Getting started with Spring Roo, STS and GWT - Part 2

In part one of this multipart blog/article, we followed along with the Spring  Roo Tutorial creating a Pizza shop. But we stopped at the back end. Now its time to create front end. For this blog we will complete the tutorial and show the front end using Spring MVC and JSP pages. Next article we will do this with GWT.

• Part 1 - Install and Create Back end
• Part 2 - Web MVC (this blog)
• Part 3 - GWT 
• Part 4 - Custom app from scratch
• 
  

Part 2 - Adding a front end with Spring MVC and JSP

To summarize the previous blog,

1. installed Spring StS
2. created a spring project named 'pizza' to package 'com.springsource.pizzashop'
3. executed the following in spring roo's shell:

// Spring Roo 1.1.4.RELEASE [rev f787ce7] log opened at 2012-03-17 10:38:04
project --topLevelPackage com.springsource.roo.pizzashop --projectName pizza --java 6
// Spring Roo 1.1.4.RELEASE [rev f787ce7] log closed at 2012-03-17 10:38:15
// Spring Roo 1.1.4.RELEASE [rev f787ce7] log opened at 2012-03-17 10:38:19
hint
hint
persistence setup --database HYPERSONIC_IN_MEMORY --provider HIBERNATE 
hint
entity --class ~.domain.Topping --testAutomatically 
field string --fieldName name --notnull --sizeMin 2
entity --class ~.domain.Base --testAutomatically 
field string --fieldName name --notNull --sizeMin 2
entity --class ~.domain.Pizza --testAutomatically
field string --fieldName name --notNull --sizeMin 2
field number --fieldName price --type java.lang.Float
 
field set --fieldName toppings --type ~.domain.Topping
field reference --fieldName base --type ~.domain.Base
entity --class ~.domain.PizzaOrder --testAutomatically
field string --fieldName name --notNull --sizeMin 2
field string --fieldName address --sizeMax 30
field number --fieldName total --type java.lang.Float
field date --fieldName deliveryDate --type java.util.Date
 
field set --fieldName pizzas --type ~.domain.Pizza
perform tests

No we will add a user interface.

Step 1 - setup Spring MVC

In Roo shell type:

1. web mvc setup

The web mvc setup does a lot. We really need to drill down here if we hope to understand the science behind the magic. But you can skip to Step 2 if you are impatient. After the code is generated it may work in a basic way, but you always have to muck with the details to make it work the way you want it to.

 Here is the output from Spring Roo shell:

Created SRC_MAIN_WEBAPP\WEB-INF\spring
Created SRC_MAIN_WEBAPP\WEB-INF\spring\webmvc-config.xml
Created SRC_MAIN_WEBAPP\WEB-INF\web.xml
Created SRC_MAIN_WEBAPP\images
Created SRC_MAIN_WEBAPP\images\create.png
Created SRC_MAIN_WEBAPP\images\list.png
Created SRC_MAIN_WEBAPP\images\resultset_previous.png
Created SRC_MAIN_WEBAPP\images\resultset_next.png
Created SRC_MAIN_WEBAPP\images\show.png
Created SRC_MAIN_WEBAPP\images\favicon.ico
Created SRC_MAIN_WEBAPP\images\delete.png
Created SRC_MAIN_WEBAPP\images\resultset_first.png
Created SRC_MAIN_WEBAPP\images\springsource-logo.png
Created SRC_MAIN_WEBAPP\images\resultset_last.png
Created SRC_MAIN_WEBAPP\images\add.png
Created SRC_MAIN_WEBAPP\images\banner-graphic.png
Created SRC_MAIN_WEBAPP\images\update.png
Created SRC_MAIN_WEBAPP\styles
Created SRC_MAIN_WEBAPP\styles\alt.css
Created SRC_MAIN_WEBAPP\styles\standard.css
Created SRC_MAIN_WEBAPP\WEB-INF\classes
Created SRC_MAIN_WEBAPP\WEB-INF\classes\standard.properties
Created SRC_MAIN_WEBAPP\WEB-INF\classes\alt.properties
Created SRC_MAIN_WEBAPP\WEB-INF\layouts
Created SRC_MAIN_WEBAPP\WEB-INF\layouts\default.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\layouts\layouts.xml
Created SRC_MAIN_WEBAPP\WEB-INF\views
Created SRC_MAIN_WEBAPP\WEB-INF\views\header.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\footer.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\views.xml
Created SRC_MAIN_WEBAPP\WEB-INF\views\index.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\index-template.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\uncaughtException.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\resourceNotFound.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\dataAccessFailure.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\update.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\create.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\dependency.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\show.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\list.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\find.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields\select.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields\display.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields\column.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields\editor.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields\checkbox.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields\simple.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields\input.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields\textarea.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields\datetime.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields\table.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\form\fields\reference.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\menu
Created SRC_MAIN_WEBAPP\WEB-INF\tags\util
Created SRC_MAIN_WEBAPP\WEB-INF\tags\util\pagination.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\util\theme.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\util\placeholder.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\util\panel.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\util\language.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\util\load-scripts.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\i18n
Created SRC_MAIN_WEBAPP\WEB-INF\i18n\messages.properties
Created SRC_MAIN_WEBAPP\images\en.png
Updated SRC_MAIN_WEBAPP\WEB-INF\i18n\application.properties
Updated SRC_MAIN_WEBAPP\WEB-INF\web.xml
Updated ROOT\pom.xml [added dependencies org.springframework:spring-web:${spring.version}, org.springframework:spring-webmvc:${spring.version}, org.springframework.webflow:spring-js-resources:2.2.1.RELEASE, commons-digester:commons-digester:2.0, commons-fileupload:commons-fileupload:1.2.1, javax.servlet:jstl:1.2, javax.el:el-api:1.0, joda-time:joda-time:1.6, javax.servlet.jsp:jsp-api:2.1, commons-codec:commons-codec:1.4; updated project type to war; added dependencies org.apache.tiles:tiles-core:2.2.1, org.apache.tiles:tiles-jsp:2.2.1]
Updated SRC_MAIN_WEBAPP\WEB-INF\spring\webmvc-config.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\footer.jspx

