Spring AOP使用教程下篇

于 2019-06-06 22:48:04 发布
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本文链接：https://blog.youkuaiyun.com/jianghuiyun/article/details/91049841

切入点的高级使用

1、使用控制流切入点

public class TestBean {
    public void foo() {
        System.out.println("foo()");
    }
}
import org.springframework.aop.Advisor;
import org.springframework.aop.Pointcut;
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.aop.support.ControlFlowPointcut;
import org.springframework.aop.support.DefaultPointcutAdvisor;

public class ControlFlowDemo {
    public static void main(String... args) {
        ControlFlowDemo ex = new ControlFlowDemo();
        ex.run();
    }

    public void run() {
        TestBean target = new TestBean();

        Pointcut pc = new ControlFlowPointcut(ControlFlowDemo.class, "test");
        Advisor advisor = new DefaultPointcutAdvisor(pc, 
            new SimpleBeforeAdvice());

        ProxyFactory pf = new ProxyFactory();
        pf.setTarget(target);
        pf.addAdvisor(advisor);

        TestBean proxy = (TestBean) pf.getProxy();
 
        System.out.println("\tTrying normal invoke");
        proxy.foo();
        System.out.println("\n\tTrying under ControlFlowDemo.test()");
        test(proxy);
    }

    private void test(TestBean bean) {
        bean.foo();
    }
}

2、使用组合切入点

import java.lang.reflect.Method;

import org.springframework.aop.Advisor;
import org.springframework.aop.ClassFilter;
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.aop.support.ComposablePointcut;
import org.springframework.aop.support.DefaultPointcutAdvisor;
import org.springframework.aop.support.StaticMethodMatcher;

public class ComposablePointcutDemo {
    public static void main(String... args) {
        GrammyGuitarist johnMayer = new GrammyGuitarist();

        ComposablePointcut pc = new ComposablePointcut(ClassFilter.TRUE, 
            new SingMethodMatcher());

        System.out.println("Test 1 >> ");
        GrammyGuitarist proxy = getProxy(pc, johnMayer);
        testInvoke(proxy);
        System.out.println();

        System.out.println("Test 2 >> ");
        pc.union(new TalkMethodMatcher());
        proxy = getProxy(pc, johnMayer);
        testInvoke(proxy);
        System.out.println();

        System.out.println("Test 3 >> ");
        pc.intersection(new RestMethodMatcher());
        proxy = getProxy(pc, johnMayer);
        testInvoke(proxy);
    }

    private static GrammyGuitarist getProxy(ComposablePointcut pc,
            GrammyGuitarist target) {
        Advisor advisor = new DefaultPointcutAdvisor(pc, 
            new SimpleBeforeAdvice());

        ProxyFactory pf = new ProxyFactory();
        pf.setTarget(target);
        pf.addAdvisor(advisor);
        return (GrammyGuitarist) pf.getProxy();
    }

    private static void testInvoke(GrammyGuitarist proxy) {
        proxy.sing();
        proxy.sing(new Guitar());
        proxy.talk();
        proxy.rest();
    }

    private static class SingMethodMatcher extends StaticMethodMatcher {
        @Override
        public boolean matches(Method method, Class<?> cls) {
            return (method.getName().startsWith("si"));
        }
    }

    private static class TalkMethodMatcher extends StaticMethodMatcher {
        @Override
        public boolean matches(Method method, Class<?> cls) {
            return "talk".equals(method.getName());
        }
    }

    private static class RestMethodMatcher extends StaticMethodMatcher {
        @Override
        public boolean matches(Method method, Class<?> cls) {
            return (method.getName().endsWith("st"));
        }
    }
}

引入入门

当一个功能是横切的并且使用传统通知不易实现时，就需要动态添加该功能。可以通过IntroductionIntercepter接口来创建引入，该接口扩展了MethodInterceptor和DynamicIntroductionAdvice。使用addAdvisor()方法并传入IntroductionAdvisor接口的实例来创建引用。

