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本篇文章給大家分享的是有關(guān)@AspectJ怎么在Spring AOP 中使用,小編覺得挺實(shí)用的,因此分享給大家學(xué)習(xí),希望大家閱讀完這篇文章后可以有所收獲,話不多說,跟著小編一起來看看吧。
@AspectJ可以使用切點(diǎn)函數(shù)定義切點(diǎn),我們還可以使用邏輯運(yùn)算符對切點(diǎn)進(jìn)行復(fù)核運(yùn)算得到復(fù)合的切點(diǎn),為了在切面中重用切點(diǎn),我們還可以對切點(diǎn)進(jìn)行命名,以便在其他的地方引用定義過的切點(diǎn)。
當(dāng)一個(gè)連接點(diǎn)匹配多個(gè)切點(diǎn)時(shí),需要考慮織入順序的問題,此外一個(gè)重要的問題是如何再增強(qiáng)中訪問連接點(diǎn)上下文的信息。
Waiter接口:
package com.yyq.aspectJAdvanced; public interface Waiter { void greetTo(String name); void serveTo(String name); }
NaiveWaiter實(shí)現(xiàn)類:
package com.yyq.aspectJAdvanced; public class NaiveWaiter implements Waiter { @Override public void greetTo(String name) { System.out.println("NaiveWaiter:greet to " + name + "..."); } @Override public void serveTo(String name) { System.out.println("NaiveWaiter:serving to " + name + "..."); } public void smile(String clientName,int times){ System.out.println("NaiveWaiter:smile to "+clientName+ times+"times..."); } }
NaughtyWaiter實(shí)現(xiàn)類:
package com.yyq.aspectJAdvanced; public class NaughtyWaiter implements Waiter { public void greetTo(String clientName) { System.out.println("NaughtyWaiter:greet to " + clientName + "..."); } public void serveTo(String clientName) { System.out.println("NaughtyWaiter:serving " + clientName + "..."); } public void joke(String clientName, int times) { System.out.println("NaughtyWaiter:play " + times + " jokes to " + clientName + "..."); } }
Seller接口:
package com.yyq.aspectJAdvanced; public interface Seller { int sell(String goods, String clientName); }
SmallSeller實(shí)現(xiàn)類:
package com.yyq.aspectJAdvanced; public class SmartSeller implements Seller { public int sell(String goods,String clientName) { System.out.println("SmartSeller: sell "+goods +" to "+clientName+"..."); return 100; } public void checkBill(int billId){ if(billId == 1) throw new IllegalArgumentException("iae Exception"); else throw new RuntimeException("re Exception"); } }
beans.xml配置文件:
<?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:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd"> <aop:aspectj-autoproxy proxy-target-class="true"/> <bean id="naiveWaiter" class="com.yyq.aspectJAdvanced.NaiveWaiter"/> <bean id="naughtyWaiter" class="com.yyq.aspectJAdvanced.NaughtyWaiter"/> <bean id="seller" class="com.yyq.aspectJAdvanced.SmartSeller"/> <!-- <bean class="com.yyq.aspectJAdvanced.TestAspect"/> <bean class="com.yyq.aspectJAdvanced.TestAspect2"/> <bean class="com.yyq.aspectJAdvanced.TestAspect3"/> <bean class="com.yyq.aspectJAdvanced.TestAspect4"/> <bean class="com.yyq.aspectJAdvanced.TestAspect5"/> <bean id="naiveWaiter2" class="com.yyq.aspectJAdvanced.NaiveWaiter2"/> <bean class="com.yyq.aspectJAdvanced.TestAspect6"/> <bean class="com.yyq.aspectJAdvanced.TestAspect7"/> <bean class="com.yyq.aspectJAdvanced.TestAspect8"/> --> </beans>
使用切點(diǎn)符合運(yùn)算符,我們將擁有強(qiáng)大而靈活的切點(diǎn)表達(dá)能力。
