Question

I have a Spring MVC based Web Application with Hibernate. Following is the directory structure:

• src
  • com/myproject/abstractmodels/ <- contains some abstract java files for domain objects
  • com/myproject/dao/personsmodel/ <- dao layer, using hibernate to get data
  • com/myproject/dao/anothermodel/
  • com/myproject/domain/personsmodel/ <- Domain/BusinessObjects and HBM files for hibernate mappings
  • com/myproject/domain/anothermodel/
  • com/myproject/service/personsmodelservice <- Service layer talks to DAO layer
  • com/myproject/service/anothermodelservice
  • com/myproject/controller/ <- Servlets, using Service layer and Domain objects for web presentation (JSP files)
• WebRoot
  • WEB-INF
    • web.xml <- sets up the web app and spring framework to use the below xmls to configure the layers.
    • config
      • services.xml <- Sets up the service layer, that is glues the service interface with its implementations and injects the DAO beans
      • hibernate.xml <- uses hibernate hbm files for mappings and defines DAO beans
      • servlets.xml <- beans for controllers and service beans are injected into it
      • views.xml <- jsp files

Now I need to create a library (jar) using the Service, DAO, Domain, and AbstractModels packages. Basically, the idea is, that when given this jar file, and the database any one can create their own servlets/user interfaces or make web services based using our hibernate, service and domain objects.

I have simply made the jar file containing the directories:

 - com/myproject/abstractmodels/
 - com/myproject/dao/personsmodel/
 - com/myproject/dao/anothermodel/
 - com/myproject/domain/personsmodel/
 - com/myproject/domain/anothermodel/
 - com/myproject/service/personsmodelservice
 - com/myproject/service/anothermodelservice

with out the servlets and added it to build path of the web app. The project compiles, meaning that the servlets can find the service beans and domain objects but it does not run. The beans defined in services.xml could not be created. I checked the jar file and the package structure is correct and contains the class file. But when run, it would still give this error:

Loading XML bean definitions from ServletContext resource [/WEB-INF/config/servlet.xml]
Loading XML bean definitions from ServletContext resource [/WEB-INF/config/services.xml]
Context initialization failed
org.springframework.beans.factory.BeanDefinitionStoreException: Unexpected exception parsing XML document from ServletContext resource [/WEB-INF/config/services.xml]; nested exception is org.springframework.beans.FatalBeanException: Unable to create DWR bean creator for 'com.myproject.abstractmodels.ModelConstants#0'.; nested exception is java.lang.ClassNotFoundException: com.myproject.abstractmodels.ModelConstants

How can I make the jar file to correct this issue? Do I need to put the WEB-INF directory in the jar file as well? Is there some special Manifest configuration required?

Answer 1

The jar must not be put in the project’s build path. It must be put in the WEB-INF/lib folder, and Eclipse will

• put this jar in the build path automatically
• deploy this jar as part of the web app, where it will be in the webapp’s classpath, as per the servlet specification.

If you put the jar in the project build path, the project will compile, but the jar won’t be part of the deployed webapp.