使用引入进行对象修改检查

public interface IsModified {
    boolean isModified();
}

import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

import org.aopalliance.intercept.MethodInvocation;
import org.springframework.aop.support.DelegatingIntroductionInterceptor;

public class IsModifiedMixin extends DelegatingIntroductionInterceptor 
        implements IsModified {
    private boolean isModified = false;

    private Map<Method, Method> methodCache = new HashMap<>();

    @Override
    public boolean isModified() {
        return isModified;
    }

    @Override
    public Object invoke(MethodInvocation invocation) throws Throwable {
        if (!isModified) {
            if ((invocation.getMethod().getName().startsWith("set"))
                && (invocation.getArguments().length == 1)) {

                Method getter = getGetter(invocation.getMethod());

                if (getter != null) {
                    Object newVal = invocation.getArguments()[0];
                    Object oldVal = getter.invoke(invocation.getThis(),null);

                    if((newVal == null) && (oldVal == null)) {
                        isModified = false;
                    } else if((newVal == null) && (oldVal != null)) {
                        isModified = true;
                    } else if((newVal != null) && (oldVal == null)) {
                        isModified = true;
                    } else {
                        isModified = !newVal.equals(oldVal);
                    }
                }
            }
        }

        return super.invoke(invocation);
    }

    private Method getGetter(Method setter) {
        Method  getter = methodCache.get(setter);

        if (getter != null) {
            return getter;
        }

        String getterName = setter.getName().replaceFirst("set", "get");
        try {
            getter = setter.getDeclaringClass().getMethod(getterName, null);
            synchronized (methodCache) {
                methodCache.put(setter, getter);
            }
            return getter;
        } catch (NoSuchMethodException ex) {
            return null;
        }
    }
}
import org.springframework.aop.support.DefaultIntroductionAdvisor;

public class IsModifiedAdvisor extends DefaultIntroductionAdvisor {
    public IsModifiedAdvisor() {
        super(new IsModifiedMixin());
    }
}
public class Contact {

	private String name;
	private String phoneNumber;
	private String email;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getPhoneNumber() {
		return phoneNumber;
	}

	public void setPhoneNumber(String phoneNumber) {
		this.phoneNumber = phoneNumber;
	}

	public String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}
}
import org.springframework.aop.IntroductionAdvisor;
import org.springframework.aop.framework.ProxyFactory;

public class IntroductionDemo {
    public static void main(String... args) {
        Contact target = new Contact();
        target.setName("John Mayer");

        IntroductionAdvisor advisor = new IsModifiedAdvisor();

        ProxyFactory pf = new ProxyFactory();
        pf.setTarget(target);
        pf.addAdvisor(advisor);
        pf.setOptimize(true);

        Contact proxy = (Contact) pf.getProxy();
        IsModified proxyInterface = (IsModified)proxy;

        System.out.println("Is Contact?: " + (proxy instanceof Contact));
        System.out.println("Is IsModified?: " + (proxy instanceof IsModified));

        System.out.println("Has been modified?: " + 
            proxyInterface.isModified());

        proxy.setName("John Mayer");

        System.out.println("Has been modified?: " + 
            proxyInterface.isModified());

        proxy.setName("Eric Clapton");

        System.out.println("Has been modified?: " + 
            proxyInterface.isModified());
    }
}

AOP服务框架

 

  1. 使用ProxyFactoryBean
  2. 使用Spring aop名称空间
  3. 使用@AspectJ样式注解

使用ProxyFactoryBean

public class GrammyGuitarist {
	public void sing() {
		System.out.println("sing: Gravity is working against me\n" +
				"And gravity wants to bring me down");
	}

	public void sing(Guitar guitar) {
		System.out.println("play: " + guitar.play());
	}

	public void talk(){
		System.out.println("talk");
	}

}
public class Documentarist {

	protected GrammyGuitarist guitarist;

