Una presentacion de Spring ONE de lo nuevo en Spring 3.0

1. Spring Framework 3.0
The Next Generation
Jürgen Höller
VP & Distinguished Engineer
SpringSource
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2. Agenda
• Quick Review: Spring 2.5
• Spring 3.0 Themes and Features
• Spring 3.0 Roadmap
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3. Spring Framework 2.5
• Comprehensive support for
annotation-based configuration
– @Autowired
• with optional @Qualifier or custom qualifier
– @Transactional
– @Service, @Repository, @Controller
• Common Java EE 5 annotations supported too
– @PostConstruct, @PreDestroy
– @PersistenceContext, @PersistenceUnit
– @Resource, @EJB, @WebServiceRef
– @TransactionAttribute
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4. Annotated Bean Component
@Service
public class RewardNetworkService
implements RewardNetwork {
@Autowired
public RewardNetworkService(AccountRepository ar) {
…
}
@Transactional
public RewardConfirmation rewardAccountFor(Dining d) {
…
}
}
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5. Minimal XML Bean Definitions
<!– Activating annotation-based configuration -->
<context:annotation-config/>
<bean class=”com.myapp.rewards.RewardNetworkImpl”/>
<bean class=”com.myapp.rewards.JdbcAccountRepository”/>
<!– Plus shared infrastructure configuration beans:
PlatformTransactionManager, DataSource, etc -->
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6. Test Context Framework
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration
public class RewardSystemIntegrationTests {
@Autowired
private RewardNetwork rewardNetwork;
@Test
@Transactional
public void testRewardAccountForDining() {
// test in transaction with auto-rollback
}
}
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7. @MVC Controller Style
@Controller
public class MyController {
private final MyService myService;
@Autowired
public MyController(MyService myService) {
this.myService = myService;
}
@RequestMapping("/removeBook")
public String removeBook(@RequestParam("book") String bookId) {
this.myService.deleteBook(bookId);
return "redirect:myBooks";
}
}
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8. Spring 3.0 Themes
• Java 5+ foundation
– even stronger support for annotated components
• Spring Expression Language
– Unified EL++
• Comprehensive REST support
– and other Spring @MVC additions
• Declarative model validation
– Hibernate Validator, JSR 303
• Support for Portlet 2.0
– action/event/resource request mappings
• Early support for Java EE 6
– JSF 2.0, JPA 2.0, etc
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9. New Project Layout
• Framework modules revised
– now managed in Maven style
– one source tree per module jar
• spring-beans.jar, spring-aop.jar, etc
– no spring.jar anymore!
• Built with new Spring build system as known
from Spring Web Flow 2.0
– Ivy-based "Spring Build" system
– consistent deployment procedure
– consistent dependency management
– consistent generation of OSGi manifests
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10. Core APIs updated for Java 5
• BeanFactory interface returns typed bean
instances as far as possible
– T getBean(String name, Class<T> requiredType)
– Map<String, T> getBeansOfType(Class<T> type)
• Spring's TaskExecutor interface extends
java.util.concurrent.Executor now
– extended AsyncTaskExecutor supports standard
Callables with Futures
• Typed ApplicationListener<E>
– ApplicationEventMulticaster detects declared event
type and filters accordingly
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11. Portfolio Rearrangements
• Spring 3.0 includes a revised version of the
Object/XML Mapping (OXM) module
– known from Spring Web Services
– supported for REST-style payload conversion
– also useful e.g. for SQL XML access
• Spring 3.0 features a revised binding and
type conversion infrastructure
– including the capabilities of Spring Web Flow's binding
– stateless Java 5+ type converters with EL integration
– superseding standard JDK PropertyEditors
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12. Annotated Factory Methods
• Spring 3.0 includes the core functionality of the
Spring JavaConfig project
– configuration classes defining managed beans
– common handling of annotated factory methods
@Bean @Primary @Lazy
public RewardsService rewardsService() {
RewardsServiceImpl service = new RewardsServiceImpl();
service.setDataSource(…);
return service;
}
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13. Use of Meta-Annotations
• More powerful options for custom annotations
– combining meta-annotations e.g. on stereotype
– automatically detected (no configuration necessary!)
