web mvc URL-service mapping

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GitHub: https://github.com/SylkeWay/synthful

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Spring web mvc URL mapping involves these stages.

web.xml: Declaration of DispatcherServlet bootstrap.

<servlet>
  <servlet-name>mvc-dispatcher</servlet-name>
  <servlet-class>
    org.springframework.web.servlet.DispatcherServlet
  </servlet-class>
  <init-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:/springweb/**-context.xml
    </param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
</servlet>

web.xml: Mapping the bootstrap to request URL pattern in web.xml.
The following maps any request URL with the pattern

http://{hostname}:{port}/{context}/v/{anything else}

to be handled by DispatcherServlet.

<servlet-mapping>
  <servlet-name>mvc-dispatcher</servlet-name>
  <url-pattern>/v/*</url-pattern>
</servlet-mapping>

In mvc-context.xml:

• Declaring InternalResourceViewResolver as a bean to be instantiated
• Using the prefix parameter to instruct the bean where to find the resource
• Using the suffix parameter to indicate to the bean the file suffix to expect

<bean id="viewResolver"
  class="org.springframework.web.servlet.view.InternalResourceViewResolver">
  <property name="prefix">
    <value>/WEB-INF/views/</value>
  </property>
  <property name="suffix">
    <value>.jsp</value>
  </property>
</bean>

In DurianMVController:

• Annotating DurianMVController class to indicate it as an MVC controller,
• for DispatcherServlet thread to instantiate as a singleton.

@Controller
public class DurianMVController

DurianMVController:

• DispatcherServlet thread to discover request handlers in DurianMVController, where request handlers are annotated by @RequestMapping.
• Map the request handler to its final URL declared in @RequestMapping.
• Construct the select-options HTML-fragment from the util:map zipMap.
• Pass the select-options HTML-fragment to Hello.jsp, as model attribute "zippers".
• request handler method to return the name of the resource ("Hello") which will service the request

@RequestMapping(value = "/h1", method = RequestMethod.GET)
public String handleRequestJoyfully(ModelMap model) throws Exception {

    StringBuilder selectOpts = generateSelectOptions(zipMap);
    model.addAttribute("zippers", selectOpts.toString());

    logger.info("handleRequestJoyfully");
    return "Hello";
}

The URL to be used as mapping key is constructed as

• http://{hostname}:{port}/{context} +
• {web.xml servlet mapping = /v/} +
• {class level @RequestMapping in mvc controller = none} +
• {@RequestMapping in request handler in mvc controller = /h1 }

There is no @RequestMapping annotation at DurianMVController class declaration level. Presuming default and local deployment, the URL works out to be

http://localhost:8080/durian/v/h1

The resource to be invoked to service this URL is constructed as

• {mvc-context.xml:viewResolver prefix = /WEB-INF/views/} +
• {String returned byhandleRequestJoyfully = Hello} +
• {mvc-context.xml:viewResolver suffix = .jsp}

Therefore, the following resource needs to be created to service the request thro that URL

/WEB-INF/views/Hello.jsp