一擂找、注解創(chuàng)建切面

@Aspect: 表明該類為切面
@Before: 通知方法會在目標(biāo)方法調(diào)用之前執(zhí)行
@After: 通知方法會在目標(biāo)方法返回或拋出異常后執(zhí)行
@AfterReturning: 通知方法會在目標(biāo)方法返回后執(zhí)行
@AfterThrowing: 通知方法會在拋出異常后執(zhí)行
@Around: 通知方法將目標(biāo)方法封裝起來
@Pointcut: 定義切點(diǎn)表達(dá)式
@EnableAspectJ-AutoProxy: 啟用自動(dòng)代理

execution(): 切點(diǎn)表達(dá)式
args(): 執(zhí)行方法參數(shù)
with(): 指定匹配類型

public interface Performance{
    public void perform();
    public void playTrack(int i);
}

@Aspect
public class Audience{
    @Pointcut("execution(** concert.Performance.perform(..))")
    public void perform(){}
    @Pointcut("execution(** concert.Performance.playTrack(int)) && args(trackNum)")
    public void playTrack(int trackNum){}

    @Before("perform()")
    public void silenceCellPhones(){
        System.out.println("Silencing cell phones");
    }
    @Before("playTrack(trackNum)")
    public void playTrack(int trackNum){
        System.out.println("trackNum");
    }
    @AfterReturning("perform()")
    public void applause(){
        System.out.println("CLAP CLAP CLAP");
    }
    @AfterThrowing("perform()")
    public void demandRefund(){
        System.out.println("Demanding a refund");
    }
}

@Configuration
@EnableAspectJ-AutoProxy
@ComponentScan
public class ConcertConfig{
    @Bean
    public Audience audience(){
        return new Audience();
    }
}

二、XML聲明切面

<aop:config>: 頂級AOP配置元素
<aop:aspect>: 定義一個(gè)切面
<aop:pointcut>: 定義一個(gè)切點(diǎn)
<aop:aspectj-autoproxy>: 啟用自動(dòng)代理
<aop:before>: AOP前置通知
<aop:after>: AOP后置通知（不管被執(zhí)行方法是否執(zhí)行成功）
<aop:after-returning>: AOP返回通知
<aop:after-throwing>: AOP異常通知

public interface Performance{
    public void perform();
    public void playTrack(int i);
}

public class Audience{
    public void perform(){}
    public void playTrack(int trackNum){}

    public void silenceCellPhones(){
        System.out.println("Silencing cell phones");
    }
    public void silenceCellPhones(int trackNum){
        System.out.println("trackNum");
    }
    public void applause(){
        System.out.println("CLAP CLAP CLAP");
    }
    public void demandRefund(){
        System.out.println("Demanding a refund");
    }
}

<aop:config>
    <aop:aspect ref="audience">
        <aop:pointcut 
            id="performance"
            expression="execution(** concert.Performance.perform(..))" />
        <aop:pointcut 
            id="trackCounter"
            expression="execution(** concert.Performance.playTrack(int)) && args(trackNum)" />
        <aop:before
            pointcut-ref="performance"
            method="silenceCellPhones" />
        <aop:before
            pointcut-ref="trackCounter"
            method="playTrack" />
        <aop:after-returning
            pointcut-ref="performance"
            method="applause" />
        <aop:after-throwing
            pointcut-ref="performance"
            method="demandRefund" />
    </aop:aspect>
</aop:config>