spring5核心原理 - Bean 作用域

1. Spring Bean Scopes 类型

1.1。单例作用域

@Component
//This statement is redundant - singleton is default scope
@Scope("singleton")  //This statement is redundant
public class BeanClass {
 
}

<!-- To specify singleton scope is redundant -->
<bean id="beanId" class="com.leftso.BeanClass" scope="singleton" />
//or
<bean id="beanId" class="com.leftso.BeanClass" />

1.2. prototype 作用域

@Component
@Scope("prototype")
public class BeanClass {
}

<bean id="beanId" class="com.leftso.BeanClass" scope="prototype" />

通常，您应该更喜欢使用prototype所有有状态 bean 的singleton作用域和无状态 bean 的作用域。

要在请求、会话、应用程序和 websocket 作用域内使用 bean，您需要注册RequestContextListeneror RequestContextFilter。

1.3. request 作用域

@Component
@Scope("request")
public class BeanClass {
}
 
//or
 
@Component
@RequestScope
public class BeanClass {
}

<bean id="beanId" class="com.leftso.BeanClass" scope="request" />

1.4. session作用域

@Component
@Scope("session")
public class BeanClass {
}
 
//or
 
@Component
@SessionScope
public class BeanClass {
}

<bean id="beanId" class="com.leftso.BeanClass" scope="session" />

1.5。application作用域

1. applicationscoped bean 是 singleton per ServletContext，而singletonscoped bean 是 singleton per ApplicationContext。请注意，单个应用程序可以有多个应用程序上下文。
2. applicationscoped bean 作为ServletContext属性可见。

@Component
@Scope("application")
public class BeanClass {
}
 
//or
 
@Component
@ApplicationScope
public class BeanClass {
}

<bean id="beanId" class="com.leftso.BeanClass" scope="application" />

1.6. websocket作用域

@Component
@Scope("websocket")
public class BeanClass {
}

<bean id="beanId" class="com.leftso.BeanClass" scope="websocket" />

2.自定义线程作用域

<bean class="org.springframework.beans.factory.config.CustomScopeConfigurer">
    <property name="scopes">
        <map>
            <entry key="thread">
                <bean class="org.springframework.context.support.SimpleThreadScope"/>
            </entry>
        </map>
    </property>
</bean>

@Component
@Scope("thread")
public class BeanClass {
}

<bean id="beanId" class="com.leftso.BeanClass" scope="thread" />

三、总结

spring核心原理 spring5 Bean作用域

https://www.leftso.com/article/984.html