INTRODUCTION:
The Power of the Spring Framework:
The Spring Framework is a lightweight, open source programming and configuration model for developing Java based enterprise applications. This framework is used in HCL Commerce for building and configuring Management Center, including the managing of URL requests from Management Center to retrieve and process object data. Management Center built with the Spring framework, which includes built-in best practices and design patterns, your site developers can customize Management Center more easily.
Developers can focus more on application-level programming to meet business needs when customizing Management Center and less on the underlying infrastructure of Management Center.
The Spring framework is a modular framework for building enterprise applications and includes many different modules. Within HCL Commerce, the following Spring framework layers and modules are used to build Management Center:
- The Core Container layer, specifically the spring-core, spring-beans, spring-context, and spring-expression modules. The spring-core and spring-beans modules are the fundamental parts of the Spring framework.
- All other Spring framework modules are built upon these core modules. These modules provide the Inversion of Control (IoC), dependency injection, and Spring bean features of the framework, which are used in HCL Commerce.
- The Spring framework uses the spring-context module to access objects and adds support for internalization. This module also supports the use of Java EE features, such as EJB, within the framework. The spring-expression module provides the expression language that the framework uses to query and process a bean object.
- The Spring web layer, specifically the spring-web, and spring-webmvc modules. The spring-web module provides the basic web-specific integration features that are required by Management Center. The framework uses this module to initialize the Spring IoC container.
- The spring-webmvc module, which is also known as the Spring Web-Servlet module, provides the Spring Model-View-Controller (MVC) framework that HCL Commerce uses with Management Center.
- The spring framework MVC can be used with a servlet or portlet environment. The MVC framework that is used in HCL Commerce is non-portlet. The MVC framework that is used in HCL Commerce uses the Spring dispatcher servlet.
Spring Bean:
A Spring bean is an element is defined in a Spring framework configuration file. These bean definitions define the Management Center objects that are managed by the Spring framework IoC container.
The framework can instantiate or destroy these bean objects as needed, and uses the beans to create class instances. The bean definitions, which are also called controller configurations within HCL Commerce, include the properties and dependencies that the Spring framework uses to create, update, and delete the bean objects.
The attributes, properties, and dependencies in each configuration must define the following information for the Spring bean object:
- The associated controller (application) class to use to retrieve or process the bean object or service URL request from Management Center. Each bean must map to a class with the package-qualified class name.
- The unique identifier for the controller configuration bean element. This identifier is used by the framework to identify the configuration. The identifier also maps the bean object to an object definition or search definition for the Management Center object or service.
- The properties that are to be used to define how the associated controller class is to process the URL request and use the bean object.
- The dependencies that reference other beans or resource bundles that are needed for the class to handle the bean object and URL request.
- Any other configuration settings or parameters to include within the bean object.
HCL Commerce currently uses the Spring framework 4.1.7 release. For more information about this version of the Spring framework, including the framework layers and modules that are used in HCL Commerce, and Spring beans, see Spring framework 4.1.7 release.
For more information about the Spring framework in general, see Spring framework.
Spring MVC framework:
The Spring MVC framework is request-driven framework that uses a central dispatcher servlet to handle the URL requests from Management Center.
This Spring Dispatcher Servlet dispatches requests to the controller classes that are identified within bean definition controller configurations for retrieving and processing data.
The Spring MVC framework is composed of the following parts:
- Model, which represents the business or database code; the actual Management Center object data. The Model object is a map interface, which the framework transforms into the XML formatted View that is expected by Management Center. The framework uses the appropriate serialization JSP fragments identified by the Controller to transform the Model to create the View.
- View, which represents code for designing the XML-formatted response of the Model that displays to Management Center users.
- Controller, which represents the controller class that retrieves or processes the data to generate the Model. The Controller receives a URL request from Management Center and uses the corresponding controller configuration to generate the Model and select the JSP file to use to transform the Model into the View.
For more information about the MVC framework, see Spring MVC framework.
For more information about the Spring dispatcher servlet, see Spring class DispatchServlet.
Customizing the Management Center Spring framework definitions:
All major aspects of the Management Center web application are configured within Spring framework configuration files. HCL Commerce uses multiple Spring definition files to configure Management Center. A different configuration file is used for mapping the configurations for each Management Center component. There is also an extension configuration file for you to use to define your own custom mappings for custom objects or to override existing mappings in the configuration files that are provided by HCL Commerce.
- A spring-ibm-component.xml file is provided for each Management Center component to define the URL mappings that are required for retrieving and processing data for the component objects.
For example, the spring-ibm-catalog.xml file defines the mappings for the catalog component. - A spring-extension.xml file is provided for you to use to override existing mappings or to define mappings for custom objects and views. Do not modify any spring-ibm-component.xml files. Use only the spring-extension.xml file to change or define mappings.
