start a background thread to do checks every N seconds (in the example below, every 60 sec):