Spring 3.1 introduced several eagerly awaited features including bean definition profiles (a.k.a., environment-specific configuration), enhanced Java-based application and infrastructure configuration (a la XML namespaces), and a new cache abstraction. This session will provide attendees a high-level overview of these major new features plus a quick look at additional enhancements to the framework such as the new c: namespace for constructor arguments, support for Servlet 3.0, improvements to Spring MVC and REST, and Spring's new integration testing support for profiles and configuration classes. In addition, this talk will introduce new features under development in the Spring 3.2 roadmap.

1. Spring 3.1 to 3.2
in a Nutshell
Sam Brannen
Swiftmind

2. Speaker Profile
• Spring & Java consultant @ Swiftmind
• Developing Java for over 14 years
• Spring Framework Core Developer
• Spring Trainer
• Lead author of “Spring in a Nutshell”

3. Show of hands…

4. Agenda
• Major Themes in 3.x
• Environment and Profiles
• Java-based Configuration
• Testing
• Caching
• MVC and REST
• Servlet 3.0
• 3.2 Roadmap

5. Major Themes in Spring 3.0

6. Java-based configuration

7. custom stereotypes

8. annotated factory methods

9. JSR-330 – DI for Java

10. Spring Expression Language

11. REST support in Spring MVC

12. Portlet API 2.0

13. JSR-303 – bean validation

14. Java EE 6 support: JPA 2.0, JSF 2.0

15. Major Themes in Spring 3.1
– Environment abstraction
– Java-based application configuration
– @Configuration class test support
– High-level cache API
– Customizable @MVC processing
– Flash maps and redirect attributes
– Explicit support for Servlet 3.0

16. Environment and Profiles

17. Environment Abstraction
– Injectable environment abstraction API
• org.springframework.core.env.Environment
– Two core concepts
• Property Sources
• Bean Profiles
Property Source: Bean Profile:
A variety of sources: property A logical group of bean
files, system properties, definitions. Registered only if
servlet context, JNDI, etc. the profile is active.

18. Property Source Abstraction
– Property source
– Property resolution
– Placeholders

19. PropertySource(s)
– PropertySource
• a single property source
– PropertySources
• a hierarchy of PropertySource objects
• potentially varying across deployment environments

20. Property Resolution SPI
– org.springframework.core.env.PropertyResolver
– Environment extends PropertyResolver

21. Custom Placeholder Resolution
– dependent on the actual environment
– PropertySourcesPlaceholderConfigurer
supersedes PropertyPlaceholderConfigurer

22. Managing Property Sources
– Stand-alone code
– Web application
• Implement ApplicationContextInitializer
• Register via contextInitializerClasses context parameter in
web.xml

23. Accessing Properties
– By injecting the Environment

24. Bean Definition Profiles
– Logical grouping of bean definitions
• for activation in specific environments
• e.g., dev, staging, prod
• possibly different deployment platforms
– Configuration
• XML via <beans profile=“…”>
• Java-based configuration via @Profile

25. Configuring Profiles in XML
– All bean definitions
– Subset of bean definitions

26. Configuring Profiles in Java Config
– @Profile can also be used on components
• @Component, @Service, @Repository, etc. 26

27. Profile Activation Options
– programmatically
– system property
– in web.xml
– in tests via @ActiveProfiles

28. Activating Profiles…
programmatically

29. Activating Profiles…
via system properties
-Dspring.profiles.active=“dev”
-Dspring.profiles.default=“common”

30. Activating Profiles…
in web apps

31. Activating Profiles…
in integration tests

32. Java-based Configuration

33. Java Config ~= XML
– XML namespaces  @Enable*
– FactoryBeans  builders
– GenericXmlContextLoader 
AnnotationConfigContextLoader
– Not a one-to-one mapping
• Make the most of what Java has to offer
• Intuitive annotation-oriented container configuration

34. Typical Infrastructure Setup
– Transactions
– Scheduling
– MVC customization
– AOP

35. @Enable* Annotations
– Applied at the class-level on @Configuration
classes
– Roughly equivalent to their XML namespace
counterparts

