问题描述

初学Spring aop ，遇到了object is not an instance of declaring class的问题

CompareInterceptor类

package com.spring.advice;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
public class CompareInterceptor implements MethodInterceptor {

@Overridepublic Object invoke(MethodInvocation invocation) throws Throwable {    // TODO Auto-generated method stub    Object result = null;    String sname = invocation.getArguments()[0].toString();      if(sname.equals(""forever"")){         result = invocation.proceed();    }    else{     System.out.println(""此学生是：""+sname+""，而不是forever"");    }    return result;}

}

Test 类
package com.spring.test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.spring.aop.Istudent;

public class Test {
public static void main(String args[]){
ApplicationContext context = new ClassPathXmlApplicationContext(""applicationContext.xml"");
Istudent st = (Istudent)context.getBean(""student"");
st.addStudent(""forever"");
}
}

applicationContext.xml

<?xml version=""1.0"" encoding=""UTF-8""?>
xmlns=""http://www.springframework.org/schema/beans""
xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance""
xmlns:p=""http://www.springframework.org/schema/p""
xsi:schemaLocation=""http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"">

<bean id=""beforeAdvice"" class=""com.spring.advice.BeforeAdvice""  /><bean id=""afterAdvice"" class=""com.spring.advice.AfterAdvice""  /> <bean id=""compareInterceptor"" class=""com.spring.advice.CompareInterceptor""  /><bean id=""studentTarget"" class=""com.spring.aop.StudentImpl""  /><bean id=""student"" class=""org.springframework.aop.framework.ProxyFactoryBean""  >  <property name=""proxyInterfaces"">      <value>com.spring.aop.Istudent</value>  </property>  <property name=""interceptorNames"">       <list>           <value>beforeAdvice</value>           <value>afterAdvice</value>           <value>compareInterceptor</value>       </list>  </property>  <property name=""target"">       <value>studentTarget</value>  </property></bean>     

只要不是参数不是forever，一切都正常。。。求帮助！

解决方案

你这段代码有问题！