TestAspect:切點(diǎn)符合運(yùn)算定義切面
package com.yyq.aspectJAdvanced; import org.aspectj.lang.annotation.After; import org.aspectj.lang.annotation.AfterReturning; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Before; @Aspect public class TestAspect { //與非運(yùn)算 @Before("!target(com.yyq.aspectJAdvanced.NaiveWaiter) && execution(* serveTo(..))") public void notServeInNaiveWaiter(){ System.out.println("--notServeInNaiveWaiter() executed!--"); } //與運(yùn)算 @After("within(com.yyq.aspectJAdvanced.*) && execution(* greetTo(..))") public void greetToFun(){ System.out.println("--greetToFun() executed!--"); } //或運(yùn)算 @AfterReturning("target(com.yyq.aspectJAdvanced.Waiter) || target(com.yyq.aspectJAdvanced.Seller)") public void waiterOrSeller(){ System.out.println("--waiterOrSeller() executed!--"); } }
測試方法:
@Test public void pointAspectJTest() { String configPath = "com\\yyq\\aspectJAdvanced\\beans.xml"; ApplicationContext ctx = new ClassPathXmlApplicationContext(configPath); Waiter naiveWaiter = (Waiter) ctx.getBean("naiveWaiter"); Waiter naughtyWaiter = (Waiter) ctx.getBean("naughtyWaiter"); naiveWaiter.greetTo("John"); naiveWaiter.serveTo("John"); naughtyWaiter.greetTo("Tom"); naughtyWaiter.serveTo("Tom"); }
輸出結(jié)果:
NaiveWaiter:greet to John... --greetToFun() executed!-- --waiterOrSeller() executed!-- NaiveWaiter:serving to John... --waiterOrSeller() executed!-- NaughtyWaiter:greet to Tom... --greetToFun() executed!-- --waiterOrSeller() executed!-- --notServeInNaiveWaiter() executed!-- NaughtyWaiter:serving Tom... --waiterOrSeller() executed!--
切點(diǎn)直接聲明在增強(qiáng)方法處被稱為匿名切點(diǎn),匿名切點(diǎn)只能在聲明處使用。如果希望在其他地方重用一個(gè)切點(diǎn),我們可以通過@Pointcut注解以及切面類方法對切點(diǎn)進(jìn)行命名。
TestNamePointcut:命名切點(diǎn)類
package com.yyq.aspectJAdvanced; import org.aspectj.lang.annotation.Pointcut; public class TestNamePointcut { //通過注解方法inPackage()對該切點(diǎn)進(jìn)行命名,方法可視域修飾符為private,表明該命名切點(diǎn)只能在本切面類中使用 @Pointcut("within(com.yyq.aspectJAdvaned.*)") private void inPackage(){} @Pointcut("execution(* greetTo(..))") protected void greetTo(){} @Pointcut("inPackage() and greetTo()") public void inPkgGreetTo(){} }
TestAspect2:切面實(shí)現(xiàn)類
package com.yyq.aspectJAdvanced; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Before; @Aspect public class TestAspect2 { @Before("TestNamePointcut.inPkgGreetTo()") public void pkgGreetTo(){ System.out.println("--pkgGreetTo() executed!--"); } @Before("target(com.yyq.aspectJAdvanced.NaiveWaiter) || TestNamePointcut.inPkgGreetTo()") public void pkgGreetToNotnaiveWaiter(){ System.out.println("--pkgGreetToNotnaiveWaiter() executed!--"); } }
測試方法:
@Test public void pointAspectJTest2() { String configPath = "com\\yyq\\aspectJAdvanced\\beans.xml"; ApplicationContext ctx = new ClassPathXmlApplicationContext(configPath); NaiveWaiter naiveWaiter = (NaiveWaiter) ctx.getBean("naiveWaiter"); naiveWaiter.smile("Andy", 2); }
輸出結(jié)果:
--pkgGreetToNotnaiveWaiter() executed!-- NaiveWaiter:smile to Andy2times...
