Spring、Bean的生命周期

1、默认情况下，在Bean容器被实例化的时候，bean对象将被创建：

public class PersonServiceImpl implements PersonIService {

	public PersonServiceImpl(){
		System.out.println("初始化！！！");
	}
	@Override
	public void helloSpring() {
		System.out.println("Hello Spring!");
	}
}

<bean id="personIService" class="cn.server.impl.PersonServiceImpl"/>

测试：

	@Test
	public void test() {
		ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
		//PersonIService personIService=(PersonIService)ac.getBean("personIService");
	}

结果：

2、设置bean的lazy-init属性可以决定Bean是的实例对象是否使用懒加载，默认lazy-init=“false”:   当lazy-init设置为True的时候，只有Bean被实例的时候才调用：

	@Test
	public void test() {
		ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
		PersonIService personIService=(PersonIService)ac.getBean("personIService");
	}

<bean id="personIService" class="cn.server.impl.PersonServiceImpl" lazy-init="true"/>

3、在bean被实例之前和在bean实例之后都可以执行某些方法，只要设置bean的init-method属性和destroy-method方法即可：

public class PersonServiceImpl implements PersonIService {

	public void initBean(){
		System.out.println("被实例之前调用");
	}
	public void destoryBean(){
		System.out.println("实例被关闭之后调用");
	}
	@Override
	public void helloSpring() {
		System.out.println("Hello Spring!");
	}
}

<bean id="personIService" class="cn.server.impl.PersonServiceImpl" 
	lazy-init="false" init-method="initBean" destroy-method="destoryBean"/>

测试代码：

	@Test
	public void test() {
		AbstractApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
		PersonIService personIService=(PersonIService)ac.getBean("personIService");
		personIService.helloSpring();
		ac.close();
	}