36. @Enable* in 3.1
– @EnableTransactionManagement
– @EnableCaching
– @EnableAsync
– @EnableScheduling
– @EnableAspectJAutoProxy
– @EnableLoadTimeWeaving
– @EnableSpringConfigured
– @EnableWebMvc

37. Hibernate and JPA
– Hibernate LocalSessionFactoryBuilder API
• Hibernate 4 replacement for both
LocalSessionFactoryBean and
AnnotationSessionFactoryBean
– XML-free JPA configuration
• LocalContainerEntityManagerFactoryBean has a
new property
• packagesToScan: analogous to
AnnotationSessionFactoryBean

38. Java Configuration Example
Actually:
LocalSessionFactoryBuilder

39. New Testing Features in 3.1
– @Configuration class support
– Environment profile support
– SmartContextLoader
– AnnotationConfigContextLoader
– DelegatingSmartContextLoader
– Updated context cache key generation

40. SmartContextLoader SPI
– Supersedes ContextLoader
– Strategy for loading application contexts
– From @Configuration classes or resource
locations
– Supports environment profiles

41. @ContextConfiguration
accepts a new `classes` attribute...

42. Ex: @Configuration Test #1

43. Ex: @Configuration Test #2

44. Caching

45. Caching Abstraction
– Declarative caching for Spring applications
• Minimal impact on code
• Plug in various caching solutions

46. Caching Abstraction
– Key annotations
• @Cacheable
• @CacheEvict

47. Cache Key
– All method arguments used by default
– Use SpEL to select more specifically (use
class, method, or argument name)

48. Conditional Caching

49. Cache Providers (1/2)
– Cache and CacheManager SPI
• org.springframework.cache
– Cache Implementations
• EhCacheCache
• ConcurrentMapCache and
ConcurrentMapCacheFactoryBean

50. Cache Providers (2/2)
– CacheManager Implementations
• EhCacheCacheManager
• ConcurrentMapCacheManager
• SimpleCacheManager
• NoOpCacheManager
– Any other implementation can be plugged in
• GemFire, Coherence, etc.

51. Cache Configuration
– Cache namespace
• <cache:annotation-driven />
• “cacheManager” bean

52. MVC and REST

53. @MVC 3.0 Config
– Built-in defaults
• Based on DispatcherServlet.properties
– Spring MVC namespace
• <mvc:annotation:driven>, <mvc:interceptors>, …

54. Java-based @MVC 3.1 Config
– Most Spring MVC configuration is in Java already
• @Controller, @RequestMapping, etc.
– Servlet 3.0 enhancements will further reduce the
need for web.xml
– XML namespace is convenient but …
• Not transparent
• Not easy to offer the right degree of customization
– … What should a Java equivalent to the MVC
namespace look like?

55. @EnableWebMvc
– Enables Spring MVC default configuration
• Registers components expected by the
DispatcherServlet
– Allows for configuration similar to the
Spring MVC namespace
• … and the DispatcherServlet.properties combined

56. A More Complete Example …
– Add component scanning for @Controllers
and other beans

57. Q: Where is the “Enabled”
Configuration ?!
– A: a framework-provided @Configuration class
(actually DelegatingWebMvcConfiguration)

58. How Do I Customize All This?
– Simply implement the WebMvcConfigurer
interface
Allows selective overriding

59. HandlerMethod Abstraction
– HandlerMethod
• A proper abstraction for the selected “handler” in Spring MVC
– Not just for @RequestMapping methods
• Also @InitBinder, @ModelAttribute, @ExceptionHandler
methods
– “HandlerMethod” support classes
• RequestMappingHandlerMapping
• RequestMappingHandlerAdapter
• ExceptionHandlerExceptionResolver

60. Path Variables in the Model
– @PathVariable arguments automatically
added to the model
These can be deleted

61. URI Templates in Redirect Strings
– URL templates supported in “redirect:”
strings
Expanded from model attributes,
which now include @PathVariables