	public void execute() {
		guitarist.sing();
		guitarist.talk();
	}

	public void setGuitarist(GrammyGuitarist guitarist) {
		this.guitarist = guitarist;
	}
}

import org.aspectj.lang.JoinPoint;
import org.springframework.aop.MethodBeforeAdvice;

import java.lang.reflect.Method;

public class AuditAdvice implements MethodBeforeAdvice {

    @Override
    public void before(Method method, Object[] args, Object target)
            throws Throwable {
        System.out.println("Executing: " + method);
    }
}
import org.springframework.context.support.GenericXmlApplicationContext;

public class ProxyFactoryBeanDemo {
    public static void main(String... args) {
        GenericXmlApplicationContext ctx = new GenericXmlApplicationContext();
        ctx.load("spring/app-context-xml.xml");
        ctx.refresh();

        Documentarist documentaristOne = ctx.getBean("documentaristOne", Documentarist.class);
        Documentarist documentaristTwo = ctx.getBean("documentaristTwo", Documentarist.class);

        System.out.println("Documentarist One >>");
        documentaristOne.execute();

        System.out.println("\nDocumentarist Two >> ");
        documentaristTwo.execute();
    }
}
<?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:p="http://www.springframework.org/schema/p"
       xmlns:util="http://www.springframework.org/schema/util"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/util
        http://www.springframework.org/schema/util/spring-util.xsd">

    <bean id="johnMayer" class="com.apress.prospring5.ch5.GrammyGuitarist"/>
    <bean id="advice" class="com.apress.prospring5.ch5.AuditAdvice"/>

    <bean id="documentaristOne" class="com.apress.prospring5.ch5.Documentarist"
          p:guitarist-ref="proxyOne"/>

    <bean id="proxyOne" class="org.springframework.aop.framework.ProxyFactoryBean"
          p:target-ref="johnMayer" p:interceptorNames-ref="interceptorAdviceNames"/>

    <util:list id="interceptorAdviceNames">
        <value>advice</value>
    </util:list>


    <bean id="documentaristTwo" class="com.apress.prospring5.ch5.Documentarist"
          p:guitarist-ref="proxyTwo"/>

    <bean id="proxyTwo" class="org.springframework.aop.framework.ProxyFactoryBean"
          p:target-ref="johnMayer" p:interceptorNames-ref="interceptorAdvisorNames">
    </bean>

    <util:list id="interceptorAdvisorNames">
        <value>advisor</value>
    </util:list>

    <bean id="advisor" class="org.springframework.aop.support.DefaultPointcutAdvisor"
          p:advice-ref="advice">
        <property name="pointcut">
            <bean class="org.springframework.aop.aspectj.AspectJExpressionPointcut"
                  p:expression="execution(* sing*(..))"/>
        </property>
    </bean>

</beans>

使用ProxyFactoryBean进行引入

import org.springframework.aop.IntroductionAdvisor;
import org.springframework.aop.framework.ProxyFactory;

public class IntroductionDemo {
    public static void main(String... args) {
        Contact target = new Contact();
        target.setName("John Mayer");

        IntroductionAdvisor advisor = new IsModifiedAdvisor();

        ProxyFactory pf = new ProxyFactory();
        pf.setTarget(target);
        pf.addAdvisor(advisor);
        pf.setOptimize(true);

        Contact proxy = (Contact) pf.getProxy();
        IsModified proxyInterface = (IsModified)proxy;

        System.out.println("Is Contact?: " + (proxy instanceof Contact));
        System.out.println("Is IsModified?: " + (proxy instanceof IsModified));

        System.out.println("Has been modified?: " + 
            proxyInterface.isModified());

        proxy.setName("John Mayer");

        System.out.println("Has been modified?: " + 
            proxyInterface.isModified());

        proxy.setName("Eric Clapton");

        System.out.println("Has been modified?: " + 
            proxyInterface.isModified());
    }
}

