RE: webapps' classpath
I think I can get around this problem by moving to tomcat 4. There seems to be a shared classloader for all the webapps. But I am wondering if other app servers also support tomcat-4's classloading structure, otherwise my app will become tc4-only. --- Brendan Johnston [EMAIL PROTECTED] wrote: Theoretically when a class wants to load a class it asks its own classloader to do it. Its own classloader then asks its parent to do it and if its parent can't it tries. Some concept of how to work around this might be: 1. Have a factory class that return the instances you want in A1 (therefore A1 classloader) 2. Register the factory it in some collection that the soap classloader can see (potentially create some factory registry and load it with the application servers classloader) 3. Call methods on the factory to get instances I have not tested this I may have missed something, and don't recommend this complex approach. I think the answer in your case is to have fewer (one) web applications. Brendan -Original Message- From: E B [mailto:[EMAIL PROTECTED]] Sent: Monday, October 15, 2001 11:34 PM To: [EMAIL PROTECTED] Subject: RE: webapps' classpath So that means there are two classloaders: soap's and the other webapps's (in my case A1). now when the contol goes from soap to A1's class, which class loader loads the classes of A1. ? Can I make A1's classloader come into picture and take over things ? --- Brendan Johnston [EMAIL PROTECTED] wrote: Each Web Application gets its own private class loader. A class loader can only see classes loaded/loadable by it and by its parents. The Two Web Applications are siblings, independant from each other. I think you should give each WebApplication a complete set of its own classes so that you can upgrade each independantly. Brendan -Original Message- From: E B To: [EMAIL PROTECTED] Sent: 10/15/01 9:04 PM Subject: webapps' classpath I am using apache soap 2.2 with tomcat 3.2.1. There seem to be 2 classpaths, one tomcat's and the other webappp's WEB-INF/classes. For a SOAP service class, which of these two is visible first ? which of the two is recommended and why ? I have two web-app's: A1 and A2. (A2 is soap). I want to refer A1's objects in A2's class. But A1's classes are not visible to A2. why ? I had to put A1's classes in tomcat's classpath to get it working. thanks. Do You Yahoo!? Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk or your free @yahoo.ie address at http://mail.yahoo.ie Do You Yahoo!? Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk or your free @yahoo.ie address at http://mail.yahoo.ie Nokia Game is on again. Go to http://uk.yahoo.com/nokiagame/ and join the new all media adventure before November 3rd.
RE: webapps' classpath
On Thu, 18 Oct 2001, E B wrote: Date: Thu, 18 Oct 2001 09:52:50 +0100 (BST) From: E B [EMAIL PROTECTED] Reply-To: [EMAIL PROTECTED] To: '[EMAIL PROTECTED]' [EMAIL PROTECTED], [EMAIL PROTECTED] Cc: 'E B' [EMAIL PROTECTED] Subject: RE: webapps' classpath I think I can get around this problem by moving to tomcat 4. There seems to be a shared classloader for all the webapps. But I am wondering if other app servers also support tomcat-4's classloading structure, otherwise my app will become tc4-only. All servlet containers that support the 2.2 or 2.3 specification are required to provide a separate classloader per web application. The availability of a shared JAR mechanism is not required by the spec, but is very commonly implemented. In a servlet 2.3 environment, the following additional notes are relevant: * There is a SHOULD statement in the specification with regards to checking in the webapp's class loader first before checking higher up the class loader hierarchy. Tomcat 4 implements this SHOULD (although you can turn it off if you want to), but I don't know how others are handling it. * Web applications can count on the Thread context class loader being set to the webapp's class loader. This means that, in library code that *is* loaded from a shared classloader, you can still load application classes from the webapp class loader if you take steps like this: ClassLoader cl = Thread.currentThread().getContextClassLoader(); Class clazz = cl.loadClass(... classname ...); Craig McClanahan