62. URI Template Vars in Data Binding
– URI template variables used in data binding

63. Matching MediaTypes < @MVC 3.1
– Using the 'headers' condition

64. Matching MediaTypes in @MVC 3.1
– The 'consumes' and 'produces' conditions
If not matched, results in:
UNSUPPORTED_MEDIA_TYPE (415)
If not matched, results in:
NOT_ACCEPTABLE (406)

65. Servlet 3.0

66. Servlet 3.0 Containers
• Tomcat 7 and GlassFish 3
– Explicitly supported
• While preserving compatibility with Servlet
2.4+

67. XML-free Web-app Config
• Support for XML-free web application setup
– no web.xml
• Made possible via:
– Servlet 3.0's ServletContainerInitializer
– Spring 3.1's
AnnotationConfigWebApplicationContext
– Spring 3.1’s environment abstraction

68. Native Servlet 3.0 in @MVC
• Asynchronous request processing
• Standard Servlet 3.0 file upload
– behind Spring's MultipartResolver abstraction

69. Bonus

70. "c:" Namespace
– Shortcut for <constructor-arg>
• inline argument values
• analogous to existing "p:" namespace
– Use of constructor argument names
• recommended for readability
• debug symbols have to be available in the
application's class files

71. Spring 3.1 in a Nutshell
• Environment and Profiles
• Java-based Configuration and @Enable*
• Testing with @Configuration and Profiles
• Cache Abstraction
• MVC and REST Improvements
• Servlet 3.0
• c: Namespace

72. Spring 3.2 Roadmap

73. Build System & Source Control
• Moved from Subversion to Git(hub)
– Spring 3.1.1
– github.com/SpringSource/spring-framework
• Moving from Spring Build (i.e., Ant + Ivy) to
Gradle
• SPR-8120

74. Servlet 3.0/3.1 Async Requests
• Servlet 3.0/3.1 asynchronous request
processing
– Explicit support in Spring @MVC
• SPR-8517

75. Java EE 7
• JPA 2.1 (JSR-338)
– Building on JPA 2.0 support in Spring 3.0
– SPR-8194
• JSF 2.2 (JSR-344)
– Specification compatibility
– SPR-8104
• JMS 2.0 (JSR-343)
– Long overdue, major overhaul to JMS
– Exploring a native JMS API style for use with Spring
– SPR-8197

76. Caching
• Support for JCache (JSR-107) compliant cache providers
– JCacheCacheManager/Cache adapters for Spring's SPI
– JCacheManager/JCacheFactoryBean
• Support for JCache's standardized caching annotations
– ideally automatically through Spring’s
<cache:annotation-driven>
• SPR-8774

77. Validation
• Bean Validation 1.1 (JSR-349)
– Specification compatibility
– Building on 1.0 support in Spring 3.0
• SPR-8199

78. Spring Core
• Migrate from CGLIB to Javassist
– For class-based proxies (AOP)
– SPR-8190
• Bean definition visibility and overriding
– Final bean definitions
– Profile-scoped beans
– @Bean methods override XML beans
– SPR-8189

79. Spring MVC Testing Support
• Unit tests with Mock MVC classes
– Simulates the DispatcherServlet
• Integration tests with XmlWebApplicationContext
– Configured via @ContextConfiguration and other
annotations
– Loaded via a new ContextLoader

80. In Closing…

81. Further Resources
• Spring Framework
– http://springframework.org
– Spring Reference Manual
– JavaDoc
• Spring Forums
– http://forum.springframework.org
• Spring JIRA
– http://jira.springframework.org

82. Blogs
• SpringSource Team Blog – category 3.1
– http://blog.springsource.com/category/spring/31/
• Swiftmind Blog
– http://www.swiftmind.com/blog/

83. Q&A
Sam Brannen
twitter: @sam_brannen
www.slideshare.net/sbrannen
www.swiftmind.com
“Spring in a Nutshell”
http://oreilly.com/catalog/9780596801946
available from O’Reilly in 2012