Let's look at a couple of things here to understand what happened. This is just the 'framework' of supporting configurations and code of a fully functional web application based on Spring MVC with JSP pages and Apache Tiles with layout. In spring MVC, one place to look in Spring MVC is the spring config file so see how your application is configured, here it is found in SRC_MAIN_WEBAPP\WEB-INF\spring\webmvc-config.xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:p="http://www.springframework.org/schema/p" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 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     http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">
    
 <!-- The controllers are autodetected POJOs labeled with the @Controller annotation. -->
 <context:component-scan base-package="com.springsource.roo.pizzashop" use-default-filters="false">
  <context:include-filter expression="org.springframework.stereotype.Controller" type="annotation"/>
 </context:component-scan>
 
 <!-- Turns on support for mapping requests to Spring MVC @Controller methods
      Also registers default Formatters and Validators for use across all @Controllers -->
 <mvc:annotation-driven/>
 
 <!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources -->
 <mvc:resources location="/, classpath:/META-INF/web-resources/" mapping="/resources/**"/>
 
 <!-- Allows for mapping the DispatcherServlet to "/" by forwarding static resource requests to the container's default Servlet -->
 <mvc:default-servlet-handler/>
 
 <!-- register "global" interceptor beans to apply to all registered HandlerMappings -->
 <mvc:interceptors>
  <bean class="org.springframework.web.servlet.theme.ThemeChangeInterceptor"/>
  <bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor" p:paramName="lang"/>
 </mvc:interceptors>
 
 <!-- selects a static view for rendering without the need for an explicit controller -->
 <mvc:view-controller path="/" view-name="index"/>
 <mvc:view-controller path="/uncaughtException"/>
 <mvc:view-controller path="/resourceNotFound"/>
 <mvc:view-controller path="/dataAccessFailure"/>

 <!-- Resolves localized messages*.properties and application.properties files in the application to allow for internationalization. 
  The messages*.properties files translate Roo generated messages which are part of the admin interface, the application.properties
  resource bundle localizes all application specific messages such as entity names and menu items. -->
 <bean class="org.springframework.context.support.ReloadableResourceBundleMessageSource" id="messageSource" p:basenames="WEB-INF/i18n/messages,WEB-INF/i18n/application" p:fallbackToSystemLocale="false"/>
 
 <!-- store preferred language configuration in a cookie -->
 <bean class="org.springframework.web.servlet.i18n.CookieLocaleResolver" id="localeResolver" p:cookieName="locale"/> 
 
 <!-- resolves localized <theme_name>.properties files in the classpath to allow for theme support -->
 <bean class="org.springframework.ui.context.support.ResourceBundleThemeSource" id="themeSource"/>
 
 <!-- store preferred theme configuration in a cookie -->
 <bean class="org.springframework.web.servlet.theme.CookieThemeResolver" id="themeResolver" p:cookieName="theme" p:defaultThemeName="standard"/>

 <!-- This bean resolves specific types of exceptions to corresponding logical - view names for error views. 
      The default behaviour of DispatcherServlet - is to propagate all exceptions to the servlet container: 
      this will happen - here with all other types of exceptions. -->
 <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver" p:defaultErrorView="uncaughtException">
  <property name="exceptionMappings">
   <props>
    <prop key=".DataAccessException">dataAccessFailure</prop>
    <prop key=".NoSuchRequestHandlingMethodException">resourceNotFound</prop>
    <prop key=".TypeMismatchException">resourceNotFound</prop>
    <prop key=".MissingServletRequestParameterException">resourceNotFound</prop>
   </props>
  </property>
 </bean>
 
 <!-- allows for integration of file upload functionality -->
 <bean class="org.springframework.web.multipart.commons.CommonsMultipartResolver" id="multipartResolver"/>
<bean class="org.springframework.web.servlet.view.UrlBasedViewResolver" id="tilesViewResolver">
    <property name="viewClass" value="org.springframework.web.servlet.view.tiles2.TilesView"/>
  </bean>
    <bean class="org.springframework.web.servlet.view.tiles2.TilesConfigurer" id="tilesConfigurer">
    <property name="definitions">
      <list>
        <value>/WEB-INF/layouts/layouts.xml</value>
        <!-- Scan views directory for Tiles configurations -->
        <value>/WEB-INF/views/**/views.xml</value>
      </list>
    </property>
  </bean>
</beans>

Most of this is well documented and standard. But I would point out a couple of things. The top of this configuration defines how controllers are found. In spring MVC, rather than a monolythic servlet, the url requests are dispatched to controllers. Controllers are java classes annotated with @Controller that handle the requests and generate responses (typically by delegating to a view resolver that can render a jspx page or a tiles definition (or other technology)).
The below snippet shows that we are using spring MVCs component scan ccapability to find controllers by looking for the Controller stereotype (@Controller marker) in the com.springsource.roo.pizzashop base package. The next command will generate these contollers for each domain class we have created.

<!-- The controllers are autodetected POJOs labeled with the @Controller annotation. -->
 <context:component-scan base-package="com.springsource.roo.pizzashop" use-default-filters="false">
  <context:include-filter expression="org.springframework.stereotype.Controller" type="annotation"/>
 </context:component-scan>
 
 <!-- Turns on support for mapping requests to Spring MVC @Controller methods
      Also registers default Formatters and Validators for use across all @Controllers -->
 <mvc:annotation-driven/>

The last part, usage of Titles. this bean configuration shows where the layouts.xml and views.xml files are. You will need to understand Tiles

<bean class="org.springframework.web.servlet.view.UrlBasedViewResolver" id="tilesViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.tiles2.TilesView"/>
    </bean>
    <bean class="org.springframework.web.servlet.view.tiles2.TilesConfigurer" id="tilesConfigurer">
      <property name="definitions">
        <list>
          <value>/WEB-INF/layouts/layouts.xml</value>
          <!-- Scan views directory for Tiles configurations -->
          <value>/WEB-INF/views/**/views.xml</value>
        </list>
      </property>
    </bean>

The layout.xml class defines some basic arrangements of the pages that we can reuse. Tiles 'composes' pages from smaller parts based on these definition files.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE tiles-definitions PUBLIC
       "-//Apache Software Foundation//DTD Tiles Configuration 2.1//EN"
       "http://tiles.apache.org/dtds/tiles-config_2_1.dtd">