使用aop名称空间

public class NewDocumentarist extends Documentarist {

	@Override
	public void execute() {
		guitarist.sing();
		Guitar guitar = new Guitar();
		guitar.setBrand("Gibson");
		guitarist.sing(guitar);
		//guitarist.sing(new Guitar());
		guitarist.talk();
	}

}
public class SimpleAdvice {

	public void simpleBeforeAdvice(JoinPoint joinPoint) {
		System.out.println("Executing: " +
				joinPoint.getSignature().getDeclaringTypeName() + " "
				+ joinPoint.getSignature().getName());
	}
}
public class AopNamespaceDemo {
    public static void main(String... args) {
        GenericXmlApplicationContext ctx = new GenericXmlApplicationContext();
        //ctx.load("classpath:spring/app-context-xml-01.xml");
        //ctx.load("classpath:spring/app-context-xml-02.xml");
        ctx.load("classpath:spring/app-context-xml-03.xml");
        ctx.refresh();

        NewDocumentarist documentarist = ctx.getBean("documentarist", NewDocumentarist.class);
        documentarist.execute();

        ctx.close();
    }
}

<?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:p="http://www.springframework.org/schema/p"
      xmlns:aop="http://www.springframework.org/schema/aop"
      xsi:schemaLocation="http://www.springframework.org/schema/beans
          http://www.springframework.org/schema/beans/spring-beans.xsd
          http://www.springframework.org/schema/aop
          http://www.springframework.org/schema/aop/spring-aop.xsd">

    <aop:config>
        <aop:pointcut id="singExecution"
            expression="execution(* com.apress.prospring5.ch5..sing*(com.apress.prospring5.ch2.common.Guitar))"/>

        <aop:aspect ref="advice">
            <aop:before pointcut-ref="singExecution"
                method="simpleBeforeAdvice"/>
        </aop:aspect>
    </aop:config>

    <bean id="advice"
          class="com.apress.prospring5.ch5.SimpleAdvice"/>

    <bean id="johnMayer"
          class="com.apress.prospring5.ch5.GrammyGuitarist"/>

    <bean id="documentarist"
          class="com.apress.prospring5.ch5.NewDocumentarist"
          p:guitarist-ref="johnMayer"/>
</beans>
<?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:p="http://www.springframework.org/schema/p"
      xmlns:aop="http://www.springframework.org/schema/aop"
      xsi:schemaLocation="http://www.springframework.org/schema/beans
          http://www.springframework.org/schema/beans/spring-beans.xsd
          http://www.springframework.org/schema/aop
          http://www.springframework.org/schema/aop/spring-aop.xsd">

    <aop:config>
        <aop:pointcut id="singExecution"
            expression="execution(* sing*(com.apress.prospring5.ch2.common.Guitar)) and args(value) and bean(john*)"/>


        <aop:aspect ref="advice">
            <aop:before pointcut-ref="singExecution"
                method="simpleBeforeAdvice"/>
        </aop:aspect>
    </aop:config>

    <bean id="advice"
          class="com.apress.prospring5.ch5.ComplexAdvice"/>

    <bean id="johnMayer"
          class="com.apress.prospring5.ch5.GrammyGuitarist"/>

    <bean id="documentarist"
          class="com.apress.prospring5.ch5.NewDocumentarist"
          p:guitarist-ref="johnMayer"/>
</beans>

 

<?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:p="http://www.springframework.org/schema/p"
      xmlns:aop="http://www.springframework.org/schema/aop"
      xsi:schemaLocation="http://www.springframework.org/schema/beans
          http://www.springframework.org/schema/beans/spring-beans.xsd
          http://www.springframework.org/schema/aop
          http://www.springframework.org/schema/aop/spring-aop.xsd">

    <aop:config>
        <aop:pointcut id="singExecution"
            expression="execution(* sing*(com.apress.prospring5.ch2.common.Guitar)) and args(value) and bean(john*)"/>


