- Place the following <servlet> declaration in your application’s web.xml file:
<servlet>
<servlet-name>training</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>By default, when Dispatcher-
Servlet is loaded, it will load the Spring application context from an XML file
whose name is based on the name of the servlet. In this case, because the servlet is
named training, DispatcherServlet will try to load the application context from
a file named training-servlet.xml. - Next you must indicate what URLs will be handled by the DispatcherServlet.
Add the following <servlet-mapping> to web.xml to let DispatcherServlet handle
all URLs that end in “.htm”:
<servlet-mapping>
<servlet-name>training</servlet-name>
<url-pattern>*.htm</url-pattern>
</servlet-mapping> - you’ll be deploying to a web container that supports the
Servlet 2.3 specification (or higher) and initializes servlet listeners before servlets.
If that’s the case, you’ll want to configure ContextLoaderListener in your
web.xml file as follows:
<listener>
<listener-class>org.springframework.
web.context.ContextLoaderListener</listener-class>
</listener> - You can specify one or more Spring configuration files for the context loader
to load by setting the contextConfigLocation parameter in the servlet context:
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/training-service.xml,
/WEB-INF/training-data.xml</param-value>
</context-param> - The default handler mapping used by DispatcherServlet is BeanNameUrlHandler-
Mapping, which uses the base name as the URL pattern.The following chunk of XML declares the
HomeController:
<bean name="/home.htm"
class="com.springinaction.training.mvc.HomeController">
<property name="greeting">
<value>Welcome to Spring Training!</value>
</property>
</bean> - InternalResourceViewResolver:
<bean id="viewResolver" class="org.springframework.web.
servlet.view.InternalResourceViewResolver">
<property name="prefix">
<value>/WEB-INF/jsp/</value>
</property>
<property name="suffix">
<value>.jsp</value>
</property>
</bean> - SimpleUrlHandlerMapping: <bean id="simpleUrlMapping" class=
"org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="/listCourses.htm">listCoursesController</prop>
<prop key="/admin/register.htm">registerStudentController</prop>
<prop key="/admin/displayCourse.htm">displayCourseController</prop>
<prop key="/login.htm">loginController</prop>
<prop key="/enroll.htm">enrollController</prop>
</props>
</property>
</bean> - To use CommonsPathMapHandlerMapping, simply declare it as a <bean> in your
context configuration file as follows:
<bean id="urlMapping" class="org.springframework.web.
➥ servlet.handler.metadata.CommonsPathMapHandlerMapping"/> to map DisplayCourseController to “/displayCourse.htm”, tag DisplayCourseController as follows:
/**
* @@org.springframework.web.servlet.handler.
commonsattributes.PathMap("/displayCourse.htm")
*/
public class DisplayCourseController
extends AbstractCommandController {
…
}See chapter
5, section 5.5.2 for details on how to add the attributes compiler to your build. -
■ BeanNameUrlHandlerMapping—Maps controllers to URLs that are based on
the controllers’ bean name
■ SimpleUrlHandlerMapping—Maps controllers to URLs using a property collection
defined in the context configuration file■ CommonsPathMapHandlerMapping—Maps controllers to URLs using sourcelevel
metadata placed in the controller code -
Working with multiple handler mappings ,You may also have to declare it explicitly if you are using multiple handler mappings and need to specify ordering <bean id="beanNameUrlMapping" class="org.springframework.web.
servlet.handler.BeanNameUrlHandlerMapping">
<property name="order"><value>1</value></property>
</bean>
<bean id="simpleUrlMapping" class="org.springframework.web.
servlet.handler.SimpleUrlHandlerMapping">
<property name="order"><value>0</value></property>
<property name="mappings">
…
</property>
</bean> -
public class DisplayCourseController
extends AbstractCommandController {
public DisplayCourseController() {
setCommandClass(DisplayCourseCommand.class);
}
protected ModelAndView handle(HttpServletRequest request,
HttpServletResponse response, Object command,
BindException errors) throws Exception {
DisplayCourseCommand displayCommand =
(DisplayCourseCommand) command;
Course course = courseService.getCourse(displayCommand.getId());
return new ModelAndView("courseDetail", "course", course);
}
private CourseService courseService;
public void setCourseService(CourseService courseService) {
this.courseService = courseService;
}
} -
public class RegisterStudentController
extends SimpleFormController {
public RegisterStudentController() {
setCommandClass(Student.class);
}
protected void doSubmitAction(Object command)
throws Exception {
Student student = (Student) command;
studentService.enrollStudent(student);
}
private StudentService studentService;
public void setStudentService(StudentService studentService) {
this.studentService = studentService;
}
} <bean id="registerStudentController" class="com.springinaction.
training.mvc.RegisterStudentController">
<property name="studentService">
<ref bean="studentService"/>
</property>
<property name="formView">
<value>newStudentForm</value>
</property>
<property name="successView">
<value>studentWelcome</value>
</property>
</bean>Just as with the other controllers, the registerStudentController bean is wired
with any services that it may need (e.g., studentService). But here you also specify
a formView property and a successView property. The formView property is the
logical name of a view to display when the controller receives an HTTP GET
request or when any errors are encountered. Likewise, the successView is the logical
name of a view to display when the form has been submitted successfully. A
view resolver (see section 8.4) will use these values to locate the View object that
will render the output to the user.for you, depending on whether you need to display model data on the success view.
If you need to send data to be displayed by the view, you should override the
onSubmit() method instead of doSubmitAction(). For example, suppose that
after enrolling the new student you want to send the user to a page where the
student’s information is displayed. You’ll need to send the Student object to
the view. To do this, replace the doSubmitAction() from listing 8.4 with the following
onSubmit() method: protected ModelAndView onSubmit(Object command,
BindException errors) throws Exception {
Student student = (Student) command;
studentService.enrollStudent(student);
return new ModelAndView(getSuccessView(),"student", student);
}
