How to fix failing service calls in a web environment

Author: Peter_Jodeleit
Publication Date: 3/27/2014 10:15

Recently more people seem to use FirstSpirits capabilities to extend functionality with custom services and custom components.And I'm always happy to support this. :smileyhappy:

 

One common pitfall seems to be the communication between a custom input component (aka Gadget) and a service, which fails with a ServiceNotFoundException caused by a ClassNotFoundException.

 

This is the common failure trace:

de.espirit.firstspirit.access.ServiceNotFoundException: Service '<custom service interface name>' not found

     at de.espirit.firstspirit.server.io.AbstractServiceLocator.getService(AbstractServiceLocator.java:52)

     at de.espirit.firstspirit.server.io.AbstractServiceLocator.getService(AbstractServiceLocator.java:92)

     at de.espirit.firstspirit.server.io.AbstractServerConnection.getService(AbstractServerConnection.java:553)

     at de.espirit.firstspirit.client.io.WebConnection.getService(WebConnection.java:254)

     at de.espirit.firstspirit.agency.ServicesBrokerImpl.getService(ServicesBrokerImpl.java:26)

     <part from custom code>    

     <long part from FirstSpirit code>

Caused by: java.lang.IllegalStateException: java.lang.ClassNotFoundException: <custom service interface name>

     at de.espirit.firstspirit.server.io.RemoteServiceLocator.createService(RemoteServiceLocator.java:93)

     at de.espirit.firstspirit.server.io.AbstractServiceLocator.getService(AbstractServiceLocator.java:50)

     ... XX more

Caused by: java.lang.ClassNotFoundException: <custom service interface name>

     <potentially long part from web container code>

     at java.lang.ClassLoader.loadClass(ClassLoader.java:358)

     at de.espirit.firstspirit.server.io.RemoteServiceLocator.createService(RemoteServiceLocator.java:50)

     ... ZZ more

 

The cause is that the class is simply not known within the scope of the web environment.

 

To fix this, first your module needs to define the web-app block in the descriptor (module.xml):

<module>

          ...

          <components>

                    ...

                    <web-app>

                              <name>...</name>

                              <displayname>...</displayname>

                              <description>...</description>

                              <web-xml>web.xml</web-xml>

                              <web-resources>

                                        <resource>lib/your.jar</resource>

                              </web-resources>

                    </web-app>

                        ...

          </components>

        ...

</module>

 

Relevant are the web-resources line which must reference your JAR file and the web-xml line.

 

The web.xml file itself may have minimal content:

<?xml version="1.0" encoding="ISO-8859-1"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/j2ee" 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>...</display-name>

    <description>...</description>

</web-app>

 

The structure of your FSM file should then (at least) look like this:

+ lib

    - your.jar

+ META-INF

   -  MANIFEST.MF

   -  module.xml

- web.xml

 

The next step is to add and deploy the web application (at least into the Preview scope):

 

After these steps, the ClassNotFoundException is history.

 

[tested with upcoming 5.1 release - release 5.0 may be less restrictive when "Internal Jetty" is used as web server]

Tags: classnotfoundexception, fsm, module, service, servicenotfoundexception