<tiles-definitions>

  <definition name="default" template="/WEB-INF/layouts/default.jspx">
    <put-attribute name="header" value="/WEB-INF/views/header.jspx" />
    <put-attribute name="menu" value="/WEB-INF/views/menu.jspx" />
    <put-attribute name="footer" value="/WEB-INF/views/footer.jspx" />
  </definition>

  <definition name="public" template="/WEB-INF/layouts/default.jspx">
    <put-attribute name="header" value="/WEB-INF/views/header.jspx" />
    <put-attribute name="footer" value="/WEB-INF/views/footer.jspx" />
  </definition>

</tiles-definitions>

And the views.xml file contains configurations of specific pages. when spring navigates to a page, the view resolver translates the view names found here into tiles configurations, which then allow tiles to render the final page by assembling the pieces together. Notice the view definitions 'extend' the definitions in layouts.xml. Layouts.xml reference the exact layout jspx pages and standard parts (header, menu, footer) that are reusable. The view definition supplies the body that is unique to the view. Initially only standard 'error' pages are configured. The next command will add specific pages generated based on analyzing the domain classes we have created in Roo.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE tiles-definitions PUBLIC
 "-//Apache Software Foundation//DTD Tiles Configuration 2.1//EN"
 "http://tiles.apache.org/dtds/tiles-config_2_1.dtd">

<tiles-definitions>

  <definition name="index" extends="default">
    <put-attribute name="body" value="/WEB-INF/views/index.jspx" />
  </definition>

  <definition name="dataAccessFailure" extends="public">
    <put-attribute name="body" value="/WEB-INF/views/dataAccessFailure.jspx" />
  </definition>

  <definition name="resourceNotFound" extends="public">
    <put-attribute name="body" value="/WEB-INF/views/resourceNotFound.jspx" />
  </definition>

  <definition name="uncaughtException" extends="public">
    <put-attribute name="body" value="/WEB-INF/views/uncaughtException.jspx" />
  </definition>

</tiles-definitions>

Step 2 - create the scaffold pages for our classes

1. web mvc all --package ~.web 

This also does a lot of code generation.

Here is what Roo responded with:

Created SRC_MAIN_JAVA\com\springsource\roo\pizzashop\web
Created SRC_MAIN_JAVA\com\springsource\roo\pizzashop\web\BaseController.java
Created SRC_MAIN_JAVA\com\springsource\roo\pizzashop\web\PizzaOrderController.java
Created SRC_MAIN_JAVA\com\springsource\roo\pizzashop\web\ToppingController.java
Created SRC_MAIN_JAVA\com\springsource\roo\pizzashop\web\PizzaController.java
Created SRC_MAIN_JAVA\com\springsource\roo\pizzashop\web\ApplicationConversionServiceFactoryBean.java
Created SRC_MAIN_WEBAPP\WEB-INF\views\toppings
Created SRC_MAIN_WEBAPP\WEB-INF\views\toppings\views.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\toppings\views.xml
Created SRC_MAIN_WEBAPP\WEB-INF\views\menu.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\menu\menu.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\menu\item.tagx
Created SRC_MAIN_WEBAPP\WEB-INF\tags\menu\category.tagx
Updated SRC_MAIN_WEBAPP\WEB-INF\views\menu.jspx
Updated SRC_MAIN_WEBAPP\WEB-INF\views\toppings\views.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\menu.jspx
Updated SRC_MAIN_WEBAPP\WEB-INF\i18n\application.properties
Created SRC_MAIN_WEBAPP\WEB-INF\views\bases
Created SRC_MAIN_WEBAPP\WEB-INF\views\bases\views.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\bases\views.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\menu.jspx
Updated SRC_MAIN_WEBAPP\WEB-INF\views\bases\views.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\menu.jspx
Updated SRC_MAIN_WEBAPP\WEB-INF\i18n\application.properties
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzas
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzas\views.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\pizzas\views.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\menu.jspx
Updated SRC_MAIN_WEBAPP\WEB-INF\views\pizzas\views.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\menu.jspx
Updated SRC_MAIN_WEBAPP\WEB-INF\i18n\application.properties
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzaorders
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzaorders\views.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\pizzaorders\views.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\menu.jspx
Updated SRC_MAIN_WEBAPP\WEB-INF\views\pizzaorders\views.xml
Updated SRC_MAIN_WEBAPP\WEB-INF\views\menu.jspx
Updated SRC_MAIN_WEBAPP\WEB-INF\i18n\application.properties
Updated SRC_MAIN_WEBAPP\WEB-INF\spring\webmvc-config.xml
Created SRC_MAIN_JAVA\com\springsource\roo\pizzashop\web\ApplicationConversionServiceFactoryBean_Roo_ConversionService.aj
Created SRC_MAIN_JAVA\com\springsource\roo\pizzashop\web\ToppingController_Roo_Controller.aj
Created SRC_MAIN_WEBAPP\WEB-INF\views\toppings\list.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\toppings\show.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\toppings\create.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\toppings\update.jspx
Created SRC_MAIN_JAVA\com\springsource\roo\pizzashop\web\BaseController_Roo_Controller.aj
Created SRC_MAIN_WEBAPP\WEB-INF\views\bases\list.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\bases\show.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\bases\create.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\bases\update.jspx
Created SRC_MAIN_JAVA\com\springsource\roo\pizzashop\web\PizzaController_Roo_Controller.aj
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzas\list.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzas\show.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzas\create.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzas\update.jspx
Created SRC_MAIN_JAVA\com\springsource\roo\pizzashop\web\PizzaOrderController_Roo_Controller.aj
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzaorders\list.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzaorders\show.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzaorders\create.jspx
Created SRC_MAIN_WEBAPP\WEB-INF\views\pizzaorders\update.jspx

Looking at this output we can see that there is some repition. For each main domain class (Toppping, Bse, Pizza and PizzaOrder) we generate a controller and four jspx pages (views) list.jspx, show.jspx, create.jspx and update.jspx tied together in a menu system (menu.jspx). For tiles, each has its own views.xml file to show what layout is used.

