Error launching application after upgrading to 10.1.3 production

Question

Our web structure looks like this:
+ web
    + bin             project jar files and client jar libraries
    + images
    + WEB-INF
       + conf        application property files
       + lib           project jar files and server jar libraries
       + logs
    + xml
+ META-INFWith previous versions of OC4J this web.xml would suffice:
<?xml version="1.0"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee  http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
         version="2.4">
  <display-name>ch_web</display-name>
  <description>web.xml file for Casthouse</description>
  <servlet>
    <servlet-name>afc.system.server.StartupServlet</servlet-name>
    <servlet-class>afc.system.server.StartupServlet</servlet-class>
    <init-param>
      <param-name>CONFIGURATION_HOME</param-name>
      <param-value>C:\oracle\JDeveloper10g\j2ee\home\applications\ch_web\ch_web\WEB-INF\conf\</param-value>
    </init-param>
    <init-param>
      <param-name>SERVLET_HOME</param-name>
      <param-value>/ch_web/servlet/</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet>
    <servlet-name>casthouse.analysis.server.spectro.AnalysisReceiverService</servlet-name>
    <servlet-class>casthouse.analysis.server.spectro.AnalysisReceiverService</servlet-class>
    <load-on-startup>2</load-on-startup>
  </servlet>
  <session-config>
    <session-timeout>30</session-timeout>
  </session-config>
  <mime-mapping>
    <extension>html</extension>
    <mime-type>text/html</mime-type>
  </mime-mapping>
  <mime-mapping>
    <extension>txt</extension>
    <mime-type>text/plain</mime-type>
  </mime-mapping>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
  </welcome-file-list>
  <login-config>
    <auth-method>BASIC</auth-method>
  </login-config>
</web-app> But after upgrading, the server side initializes allright, but the client cannot connect. I get a 404- page cannot be found when trying.
After adding the following to my web.xml...
   <servlet>
     <servlet-name>LoginServlet</servlet-name>
     <servlet-class>afc.login.server.LoginServlet</servlet-class>
   </servlet>
   <servlet-mapping>
     <servlet-name>LoginServlet</servlet-name>
     <url-pattern>/servlet/*</url-pattern>
   </servlet-mapping>The client did locate some code, but not all. From the java console, I discovered several exceptions due to servlets referred and not found. I tried to map some of the central servlets in our application, but stopped. I thought, this cannot be right. We have very many servlets in our application. It shouldn't be nescessary to map them all in our web.xml... Is it?
What am I missing?

Answer 1

Ok.. hmm, life was easier before...
I tried to add the http.webdir.enable="true" to the only orion-web.xml I could find (under j2ee\home\application-deployments\{web-root}\{context-root}\orion-web.xml
Don't know if this should be in another location, we do not deploy this. This is generated during deployment from our JDeveloper deployment profile). But after the container was restarted, the file was reverted to the old version without this attribute set. Frustrating...
45 servlets are now registered in our web.xml. That is 3 servlets which should be accessible to the user from the address bar in the browser, and 42 servlets accessible from either the client or the server programmatically.
But is it then nescessary to add both <servlet> tag and <servlet-mapping> tag for one servlet, or is the <servlet-mapping> tag only nescessary for those servlets, which should be available to the end user, and not directlly called from the application itself?
I still get an exception when trying to instanciate the application. Our application uses one or two properties files which it needs to read upon instanciation. They live in {context-root}\WEB-INF\conf\
OC4J doesn't seem to give access to this folder anymore. What do I have to include in our web.xml in order to give the appropriate read access to this folder? Should only be readable server side from a Servlet. Contents are communicated to the client through this servlet.