Spring中Bean的完整生命周期
1) instantiate bean对象实例化
2) populate properties 封装属性
3) 如果Bean实现BeanNameAware 执行 setBeanName
4) 如果Bean实现BeanFactoryAware 或者 ApplicationContextAware 设置工厂 setBeanFactory 或者上下文对象 setApplicationContext
5) 如果存在类实现 BeanPostProcessor(后处理Bean) ,执行postProcessBeforeInitialization
6) 如果Bean实现InitializingBean 执行 afterPropertiesSet
7) 调用<bean init-method="XXX"> 指定初始化方法
8) 如果存在类实现 BeanPostProcessor(处理Bean) ,执行postProcessAfterInitialization
9) 执行业务处理
10)如果Bean实现 DisposableBean 执行 destroy
11)调用<bean destroy-method="XXX"> 指定销毁方法
接口
public interface ILifecycle { public void method(); }
实现类
public class LifecycleImpl implements ILifecycle, BeanNameAware, ApplicationContextAware, InitializingBean, DisposableBean { public LifecycleImpl() { System.out.println("1) instantiate bean对象实例化"); } public void myInit() { System.out.println("7) 调用<bean init-method=\"myInit\"> 指定初始化方法 "); } public void myDestroy(){ System.out.println("11)调用<bean destroy-method=\"myDestroy\"> 指定销毁方法 "); } @Override public void method() { System.out.println("9) 执行业务处理"); } public void setProperty(String info) { System.out.println("2) populate properties 封装属性"); } @Override public void setBeanName(String name) { System.out.println("3) 如果Bean实现BeanNameAware 执行 setBeanName.--->" + name); } @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { System.out.println("4) 如果Bean实现BeanFactoryAware 或者 ApplicationContextAware 设置工厂 setBeanFactory 或者上下文对象 setApplicationContext.--->" + applicationContext); } @Override public void afterPropertiesSet() throws Exception { System.out.println("6) 如果Bean实现InitializingBean 执行 afterPropertiesSet "); } @Override public void destroy() throws Exception { System.out.println("10)如果Bean实现 DisposableBean 执行 destroy"); } }
后处理bean,对容器内所有bean有效
public class BeanProcessor implements BeanPostProcessor { @Override public Object postProcessBeforeInitialization(final Object bean, String beanName) throws BeansException { System.out.println("5) 如果存在类实现 BeanPostProcessor(后处理Bean) ,执行postProcessBeforeInitialization"); return bean; } @Override public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException { System.out.println("8) 如果存在类实现 BeanPostProcessor(处理Bean) ,执行postProcessAfterInitialization"); return bean; } }
配置
<bean id="lifecycle" class="demo02.LifecycleImpl" init-method="myInit" destroy-method="myDestroy"> <property name="property" value="注入"></property> </bean> <bean class="demo02.BeanProcessor"></bean>
测试
@Test public void demo1(){ ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); LifecycleImpl bean = context.getBean("lifecycle",LifecycleImpl.class); bean.method(); context.close(); } /** 1) instantiate bean对象实例化 2) populate properties 封装属性 3) 如果Bean实现BeanNameAware 执行 setBeanName.--->lifecycle 4) 如果Bean实现BeanFactoryAware 或者 ApplicationContextAware 设置工厂 setBeanFactory 或者上下文对象 setApplicationContext.--->org.springframework.context.support.ClassPathXmlApplicationContext@6fc5f743: startup date [Mon Sep 07 22:27:22 CST 2015]; root of context hierarchy 5) 如果存在类实现 BeanPostProcessor(后处理Bean) ,执行postProcessBeforeInitialization 6) 如果Bean实现InitializingBean 执行 afterPropertiesSet 7) 调用<bean init-method="myInit"> 指定初始化方法 8) 如果存在类实现 BeanPostProcessor(处理Bean) ,执行postProcessAfterInitialization 9) 执行业务处理 22:27:22,535 INFO ClassPathXmlApplicationContext:1042 - Closing org.springframework.context.support.ClassPathXmlApplicationContext@6fc5f743: startup date [Mon Sep 07 22:27:22 CST 2015]; root of context hierarchy 22:27:22,535 INFO DefaultListableBeanFactory:444 - Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@731d2572: defining beans [lifecycle,demo02.BeanProcessor#0]; root of factory hierarchy 10)如果Bean实现 DisposableBean 执行 destroy 11)调用<bean destroy-method="myDestroy"> 指定销毁方法 */
可以在实现BeanPostProcessor类里对原有业务方法进行增强处理
public class BeanProcessor implements BeanPostProcessor { @Override public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException { System.out.println("5) 如果存在类实现 BeanPostProcessor(后处理Bean) ,执行postProcessBeforeInitialization"); return bean; } @Override public Object postProcessAfterInitialization(final Object bean, String beanName) throws BeansException { System.out.println("8) 如果存在类实现 BeanPostProcessor(处理Bean) ,执行postProcessAfterInitialization"); if (beanName.equals("lifecycle")) { return Proxy.newProxyInstance(bean.getClass().getClassLoader(), bean.getClass().getInterfaces(), new InvocationHandler() { @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { if (method.getName().equals("method")) { System.out.println("增强method======================================="); } return method.invoke(bean, args); } }); } return bean; } }
输出:
/** 1) instantiate bean对象实例化 2) populate properties 封装属性 3) 如果Bean实现BeanNameAware 执行 setBeanName.--->lifecycle 4) 如果Bean实现BeanFactoryAware 或者 ApplicationContextAware 设置工厂 setBeanFactory 或者上下文对象 setApplicationContext.--->org.springframework.context.support.ClassPathXmlApplicationContext@2dec8909: startup date [Tue Sep 08 09:10:45 CST 2015]; root of context hierarchy 5) 如果存在类实现 BeanPostProcessor(后处理Bean) ,执行postProcessBeforeInitialization 6) 如果Bean实现InitializingBean 执行 afterPropertiesSet 7) 调用<bean init-method="myInit"> 指定初始化方法 8) 如果存在类实现 BeanPostProcessor(处理Bean) ,执行postProcessAfterInitialization 增强method======================================= 9) 执行业务处理 09:10:45,408 INFO ClassPathXmlApplicationContext:1042 - Closing org.springframework.context.support.ClassPathXmlApplicationContext@2dec8909: startup date [Tue Sep 08 09:10:45 CST 2015]; root of context hierarchy 09:10:45,408 INFO DefaultListableBeanFactory:444 - Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@7e859a68: defining beans [lifecycle,demo02.BeanProcessor#0]; root of factory hierarchy 10)如果Bean实现 DisposableBean 执行 destroy 11)调用<bean destroy-method="myDestroy"> 指定销毁方法 */