2009/10/4 Caldarale, Charles R <chuck.caldar...@unisys.com>: >> From: news [mailto:n...@ger.gmane.org] On Behalf Of Eric B. >> Subject: Re: Loading Jar files in a particular order on Tomcat 6 >> >> I've always noticed that the classloader loads things in alphabetical >> order. > > ??? Which classloader are you referring to? And by "things", do you mean > classes or jars? If you're referring to jars, the order of jar processing is > determined solely by the specific classloader instance; it can choose to > process the jars in the order they're encountered, alphabetically, by > date/time, or any other means. Relying on any particular observed behavior > is extremely risky, unless it's defined in the spec. > >> Additionally, if it finds the same class in 2 different jars, it only >> seems to use the class from the first jar. > > That is normal behavior for all classloaders. >
> the order of jar processing is determined solely by the specific classloader > instance I am rather sure that it is an official rule (I must be somewhere documented [1]), that jars in a classpath are searched in the order they are specified there. [1] e.g. in URLClassLoader constructor JavaDoc: [cite] The URLs will be searched in the order specified [/cite] Also http://java.sun.com/javase/6/docs/technotes/tools/windows/classpath.html "If a specific order is required then the JAR files can be enumerated explicitly in the class path." Certain file systems (e.g. NTFS as far as I know) return file lists in alphabetical order, but that is all that stands behind that advice of naming the jar. There is also an explicit rule that classes in /WEB-INF/classes take precedence over any jars in /WEB-INF/lib -- see SRV.9.5 "The Web application class loader must load classes from the WEB-INF/ classes directory first" Thus the solution in this case is to unpack those jars that must come first. If those are shared libraries, e.g. in ${catalina.base}/lib, you can specify an order in catalina.properties Best regards, Konstantin Kolinko --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