Lets look at a couple of parts. Here is the controllers it created for Pizza:

File: ~.web.PizzaController.java

package com.springsource.roo.pizzashop.web;

import com.springsource.roo.pizzashop.domain.Pizza;
import org.springframework.roo.addon.web.mvc.controller.RooWebScaffold;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@RooWebScaffold(path = "pizzas", formBackingObject = Pizza.class)
@RequestMapping("/pizzas")
@Controller
public class PizzaController {
}

This looks pretty simple. From spring mvc the @Controller annoation marks this as a controller for the dispatcher to find. The @RequestMapping annotation indicates how to find this controller based on the request uri. The @RooWebScaffold annotation is the secret sauce that supports the Roo generated scaffold application, allowing for CRUD based functionality with List and Form views.

In fact, the annotations leverage several aspects that inject a lot of behavior here. STS can show you these using the Cross references panel to the right of the code (typically)

We can see here, that the aspects inject methods like:

• create
• createForm
• delete
• encode
• list
• populateBases (many-one relationship)
• populatePizzas (for lists)
• populateToppings (many-many relationship)

Each one of these methods is very useful and relatively generic. Because roo generates this aspect j inter type generation ITD file (see spring roo architecture page) which will  add these neumerous methods to your controller separating the maintenance of your customization of you particular controller class from this standardized template like methods.

For real applications, to customize behavior, we need to understand what is injected in the ITD.

Generated PizzaController_Roo_Controller.aj

// WARNING: DO NOT EDIT THIS FILE. THIS FILE IS MANAGED BY SPRING ROO.
// You may push code into the target .java compilation unit if you wish to edit any member(s).

package com.springsource.roo.pizzashop.web;

import com.springsource.roo.pizzashop.domain.Base;
import com.springsource.roo.pizzashop.domain.Pizza;
import com.springsource.roo.pizzashop.domain.Topping;
import java.io.UnsupportedEncodingException;
import java.lang.Integer;
import java.lang.Long;
import java.lang.String;
import java.util.Collection;
import javax.servlet.http.HttpServletRequest;
import javax.validation.Valid;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.util.UriUtils;
import org.springframework.web.util.WebUtils;

privileged aspect PizzaController_Roo_Controller {
    
    @RequestMapping(method = RequestMethod.POST)
    public String PizzaController.create(@Valid Pizza pizza, BindingResult bindingResult, Model uiModel, HttpServletRequest httpServletRequest) {
        if (bindingResult.hasErrors()) {
            uiModel.addAttribute("pizza", pizza);
            return "pizzas/create";
        }
        uiModel.asMap().clear();
        pizza.persist();
        return "redirect:/pizzas/" + encodeUrlPathSegment(pizza.getId().toString(), httpServletRequest);
    }
    
    @RequestMapping(params = "form", method = RequestMethod.GET)
    public String PizzaController.createForm(Model uiModel) {
        uiModel.addAttribute("pizza", new Pizza());
        return "pizzas/create";
    }
    
    @RequestMapping(value = "/{id}", method = RequestMethod.GET)
    public String PizzaController.show(@PathVariable("id") Long id, Model uiModel) {
        uiModel.addAttribute("pizza", Pizza.findPizza(id));
        uiModel.addAttribute("itemId", id);
        return "pizzas/show";
    }
    
    @RequestMapping(method = RequestMethod.GET)
    public String PizzaController.list(@RequestParam(value = "page", required = false) Integer page, @RequestParam(value = "size", required = false) Integer size, Model uiModel) {
        if (page != null || size != null) {
            int sizeNo = size == null ? 10 : size.intValue();
            uiModel.addAttribute("pizzas", Pizza.findPizzaEntries(page == null ? 0 : (page.intValue() - 1) * sizeNo, sizeNo));
            float nrOfPages = (float) Pizza.countPizzas() / sizeNo;
            uiModel.addAttribute("maxPages", (int) ((nrOfPages > (int) nrOfPages || nrOfPages == 0.0) ? nrOfPages + 1 : nrOfPages));
        } else {
            uiModel.addAttribute("pizzas", Pizza.findAllPizzas());
        }
        return "pizzas/list";
    }
    
    @RequestMapping(method = RequestMethod.PUT)
    public String PizzaController.update(@Valid Pizza pizza, BindingResult bindingResult, Model uiModel, HttpServletRequest httpServletRequest) {
        if (bindingResult.hasErrors()) {
            uiModel.addAttribute("pizza", pizza);
            return "pizzas/update";
        }
        uiModel.asMap().clear();
        pizza.merge();
        return "redirect:/pizzas/" + encodeUrlPathSegment(pizza.getId().toString(), httpServletRequest);
    }
    
    @RequestMapping(value = "/{id}", params = "form", method = RequestMethod.GET)
    public String PizzaController.updateForm(@PathVariable("id") Long id, Model uiModel) {
        uiModel.addAttribute("pizza", Pizza.findPizza(id));
        return "pizzas/update";
    }
    
    @RequestMapping(value = "/{id}", method = RequestMethod.DELETE)
    public String PizzaController.delete(@PathVariable("id") Long id, @RequestParam(value = "page", required = false) Integer page, @RequestParam(value = "size", required = false) Integer size, Model uiModel) {
        Pizza.findPizza(id).remove();
        uiModel.asMap().clear();
        uiModel.addAttribute("page", (page == null) ? "1" : page.toString());
        uiModel.addAttribute("size", (size == null) ? "10" : size.toString());
        return "redirect:/pizzas";
    }
    
    @ModelAttribute("bases")
    public Collection PizzaController.populateBases() {
        return Base.findAllBases();
    }
    
    @ModelAttribute("pizzas")
    public Collection PizzaController.populatePizzas() {
        return Pizza.findAllPizzas();
    }
    
    @ModelAttribute("toppings")
    public Collection PizzaController.populateToppings() {
        return Topping.findAllToppings();
    }
    
    String PizzaController.encodeUrlPathSegment(String pathSegment, HttpServletRequest httpServletRequest) {
        String enc = httpServletRequest.getCharacterEncoding();
        if (enc == null) {
            enc = WebUtils.DEFAULT_CHARACTER_ENCODING;
        }
        try {
            pathSegment = UriUtils.encodePathSegment(pathSegment, enc);
        }
        catch (UnsupportedEncodingException uee) {}
        return pathSegment;
    }
    
}

Step 3 - Run the Application on the Web Server

Right click the application 'pizza' and choose Run... > Run on server. This will open the run on server dialog.

