Spring 17 AOP

SpringAOP : simple to understand. 3

Spring-aop-demo. 7

SpringMkyongAOP. 8

Using Pointcut : 11

DefaultAdvisorAutoProxyCreator : 11

AOP Weaving:

SpringAOP : simple to understand

public interface Customer {

public void browse() throws Exception;

}

public class CustomerImpl implements Customer{

public void browse() throws Exception{

System.out.println("Browsing the internet");

//throw new Exception("Connection lost");

}

}

public class CafeOwner {

public void LogInTime(){

System.out.println("Log the In Time and Name of the Customer");

}

public void LogOutTime(){

System.out.println("Log Out Time");

}

public void issueUsageBill(){

System.out.println("Calculate and Issue Bill");

}

public void cancelBilling(){

System.out.println("Cancel Billing");

}

}

public class InternetAdvice implements MethodBeforeAdvice, AfterReturningAdvice, ThrowsAdvice, MethodInterceptor

{

private CafeOwner cafeOwner;

public void setCafeOwner(CafeOwner cafeOwner) {

this.cafeOwner = cafeOwner;

}

public CafeOwner getCafeOwner() {

return cafeOwner;

}

public void before(Method arg0, Object[] arg1, Object arg2)

throws Throwable {

this.getCafeOwner().LogInTime();

}

public void afterReturning(Object arg0, Method arg1, Object[] arg2,

Object arg3) throws Throwable {

this.getCafeOwner().LogOutTime();

}

public void afterThrowing(Throwable throwable){

this.getCafeOwner().cancelBilling();

}

public Object invoke(MethodInvocation method) throws Throwable {

System.out.println("Allocate a system to customer");

method.proceed();

System.out.println("Deallocate the system");

return null;

}

}

public class InternetCafe {

public static void main(String[] args) throws Exception{

ApplicationContext ctx = new ClassPathXmlApplicationContext("springAop.xml");

Customer customer = (Customer) ctx.getBean("customerProxy");

customer.browse();

}

}

<?xml version ="1.0" encoding ="UTF-8"?>

<beans>

<bean id ="customerImpl" class ="CustomerImpl"/>

<bean id = "cafeOwner" class ="CafeOwner"/>

<bean id ="internetAdvice" class ="InternetAdvice">

<property name ="cafeOwner" ref ="cafeOwner"/>

</bean>

<bean id ="customerProxy"

class ="org.springframework.aop.framework.ProxyFactoryBean">

<property name ="target" ref="customerImpl"/>

<property name ="interceptorNames"

value="cafeOwnerBeforeAndAfterAdvice" />

<!--         <property name ="proxyInterfaces">

                    <value>Customer</value>

             </property> -->

</bean>

<bean id ="cafeOwnerBeforeAndAfterAdvice"

class ="org.springframework.aop.support.RegexpMethodPointcutAdvisor">

<property name ="advice" ref="internetAdvice"/>

<property name ="pattern" value=".*" />

</bean>

</beans>

Spring-aop-demo

http://veerasundar.com/blog/2010/01/spring-aop-example-profiling-method-execution-time-tutorial/

spring-aop-demo :

public interface Business {

void doSomeOperation();

}

package com.veerasundar.spring.aop;

public class BusinessImpl implements Business {

public void doSomeOperation() {

System.out.println("I do what I do best, i.e sleep.");

try {

Thread.sleep(2000);

} catch (InterruptedException e) {

System.out.println("How dare you to wake me up?");

}

System.out.println("Done with sleeping.");

}

}

@Aspect

public class BusinessProfiler {

@Pointcut("execution(* com.veerasundar.spring.aop.*.*(..))")

public void businessMethods() { }

@Around("businessMethods()")

public Object profile(ProceedingJoinPoint pjp) throws Throwable {

long start = System.currentTimeMillis();

System.out.println("Going to call the method.");

Object output = pjp.proceed();

System.out.println("Method execution completed.");

long elapsedTime = System.currentTimeMillis() - start;

System.out.println("Method execution time: " + elapsedTime + " milliseconds.");

return output;

}

}

public class SpringAOPDemo {

public static void main(String[] args) {

ApplicationContext context = new ClassPathXmlApplicationContext(

"applicationContext.xml");

Business bc = (Business) context.getBean("myBusinessClass");

bc.doSomeOperation();

}

<beans>

<aop:aspectj-autoproxy />

<bean id="businessProfiler" class="com.veerasundar.spring.aop.BusinessProfiler" />

<bean id="myBusinessClass" class="com.veerasundar.spring.aop.BusinessImpl" />

Output:

Going to call the method.

I do what I do best, i.e sleep.

Done with sleeping.

Method execution completed.

Method execution time: 2001 milliseconds.

