I think your only valid point is the one about the need to make errorOnUseBeanInvalidClassAttribute be switchable from Jspc main, but we are not bundling jspc scripts anymore, so I didn't feel there is a need for it. Anyway, its value can be set with an ant task.
Otherwise, Jasper behaves the same as before when errorOnUseBeanInvalidClassAttribute is set to false. Well, maybe it take more time to compile, but that's a compile-time vs. runt-time tradeoff that all compilers make. The ideas behind the fix, both in the Jasper and the JSP 2.0 spec, is to allow the Jasper to generate faster code and to catch as much errors as possible at compile time. For the embedded compilations, the comile environment is the same as the runitme (request time) environment, so there is no problem. For Jspc compilations, you'll just need to make sure that they are the same, otherwise you'll need to set errorOnUseBeanInvalidClassAttribute to false there. If you have ideas about how to modify Generator that works better, please submit a patch, and I'll see if it can be incorporated. -Kin-man > Date: Wed, 24 Mar 2004 09:50:43 -0600 > From: Jess Holle <[EMAIL PROTECTED]> > Subject: Tomcat 5.0.20 Issue > To: Tomcat Developers List <[EMAIL PROTECTED]> > X-OriginalArrivalTime: 24 Mar 2004 15:50:43.0599 (UTC) FILETIME=[C3DDB1F0:01C411B7] > > Jess Holle wrote: > > > Works just great in quick testing at least. > > > > I'm still waiting for my precompilation script to return to determine > > whether Jasper still compiles everything it used to (and should have). > > Unfortunately, Tomcat 5.0.20 cannot compile 6 out our 985 JSP pages > (which Tomcat 5.0.19 compiled just fine). > > The issue can be traced directly to a single entry in the change log: > > Add some intellignece to the compiler for generating code for > useBean action. Generate direct instantiation (use new) when > possible, use bean.instantiate when bean name is specified, and for > the case of invalid bean class, either issue a translation time > error (instead of javac error), or generate codes to throw > InstantiationException at runtime, depending on a new compiler > switch, errorOnUseBeanInvalidClassAttribute(defaulted to true) (kinman) > > There are several issues with this change: > > 1. The new logic assumes that the bean can be directly instantiated > /at compile time/ and throws a page compilation error when this is > not the case. > * There are beans that can be directly instantiated at run > time but not at compile time (e.g. upon precompilation). > This was the case in all 6 of our failures. [Examples as to > when this might occur include requirements for databases > being accessible, other servers running, etc, etc, for > successful bean instantiation.] > * The error occurs in such a way that a partial Java source > file is written, so later attempts to recompile the page > (when the runtime environment is duplicated) also fail > unless the partial Java source file is first deleted. > 2. I note the errorOnUseBeanInvalidClassAttribute setting but there > are issues here as well: > * The default value, true, breaks existing code. > * If errorOnUseBeanInvalidClassAttribute is set to false: > o Instantiation of some (e.g. session or application > scope) beans can be time and/or resource consuming. > Besides being an invalid test as to whether a bean can > be directly instantiated, instantiating such beans > during compilation can be costly. [The combined time > for precompiling all pages was longer in 5.0.20 with > this behavior in place than when I removed it.] > o The new behavior will cause beans to be instantiated > via Beans.instantiate() rather than directly > instantiated when compile time direct instantiation > fails. This leads to a performance degradation > whenever a bean has a runtime instantiation dependency. > * As best I can tell, errorOnUseBeanInvalidClassAttribute is > not accessible from / exposed via JspC main -- which I use > from my pre-compilation scripts for various reasons. > > Due to these issues I have reverted this change in Generator to the > 5.0.19 state (leaving the other valuable changes in this class intact). > Once I did so all 985 JSP pages compiled -- including the 6 that had > previously failed. > > I would urge that this change be reverted -- either in this release (or > an immediate 5.0.21 release) or immediately changed in HEAD for the next > release. > > -- > Jess Holle > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