Select the default app server. STS already configures the VMWare vFabric server which will work for us for the spring mvc. For GWT eventually we will choose other options (see next articles).

Press Next and make sure the pizza application is deployed (moved from Available to Configured)
And press 'Finish'

Now the application is deployed and stared. STS will try and start this in its own default browser, which wont really run it well (unless configured otherwise). So mke sure to open your favorite browser (aka Chrome) and see the results from the url

http://localhost:8080/pizza/

When started you should see:

Notice that tiles has assembled this page by bringing together a standard header, and a menu. The content area changes depending on what is selected.

The menu shows each domain class with two actions: Create new and List all . You can experiment with this scaffold application, create stuff etc. Notice how it handles the relationships from Pizza to Topping, or Pizza to Base. Or how PizzaOrders works.

This is not a deliverable application by far, but it will demonstrate your model. The technology configuration that it uses has a lot of assumptions on the tag @RooWebScaffold annotation to make it all work for actions like:

• List
• Create
• View
• Edit
• Remove

The scaffold also uses custom tags to handle these forms and expose this functionality.

You can customize what it generates incrementally to move closer to your application.

• You can modify messages
• you can modify csss
• you can play with layout (remember tiles)
• And parts of the JSP

Opinion

But real customization to the desired application design is hard if you start with a web site design in mind and try to map it to the scaffold UI. For the controller, the ITD (intertype files) created add very useful standard form based behavior to your applicaitons which can be leveraged by a variety of UI approaches.  But for the JSP generated, if you don't care as much and are doing an administrative application, this approach may suit you. You can compromise the UI design to best fit what has been generated and make customization's where needed. My experience is that this is rare. You can look at what is generated, but day 2 you are on your own. The basic configuration of spring mvc with tiles is good. The scaffold tags and jsps may not be what you need. You will need to really understand the annotated controllers and be able to write your own front end.

Next Steps

Next we will configure to use with GWT and see how this looks

Getting started with Spring Roo, GWT and STS - Part 1

This is a multi-part article. This article walks through my experiences getting started with spring's Roo framework using the Spring Tools Suite (STS). The next articles will walk through different aspects of building an application from scratch.
Also see

• Part 1 - Install and create - back end (this blog)
• Part 2 - Web MVC
• Part 3 - GWT
• Part 4 - Custom app from scratch
• 
  

Part One - Getting started with Roo using STS - The Roo tutorial 

Time to get started. I'm going to run through the introductory materials on building a Spring Roo application using the Roo tutorial. In the next articles I will build a custom example using Spring Roo with the Google Web Toolkit front end. I will be using the Spring Tools Suite as the IDE (based on Eclipse).

I will start by following some initial advice:

• on the Google side: here is a google code blog
• on the Spring side: here is springsource roo page and the springroo start and the Beginning with Roo: The tutorial from Spring Framework reference documentation
• another blog (gwtsts.blogspot.com) by Cengiz Öner describing this effort has multi-part instructions

Installation

What I have

• Java 6 SDK r26 from here
• Running on a Windows 7 Laptop (64 bit)

Step 1 - Install STS  
Download from here and follow the simple instructions.
I installed SpringSource Tool Suite: Version: 2.9.0.RELEASE Build Id: 201203011000

Step 2 - Configure to use Google Web Toolkit and Google App Engine
After running STS, go to the dashboard and select the 'extensions' tab (bottom). Find and Check Google Plugin for Eclipse and press 'Install' (bottom left)

Restart STS and thats it (for now)

Running through the Spring Roo Tutorial

Overview of Spring Pizza Shop Demo

Lets use the Spring Framework Roo tutorial to get started.This tutorial walks us through creating a Roo project including entities controllers and the UI/scaffold. I will try to emphasise use of the STS tool as well as focusinging on using GWT as the front end. To begin with, we will follow the tutorial fairly closely.

Here is the project UML from the spring tutorial that we will create

This is the Roo Pizza Shop demo

First Step Basic Roo Configuration

Spring Roo builds upon Spring framework 3.0 with JPA 2.0. It uses a command line tool to create basic elements of a project, from persistence setup, to creating entities, to creating Spring MVC controllers, to generating Scaffold ui (later we will be using GWT).

We can use spring STS to create a new spring Roo project project

1. From the Dashboard, select Create a Spring Roo Project
2. Fill out dialog: Project Name: pizza, top level package: com.springsource.roo.pizzashop
3. Accept all other defaults and press Next (and then Finish). This will create the Roo project and open the roo shell. Actually, STS is executing the roo shell to create the project directory and the roo command:

   roo> project --topLevelPackage com.springsource.roo.pizzashop

We see the ROO command shell at the bottom with a command promt inviting us to execute roo commands.

Note: Using the Roo shell in StS 

Roo uses a shell similar to Rails to invoke commands that create essential structures and configurations around the Roo project. It saves a lot of time writing repetitive code or digging around to configure stuff. the shell is a bit smart in that it knows what you have done in your project and what steps can be next.

The window has a top part showing a console with roo commands as well as a prompt, but don't be fooled. The roo prompt we use in StS is below (a single line edit).
The spring ROO project leverages Maven2 and its unique project structure.

One cool roo command you will use right away is hint. This will give you possible options to do from the point in your project.

After creating a roo project, you can type HINT in the Roo shell. It will respond with:

Roo requires the installation of a JPA provider and associated database.

Type 'persistence setup' and then hit CTRL+SPACE three times.
We suggest you type 'H' then CTRL+SPACE to complete "HIBERNATE".
After the --provider, press CTRL+SPACE twice for database choices.
For testing purposes, type (or CTRL+SPACE) HYPERSONIC_IN_MEMORY.
If you press CTRL+SPACE again, you'll see there are no more options.
As such, you're ready to press ENTER to execute the command.

Once JPA is installed, type 'hint' and ENTER for the next suggestion.

It knows what you have done before so it can provide hints for the next steps. Very smart!