SpringMkyongAOP

public class CustomerService {

private String name;

private String url;

public void setName(String name) {

this.name = name;

}

public void setUrl(String url) {

this.url = url;

}

public void printName() {

System.out.println("Customer name : " + this.name);

}

public void printURL() {

System.out.println("Customer website : " + this.url);

}

public void printThrowException() {

throw new IllegalArgumentException();

}

}

public class HijackBeforeMethod implements MethodBeforeAdvice {

@Override

public void before(Method method, Object[] args, Object target)

throws Throwable {

System.out.println("HijackBeforeMethod : Before method hijacked!" + method.getName());

}

}

public class HijackAfterMethod implements AfterReturningAdvice {

@Override

public void afterReturning(Object returnValue, Method method,

Object[] args, Object target) throws Throwable {

System.out.println("HijackAfterMethod : After method hijacked!");

}

}

public class HijackThrowException implements ThrowsAdvice {

public void afterThrowing(IllegalArgumentException e) throws Throwable {

System.out.println("HijackThrowException : Throw exception hijacked!");

}

}

public class HijackAroundMethod implements MethodInterceptor {

@Override

public Object invoke(MethodInvocation methodInvocation) throws Throwable {

System.out.println("Method name : "

+ methodInvocation.getMethod().getName());

System.out.println("Method arguments : "

+ Arrays.toString(methodInvocation.getArguments()));

// same with MethodBeforeAdvice

System.out.println("HijackAroundMethod : Before method hijacked!");

try {

// proceed to original method call

Object result = methodInvocation.proceed();

// same with AfterReturningAdvice

System.out.println("HijackAroundMethod :

                          Before after hijacked!");

return result;

} catch (IllegalArgumentException e) {

// same with ThrowsAdvice

System.out.println("HijackAroundMethod :

                          Throw exception hijacked!");

throw e;

}

}

}

public class App {

public static void main(String[] args) {

ApplicationContext appContext = new ClassPathXmlApplicationContext(

new String[] { "Spring-Customer.xml" });

CustomerService cust = (CustomerService)

appContext.getBean("customerServiceProxy");

System.out.println("*************************");

cust.printName();

System.out.println("*************************");

cust.printURL();

System.out.println("*************************");

try {

cust.printThrowException();

} catch (Exception e) {

}

}

}ring-Customer.xml :

<beans>

<bean id="customerService"

class="com.mkyong.customer.services.CustomerService">

<property name="name" value="Yong Mook Kim" />

<property name="url" value="http://www.mkyong.com" />

</bean>

<bean id="hijackBeforeMethodBean"

             class="com.mkyong.aop.HijackBeforeMethod" />

<bean id="hijackAfterMethodBean"

class="com.mkyong.aop.HijackAfterMethod" />

<bean id="hijackThrowExceptionBean"

class="com.mkyong.aop.HijackThrowException" />

<bean id="hijackAroundMethodBean"

class="com.mkyong.aop.HijackAroundMethod" />

<bean id="customerServiceProxy"

class="org.springframework.aop.framework.ProxyFactoryBean">

<property name="target" ref="customerService" />

<property name="interceptorNames" >

<list>

<value>hijackBeforeMethodBean</value>

<value>hijackAfterMethodBean</value>

<value>hijackThrowExceptionBean</value>

<value>hijackAroundMethodBean</value>

</list>

</property>

</bean>

</beans>

Using Pointcut :

<bean id="customerServiceProxy"

class="org.springframework.aop.framework.ProxyFactoryBean">

<property name="target" ref="customerService" />

<property name="interceptorNames" value="customerAdvisor" />

</bean>

<bean id="customerAdvisor"

class="org.springframework.aop.support.DefaultPointcutAdvisor">

<property name="pointcut" ref="customerPointcut" />

<property name="advice" ref="hijackAroundMethodBeanAdvice" />

</bean>

<bean id="customerPointcut"

class="org.springframework.aop.support.NameMatchMethodPointcut">

<property name="mappedName" value="printName" />

</bean>

<bean id="customerAdvisor"                                        class="org.springframework.aop.support.NameMatchMethodPointcutAdvisor">

<property name="mappedName" value="printName" />

<property name="advice" ref="hijackAroundMethodBeanAdvice" />

</bean>>

se the RegexpMethodPointcut

<bean id="customerAdvisor"

class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">

<property name="patterns" value=".*URL.*" />

<property name="advice" ref="hijackAroundMethodBeanAdvice" />

</bean>

BProxyFactoryBean

<bean

class="org.springframework.aop.

                    framework.autoproxy.BeanNameAutoProxyCreator">

<property name="beanNames" value="*Service" />

<property name="interceptorNames" value="customerAdvisor" />

</bean>

DefaultAdvisorAutoProxyCreator : ProxyFactoryBean nor use BeanNameAutoProxyCreator.

<bean class="org.springframework.aop.

             framework.autoproxy.DefaultAdvisorAutoProxyCreator" />

<bean id="hijackAroundMethodBeanAdvice"

class="com.mkyong.aop.HijackAroundMethod" />

<bean id="customerAdvisor"

class="org.springframework.aop.support.NameMatchMethodPointcutAdvisor">

<property name="mappedName" value="printName" />

<property name="advice" ref="hijackAroundMethodBeanAdvice" />

</bean>