@Service
@Scope("request")
@Transactional(rollbackFor=Exception.class)
@Retention(RetentionPolicy.RUNTIME)
public @interface MyService {}
@MyService
public class RewardsService {
…
}
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14. EL in Bean Definitions
<bean class="mycompany.RewardsTestDatabase">
<property name="databaseName"
value="“#{systemProperties.databaseName}”/>
<property name="keyGenerator"
value="“#{strategyBean.databaseKeyGenerator}”/>
</bean>
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15. EL in Component Annotations
@Repository
public class RewardsTestDatabase {
@Value(“#{systemProperties.databaseName}”)
public void setDatabaseName(String dbName) { … }
@Value(“#{strategyBean.databaseKeyGenerator}”)
public void setKeyGenerator(KeyGenerator kg) { … }
}
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16. Powerful Spring EL Parser
• Custom expression parser implementation
shipped as part of Spring 3.0
– package org.springframework.expression
– next-generation expression engine
• inspired by Spring Web Flow 2.0's expression support
– pluggable and customizable
• Compatible with Unified EL but significantly
more powerful
– navigating bean properties, maps, etc
– method invocations
– construction of value objects
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17. EL Context Attributes
• Example showed access to EL attributes
– "systemProperties", "strategyBean"
– implicit references in expressions
• Implicit attributes to be exposed by default,
depending on runtime context
– e.g. "systemProperties", "systemEnvironment"
• global platform context
– access to all Spring-defined beans by name
• similar to managed beans in JSF expressions
– extensible through Scope SPI
• e.g. for step scope in Spring Batch
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18. Web Context Attributes
• Implicit web-specific attributes to be
exposed by default as well
– "contextParameters": web.xml init-params
– "contextAttributes": ServletContext attributes
– "request": current Servlet/PortletRequest
– "session": current Http/PortletSession
• Exposure of all implicit JSF objects when
running within a JSF request context
– "param", "initParam", "facesContext", etc
– full compatibility with JSF managed bean facility
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19. REST Support
• Spring MVC to provide first-class support for
REST-style mappings
– extraction of URI template parameters
– content negotiation in view resolver
• Goal: native REST support within Spring
MVC, for UI as well as non-UI usage
– in natural MVC style
• Alternative: using JAX-RS through integrated
JAX-RS provider (e.g. Jersey)
– using the JAX-RS component model to build
programmatic resource endpoints
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20. REST in MVC - @PathVariable
http://rewarddining.com/rewards/12345
@RequestMapping(value = "/rewards/{id}", method = GET)
public Reward reward(@PathVariable("id") long id) {
return this.rewardsAdminService.findReward(id);
}
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21. Different Representations
• JSON
GET http://rewarddining.com/accounts/1 accepts application/json
GET http://rewarddining.com/accounts/1.json
• XML
GET http://rewarddining.com/accounts/1 accepts application/xml
GET http://rewarddining.com/accounts/1.xml
• ATOM
GET http://rewarddining.com/accounts/1 accepts application/atom+xml
GET http://rewarddining.com/accounts/1.atom
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22. Common @MVC Refinements
• More options for handler method parameters
– in addition to @RequestParam and @PathVariable
– @RequestHeader: access to request headers
– @CookieValue: HTTP cookie access
– supported for Servlet MVC and Portlet MVC
@RequestMapping("/show")
public Reward show(@RequestHeader("region") long regionId,
@CookieValue("language") String langId) {
...
