Expert Spring MVC and Web Flow

Listing 6-58 contains an example bean definition and configuration of a

PropertiesMethodNameResolver.

Listing 6-58.Example of PropertiesMethodNameResolver

<bean id="methodNameResolver"

class=

"org.springframework.web.servlet.mvc.multiaction.PropertiesMethodNameResolver">

<property name="mappings">

<props>

<prop key="/account/findByUsername">findByUsername</prop>

<prop key="/account/*">index</prop> <!-- treated as default -->

</</props>

</property>

</bean>

<bean name="/account/*"

class="com.apress.expertspringmvc.flight.web.ViewAccountController">

<property name="methodNameResolver" ref="methodNameResolver" />

<property name="accountService" ref="accountService" />

</bean>

The default case, in the preceding listing as /account/*, should be the last property

specified, so it will attempted last. Also, notice how the mapping path begins with the

mapping specified for the controller. If you wish to change this behavior, consult the

AbstractUrlMethodNameResolversuperclass for options on how to configure the treatment

of the URL path.

MethodNameResolver Summary

You’ve seen three distinct strategies for mapping a request to a method on a

MultiActionController. The InternalPathMethodNameResolverwill parse the URL path for the

last element and use it as a method name. The ParameterMethodNameResolverlooks for request

parameters, either by value or by name, to resolve a method name. This strategy also supports

a default method name if no name was resolved. Finally, the PropertiesMethodNameResolveris

the least restrictive of the bunch, as it allows for a mapping of arbitrary URL paths to method

names.

Which one should you use? As with everything Spring Framework, the choice is ultimately

yours, and the framework doesn’t lean toward any preference. You should weigh how much

configuration each strategy will take under your circumstances, as generally less configuration

is better. We favor not relying on request parameters for method names, as we feel URL paths

are cleaner and generally friendlier to work with.

MultiActionController Example

For an example of the MultiActionController, we will create a ViewAccountControllerthat

exposes many different ways to find an Account. For instance, a user may want to find an

Accountby username or first name or last name. These are simple read-only methods without

172 CHAPTER 6 ■THE CONTROLLER MENAGERIE