Spring & AOP. Margus Jäger Lauri Tulmin

Transcription

1 Spring & AOP Margus Jäger Lauri Tulmin 1

2 Sissejuhatus 3. peatükk raamatus Spring in Action 4. peatükk raamatus Professional Java Development with the Spring Framework Spring Spring AOP Võrdlus AspectJ ga 2

3 Spring 3

4 Spring Kergekaaluline (Lightweight) Kontrolli ümberpööramine (Inversion of control) Aspektidele orienteeritud (Aspect-oriented) Konteiner Raamistik (Framework) 4

5 Hello World näide 1 public interface IHello { public void sayhello(); public class Hello implements IHello { private IGreeting greeting; public void setgreeting(igreeting greeting) { this.greeting = greeting; public void sayhello() { System.out.println(greeting.getGreeting()); 5

6 Hello World näide 2 public interface IGreeting { public String getgreeting(); public class Greeting implements IGreeting { private String greeting; public String getgreeting() { return greeting; public void setgreeting(string greeting) { this.greeting = greeting; 6

7 Hello World näide 3 <?xml version="1.0" encoding="utf-8"?> <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" " <beans> <bean id="hello" class="hello"> <property name="greeting"> <ref local="greeting" /> </property> </bean> <bean id="greeting" class="greeting"> <property name="greeting"> <value>hello world</value> </property> </bean> </beans> 7

8 Hello World näide 4 public class Main { public static void main(string[] args) { Resource res = new FileSystemResource("beans.xml"); XmlBeanFactory factory = new XmlBeanFactory(res); IHello hello = (IHello)factory.getBean("hello"); hello.sayhello(); 8

9 Spring & AOP 9

10 Spring AOP Aspektid kirjutatakse javas Ühendpunktideks on meetodid Aspektide rakendamine programselt või deklaratiivselt Springi konfiguratsioonifailis 10

11 AOP Alliance Kõik Springis kasutatavad juhised realiseerivad AOP Alliance i spetsifitseeritud või neist päritud liideseid 11

12 Juhised Before After returning Around Throws Introduction 12

13 Around juhis public interface MethodInterceptor extends Interceptor { Object invoke(methodinvocation invocation) throws Throwable; 13

14 public class PerformanceInterceptor implements MethodInterceptor { { public Object invoke(methodinvocation method) throws Throwable long start = System.currentTimeMillis(); try { finally { Object result = method.proceed(); return result; long end = System.currentTimeMillis(); long timems = end - start; System.out.println("Method: " + method.tostring() + " took: " + timems +"ms."); 14

15 Before juhis public interface MethodBeforeAdvice extends BeforeAdvice { void before(method m, Object[] args, Object target) throws Throwable; 15

16 Before juhise näide public class CountingBeforeAdvice implements MethodBeforeAdvice { private int count; public void before(method m, Object[] args, Object target) { ++count; public int getcount() { return count; 16

17 After Returning juhis public interface AfterReturningAdvice extends Advice { void afterreturning(object returnvalue, Method m, Object[] args, Object target) throws Throwable; 17

18 After Returning juhise näide public class CountingAfterReturningAdvice implements AfterReturningAdvice { private int count; public void afterreturning (Object returnvalue, Method m, Object[] args, Object target) { ++count; public int getcount() { return count; 18

19 Throws juhis org.springframework.aop.throwsadvice afterthrowing ([Method, args, target,] Throwable) 19

20 Throws juhise näide public static class ServletThrowsAdviceWithArguments implements ThrowsAdvice { public void afterthrowing (Method m, Object[] args, Object target, ServletException ex) { // Do something with all arguments public void afterthrowing(remoteexception ex) throws Throwable { // Do something with remote exception 20

21 Lõikepunktid Ühendpunktid (JoinPoints) on Springis alati meetodid Lõikepunktid (Pointcuts) defineerivad, millistele meetoditele juhiseid rakendatakse 21

22 Lõikepunktid Springis org.springframework.aop.support.namematchmethodpointcut org.springframework.aop.support.dynamicmethodmatcherpointcut org.springframework.aop.staticmethodmatcherpointcut org.springframework.aop.support.jdkregexpmethodpointcut org.springframework.aop.support.perl5regexpmethodpointcut org.springframework.aop.support.controlflowpointcut org.springframework.aop.support.composablepointcut 22

23 NameMatchMethodPointcut klass NameMatchMethodPointcut addmethodname(string methodname) void setmappedname(string methodname) void setmappednames(string methodname) 23

24 NameMatchMethodPointcuti kasutamise näide Javas Pointcut pc = new NameMatchMethodPointcut().addMethodName("setAge").addMethodName("setName"); 24

25 Regulaaravaldistega lõikepunktid <bean id="settersandabsquatulatepointcut" class="org.springframework.aop.support.jdkregexpmethodpointcut"> <property name="patterns"> </bean> <list> <value>.*get.*</value> <value>.*absquatulate</value> </list> </property> 25

26 Staatiline (ei sõltu argumentidest) public class MyBeanPointcut extends StaticMethodMatcherPointcut { public boolean matches(method themethod, Class theclass) { return (MyBean.class.isAssignableFrom(theClass) && themethod.equals(...)); 26

