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Spring Bean

Spring

spring

Bean attributes

Attribute Description
class Necessary, define the class used to create the bean
name unique name identifier, you can use “id” or “name” in XML
scope Define the scope of bean
constructor-arg DI
properties DI
autowiring mode DI
lazy-initialization mode Delay the init until the first use
initialization Define the method that initialize bean
destruction Define the method that destruction bean

Spring config meta data

There are three ways of Spring container configuration

  • Base on XML file
  • Base on annotation
  • Base on Java

An example of Spring XML config file

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<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

   <!-- A simple bean definition -->
   <bean id="..." class="...">
       <!-- collaborators and configuration for this bean go here -->
   </bean>

   <!-- A bean definition with lazy init set on -->
   <bean id="..." class="..." lazy-init="true">
       <!-- collaborators and configuration for this bean go here -->
   </bean>

   <!-- A bean definition with initialization method -->
   <bean id="..." class="..." init-method="...">
       <!-- collaborators and configuration for this bean go here -->
   </bean>

   <!-- A bean definition with destruction method -->
   <bean id="..." class="..." destroy-method="...">
       <!-- collaborators and configuration for this bean go here -->
   </bean>

   <!-- more bean definitions go here -->

</beans>

Bean scope

The scope of bean must be defined. The default scope is singleton

Scope Description
singleton This scopes the bean definition to a single instance per Spring IoC container (default).
prototype This scopes a single bean definition to have any number of object instances.
request This scopes a bean definition to an HTTP request. Only valid in the context of a web-aware Spring ApplicationContext.
session This scopes a bean definition to an HTTP session. Only valid in the context of a web-aware Spring ApplicationContext.
global-session This scopes a bean definition to a global HTTP session. Only valid in the context of a web-aware Spring ApplicationContext.

Bean lifecycle

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