Java EE Architecture with the Spring Framework Peter Thomas

Transcription

1 Java EE Architecture with the Spring Framework Peter Thomas Peter Thomas Satyam Computer Services Ltd. 1

2 Overview Spring: quick intro JTrac a real-life Spring web-app Architecture DI / IoC Spring DAO / Hibernate support Spring AOP / Declarative TX Spring MVC / Webflow Acegi Security Framework Spring Modules Spring implications Selected best practices 2

3 Spring History Feb 2003: SourceForge Project founded Nov 2002 Aug 2003: 1.0 M1 Jul 2004 Mar 2004: 1.0 3

4 JTrac JTrac: highly customizable issue tracking 4

5 JTrac Architecture JSP / JSTL Presentation Spring MVC Service Spring Security (Acegi) Spring WebFlow POJO POJO POJO Spring AOP Spring Context (DI / IoC container) Spring TX Spring DAO / Hibernate Support Persistence Hibernate 3 Database 5

6 Dependency Injection JtracImpl.java 6

7 Dependency Injection (2) Controllers Service Interface Service Implementation DAO Interface DAO Implementation 7

8 Hibernate with Spring One liners Template pattern No need to deal with TX, Session etc. 8

9 Spring DAO Exception Hierarchy 9

10 Spring AOP / Declarative TX Mgmt. Controllers Service Interface jtrac TX Proxy jtractarget Service Implementation DAO Interface DAO Implementation 10

11 Spring AOP (contd ) MVC Action Spring TX Proxy (AOP) Service Layer Method call DAO method 11

12 Spring Web Flow Logical View Name State Transitions backend logic call (normal Java method) Flow Decision Re-usable Flow invocation submit userform Handler Space == null? yes user Allocate Flow userform no cancel userlist View 12

13 Security with Acegi Any other request has to be allowed only for authenticated users any URL request within the /admin/ directory or path can only be allowed for ROLE_ADMIN 13

14 Spring Modules example: Lucene 14

15 JTrac: Spring implications Application deployed as a WAR file Portable: Tomcat, Jetty, JBoss or any Java EE app server Easily unit-testable Faster build-deploy-test cycles Clean OO design, designed to interfaces No EJBs No Singletons No Service Locator / JNDI lookup No custom Factory Pattern implementation No DTOs / VOs No Annotations (optional) JSTL / JSP 15

16 Why not RoR :) Spring Hibernate Lazy Loading HSQLDB Jetty Embedded database Small footprint Embedded app-server + web server! Libraries i18n JavaSVN, JFreeChart, Lucene, Apache POI 16

17 Notable in Spring 2.0 Async task execution Portlet MVC Use Groovy, JRuby etc. for config MVC: Custom taglib for form controls (like Struts) Message driven POJOs JPA support Simplified XML config option AspectJ integration 17

18 Agile Development with Spring + Hibernate Spring No need of container JUnit support classes POJOs inherently easy to test Hibernate Completely abstracts DB HSQLDB can be used for testing Unit tests can assume that DB exists, no mocks reqd. clean compile db-start db-create test db-stop reports Delete all previous build artifacts / database files from file system Compile all code and unit tests Boot a fresh instance of the HSQLDB database server Connect to the database and forward-generate the schema from the mapping files using Hibernate. Run unit-tests. Shutdown database. Generate Reports 18

19 DEMO Unit + Integration Testing 19

20 Watij [ ] A new class of web test automation tools Watir Web Application Testing in Ruby Selenium Watij Web Application Testing in Java Focus on using a real browser, not simulating one Especially important when lots of Javascript / AJAX 20

21 Watij Features Write tests in pure Java Interactively script tests using BeanShell Possible to drive tests using JUnit No setup required on the Server Under Test Support for nested tables, frames Good popup and multi-window support And also brute-force keystroke support 21

22 Watij in conjunction with JUnit 22

23 DEMO Watij Driving functional tests with JUnit 23

24 Thank you 24