一個(gè)連接點(diǎn)可以同時(shí)匹配多個(gè)切點(diǎn),切點(diǎn)對應(yīng)的增強(qiáng)在連接點(diǎn)上的織入順序的安排主要有以下3種情況:
1)如果增強(qiáng)在同一個(gè)切面類中聲明,則依照增強(qiáng)在切面類中定義的順序進(jìn)行織入;
2)如何增強(qiáng)位于不同的切面類中,且這些切面類都實(shí)現(xiàn)了org.springframework.core.Order接口,則由接口方法的順序號決定(順序號小的先織入);
3)如果增強(qiáng)位于不同的切面類中,且這些切面類沒有實(shí)現(xiàn)org.springframework.core.Order接口,織入的順序是不確定的。
AspectJ使用org.aspectj.lang.JoinPoint接口表示目標(biāo)類連接點(diǎn)對象,如果是環(huán)繞增強(qiáng)時(shí),使用org.aspectj.lang.ProceedingJoinPoint表示連接點(diǎn)對象,該類是JoinPoint的子接口,任何一個(gè)增強(qiáng)方法都可以通過將第一個(gè)入?yún)⒙暶鳛镴oinPoint訪問到連接點(diǎn)上下文的信息。
TestAspect3:切面實(shí)現(xiàn)類
@Aspect public class TestAspect3 { @Around("execution(* greetTo(..)) && target(com.yyq.aspectJAdvanced.NaiveWaiter)") public void joinPointAccess(ProceedingJoinPoint pjp) throws Throwable { System.out.println("---joinPointAccess---"); System.out.println("args[0]:" + pjp.getArgs()[0]); System.out.println("signature:" + pjp.getTarget().getClass()); pjp.proceed(); System.out.println("---joinPointAccess---"); } }
測試方法:
@Test public void pointAspectJTest3() { String configPath = "com\\yyq\\aspectJAdvanced\\beans.xml"; ApplicationContext ctx = new ClassPathXmlApplicationContext(configPath); Waiter naiveWaiter = (Waiter) ctx.getBean("naiveWaiter"); naiveWaiter.greetTo("Andy"); }
輸出結(jié)果:
---joinPointAccess--- args[0]:Andy signature:class com.yyq.aspectJAdvanced.NaiveWaiter NaiveWaiter:greet to Andy... ---joinPointAccess---
args()用于綁定連接點(diǎn)方法的入?yún)?;@annotation()用于綁定連接點(diǎn)方法的注解對象;而@args()用于綁定連接點(diǎn)方法入?yún)⒌淖⒔狻?/p>
TestAspect4:切面實(shí)現(xiàn)類
@Aspect public class TestAspect4 { @Before("target(com.yyq.aspectJAdvanced.NaiveWaiter) && args(name,num,..)") public void bindJoinPointParams(int num, String name) { System.out.println("---bindJoinPointParams---"); System.out.println("name:" + name); System.out.println("num:" + num); System.out.println("---bindJoinPointParams---"); } }
測試方法:
@Test public void pointAspectJTest4() { String configPath = "com\\yyq\\aspectJAdvanced\\beans.xml"; ApplicationContext ctx = new ClassPathXmlApplicationContext(configPath); NaiveWaiter naiveWaiter = (NaiveWaiter) ctx.getBean("naiveWaiter"); naiveWaiter.smile("Andy", 3); }
輸出結(jié)果:
---bindJoinPointParams--- name:Andy num:3 ---bindJoinPointParams--- NaiveWaiter:smile to Andy 3 times...
