spring4 初始化bean回调

初始化回调的几种方式

     1）采用xml配置

<bean id="exampleInitBean" class="examples.ExampleBean" init-method="init"/>

public class ExampleBean {

    public void init() {
        // do some initialization work
    }

}

   
     2）采用实现spring接口InitializingBean  然后实现方法afterPropertiesSet

public class AnotherExampleBean implements InitializingBean {

    public void afterPropertiesSet() {
        // do some initialization work
    }

}

    3）第三种定义初始化方式

public class DefaultBlogService implements BlogService {

    private BlogDao blogDao;

    public void setBlogDao(BlogDao blogDao) {
        this.blogDao = blogDao;
    }

    // this is (unsurprisingly) the initialization callback method
    public void init() {
        if (this.blogDao == null) {
            throw new IllegalStateException("The [blogDao] property must be set.");
        }
    }

}

<beans default-init-method="init">

    <bean id="blogService" class="com.foo.DefaultBlogService">
        <property name="blogDao" ref="blogDao" />
    </bean>

</beans>