Spring 学习（四）Bean生命周期

Bean的初始化、销毁三种方式
（一）
1、先看第一种直接在BeanLifeCycle.xml中设置，init-method和destory-method两个方法

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

        <bean id = "beanLifeCycle" class="com.yuna.cycle.BeanLifeCycle" init-method="start" destroy-method="stop"></bean>

 </beans>

2、我们新建一个BeanLifeCycle来实现这两个方法

public class BeanLifeCycle {

    public void start() {
        System.out.println("Bean start .");
    }

    public void stop() {
        System.out.println("Bean stop.");
    }
}

3、写个测试类TestBeanLiftCycle

public class TestBeanLiftCycle extends UnitTestBase {

    public TestBeanLiftCycle() {
        super("classpath:BeanLifeCycle.xml");
    }

    @Test
    public void testSetingBean() {
        super.getBean("beanLifeCycle");
    }
}

可以看到打印的结果

（二）
1、新建BeanCycleImpl类实现InitializingBean,DisposableBean接口，并实现相关destroy()和afterPropertiesSet()方法

public class BeanCycleImpl implements InitializingBean,DisposableBean {

    @Override
    public void destroy() throws Exception {
        System.out.println("bean destroy");

    }

    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("bean afterPropertiesSet");

    }

}

2、将BeanLifeCycle.xml文件修改如下

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

        <!-- 方式一：直接在bean里设置属性  init-method 和 destroy-method-->
       <!--  <bean id = "beanLifeCycle" class="com.yuna.cycle.BeanLifeCycle" init-method="start" destroy-method="stop"></bean> -->

        <!-- 方式二：在BeanCycleImpl类中实现InitializingBean,DisposableBean接口 -->
        <bean id = "BeanCycleImpl" class="com.yuna.cycle.BeanCycleImpl" ></bean>
 </beans>

3、在测试TestBeanLiftCycle类中添加测试方法

@Test
    public void testBeanImpl() {
        super.getBean("BeanCycleImpl");
    }

4、运行打印的结果如下

bean afterPropertiesSet

bean destroy

（三）
1、修改BeanLifeCycle.xml的相关属性

<?xml version="1.0" encoding="UTF-8"?>
<beans  xmlns="http://www.springframework.org/schema/beans" 
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd" 
          default-init-method="defautInit" default-destroy-method="defaultDestroy"
        >

        <!-- 方式三：在beans中设置相关的属性 ：default-init-method和default-destroy-method-->
          <bean id = "BeanDefaultCycle" class="com.yuna.cycle.BeanDefaultImpl" ></bean>

        <!-- 方式一：直接在bean里设置属性  init-method 和 destroy-method-->
       <!--  <bean id = "beanLifeCycle" class="com.yuna.cycle.BeanLifeCycle" init-method="start" destroy-method="stop"></bean> -->

        <!-- 方式二：在BeanCycleImpl类中实现InitializingBean,DisposableBean接口 -->
        <!-- <bean id = "BeanCycleImpl" class="com.yuna.cycle.BeanCycleImpl" ></bean> -->
 </beans>

2、新建相关类BeanDefaultImpl，新增相关两个方法

public class BeanDefaultImpl {

    public void defautInit() {
        System.out.println("Bean defautInit .");
    }

    public void defaultDestroy() {
        System.out.println("Bean defaultDestroy.");
    }

}

3、在测试类中新增测试方法

@Test
    public void testBeanDefaultImpl() {
        super.getBean("BeanDefaultCycle");
    }

4、可以看到打印结果如下：

Bean defautInit .

Bean defaultDestroy.