Next: Setup project with persistence library

As mentioned before, Spring Roo requires the configuration of a JPA provider such as Eclipselink,, OpenJPA or Hibernate.

configure persistence for this project: in Roo shell,

1. As explained above, type hint and roo will prompt you to setup persistence for your project
2. type' persitence setup' and press ctrl+space. In StS, this will use code assist to allow you to select possible next options for the command (the command line, you press the TAB key). In this case we will select --provider HIBERNATE and --database HYPERSONIC_IN_MEMORY
3. The complete roo command is:

   persistence setup --provider HIBERNATE --database HYPERSONIC_IN_MEMORY
   

4. Roo will generate the JPA configuration files and initial spring context

Note: the roo log file

Spring keeps a log of your commands in the root project: log.roo. This may be handy to track what you have done, and in fact can be re-executed line by line to repeat your steps.

Next: Create your first Entity

In JPA, classes annotated as Entity are persistable, and generally map one-to-one to a table. Class properties generally map to columns in that table. The first class we will create will be Topping (see above UML model).

Using Roo shell:

1. Type Hint again, and Roo will advise you to type ent and press TAB to get the next option (from STS, ctrl+space). This will allow us to create an entity with a specific class name: Topping
2. Type entity then press (ctrl+space) . This will produce --class
3. Type ~.domain.Topping for the class name (the tilda will indicate the project's package root (remember we specified com.springsource.roo.pizzashop)
4. Now ctrl+space doesn't give us more hints since all required options are satisfied, but type double dash (--) and then ctrl+space will give us a bunch more options.
5. type or select --testAutomatically to generate test classes for the new entity and press enter

 (the complete roo command: entity --class ~.domain.Topping --testAutomatically)

Roo creates a whole bunch of files and aspects. Notice the actual entity "SRC_MAIN_JAVA\com\springsource\roo\pizzashop\domain\Topping.java" is created. You can see it in the packag tree. However, STS starts with an inital filter in the package tree to 'Focus on Active Task'.

Click the filter icon in the top toolbar of the Package view to reveal the entire project. Now navigate to src/main/java. See the com.springsource.roo.pizzashop.domain package and the created Topping.java class just created.

Next: Create Fields for Our Entity

Now lets add a field.
Use the roo command to type:

1.  field string --fieldName name --notnull --sizeMin 2

This will add a field, and update/add to the generated aspects based on the annotaitions.

Opening this class, all you see is

File: Topping.java

package com.springsource.roo.pizzashop.domain;  
import org.springframework.roo.addon.entity.RooEntity; 
import org.springframework.roo.addon.javabean.RooJavaBean; 
import org.springframework.roo.addon.tostring.RooToString; 
import javax.validation.constraints.NotNull; 
import javax.validation.constraints.Size;  
@RooJavaBean 
@RooToString 
@RooEntity 
public class Topping { 
     @NotNull
     @Size(min = 2)
     private String name; 
} 

Notice the classs annotations that roo adds @RooJavaBean, @RooToString and @RooEntity. These annotations generate aspects with extensions .aj for inter type definitions. Spring also adds JSR 303 bean validation annotations on the field based on the options we specified: @NotNull and @Size(min = 2).

The principle that Roo introduces here is the heavy leveraging of AspectJ's Inter-Type Declaration (ITD). The ITD code generates as a separately complied file, but is encorporated into the class byte code of the advised class. Generally we don't need to bother about what is generated here. But lets look anyway. For instance, the @RooJavaBean annotaion creates the class Topping_Roo_JavaBean.aj. Peeking at it, we see:

File: Topping_Roo_Entity.aj

// WARNING: DO NOT EDIT THIS FILE. THIS FILE IS MANAGED BY SPRING ROO. 
// You may push code into the target .java compilation unit if you wish to edit any member(s).  
package com.springsource.roo.pizzashop.domain; 

import java.lang.String; 

privileged aspect Topping_Roo_JavaBean { 
    public String Topping.getName() { 
        return this.name; 
    }     

    public void Topping.setName(String name) { 
        this.name = name; 
    }      
}  

We see that the name field produced a getter and a setter for the field. As we add new fields, this aspect will be updated. Using aspects this way allows the domain class to remain particularly pure.

As another example, lets look at what was generated for the @RooToString annotation:

File: Topping_Roo_ToString.aj

package com.springsource.roo.pizzashop.domain;  
import java.lang.String;  
privileged aspect Topping_Roo_ToString {      
    public String Topping.toString() { 
        StringBuilder sb = new StringBuilder(); 
        sb.append("Id: ").append(getId()).append(", "); 
        sb.append("Name: ").append(getName()).append(", "); 
        sb.append("Version: ").append(getVersion()); 
        return sb.toString(); 
    } 
}

Pretty nifty, huh! this is the Secret Sauce of Roo as described in Ben Alex' Blog on Roo's Architecture

Finally, lets' look at what Roo does with the @RooEntity declairation

File: Topping_Roo_Entity.aj

// WARNING: DO NOT EDIT THIS FILE. THIS FILE IS MANAGED BY SPRING ROO.
// You may push code into the target .java compilation unit if you wish to edit any member(s).

package com.springsource.roo.pizzashop.domain;

import com.springsource.roo.pizzashop.domain.Topping;
import java.lang.Integer;
import java.lang.Long;
import java.util.List;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.EntityManager;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.PersistenceContext;
import javax.persistence.Version;
import org.springframework.transaction.annotation.Transactional;

privileged aspect Topping_Roo_Entity {
    
    declare @type: Topping: @Entity;
    
    @PersistenceContext
    transient EntityManager Topping.entityManager;
    
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private Long Topping.id;
    
    @Version
    @Column(name = "version")
    private Integer Topping.version;
    
    public Long Topping.getId() {
        return this.id;
    }
    
    public void Topping.setId(Long id) {
        this.id = id;
    }
    
    public Integer Topping.getVersion() {
        return this.version;
    }
    
    public void Topping.setVersion(Integer version) {
        this.version = version;
    }
    
    @Transactional
    public void Topping.persist() {
        if (this.entityManager == null) this.entityManager = entityManager();
        this.entityManager.persist(this);
    }
    
    @Transactional
    public void Topping.remove() {
        if (this.entityManager == null) this.entityManager = entityManager();
        if (this.entityManager.contains(this)) {
            this.entityManager.remove(this);
        } else {
            Topping attached = Topping.findTopping(this.id);
            this.entityManager.remove(attached);
        }
    }
    
    @Transactional
    public void Topping.flush() {
        if (this.entityManager == null) this.entityManager = entityManager();
        this.entityManager.flush();
    }
    
