这是让我疯狂的情景.
>我有一个具有查找方法的类 – createOther()
> createOther应该创建一个Other类型的对象.其他实现OtherInterface,另外还有一个标记为@Async的方法doSomething
>由于Other实现了OtherInterface,Spring给了我一个JDK代理,我不能将其作为其他.
> Spring文档建议使用< aop:config proxy-target-class =“true”> – 但我是新手,使用它似乎没有帮助.
问题:我如何告诉Spring我需要一个针对Other类的CGLib代理?
下面的代码失败,带有classcastexception.
Exception in thread "main" java.lang.ClassCastException: $Proxy4 cannot be cast to scratch.Other
at scratch.App$$EnhancerByCGLIB$$82d16307.createOther(<generated>)
at scratch.App.main(App.java:19)
App.java:
public class App {
public Other createOther() {
throw new UnsupportedOperationException();
}
public static void main(final String[] args) {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("appcontext.xml");
App app = (App) context.getBean("app");
Other oth = app.createOther();
oth.doSomething();
System.out.println("Other created");
}
}
** Other.java **
public interface OtherInterface {
}
class Other implements OtherInterface {
@Async
public void doSomething() {
System.out.println("did something");
}
}
** appcontext.xml **
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:task="http://www.springframework.org/schema/task"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
<aop:config proxy-target-class="true"></aop:config>
<bean name="app" class="scratch.App">
<lookup-method bean="otherBean" name="createOther" />
</bean>
<bean name="otherBean" class="scratch.Other" scope="prototype">
</bean>
<task:executor id="workflowExecutorSvcPool" pool-size="5-50"
queue-capacity="1000" keep-alive="60" />
<task:annotation-driven executor="workflowExecutorSvcPool" />
</beans>
解决方法:
一切似乎都很好 – 这是告诉spring使用cglib代理的正确方法.实际上,默认情况下它会生成cglib代理的documentation states.唯一的要求是在类路径上使用cglib.确保你有cglib jar.