Spring Annotation Portlet

Posted by loongest on March 9th, 2010

The following article i will show how to convert from declaration xml base to annotation based. The example will base on the manning portlet in action book. I pick up the chapter 7 as learning point, you may download the original source code to compare.

The example downloaded from manning website basically is a simple book portlet, the functionality of this portlet is show a list of books, and new book function, remove and edit book functions.

There are totally 7 controllers you can found from the controller packages.

AddBookController
BooksController
EditBookController
EditModeController
HelpModeController
RemoveBookController
ViewModeController

Let’s get started from BooksController. In order to convert/develop a spring annotation portlet, few thing you will need to do first before we can continue.

Add/Edit existing portlet declaration in portlet.xml
Add/Edit existing portlet declaration in liferay-portlet.xml
Create an existing a book-portlet.xml

Next, we quickly look through the following xml files.

portletModeParameterHandlerMappingExample-portlet.xml and
portletModeHandlerMappingExample-portlet.xml

As we can see, portletModeHandlerMappingExample-portlet.xml is mainly declare the portlet mode. ‘VIEW’, ‘EDIT’,'HELP’. We can delete this xml file now because it is able to achieved by using annotation within the controller class later. Next, we will start writing new stuff in our book-portlet.xml base on the portletModeParameterHandlerMappingExample-portlet.xml

book-portlet.xml, all we need to have is show on below.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans
xmlns="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"</span>
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
"http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
"http://www.springframework.org/schema/context
"http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:component-scan base-package="com.loongest.book.controller>
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass"
value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/view/book/" />
<property name="suffix" value=".jsp" />
</bean>
</beans>

Modify BooksController

package com.loongest.book.controller;
import ……..;
@RequestMapping("VIEW")
public class BooksController {
@Autowired private BookService bookService;
@RequestMapping
publi void postAction() {
// – if void method mean ‘POST’, default view mode nothing do post,
// – so leave it blank implementation
}
@RequestMapping
// – Return type is String, means we will return books jsp for render.
public String showForm(ModelMap map) throws Exception {
List<Books> books = bookService.getBooks();
map.put("books",books);
return "books";
}
// – Refer to the original xml declaration,
// – addBookForm are map to addBookController to render addBook.jsp
@RequestMapping(params = "myaction=addBookForm")
public String showAddBookForm() {
return "addBook";
}
// – form submit action, when user click add book button, portlet will get form parameter and
// – validate. if contains errors, will show form again else back to default view. myaction=""
@RequestMapping(params = "myaction=addBook")
public void saveBook(
@RequestParam(required=false, value = "name") String name,
@RequestParam(required=false, value = "author") String author,
@RequestParam(required=false, value = "isbnNumber") String isbnNumber,
ActionRequest request, ActionResponse response) throws Exception {
Map<String, String> errorMap = new HashMap<String, String>();
…
…
// – The rest of implementation are same.
…
if(!errorMap.isEmpty()) {
…
response.setRenderParameter("myaction","addBookForm");
} else {
bookService.addBook(
new Book(name,author,Long.valueOf(isbnNumber)));
response.setRenderParameter("myaction","");
}

Configuration

<bean id="portletModeParameterHandlerMapping"
class="org.springframework.web.portlet.handler.PortletModeParameterHandlerMapping">
<property name="parameterName" value="myaction" />;
<property name="order" value="1" />
<property name="interceptors">
<list>
<ref bean="parameterInterceptor" />
</list>
</property>
<property name="defaultHandler" ref="showBooksController" />
<property name="portletModeParameterMap">
<map>
<entry key="view">
<map>
<entry key="addBook" value-ref="addBookController" />
<entry key="addBookForm" value-ref="addBookController" />
<entry key="editBook" value-ref="editBookController" />
<entry key="editBookForm" value-ref="editBookController" />
<entry key="removeBook" value-ref="removeBookController" />
</map>
</entry>
</map>
</property>
</bean>

PortletModeParameterHandlerMapping

As mentions on above bean definitions, portletModeParameterMap has entry key ‘view‘. We replace by using @RequestMapping(“VIEW”) annotation in BooksController. Which mean a view mode entry also support other sub actions, such as addBook, addBookForm, editBook, editBookForm, removeBook. We replace by using @RequestMapping(params = “action=[xxx-mappings]“).

(Note: default action name = action, can be customize in property parameterName).