@AspectJ可以使用切點函式定義切點，我們還可以使用邏輯運算子對切點進行復核運算得到複合的切點，為了在切面中重用切點，我們還可以對切點進行命名，以便在其他的地方引用定義過的切點。

當一個連線點匹配多個切點時，需要考慮織入順序的問題，此外一個重要的問題是如何再增強中訪問連線點上下文的資訊。

Waiter介面：

package com.yyq.aspectJAdvanced;
public interface Waiter {
 void greetTo(String name);
 void serveTo(String name);
}

NaiveWaiter實現類：

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實現類：

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介面：

package com.yyq.aspectJAdvanced;
public interface Seller {
 int sell(String goods,String clientName);
}

SmallSeller實現類：

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配置檔案：

<?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>

1、切點符合運算

使用切點符合運算子，我們將擁有強大而靈活的切點表達能力。

TestAspect：切點符合運算定義切面

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 {
 //與非運算
 @Before("!target(com.yyq.aspectJAdvanced.NaiveWaiter) && execution(* serveTo(..))")
 public void notServeInNaiveWaiter(){
  System.out.println("--notServeInNaiveWaiter() executed!--");
 }
 //與運算
 @After("within(com.yyq.aspectJAdvanced.*) && execution(* greetTo(..))")
 public void greetToFun(){
  System.out.println("--greetToFun() executed!--");
 }
 //或運算
 @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!--

2、命名切點

切點直接宣告在增強方法處被稱為匿名切點，匿名切點只能在宣告處使用。如果希望在其他地方重用一個切點，我們可以通過@Pointcut註解以及切面類方法對切點進行命名。

TestNamePointcut：命名切點類

package com.yyq.aspectJAdvanced;
import org.aspectj.lang.annotation.Pointcut;
public class TestNamePointcut {
 //通過註解方法inPackage()對該切點進行命名，方法可視域修飾符為private，表明該命名切點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：切面實現類

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);
 }

輸出結果：

--pkgGreetToNotnaiveWaiter() executed!--
NaiveWaiter:smile to Andy2times...

3、增強織入的順序

一個連線點可以同時匹配多個切點，切點對應的增強在連線點上的織入順序的安排主要有以下3種情況：

1）如果增強在同一個切面類中宣告，則依照增強在切面類中定義的順序進行織入；

2）如何增強位於不同的切面類中，且這些切面類都實現了org.springframework.core.Order介面，則由介面方法的順序號決定（順序號小的先織入）；

3）如果增強位於不同的切面類中，且這些切面類沒有實現org.springframework.core.Order介面，織入的順序是不確定的。

4、訪問連線點資訊

AspectJ使用org.aspectj.lang.JoinPoint介面表示目標類連線點物件，如果是環繞增強時，使用org.aspectj.lang.ProceedingJoinPoint表示連線點物件，該類是JoinPoint的子介面，任何一個增強方法都可以通過將第一個入參宣告為JoinPoint訪問到連線點上下文的資訊。

TestAspect3：切面實現類

@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");
 }

輸出結果：

---joinPointAccess---
args[0]:Andy
signature:class com.yyq.aspectJAdvanced.NaiveWaiter
NaiveWaiter：greet to Andy...
---joinPointAccess---

5、繫結連線點方法入參

args()用於繫結連線點方法的入參；@annotation()用於繫結連線點方法的註解物件；而@args()用於繫結連線點方法入參的註解。

TestAspect4：切面實現類

@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);
 }

輸出結果：

---bindJoinPointParams---
name:Andy
num:3
---bindJoinPointParams---
NaiveWaiter:smile to Andy 3 times...

6、繫結代理物件

使用this()或target()可繫結被代理物件例項，在通過類例項名繫結物件時，還依然具有原來連線點匹配的功能，只不過類名是通過增強方法中同名入參的型別間接決定罷了。

TestAspect5：切面實現類

@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");
 }

輸出結果：

---bindProxyObj---
com.yyq.aspectJAdvanced.NaiveWaiter$$EnhancerByCGLIB$$fefafe52
---bindProxyObj---
NaiveWaiter：greet to Yang...

7、繫結類註解物件

@within()和@target()函式可以將目標類的註解物件繫結到增強方法中，我們通過@within()演示註解繫結的操作。

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");
 }

輸出結果：

---bindTypeAnnoObject---
$Proxy4
---bindTypeAnnoObject---
NaiveWaiter：greet to Yang...

8、繫結返回值

在後置增強中，我們可以通過returning繫結連線點方法的返回值。

TestAspect7：切面實現類

@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");
 } 

輸出結果：

SmartSeller: sell Beer to John...
---bindReturnValue---
returnValue:100
---bindReturnValue---

9、繫結丟擲的異常

和通過切點函式繫結連線點資訊不同，連線點丟擲的異常必須使用AfterThrowing註解的throwing成員進行繫結。

TestAspect8：切面實現類

@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);
 }

輸出結果：

---bindException---
exception:iae Exception
---bindException---

以上為個人經驗，希望能給大家一個參考，也希望大家多多支援我們。如有錯誤或未考慮完全的地方，望不吝賜教。