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This article will explain in detail the example analysis of the IOC container in Spring. The editor thinks it is very practical, so I share it with you for reference. I hope you can get something after reading this article.

I. Overview of Spring's IOC container

Spring's IOC process is also known as dependency injection (DI), so objects can define their dependencies by constructor parameters, parameters of factory methods, or properties set on object instances constructed or returned by factory methods, and then the container injects these dependencies when creating bean. Spring implements the IOC container on the basis of org.springframework.be and org.springframework.context.

The core interface BeanFactory interface provides an advanced configuration mechanism that can manage any type of object. ApplicationContext is a subinterface BeanFactory. It adds easier integration with Spring's AOP capabilities; BeanFactory provides a configuration framework and basic functionality, and ApplicationContext adds more enterprise-specific features.

In Spring, the objects that make up the backbone of the application and are managed by the Spring IoC container are called bean. Bean is an object that is instantiated, assembled, and managed by the Spring IoC container.

A view of how Spring works:

II. Spring's IOC approach

Spring Container xml configuration Management

It is usually composed of multiple bean definitions. XML-based configuration metadata configures these bean as elements within the top-level element

The following figure provides the official profile template for spring (material source www.spring.io)

1. Default constructor

When you create a bean by means of a constructor, all normal classes can be used and compatible with Spring. That is, the class under development does not need to implement any specific interface or code in a particular way. Simply specifying the bean class is sufficient. However, depending on the type of IoC you use for a particular bean, you need a default (empty) constructor.

Using XML-based configuration metadata, you can specify that your bean classes are as follows:

Where class in bean is the full path of the bean initialized by spring.

two。 Static factory

When defining a bean created using a static factory method, you can use this class property to specify the class that contains the static factory method and the property that factory-method specifies the name of the factory method itself. You should be able to call this method (using the optional parameters described later) and return an instantiated object that is then considered to have been created by the constructor. What is used for this bean definition is what is called static factory creation.

Definition of static factory

Public class ClientService {

Private static ClientService clientService = new ClientService ()

Private ClientService () {}

Public static ClientService createInstance () {

Return clientService

}

}

Configure xml

The use of such a spring framework in invoking IOC instantiation is to create an object by calling the static method in the static factory through reflection creation. At this point, the object you are creating is in the hands of static methods.

3. Example chemical plant

The method of instantiating a factory is the same as the static factory method, except that a non-static method of an existing object is reflected in an instance factory, thus going to the spring container to create the instantiated bean.

Create an instantiation plant

Public class DefaultServiceLocator {

Private static ClientService clientService = new ClientServiceImpl ()

Private static AccountService accountService = new AccountServiceImpl ()

Public ClientService createClientServiceInstance () {

Return clientService

}

Public AccountService createAccountServiceInstance () {

Return accountService

}

}

Configure xml:

This is the end of the article on "sample analysis of IOC containers in Spring". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, please share it for more people to see.

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