ClassCastException $Proxy 不能转换为使用 aop [英] ClassCastException $Proxy cannot be cast to using aop
问题描述
我使用 spring 通过 bean 创建对象.现在我尝试使用 aop 创建相同的对象，但我得到 $Proxy cannot be cast to SaleRoom 异常.
I was using spring to create objects through beans. Now I tried to use aop to create the same object and I get $Proxy cannot be cast to SaleRoom exception.
之前的 xml 是:
<?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:aop="http://www.springframework.org/schema/aop/spring-aop-2.5.xsd"
xmlns:context="http://www.springframework.org/schema/context/spring-context-2.5.xsd"
xmlns:flow="http://www.springframework.org/schema/webflow-config/spring-webflow-config- 1.0.xsd"
xmlns:jm s="http://www.springframework.org/schema/jms/spring-jms-2.5.xsd"
xmlns:jee="http://www.springframework.org/schema/jee/spring-jee-2.5.xsd"
xmlns:lang="http://www.springframework.org/schema/lang/spring-lang-2.5.xsd"
xmlns:osgi="http://www.springframework.org/schema/osgi/spring-osgi.xsd"
xmlns:tx="http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"
xmlns:util="http://www.springframework.org/schema/util/spring-util-2.5.xsd"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/aop/spring-aop-2.5.xsd http://www.springframework.org/schema/aop/spring-aop-2.5.xsd/spring-spring-aop-2.5.xsd-2.5.xsd
http://www.springframework.org/schema/context/spring-context-2.5.xsd http://www.springframework.org/schema/context/spring-context-2.5.xsd/spring-spring-context-2.5.xsd-2.5.xsd
http://www.springframework.org/schema/webflow-config/spring-webflow-config-1.0.xsd http://www.springframework.org/schema/webflow-config/spring-webflow-config-1.0.xsd/spring-spring-webflow-config-1.0.xsd-2.5.xsd
http://www.springframework.org/schema/jms/spring-jms-2.5.xsd http://www.springframework.org/schema/jms/spring-jms-2.5.xsd/spring-spring-jms-2.5.xsd-2.5.xsd
http://www.springframework.org/schema/jee/spring-jee-2.5.xsd http://www.springframework.org/schema/jee/spring-jee-2.5.xsd/spring-spring-jee-2.5.xsd-2.5.xsd
http://www.springframework.org/schema/lang/spring-lang-2.5.xsd http://www.springframework.org/schema/lang/spring-lang-2.5.xsd/spring-spring-lang-2.5.xsd-2.5.xsd
http://www.springframework.org/schema/osgi/spring-osgi.xsd http://www.springframework.org/schema/osgi/spring-osgi.xsd/spring-spring-osgi.xsd-2.5.xsd
http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://www.springframework.org/schema/tx/spring-tx-2.5.xsd/spring-spring-tx-2.5.xsd-2.5.xsd
http://www.springframework.org/schema/util/spring-util-2.5.xsd http://www.springframework.org/schema/util/spring-util-2.5.xsd/spring-spring-util-2.5.xsd-2.5.xsd
">
<bean id="sale01" class="application.common.entities.BidRoom">
<property name="itemId" value="0001"/>
<property name="lifeTime" value="15"/>
</bean>
</beans>
我使用以下代码来创建销售:
And I used the following code to create the sales:
ApplicationContext context = new FileSystemXmlApplicationContext(SalesManager.getSalesSourceFile());
SaleRoom saleRoom;
List<String> salesNames = new LinkedList<String>();
List<SaleRoom> allSales = new LinkedList<SaleRoom>();
// Get all sales id's for beans
NodeList salesNodeList = salesDoc.getElementsByTagName("bean");
for (int i = 0; i < salesNodeList.getLength(); i++) {
Node nNode = salesNodeList.item(i);
salesNames.add(((Element) nNode).getAttribute("id").toString());
}
for (String saleName : salesNames) {
if(saleName.contains("sale")) {
saleRoom = (SaleRoom) context.getBean(saleName);
allSales.add(saleRoom);
}
}
return allSales;
这是新的 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:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd">
<aop:aspectj-autoproxy>
<aop:include name="logSettersCalls"/>
</aop:aspectj-autoproxy>
<bean id="logSettersCalls" class="application.logging.aop.LogSettersCalls"/>
<bean id="sale01" class="application.common.entities.BidRoom">
<constructor-arg index="0" type="int" value="0001"/>
<constructor-arg index="1" type="int" value="15"/>
</bean>
</beans>
Aspect 日志类:
The Aspect logging class:
@Aspect
public class LogSettersCalls {
@Pointcut("execution(void set*(*))")
public void setMethod() {}
@Before("setMethod()")
public void logSetterCall(JoinPoint theJoinPoint) {
String methodName = theJoinPoint.getSignature().getName();
Object newValue = theJoinPoint.getArgs()[0];
Object theObject = theJoinPoint.getTarget();
System.out.println("The method " + methodName + " is called on object "
+ theObject + " with the value " + newValue);
}
}
我使用相同的代码通过 aop 创建 bean.我得到线程main"中的异常 java.lang.ClassCastException:$Proxy11 无法转换为 application.common.entities.SaleRoom
I'm using the same code for creating the beans via aop. and I get Exception in thread "main" java.lang.ClassCastException: $Proxy11 cannot be cast to application.common.entities.SaleRoom
抛出异常的那一行:saleRoom = (SaleRoom) context.getBean(saleName);
The line that throws the exception: saleRoom = (SaleRoom) context.getBean(saleName);
任何帮助将不胜感激.谢谢.
Any help will be appreciated. Thanks.
推荐答案
您的 SaleRoom 类是否实现了某些接口?如果是，那么您应该在代码中使用接口而不是类:
Does your SaleRoom class implement some interface? If yes, then you should use interface and not class in you code:
ISaleRoom saleRoom = (ISaleRoom) context.getBean(saleName);
因为如果你的 bean 实现了一些接口，那么 Spring 默认会基于这个接口创建代理.
Because if your bean implements some interface then Spring by default will create proxy based on this interface.
如果你想为目标类创建代理，你也可以改变 Spring AOP 的代理机制.这在此处在参考文档中有所描述.
Also you can change proxying mechanism for Spring AOP if you want to create proxy for target class. This is described here in reference documentation.
这篇关于ClassCastException $Proxy 不能转换为使用 aop的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
