Bean在Spring容器中的生命周期
配置在Spring中的Bean在Spring容器中从加载到销毁会经历那些过程呢?如果实现一些特定的Spring接口,这些特定接口的方法会在什么时候被调用呢?本文简单介绍一下这些过程.
Bean在Spring容器中的生命周期如下图所示:
1,调用Bean的构造函数(或者工厂方法)实例化Bean.
2,对Bean的成员变量赋值.
3,如果Bean实现了BeanNameAware,调用Bean的setBeanName方法.
4,如果Bean实现了BeanFactoryAware,调用Bean的setBeanFactory方法.
5,如果Bean实现了ApplicationContextAware,调用Bean的setApplicationContext方法.
6,如果容器中配置了BeanPostProcessor,调用BeanPostProcessor的postProcessBeforeInitialization方法(如果有多个BeanPostProcessor,调用每一个BeanPostProcessor的postProcessBeforeInitialization方法).
6,如果Bean实现了InitializingBean,调用Bean的afterPropertiesSet方法.
7,如果Bean配置了init-method方法,调用init-method配置的Bean方法.
8,如果容器中配置了BeanPostProcessor,调用BeanPostProcessor的postProcessAfterInitialization方法.(如果有多个BeanPostProcessor,调用每一个BeanPostProcessor的postProcessAfterInitialization方法).
9,Bean处于可以使用的状态.
10,Spring容器关闭.
11,4,如果Bean实现了DisposableBean,调用Bean的destroy方法.
12,如果Bean配置了destroy-method方法,调用destroy-method配置的Bean的方法.
实例:LifeCycleBean implements InitializingBean, DisposableBean,BeanNameAware,BeanFactoryAware, ApplicationContextAware,配置了init-method="init" destroy-method="cleanup",容器中有两个BeanPostProcessor
- public class LifeCycleBean implements InitializingBean, DisposableBean,
- BeanNameAware,BeanFactoryAware, ApplicationContextAware {
- private String str = "default";
- public LifeCycleBean() {
- System.out.println("construct LifecycleBean ***************");
- }
- public LifeCycleBean(String str) {
- this.str = str;
- }
- public String getStr() {
- return str;
- }
- public void setStr(String str) {
- System.out.println("setStr ***************");
- this.str = str;
- }
- public void init() {
- System.out.println("init mtd ***************");
- }
- public void cleanup() {
- System.out.println("cleanup mtd ***************");
- }
- public void afterPropertiesSet() throws Exception {
- System.out.println("afterPropertiesSet ***************");
- }
- public void destroy() throws Exception {
- System.out.println("destroy ***************");
- }
- public void setApplicationContext(ApplicationContext arg0)
- throws BeansException {
- System.out.println("setApplicationContext***************");
- }
- public void setBeanFactory(BeanFactory arg0) throws BeansException {
- System.out.println("setBeanFactory***************");
- }
- public void setBeanName(String arg0) {
- System.out.println("setBeanName***************" + arg0);
- }
- }
- public class MyBeanPostProcessor implements BeanPostProcessor {
- public Object postProcessBeforeInitialization(Object bean, String beanName)
- throws BeansException {
- System.out.println("************** MyBeanPostProcessor postProcessBeforeInitialization Bean '" + beanName);
- return bean;
- }
- public Object postProcessAfterInitialization(Object bean, String beanName)
- throws BeansException {
- System.out.println("************** MyBeanPostProcessor postProcessAfterInitialization Bean '" + beanName);
- return bean;
- }
- }
- <beans xmlns="http://www.springframework.org/schema/beans"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
- xsi:schemaLocation="http://www.springframework.org/schema/beans
- http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
- <bean class="com.test.spring.beanfactoryCtx.MyBeanPostProcessor" />
- <bean class="com.test.spring.beanfactoryCtx.MyBeanPostProcessor1" />
- <bean name="lifeCycleBean" class="com.test.spring.beanfactoryCtx.LifeCycleBean" init-method="init" destroy-method="cleanup">
- <property name="str" value="test str"/>
- </bean>
- </beans>
- ApplicationContext ctx = new ClassPathXmlApplicationContext("classpath:conf/bfactoryCtx1.xml");
- ((ClassPathXmlApplicationContext)ctx).registerShutdownHook();
- LifeCycleBean bean1 = ctx.getBean("lifeCycleBean",LifeCycleBean.class);
- System.out.println("***********" + bean1 + " " + bean1.getStr());
- construct LifecycleBean ***************
- setStr *************** #1
- setBeanName***************lifeCycleBean
- setBeanFactory***************
- setApplicationContext***************
- ************** MyBeanPostProcessor postProcessBeforeInitialization Bean 'lifeCycleBean #2
- ************** MyBeanPostProcessor1 postProcessBeforeInitialization Bean 'lifeCycleBean #2
- afterPropertiesSet ***************
- init mtd ***************
- ************** MyBeanPostProcessor postProcessAfterInitialization Bean 'lifeCycleBean #2
- ************** MyBeanPostProcessor1 postProcessAfterInitialization Bean 'lifeCycleBean #2
- ***********com.test.spring.beanfactoryCtx.LifeCycleBean@157fb52 test4 #3
- destroy ***************
- cleanup mtd ***************
#2如果有多个BeanPostProcessor的话,每一个BeanPostProcessor都会被调用一次.
#3Bean 被客户端代码使用