spring bean beanDefinition instance(scope) 的关系

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最新推荐文章于 2023-07-04 08:17:23 发布

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分类专栏： spring

本文链接：https://blog.youkuaiyun.com/fei33423/article/details/79457496

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本文探讨了Spring框架中Bean的生命周期与不同作用域（singleton和prototype）的管理方式。通过示例代码展示了如何定义Bean及其作用域，并讨论了在不同场景下Bean实例的创建与销毁过程。

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原生 java class 和 object.

有了 spring 后, 在中间插了一个 bean 的概念. 一个 class 1:n bean , bean 1:n object (prototype) bean 1:1 object (singoton)

其中一个 bean 有对应的BeanDefinition,里面含 id,scope 等信息.

参考:

1. Bean Definition从加载、解析、处理、注册到BeanFactory的过程。

2. spring 的生命周期

2. 从线上问题谈spring生命周期类lifeCycle类和bean的生命周期

3.详解Spring事件驱动模型事件驱动模型也就是我们常说的观察者，或者发布-订阅模型；理解它的几个关键点：

2. Spring动态创建bean

3. spring bean 的生命周期.

其他类似 BeanDefinition到Bean [没有和 spring beanFactory 的生命周期和消息结合]

http://blog.youkuaiyun.com/fei33423/article/details/52331435

4.Spring中scope singleton 和 prototype详解

4. spring mvc 的生命周期

5. 对比阅读,dubbo 的线程池,和异常处理. 事件模式.

附件,单测证明上诉实体关系:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "classpath:spring/simple-test-spring.xml" })
@TransactionConfiguration(transactionManager = "tradeTransactionManager", defaultRollback = false)

@Service
public class SimpleSpringTest implements ApplicationListener<ContextClosedEvent> {

    @Override
    public void onApplicationEvent(ContextClosedEvent event) {
        System.out.println(" SimpleSpringTest closed");
    }

    @Test
    public void testThreadPoolShutDownAndBeanScope() throws InterruptedException {

        SimpleSpringTest bean = ApplicationContextUtil.getBean(SimpleSpringTest.class);
        bean.execute();
        Thread.sleep(1000 * 60 * 3);
    }

    public void execute() {
        final ApplicationContext applicationContext = ApplicationContextUtil.getApplicationContext();
        PrototypeScopeBean bean = (PrototypeScopeBean) applicationContext.getBean("PrototypeScopeBeanAnnotationName");
        bean.submit();

        PrototypeScopeBean bean2 = (PrototypeScopeBean) applicationContext.getBean("PrototypeScopeBeanAnnotationName");
        bean2.submit();
        System.out.println("12");
         ApplicationContextUtil.getApplicationContext().getBean(SingletonScopeBean.class); 
// ③ 会抛错,org.springframework.beans.factory.NoUniqueBeanDefinitionException: 
//No qualifying bean of type [com.test.SingletonScopeBean] is defined: 
// expected single matching bean but found 3: SingtonScopeBeanAnnotationName,SingtonScopeBeanXmlInit2,SingtonScopeBeanXmlInit3



    }

}

import org.springframework.context.ApplicationListener;
import org.springframework.context.annotation.Scope;
import org.springframework.context.event.ContextClosedEvent;
import org.springframework.stereotype.Service;

import java.util.concurrent.atomic.AtomicInteger;

/**
 */
@Service("SingtonScopeBeanAnnotationName")
@Scope()
public class SingletonScopeBean implements ApplicationListener<ContextClosedEvent> {
    static AtomicInteger count = new AtomicInteger();

    @Override
    public void onApplicationEvent(ContextClosedEvent event) {
        System.out.println("SingletonScopeBean closed" + count.incrementAndGet());
    }

    public void print() {
        System.out.println(" print " + count.get());
    }
}

spring 配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns="http://www.springframework.org/schema/beans"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
      http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
      http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

    <bean id="tradeApplicationContext" class="com.ApplicationContextUtil"></bean>
    <tx:annotation-driven/>
    <context:component-scan base-package="com.test.unmock.test"/>
    <context:annotation-config/>
    <bean id="PrototypeScopeBeanXmlInit1" name="PrototypeScopeBean1_name"
          class="com.test.PrototypeScopeBean" scope="prototype"></bean>

    <bean id="PrototypeScopeBeanXmlInit2" name="PrototypeScopeBean2_name"
          class="com.test.PrototypeScopeBean" scope="prototype"></bean>
    <bean id="SingtonScopeBeanXmlInit2" name="SingtonScopeBeanName2"
          class="com.test.SingletonScopeBean"></bean>
    <bean id="SingtonScopeBeanXmlInit3" name="SingtonScopeBeanName3"
          class="com.SingletonScopeBean"></bean>

</beans>