I was able to verify that you are correct the JVM treats those classes as different which is why I was getting NoSuchMethodError. After experimenting some more this method seems to be the wrong approach. Do you know of any better approaches on how to add runtime dependencies to a webapp?
On Fri, May 3, 2013 at 9:45 AM, Bryan Baugher <bjb...@gmail.com> wrote: > Sorry I tried to leave on what I thought were unnecessary details. > > You are correct my constructor has arguments. One of the arguments comes > from another dependency jar that exists in both the webapp and tomcat/lib > so I think your guess (c) could be right. I guess the solution would be to > move the dependency out of the webapp and into tomcat/lib. > > > On Fri, May 3, 2013 at 9:16 AM, Konstantin Kolinko <knst.koli...@gmail.com > > wrote: > >> 2013/5/3 Bryan Baugher <bjb...@gmail.com>: >> > Hi, >> > >> > I am running Tomcat 7.0.28 on RHEL 6.2 with a single web app. The web >> app >> > in question uses reflection to load some implementations of our classes >> > (kind of like a service loader) knowing the class name. I am trying to >> add >> > additional implementations by dropping them in the tomcat's lib >> directory >> > but I keep seeing NoSuchMethodError for the constructor to the class. >> > >> > I know the constructor is there because if I move the jar into the web >> > app's lib directory (webapp/[WEB_APP]/WEB_INF/lib) everything works. >> > >> > I figure this must be some class loader issue I am not understanding but >> > these docs[1][2] don't seem to indicate there should be any issue. >> > >> > -Bryan >> > >> > [1] - http://tomcat.apache.org/tomcat-7.0-doc/class-loader-howto.html >> > >> > [2] - >> http://download.oracle.com/otndocs/jcp/servlet-2.4-fr-spec-oth-JSpec/ >> >> Using the common classloader is somewhat tricky, because the "Webapp >> classloader has priority" rule imposed by servlet spec does mess up >> things, as explained in [1]. >> >> Your description does not have enough details, nor source code, nor >> stacktaces, and with such I would guess that you have the following: >> >> a) Your constructor has some arguments >> b) The classes mentioned as argument types in that method can be >> loaded both from common class loader and from webapp classloader. (If >> they cannot be loaded from the former, you are also in trouble). >> c) Classes loaded from different classloaders are considered different >> by JVM (even if they have the same name and bytecode),. >> You are asking for a method specifying its arguments by using classes >> loaded by webapp classloader and they do not match the ones loaded by >> common classloader >> >> Just a guess. >> >> Best regards, >> Konstantin Kolinko >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org >> For additional commands, e-mail: users-h...@tomcat.apache.org >> >> > > > -- > -Bryan > -- -Bryan