}
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23. Portlet 2.0 Support
• Portlet 2.0: major new capabilities
– explicit action name concept for dispatching
– resource requests for servlet-style serving
– events for inter-portlet communication
– portlet filters analogous to servlet filters
• Spring's Portlet MVC 3.0 to support explicit
mapping annotations
– @ActionMapping, @RenderMapping,
@ResourceMapping, @EventMapping
– specializations of Spring's @RequestMapping
• supporting action names, window states, etc
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24. Spring Portlet MVC 3.0
@Controller
@RequestMapping("EDIT")
public class MyPortletController {
…
@ActionMapping("delete")
public void removeBook(@RequestParam("book") String bookId) {
this.myService.deleteBook(bookId);
}
@EventMapping("BookUpdate")
public void updateBook(BookUpdateEvent bookUpdate) {
// extract book entity data from event payload object
this.myService.updateBook(…);
}
}
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25. Model Validation
public class Reward {
@NotNull
@Past
private Date transactionDate;
}
In view:
<form:input path="transactionDate">
• Same metadata can be used for persisting, rendering, etc
• Spring 3.0 RC1: to be supported for MVC data binding
• JSR-303 "Bean Validation" as the common ground
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26. Scoped Bean Serializability
• Problem with Spring 2.5: serializability of
session and conversation objects
– when referencing shared service objects via Spring
dependency injection
• and not marking them as transient
– typical situation: scoped bean instance holds on to
DataSource or the like
• DataSource reference is not serializable
• -> whole bean not serializable
• Solution: proxies that reobtain references
on deserialization
– from current Spring WebApplicationContext
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27. Scheduling Enhancements
• Spring 3.0 introduces a major overhaul of
the scheduling package
– extended java.util.concurrent support
• prepared for JSR-236 "Concurrency Utilities for Java EE"
– TaskScheduler interface with Triggers
• including cron expression triggers
– @Async annotation for asynchronous user methods
• @Scheduled for cron-triggered methods
• XML scheduling namespace
– cron expressions with method references
– convenient executor service setup
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28. Spring 3.0 and Java EE 6
• Early Java EE 6 API support in Spring 3.0
– integration with JSF 2.0
• full compatibility as managed bean facility
– integration with JPA 2.0
• support for lock modes, query timeouts, etc
– support for JSR-303 Bean Validation annotations
• through Hibernate Validator 4.0 integration
– all embeddable on Tomcat 5.5+ / J2EE 1.4+
• Spring 3.x: support for Java EE 6 platforms
– Servlet 3.0 (waiting for GlassFish 3 and Tomcat 7)
– JSR-236 "Concurrency Utilities for Java EE"
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29. Spring 3.0 Platform Support
• Requires Java 5 or above
– Java 6 automatically detected & supported
• Web container: Servlet 2.4 or above
– e.g. Tomcat 5.5 & 6.0
• Java EE level: J2EE 1.4 or above
– e.g. WebSphere 6.1 & 7.0
• Fully OSGi compatible out of the box
– featured in dm Server 2.0
• Also compatible with Google App Engine
– and other 'special' hosting environments
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30. Pruning & Deprecation in 3.0
• Some pruning: removal of outdated features
– Commons Attributes support
• superseded by Java 5 annotations
– traditional TopLink API support
• in favor of JPA (EclipseLink)
– subclass-style Struts 1.x support
• Some deprecation: superseded features
– traditional MVC form controller hierarchy
• superseded by annotated controller style
– traditional JUnit 3.8 test class hierarchy
• superseded by test context framework
– several outdated helper classes
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31. Spring 2.5 Mission Continued
• Spring 3 continues Spring 2.5's mission
– fully embracing Java 5 in the core Spring
programming and configuration model
– now with even the core framework requiring Java 5
• all framework classes using Java 5 language syntax
• Backwards compatibility with Spring 2.5
– 100% compatibility of programming model
– 95% compatibility of extension points
– all previously deprecated API to be removed
• Make sure you're not using outdated Spring 1.2 / 2.0
API anymore!
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32. Spring 3.0 Summary
• Spring 3.0 embraces REST and EL
– full-scale REST support
– broad Unified EL++ support in the core
• Spring 3.0 significantly extends and refines
annotated web controllers
– RESTful URI mappings
– annotation-based model validation
• Spring 3.0 remains backwards compatible
with Spring 2.5 on Java 5+
– enabling a smooth migration path
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33. Spring 3.0 Roadmap
• Spring Framework 3.0 M3 to be released
any day now
– last milestone before RC1
• Spring Framework 3.0 RC1 scheduled for
late May 2009
– GA to follow soon after
• Spring Framework 3.1 expected in
Q4 2009
– full compatibility with Java EE 6 platforms
– first-class support for conversation management
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