Spring3之 bean 定制bean特性
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2022-05-23 10:20:28
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Customizing the nature of a bean定制bean特性
Spring提供了几个标志接口(marker interface),这些接口用来改变容器中bean的行为;它们包括InitializingBean和DisposableBean。实现这两个接口的bean在初始化和析构时容器会调用前者的afterPropertiesSet()方法,以及后者的destroy()方法。
com.spring305.test.customBean.po.ImplCustom.java
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
public class ImplCustom implements InitializingBean,DisposableBean {
public ImplCustom(){
System.out.println("this is "+ImplCustom.class+"`s constractor method");
}
@Override //InitializingBean
public void afterPropertiesSet() throws Exception {
System.out.println("in "+ ImplCustom.class+" afterPropertiesSet() method");
}
@Override //DisposableBean
public void destroy() throws Exception {
System.out.println("in "+ ImplCustom.class+" destroy() method");
}
}
xml中加入 bean的定义
<bean id="implCustom" class="com.spring305.test.customBean.po.ImplCustom"></bean>
测试:
@Test
public void test(){
ApplicationContext ctx = new ClassPathXmlApplicationContext(new String[]{"testCustombean.xml"});
ImplCustom impl = ctx.getBean("implCustom",ImplCustom.class);
}
同时也可以在xml中用init-method,destroy-method来指定初始化回调与析构回调,这样就不用实现接口了
com.spring305.test.customBean.po.CustomBean.java
public class CustomBean {
public CustomBean(){
System.out.println("this is "+CustomBean.class+"`s constractor method");
}
public void init() {
System.out.println("in "+ CustomBean.class+" init() method");
}
public void destroy() {
System.out.println("in "+ CustomBean.class+" destroy() method");
}
}
xml中加入
<bean id="customBean" class="com.spring305.test.customBean.po.CustomBean" init-method="init" destroy-method="destroy"></bean>
测试:
@Test
public void testNoImpliment(){
AbstractApplicationContext ctx = new ClassPathXmlApplicationContext(new String[]{"testCustombean.xml"});
CustomBean impl = ctx.getBean("customBean",CustomBean.class);
ctx.registerShutdownHook();
}
最后一句ctx.registerShutdownHook();是2.5文档中定义的一个关闭spring IOC容器的方法.
如上还可以在beans标签下为该标签下所有bean标签来定义初始化回调方法:default-init-method="init"