Spring

Table of Contents:

Need Of Dependency Injection

• Dependency
• Typical Code without Dependency Injection
• Removing Tight-coupling through Dependency Injection
• Removing Tight-coupling through Spring's Dependency Injection

Spring IOC Container

• BeanFactory
• ApplicationContext
• Instantiating a Spring IOC container
• Retrieving a Bean from Spring IOC container

Beans Overview

• Registering existing objets as Spring Beans

Dependency Injection using Spring

• Types of Dependency Injection
• Constructor-based or setter-based Dependency Injection?
• Configuration Metadata for Dependency Injection
  • Spring Dependency Injection using XML based configuration
    • Instantiating the container
    • Instantiation of Beans
      • Instantiation with the constructor
      • Instantiation with Static Factory Method
      • Instantiation with Instance Factory Method
    • Dependency Injection
      • Constructor Injection
        • Injecting primitive types
        • Injecting reference types
        • Injecting collections
        • Complete Example demonstrating constructor injection of different types of values
          • Spring standalone collections
      • Setter/Property Injection
        • Injecting primitive types
        • Injecting reference types
        • Injecting collections
        • Complete Example demonstrating setter injection of different types of values
          • Spring standalone collections
    • Autowiring in XML based configuration
      • Autowiring Modes
      • Example demonstrating Autowiring through XML configuration
        • Autowiring byName
        • Autowiring byType
        • Autowiring by constructor
      • Excluding a bean from Autowiring
    • Composing XML based configuration metadata using <import>
    • Bean definition inheritance
  • Spring Dependency Injection using Annotation based configuration
    • Enabling Component Scanning
      • Using XML configuration file
      • Using Java configuration file
        • Enabling Component scan Programmatically
    • Autowiring in Annotation based configuration
      • Autowiring modes supported for @Autowired
      • @Autowired and Optional Dependencies
      • @Autowired on field
      • @Autowired on setter methods
      • @Autowired on constructor
      • @Autowired on arbitrary method
      • @Autowired on arrays/collections
      • Autowiring ambiguity
        • Ambiguity resolution using @Primary
        • Ambiguity resolution using name of bean (Autowiring by name)
        • Ambiguity resolution using @Qualifier
        • Java Generic types as implicit Autowirng qualifier
    • Complete example demonstrating Annotation based bean definition
    • Stereotype Annotations
  • Spring Dependency Injection using Java based configuration
    • Bean declaration using @Bean annotation and Java configuration file
    • Bean dependencies and Autowirng
    • Instantiating the Container
    • Bean Declaration in Interfaces
    • Composing Annotation based configuration metadata using @Import Annotation
    • Complete Example demonstrating Java based Bean and Container configuration
      • Externalizing the configuration to a properties file
    • Integrating XML-based bean definitions into a Java-based configuration using @ImportResource Annotation
• Lazy initialization of Beans
  • Approaches to Implement Lazy Initialization
    • Lazy initialization of Specific Beans
    • Lazy initialization of Entire configuration
  • Demo
• Dependency resolution in Spring
• Circular Dependencies
  • Example: Circular Dependency
  • Resolutions for Circular Dependencies
    • Using setter/field injection instead of constructor injection
    • Using Lazy initialization
    • Using Bean's Lifecycle initialization callback method
    • Using ApplicationContext for manual wiring
• Controlling Beans Creation order using depends-on/@DependsOn

Spring Bean Scopes

• Singleton
  • Lazy initialization of Singleton Beans
• Prototype
• Complex scope scenarios
  • Workarounds for Singleton beans with Prototype scoped dependencies
    • Configuring proxy
    • Using ApplicationContext directly
    • Using Method injection

Spring Bean Lifecycle Callbacks

• Shutting Down the Spring IoC Container Gracefully in Non-Web Applications
• Lifecycle callbacks in XML based configuration
• Lifecycle callbacks in Annotation based configuration
• Lifecycle callbacks in Java based configuration
• Lifecycle callbacks through Interfaces implementations
• Combining Lifecycle Mechanisms

Method Injection

• Method injection using @Autowired annotation
• Lookup Method injection

Asynchronous processing in Spring

Aware Interfaces

• ApplicationContextAware
  • Implementing ApplicationContextAware
  • Obtaining ApplicationContext through ApplicationContextAware interface
  • Obtaining ApplicationContext through Autowiring
  • Usages
• BeanFactoryAware
  • Implementing BeanFactoryAware
  • Obtaining BeanFactory through BeanFactoryAware interface
  • Obtaining BeanFactory through Autowiring
  • Usages
• BeanNameAware
  • Implementing BeanNameAware
  • Obtaining Bean Name through BeanNameAware interface

BeanFactoryPostProcessor

• Understanding BeanFactoryPostProcessor
• Implementing BeanFactoryPostProcessor
• Use Cases and Examples
• Core Framework Usage

BeanPostProcessor

• Understanding BeanPostProcessor
• Implementing BeanPostProcessor
• Usages
• Example : Custom Logging and Monitoring

Spring Bean Lifecycle

Externalizing the Configurations in Spring

• @Value Annotation
• Spring Expression Language (SpEL)
• Environment
• Spring Profiles
  • Defining Profile-Specific Beans
  • Profile Expression Logic
  • Using Composed @Profile Annotation
  • Profile at Method Level
  • XML Configuration with Profiles
  • Activating Profiles
  • Default Profile
• @PropertySource Annotation
• @ImportResource Annotation