    @Transactional
    public void Topping.clear() {
        if (this.entityManager == null) this.entityManager = entityManager();
        this.entityManager.clear();
    }
    
    @Transactional
    public Topping Topping.merge() {
        if (this.entityManager == null) this.entityManager = entityManager();
        Topping merged = this.entityManager.merge(this);
        this.entityManager.flush();
        return merged;
    }
    
    public static final EntityManager Topping.entityManager() {
        EntityManager em = new Topping().entityManager;
        if (em == null) throw new IllegalStateException("Entity manager has not been injected (is the Spring Aspects JAR configured as an AJC/AJDT aspects library?)");
        return em;
    }
    
    public static long Topping.countToppings() {
        return entityManager().createQuery("SELECT COUNT(o) FROM Topping o", Long.class).getSingleResult();
    }
    
    public static List Topping.findAllToppings() {
        return entityManager().createQuery("SELECT o FROM Topping o", Topping.class).getResultList();
    }
    
    public static Topping Topping.findTopping(Long id) {
        if (id == null) return null;
        return entityManager().find(Topping.class, id);
    }
    
    public static List Topping.findToppingEntries(int firstResult, int maxResults) {
        return entityManager().createQuery("SELECT o FROM Topping o", Topping.class).setFirstResult(firstResult).setMaxResults(maxResults).getResultList();
    }
    
}

}

Rather than creating a data access object (DAO) or service, Roo assumes that each entity created has its own implementation of persistence. The @RooEntity annotation generates a ITD (Inter-type Declairation) for the entity advising it to add many methods to support persistence, inclding id generation, versioning, access to the entity manager, various transactional methods:

• persist,
• remove,
• flush,
• merge,
• clear

and various finder methods

• count
• find by id
• findAll
• and pagable findAll

Next: Some More entitles and fields

As Roo creates objects, it keeps track of the last object you created. The next command defaults to this target, so there is no need to specify it explicitly. For example, when we created the field, we didn't need to specify what class to create the field for. It assumed we meant the last entity we worked with.. The spring Roo console shows what entity we last worked with in its prompt, much like a command shell might with a prompt showing the current directory path.

Using roo shell:

Now lets create another entity and some fields similar to the ones we created before. Here are the Roo commands:

entity --class ~.domain.Base --testAutomatically 
field string --fieldName name --notNull --sizeMin 2
entity --class ~.domain.Pizza --testAutomatically 
field string --fieldName name --notNull --sizeMin 2
field number --fieldName price --type java.lang.Float

That's it. As long as we follow the defaults, things are easy. This is the approach taken by Ruby on Rails: convention over configuration. The command line invokes templated commands to create objects quickly.

Our project should look basically like this (as seen from the project view)

Next: Some Relationships for our Entities

We are still in JPA land. JPA allows us to create relationships as well as if POJO java classes using well known collections. Roo supports a one-to-one or many-to-one reference, a one-to-many 'set' (and also ways to create many-many). In the above, we have a one-many relationship from Pizza to Topping (a pizza has many toppings) and a one-one relationship (reference) to a base. We'll use the Roo command shell to create these too. The tutorial shows there are two relationships from Pizza, a 'reference' to a base (m:1) where a Pizza has one base, and a set of toppings (m:m relationship to toppings), where a pizza has a set of toppings.

In roo shell, type the following:

field set --fieldName toppings --type ~.domain.Topping
field reference --fieldName base --type ~.domain.Base

The above commands assume you are creating the relationship fields to the last entity you created: Pizza as it would show you in a command prompt. If not, make sure to append --class ~.domain.Pizza to the above commands (at least the first one) to assure the relationships are created for the Pizza class.


And we can finish up with PizzaOrder, in roo shell:

entity --class ~.domain.PizzaOrder --testAutomatically
field string --fieldName name --notNull --sizeMin 2
field string --fieldName address --sizeMax 30
field number --fieldName total --type java.lang.Float
field date --fieldName deliveryDate --type java.util.Date
field set --fieldName pizzas --type ~.domain.Pizza

Note: if you make a mistake, you cn press the up arrow from the Roo shell prompt in STS and previous commands can be edited and re executed.

Notice the last command creates another relationship, this time an PizzaOrder has a set of Pizzas ordered, which Roo will create a m:m relationship for of type Set pizzas. As you can see, creating entities, fields and relationships with Roo comes down to running a set of commands to generate the appropriate Java code and Aspects according to Roo convention. In fact, you can save these commands as a 'seed' text file that will create a project for you, generating the project structure, configruation, classes and aspects required.

Next: Lets Test

We can now run the integration tests using the roo command perform tests.

perform tests

Here is a summary of the roo commands executed

// Spring Roo 1.1.4.RELEASE [rev f787ce7] log opened at 2012-03-17 10:38:04
project --topLevelPackage com.springsource.roo.pizzashop --projectName pizza --java 6
// Spring Roo 1.1.4.RELEASE [rev f787ce7] log closed at 2012-03-17 10:38:15
// Spring Roo 1.1.4.RELEASE [rev f787ce7] log opened at 2012-03-17 10:38:19
hint
hint
persistence setup --database HYPERSONIC_IN_MEMORY --provider HIBERNATE 
hint
entity --class ~.domain.Topping --testAutomatically 
field string --fieldName name --notnull --sizeMin 2
entity --class ~.domain.Base --testAutomatically 
field string --fieldName name --notNull --sizeMin 2
entity --class ~.domain.Pizza --testAutomatically
field string --fieldName name --notNull --sizeMin 2
field number --fieldName price --type java.lang.Float

field set --fieldName toppings --type ~.domain.Topping
field reference --fieldName base --type ~.domain.Base
entity --class ~.domain.PizzaOrder --testAutomatically
field string --fieldName name --notNull --sizeMin 2
field string --fieldName address --sizeMax 30
field number --fieldName total --type java.lang.Float
field date --fieldName deliveryDate --type java.util.Date

field set --fieldName pizzas --type ~.domain.Pizza
perform tests

Finally: Look at the test classes generated


The main class 'Pizza' has a name (required min size 2) and a price, but also two relationships: one a many-many relationship to Toppings class and a reference (many-one) relationship to Base class.

