PA165
Introduction to Spring framework
Petr Adámek
Content: Spring Framework
• Introduction into Spring
• Spring IoC
– XML driven
– Annotation driven
– Code driven
• AOP
• Transaction Management
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INTRODUCTION INTO SPRING
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Spring framework
• http://projects.spring.io/spring-framework/
• Rod Johnson: Expert One-on-One J2EE Design and
Development (2002)
• Non-invasive framework, very flexible, does not try to
reinvent the wheel
• Current version 3.2.4
• Very good documentation
(http://docs.spring.io/spring/docs/3.2.4.RELEASE/spring-
framework-reference/html/)
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SPRING IOC
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XML Application Context
• Configured by XML
• Different modules (different namespaces)
• Benefits
– Pure declarative approach
– Allows to change system configuration without changing code (very
useful for customizations)
• Weaknesses
– Not transparent
– Lots of configuration is needed
– Hard to maintain
– Problem with refactoring
• Example (property initialization, constructor initialization)
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Annotation driven
• Configured by annotations
• Benefits
– Less configuration needed
– More clear and transparent
– No problem with refaktoring
• Weaknesses
– Less flexibility
• Can be combined with xml configuration
(<context:annotation-config />, <context:component-scan />)
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Annotation driven
• Proprietary
– @Component, @Service, @Repository
– @Autowired, @Required
• JSR-330:
– @Named
– @Inject, @Qualifier
• Other
– @Resource, @PersistenceContext, @PersistenceUnit
• Example
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Code driven
• Benefits
– Almost any code could be evaluated during initialization
– No problem with refactoring
• Weaknesses
– Pure imperative approach
– Configuration is hardcoded into the class
• @Configuration, @Bean
• @ComponentScan, @PropertySource, @Import
• Each @Bean method is evaluated just once!
• Example
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SPRING AOP
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AOP
• We often need to include some aspects that affects lots of our
application parts
– Transaction management
– Authorization
– Validation
– Logging or auditing
– Exception handling or translation
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AOP
• Template method
– OOP approach
– You need new class for each operation
• AOP/Interceptors
– Incompatible with pure OOP
– More practical
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AOP
• http://docs.spring.io/spring/docs/3.2.4.RELEASE/spring-
framework-reference/html/aop.html
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TRANSACTION MANAGEMENT
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Transactions Management
• PlatformTransactionManager
– DataSourceTransactionManager
– JtaTransactionManager
– JpaTransactionManager
– HibernateTransactionManager
• Declarative approach (controlled with AOP, @Transactional)
• Imperative approach (API of PlatformTransactionManager)
• <tx:annotation-driven/>
• @EnableTransactionManagement
• Integration with JPA
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Questions
?
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