使用this()或target()可綁定被代理對象實(shí)例,在通過類實(shí)例名綁定對象時(shí),還依然具有原來連接點(diǎn)匹配的功能,只不過類名是通過增強(qiáng)方法中同名入?yún)⒌念愋烷g接決定罷了。
TestAspect5:切面實(shí)現(xiàn)類
@Aspect public class TestAspect5 { @Before("this(waiter)") public void bindProxyObj(Waiter waiter){ System.out.println("---bindProxyObj---"); System.out.println(waiter.getClass().getName()); System.out.println("---bindProxyObj---"); } }
測試方法:
@Test public void pointAspectJTest5() { String configPath = "com\\yyq\\aspectJAdvanced\\beans.xml"; ApplicationContext ctx = new ClassPathXmlApplicationContext(configPath); Waiter waiter = (Waiter) ctx.getBean("naiveWaiter"); waiter.greetTo("Yang"); }
輸出結(jié)果:
---bindProxyObj--- com.yyq.aspectJAdvanced.NaiveWaiter$$EnhancerByCGLIB$$fefafe52 ---bindProxyObj--- NaiveWaiter:greet to Yang...
@within()和@target()函數(shù)可以將目標(biāo)類的注解對象綁定到增強(qiáng)方法中,我們通過@within()演示注解綁定的操作。
TestAspect6:切面測試類
@Aspect public class TestAspect6 { @Before("@within(m)") public void bindTypeAnnoObject(Monitorable m) { System.out.println("---bindTypeAnnoObject---"); System.out.println(m.getClass().getName()); System.out.println("---bindTypeAnnoObject---"); } }
測試方法:
@Test public void pointAspectJTest6() { String configPath = "com\\yyq\\aspectJAdvanced\\beans.xml"; ApplicationContext ctx = new ClassPathXmlApplicationContext(configPath); Waiter waiter = (Waiter) ctx.getBean("naiveWaiter2"); ((NaiveWaiter2)waiter).greetTo("Yang"); }
輸出結(jié)果:
---bindTypeAnnoObject--- $Proxy4 ---bindTypeAnnoObject--- NaiveWaiter:greet to Yang...
在后置增強(qiáng)中,我們可以通過returning綁定連接點(diǎn)方法的返回值。
TestAspect7:切面實(shí)現(xiàn)類
@Aspect public class TestAspect7 { @AfterReturning(value = "target(com.yyq.aspectJAdvanced.SmartSeller)", returning = "retVal") public void bindReturnValue(int retVal) { System.out.println("---bindReturnValue---"); System.out.println("returnValue:" + retVal); System.out.println("---bindReturnValue---"); } }
測試方法:
@Test public void pointAspectJTest7() { String configPath = "com\\yyq\\aspectJAdvanced\\beans.xml"; ApplicationContext ctx = new ClassPathXmlApplicationContext(configPath); SmartSeller seller = (SmartSeller) ctx.getBean("seller"); seller.sell("Beer", "John"); }
輸出結(jié)果:
SmartSeller: sell Beer to John... ---bindReturnValue--- returnValue:100 ---bindReturnValue---
和通過切點(diǎn)函數(shù)綁定連接點(diǎn)信息不同,連接點(diǎn)拋出的異常必須使用AfterThrowing注解的throwing成員進(jìn)行綁定。
TestAspect8:切面實(shí)現(xiàn)類
@Aspect public class TestAspect8 { @AfterThrowing(value = "target(com.yyq.aspectJAdvanced.SmartSeller)", throwing = "iae") public void bindException(IllegalArgumentException iae) { System.out.println("---bindException---"); System.out.println("exception:" + iae.getMessage()); System.out.println("---bindException---"); } }
測試方法:
@Test public void pointAspectJTest8() { String configPath = "com\\yyq\\aspectJAdvanced\\beans.xml"; ApplicationContext ctx = new ClassPathXmlApplicationContext(configPath); SmartSeller seller = (SmartSeller) ctx.getBean("seller"); seller.checkBill(1); }
輸出結(jié)果:
---bindException--- exception:iae Exception ---bindException---
以上就是@AspectJ怎么在Spring AOP 中使用,小編相信有部分知識點(diǎn)可能是我們?nèi)粘9ぷ鲿姷交蛴玫降?。希望你能通過這篇文章學(xué)到更多知識。更多詳情敬請關(guān)注億速云行業(yè)資訊頻道。
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