File: Pizza.java

package com.springsource.roo.pizzashop.domain;

import org.springframework.roo.addon.entity.RooEntity;
import org.springframework.roo.addon.javabean.RooJavaBean;
import org.springframework.roo.addon.tostring.RooToString;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import java.util.Set;
import java.util.HashSet;
import javax.persistence.ManyToMany;
import javax.persistence.CascadeType;
import com.springsource.roo.pizzashop.domain.Topping;
import com.springsource.roo.pizzashop.domain.Base;
import javax.persistence.ManyToOne;

@RooJavaBean
@RooToString
@RooEntity
public class Pizza {

    @NotNull
    @Size(min = 2)
    private String name;

    private Float price;

    @ManyToMany(cascade = CascadeType.ALL)
    private Set toppings = new HashSet();

    @ManyToOne
    private Base base;
}

The class 'Base' has a single field 'name' but annotated with @NotNull and @Size min 2.

File: Base.java

package com.springsource.roo.pizzashop.domain;

import org.springframework.roo.addon.entity.RooEntity;
import org.springframework.roo.addon.javabean.RooJavaBean;
import org.springframework.roo.addon.tostring.RooToString;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;

@RooJavaBean
@RooToString
@RooEntity
public class Base {

    @NotNull
    @Size(min = 2)
    private String name;
}

Topping is also a simple class, with one field 'name' declaired as Min 2 (but not NotNull ?) probably should be NotNull, dont you think?

File: Topping.java

package com.springsource.roo.pizzashop.domain;

import org.springframework.roo.addon.entity.RooEntity;
import org.springframework.roo.addon.javabean.RooJavaBean;
import org.springframework.roo.addon.tostring.RooToString;
import javax.validation.constraints.Size;

@RooJavaBean
@RooToString
@RooEntity
public class Topping {

    @Size(min = 2)
    private String name;
}

Finally, PizzaOrder is the workhorse of the project. It relates the person ordering (this could be another class 'Customer' but isn't for simplicity sake (we may not need to track people or order pizza but it may help down the road)

File: PizzaOrder.java

package com.springsource.roo.pizzashop.domain;

import org.springframework.roo.addon.entity.RooEntity;
import org.springframework.roo.addon.javabean.RooJavaBean;
import org.springframework.roo.addon.tostring.RooToString;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import java.util.Date;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import org.springframework.format.annotation.DateTimeFormat;
import java.util.Set;
import com.springsource.roo.pizzashop.domain.Pizza;
import java.util.HashSet;
import javax.persistence.ManyToMany;
import javax.persistence.CascadeType;

@RooJavaBean
@RooToString
@RooEntity
public class PizzaOrder {

    @NotNull
    @Size(min = 2)
    private String name;

    @Size(max = 30)
    private String address;

    @Temporal(TemporalType.TIMESTAMP)
    @DateTimeFormat(style = "S-")
    private Date deliveryDate;

    private Float total;

    @ManyToMany(cascade = CascadeType.ALL)
    private Set pizzas = new HashSet();
}

Fixing a problem
In the above example, i noted that Toppings 'name' field doesn't have a @NotNull annotation and it probably should. How do you fix it? Using the Roo shell is good for adding stuff, but not changing or removing stuff. To do this, just go to the java code itself.

1. Open the Toppings class
2. Add the @NotNull annotation
3. Add the import for the annotation (I like to use CTRL+SHIFT+O for 'Organize Imports' in the Source menu)

And that's it!

Next steps

On next blog article we will add a user interface to this to complete the tutorial, still no GWT yet. That will be following.

Testing my RESTful controllers with Spring RESTtemplate

I have been playing with Spring's RESTtemplate as an approach to integration testing on my project.

Overview of Testing a RIA with Spring and Spring MVC

I feel I should create a set of blog posts related to how I am doing testing with this technology stack. Sometimes this aggregation is helpful. In my team, we are testing at the following levels:

• unit testing of everyting - pure tests, typically single class only, with mock (using Mockito)
• integration testing of our services - out of container (web server) testing, but with db
• integration testing of our controllers - in container testing, with db
• functional testing of our ui (TBD) - full in container testing

This blog will focus on integration testing.

Integration testing, different from unit testing, tests the code as it is wired up to other components, the server and the data base as well.

Testing the controller layer in Spring MVC

To set the stage, I am using spring 3 with Spring MVC for my application. In particular, I am leveraging a lot of Ajax, accessing the controller from the browser and transporting JSON. I am using the Jackson JSON mapping implementation to marshal to from beans to JSON.

I need to create good integration tests of my controller classes so I can run JUnit tests that connect with the deployed web app and interact RESTfully like the client UI, passing JSON objects back and forth.

A helpful blog post I have used for guidance: is ralf.schaeftlein s blog detailing an approach to integration testing of restful MVC controllers with JSON. Exactly what I was interested in.
The basic steps seem to be:

1. create a unit test with java4 leveraging Spring 3 Integration Test Annotations
2. configure your application context XML to define your mappers that will convert between JSON and beans
3. write your tests pojo style

Integration Testing with Spring uses annotations to supply a spring context to your test code. Further, the annotations specify what transaction manager to use and if a rollback should be performed after the test is complete. The tests itself are written with JUnit4. Here is a snippet showing the annotations required placed on your test class.


In this case, I am testing my Data Repository, which is essentially my Data Access Object (DAO) for you old schoolers. I will post why Repositories and not DAO in a future blog.
My application context file configures spring with the required setup for my application to run this test. First, the usual name spaces:

Then, we use automatic annotation discovery of out project

Here is wshere we configure the restTemplate to be used for this integration test of our controller
Finally the required configuration for our persistence. Notice we are using JPA configuration here


Finnaly the test code.

We write an integration test for our controller that connects remotely to the deployed application, sends beans mapped from Pojo to json for the call, and then maps back json to Pojo to assert results.

New Technology Stack

In my real life, I actually have to deliver software :). So most of my blogs are about the technologies I am using today as well as best practices I am actually practicing (or trying to practice) in my real life.

This blog will focus on the following technology stack for now:

• JQuery and JQuery UI
• Spring and Spring MVC
• Java Persistence API (JPA 2.0)

Also I will be looking at:

• Spring Roo
• and GWT (Google Web Toolkit)

Some techniques and tools include

• Sun NetBeans IDE
• SpringSource Tool Suite
• Test Driven Development
• Continuous Integration
• Maven