27 Dünaamiline (arvestab argumente) public class MyBeanPointcut extends DynamicMethodMatcherPointcut { public boolean matches(method themethod, Class theclass, Object[] arguments) { boolean matches = false; if (MyBean.class.isAssignableFrom(theClass) && themethod.equals(...)) { if (arguments[0].equals("joe Smith")) { matches = true; return matches; 27

28 ControlFlowPointcut <bean id="servletpointcut" class="org.springframework.aop.support. ControlFlowPointcut"> <constructor-arg> <value>javax.servlet.http.httpservlet</value> </constructor-arg> </bean> 28

29 Tehted lõikepunktidega public static Pointcut union(pointcut a, Pointcut b) kas a või b public static Pointcut intersection(pointcut a, Pointcut b) nii a kui b 29

30 Juhtpunktid - Advisors (pakkuge hea tõlge) Ühendavad Springis lõikepunktid ja juhised aspektiks Võivad sisaldada lõikepunktide defineerimiseks vajalikke meetodeid (pole vaja lõikepunktide jaoks eraldi klasse defineerida) 30

31 DefaultPointcutAdvisor public class DefaultPointcutAdvisor { private Pointcut pointcut; private Advice advice; public Pointcut getpointcut() { return pointcut; public Advice getadvice() { return advice; public void setpointcut(pointcut pc) { pointcut = pc; public void setadvice(advice a) { advice = a; 31

32 DefaultPointcutAdvisor (2) <bean name ="myadvisor class="org.springframework.aop.support.default PointcutAdvisor"> <property name="pointcut"> <ref local="mypointcut"/> </property> <property name="advice"> <ref local="myadvice"/> </property> </bean> 32

33 NameMatchMethodPointcutAdvisor <bean name="advisor1" class="org.springframework.aop.support.namematchmethodpointcutadvisor"> <property name="advice" ref="beforeadvicea"/> <property name="mappedname" value= mymethod"/> </bean> 33

34 RegexpMethodPointcutAdvisor <bean id= advisor2" class="org.springframework.aop.support.regexpmethodpointcutadvisor"> <property name="advice"> <ref local="myadvice"/> </property> <property name="patterns"> <list> </list> </property> <value>.*set.*</value> <value>.*getname</value> </bean> 34

35 AOP realiseerimine Kompileerimisel (AspectJ) Klassi laadimisel Programmi käimisel (Spring) 35

36 Staatiline vs dünaamiline Statiline AOP - Kompileerimisel põimitakse aspektid java klassidesse - AspectJ Dünaamiline AOP - Aspektid põimitakse programmi töö ajal - Klasse pole vaja uuesti kompileerida - Aspektide jaoks vahendaja (proxy) - Spring 36

37 Vahendajad (Proxy) JDK Dynamic Proxy - Rakendatav objektidele, mille klassid realiseerivad liideseid CGLIB Proxy - Lennult genereeritakse antud klassi laiendav klass 37

38 ProxyFactoryBean Loob vahendaja-objeti, millele rakendatakse aspekte Saab siduda objektiga nii juhiseid (advice) kui juhtpunkte (advisor) 38

39 <bean id="mydependency1" class="org.springframework.aop.framework.proxyfactorybe an"> <property name="target"> <ref local="mydependencytarget"/> </property> <property name="interceptornames"> <list> <value>myadvice</value> <value>myadvisor</value> </list> </property> </bean> 39

40 Automaatsed vahendajad BeanNameAutoProxyCreator DefaultAdvisorAutoProxyCreator 40

41 <bean id="proxycreator" class="org.springframework.aop.framework.autoproxy.beannameautoproxycreator"> <property name="beannames"> <list> <value>foo*</value> <value>barbean</value> </list> </property> <property name="interceptornames"> <list> <value>advice</value> </list> </property> </bean> 41

42 DefaultAdvisorAutoProxyCreator Juhtpunkte rakendatakse kõikidele objektidele <bean id="aapc" class="org.springframework.aop.framework.autoproxy.defaultadvisorautoproxycreator"/ > 42

43 Spring AOP vs AspectJ 43

44 Spring ja AspectJ võrdlus Spring AOP Lihtne seadistada Käimise ajal AOP Alliance i liidesed Vähem võimalusi AspectJ Väheke keerulisem Kompileerimisel Eraldi programmeerimiskeel Rohkem võimalusi 44

45 Süntaks - Spring AOP (AOP Alliance) public class SimpleMethodInterceptor implements MethodInterceptor { public Object invoke(methodinvocation invocation) throws Throwable {... return invocation.proceed(); - AspectJ public aspect SimpleServiceAroundAspect { pointcut serviceexecution(): execution(public * ee.bus.*service.*(..)); Object around(): serviceexecution() {... return proceed(); 45

46 Spring AOP piirangud Ühenduspunktideks ainult meetodid Ilma CgLibita aspektid ainult liideste meetoditel private, final, static meetoditele ei saa aspekte panna Aspektid rakendatakse ainult konteineri poolt loodud objektidele 46

47 Valmis aspektid Transaktsioonid Puulimine ACEGI security 47

48 Jõudlus 48

49 Spring AOP ja AspectJ jõudlus 1 Million Method Invocations (Adding Numbers) Invocation Time [ms] Number of Aspects AspectJ (Before/After) AspcetJ (Around) Spring AOP autor: Rein Raudjärv 49

50 Küsimused 50