try {
	ScriptEngineManager factory = new ScriptEngineManager();
	ScriptEngine engine = factory.getEngineByName("JavaScript");
 
	//Simple call to println javascript function 
	engine.eval("println('Texto JavaScript')");
 
} catch (ScriptException ex) {
 
	//Do something
}

try {
 
	ScriptEngineManager factory = new ScriptEngineManager();
	ScriptEngine engine = factory.getEngineByName("JavaScript");
	engine.eval("function amessagefunction(atext){ return 'The secret message is ' + atext;}");
	Invocable invocable = (Invocable) engine;
	Object object = invocable.invokeFunction("amessagefunction", "abc");
	System.out.println(object);
 
} catch (NoSuchMethodException ex) {
 
	//Do something
 
} catch (ScriptException ex) {
 
	//Something is wrong, perhaps
}

<?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-2.5.xsd">
 
           <bean id="postProcessor" class="com.sourcerebels.test.postprocessor.PostProcessor"/>
           <bean id="someBusinessRule" class="com.sourcerebels.test.postprocessor.SomeBusinessRule" lazy-init="true">
               <property name="message" value="someBusinessRule executed"/>
           </bean>
</beans>

package com.sourcerebels.test.postprocessor;
 
import java.lang.reflect.Method;
import org.springframework.aop.AfterReturningAdvice;
import org.springframework.aop.MethodBeforeAdvice;
 
public class TransactionAdvice implements MethodBeforeAdvice, AfterReturningAdvice {
 
    public void before(Method method, Object[] args, Object target) throws Throwable {
        System.out.println("Starting Transaction");
    }
 
    public void afterReturning(Object returnValue, Method method, Object[] args, Object target) throws Throwable {
        System.out.println("Commit Transaction");
    }
}

package com.sourcerebels.test.postprocessor;
 
public interface BusinessRule {
 
    void run();
}

package com.sourcerebels.test.postprocessor;
 
public class SomeBusinessRule implements BusinessRule {
 
    private String message;
 
    public void run() {
        System.out.println(message);
    }
 
    public String getMessage() {
        return message;
    }
 
    public void setMessage(String message) {
        this.message = message;
    }
}

package com.sourcerebels.test.postprocessor;
 
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
 
/**
 * @author edu@sourcerebels.com
 */
public class PostProcessor implements BeanPostProcessor {
 
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        System.out.println("postProcessBeforeInitialization");
        return bean;
    }
 
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        System.out.println("postProcessAfterInitialization");
        if (bean instanceof BusinessRule) {
            System.out.println("building proxy object");
            ProxyFactory proxyFactory = new ProxyFactory(bean);
            proxyFactory.addInterface(BusinessRule.class);
            proxyFactory.addAdvice(new TransactionAdvice());
            return proxyFactory.getProxy();
        }
        return bean;
    }
}

package com.sourcerebels.test.postprocessor;
 
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
 
public class Main {
 
    public static void main(String[] args) {
 
        String[] paths = { "com/sourcerebels/test/postprocessor/applicationContext.xml" };
        ApplicationContext ctx = new ClassPathXmlApplicationContext(paths);
 
        BusinessRule negocio = (BusinessRule) ctx.getBean("someBusinessRule");
        negocio.run();
 
        negocio = (BusinessRule) ctx.getBean("someOtherBusinessRule");
        negocio.run();
    }
}