spring - How to solve BeanNotOfRequiredTypeException -

i writing small application check functionality of "afteradvice" concept in spring-aop getting exception related xml file (i think) please me how solve exception

applicationcontext.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" xsi:schemalocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd"> <bean id="pincheck" class="com.nt.advice.atmpinverifieradvice" /> <bean id="targetbean" class="com.nt.service.atmpingenerator" /> <bean id="pfb" class="org.springframework.aop.framework.proxyfactorybean">     <property name="target" ref="targetbean" />     <property name="interceptornames">         <list>             <value>pincheck</value>         </list>     </property>   </bean> </beans> 

clientapp.java

import org.springframework.context.applicationcontext; import org.springframework.context.support.filesystemxmlapplicationcontext; import com.nt.service.atmpingenerator; public class clientapp { public static void main(string[] args) {     //activate ioc container     applicationcontext ctx = new    filesystemxmlapplicationcontext("src/com/nt/cfgs/applicationcontext.xml");     //get proxy obj     atmpingenerator gen = ctx.getbean("pfb",atmpingenerator.class);     //call b.method     gen.pingenerator();   }  } 

atmpingenerator.java

import java.util.random; public class atmpingenerator extends random { //generating pin public int pingenerator(){     //creat java.util.random object      random rad = new random();     //use nextint() generate random pin of 4 digits     int pin = rad.nextint(9999); return pin;   }//pingenerator } 

atmpinverifieradvice.java

import java.lang.reflect.method; import org.springframework.aop.afterreturningadvice; public class atmpinverifieradvice implements afterreturningadvice { @override public void afterreturning(object retvalue, method method, object[] args,         object target) throws throwable {     system.out.println(retvalue);     integer pin = (integer)retvalue;     //if generated pin less 4 digit throw exception     if(pin<=999)         throw new illegalargumentexception("invalid pin");   }//afterreturning }//atmpinverifieradvice 

if run above application getting exception

output

aug 17, 2015 2:03:57 pm     org.springframework.context.support.abstractapplicationcontext preparerefresh info: refreshing     org.springframework.context.support.filesystemxmlapplicationcontext@3ff14318:     startup date [mon aug 17 14:03:57 ist 2015]; root of context hierarchy aug 17, 2015 2:03:57 pm     org.springframework.beans.factory.xml.xmlbeandefinitionreader     loadbeandefinitions info: loading xml bean definitions file     [g:\java\frameworks\springaop\aopproj6(after advice - pin verifier     decl)\src\com\nt\cfgs\applicationcontext.xml] exception in thread "main"     org.springframework.beans.factory.beannotofrequiredtypeexception: bean named     'pfb' must of type [com.nt.service.atmpingenerator], of type     [com.sun.proxy.$proxy2]     @     org.springframework.beans.factory.support.abstractbeanfactory.dogetbean(abstract    beanfactory.java:375) @     org.springframework.beans.factory.support.abstractbeanfactory.getbean(abstractbe    anfactory.java:199) @     org.springframework.context.support.abstractapplicationcontext.getbean(abstracta    pplicationcontext.java:962) @ test.clientapp.main(clientapp.java:14) 

i don't why getting exception. please 1 me why exception raising?

spring default uses jdk dynamic proxies, interface based, applying aop.

your atmpingenerator extends random implements serializable. spring sees interface , uses interface based proxies. proxy implementing serializable interface.

you have 3 options solve it

1. force class based proxies configuring proxyfactorybean
2. create interface , implement it
3. force class based proxies not extending random.

the last option easiest don't extend random, force use of class-based proxies.

public class atmpingenerator {      public int pingenerator(){         random rad = new random();                   return rad.nextint(9999);     } } 

you set proxytargetclass property of proxyfactorybean true , don't need change class.

<property name="proxytargetclass" value="true" /> 

the last option introduce interface , expose pingenerator() method on , let atmpingenerator implement interface.

public interface pingenerator {      int pingenerator(); }  public class atmpingenerator implements pingenerator { ... } 

this way using interface based proxied. in main method use pingenerator interface instead of atmpingenerator.