Spring Framework

<?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: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">
<bean id="t" class="org.r4r.client.One"/>
<bean id="a" class="org.r4r.client.BeforeOne"/>
<bean id="proxy" class="org.r4r.framework.ProxyFactory">
<property name="target" ref="t"/>
<property name="advisor" ref="a"/>
</bean>
</beans>

package org.r4r.framework;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
public class BeforeAdviceHandler implements InvocationHandler {
Object target;
BeforeMethod advisor;
public BeforeAdviceHandler(Object target, BeforeMethod advisor) {
super();
this.target = target;
this.advisor = advisor;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
advisor.doBefore();
return method.invoke(target, args);
}
}

package org.r4r.framework;
public interface BeforeMethod {
public void doBefore();
}

package org.r4r.framework;
import java.lang.reflect.Proxy;
import org.springframework.beans.factory.FactoryBean;
public class ProxyFactory implements FactoryBean {
Object target;
BeforeMethod advisor;
   @Override
public Object getObject() throws Exception {
BeforeAdviceHandler handler=new BeforeAdviceHandler(target, advisor);
Object proxy=Proxy.newProxyInstance
(target.getClass().getClassLoader(), target.getClass().getInterfaces(), handler);
return proxy;
}
@Override
public Class<Proxy> getObjectType() {
return Proxy.class;
}
@Override
public boolean isSingleton() {
return true;
}
public void setTarget(Object target) {
this.target = target;
}
public void setAdvisor(BeforeMethod advisor) {
this.advisor = advisor;
}
}

package org.r4r.client;
public class One implements Showable {
@Override
public void show() {
System.out.println("Show() method of One invoked..");
}
}

package org.r4r.client;
public interface Showable {
public abstract void show();
}

package org.r4r.client;
import org.r4r.framework.BeforeMethod;
public class BeforeOne implements BeforeMethod {
@Override
public void doBefore() {
System.out.println("Before advice is applied.");
}
}

package org.r4r.client;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
public class ProxyTest {
public static void main(String[] args) {
Resource r=new ClassPathResource("applicationContext.xml");
BeanFactory f=new XmlBeanFactory(r);
System.out.println("Obtaining proxy of one..");
Showable p=(Showable)f.getBean("proxy");
System.out.println("Proxy obtaining invoked.");
p.show();
}
}