        <aop:aspect ref="advice">
            <aop:before pointcut-ref="singExecution"
                method="simpleBeforeAdvice"/>
            <aop:around pointcut-ref="singExecution"
                        method="simpleAroundAdvice"/>
        </aop:aspect>
    </aop:config>

    <bean id="advice"
          class="com.apress.prospring5.ch5.ComplexAdvice"/>

    <bean id="johnMayer"
          class="com.apress.prospring5.ch5.GrammyGuitarist"/>

    <bean id="documentarist"
          class="com.apress.prospring5.ch5.NewDocumentarist"
          p:guitarist-ref="johnMayer"/>
</beans>

 使用<aop:around>声明环绕通知

public class ComplexAdvice {
	public void simpleBeforeAdvice(JoinPoint joinPoint, Guitar value) {
		if(value.getBrand().equalsIgnoreCase("Gibson")) {
			System.out.println("Executing: " +
					joinPoint.getSignature().getDeclaringTypeName() + " "
					+ joinPoint.getSignature().getName());
		}
	}

	public Object simpleAroundAdvice(ProceedingJoinPoint pjp, Guitar value) throws Throwable {
		System.out.println("Before execution: " +
				pjp.getSignature().getDeclaringTypeName() + " "
				+ pjp.getSignature().getName()
				+ " argument: " + value.getBrand());

		Object retVal = pjp.proceed();

		System.out.println("After execution: " +
				pjp.getSignature().getDeclaringTypeName() + " "
				+ pjp.getSignature().getName()
				+ " argument: " + value.getBrand());

		return retVal;
	}
}

使用@AspectJ样式注解

@Component("johnMayer")
public class GrammyGuitarist implements Singer {

	@Override public void sing() {
		System.out.println("sing: Gravity is working against me\n" +
				"And gravity wants to bring me down");
	}

	public void sing(Guitar guitar) {
		System.out.println("play: " + guitar.play());
	}

	public void rest(){
		System.out.println("zzz");
	}

	public void talk(){
		System.out.println("talk");
	}
}
@Component("documentarist")
public class NewDocumentarist {

	protected GrammyGuitarist guitarist;

	public void execute() {
		guitarist.sing();
		Guitar guitar = new Guitar();
		guitar.setBrand("Gibson");
		guitarist.sing(guitar);
		guitarist.talk();
	}

	@Autowired
	@Qualifier("johnMayer")
	public void setGuitarist(GrammyGuitarist guitarist) {
		this.guitarist = guitarist;
	}
}
@Component
@Aspect
public class AnnotatedAdvice {
    @Pointcut("execution(* com.apress.prospring5.ch5..sing*(com.apress.prospring5.ch2.common.Guitar)) && args(value)")
    public void singExecution(Guitar value) {
    }

    @Pointcut("bean(john*)")
    public void isJohn() {
    }

    @Before("singExecution(value) && isJohn()")
    public void simpleBeforeAdvice(JoinPoint joinPoint, Guitar value) {
        if(value.getBrand().equals("Gibson")) {
        System.out.println("Executing: " + 
            joinPoint.getSignature().getDeclaringTypeName() + " "
            + joinPoint.getSignature().getName() + " argument: " + value.getBrand());
        }
    }

    @Around("singExecution(value) && isJohn()")
    public Object simpleAroundAdvice(ProceedingJoinPoint pjp, Guitar value) throws Throwable {
        System.out.println("Before execution: " +      
            pjp.getSignature().getDeclaringTypeName() + " "
            + pjp.getSignature().getName()
            + " argument: " + value.getBrand());

        Object retVal = pjp.proceed();

        System.out.println("After execution: " +   
            pjp.getSignature().getDeclaringTypeName() + " "
            + pjp.getSignature().getName()
            + " argument: " + value.getBrand());

        return retVal;
    }
}
@Configuration
@ComponentScan(basePackages = {"com.apress.prospring5.ch5"})
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class AppConfig {

}

AspectJ集成

public class MessageWriter {
    public void writeMessage() {
        System.out.println("foobar!");
    }

    public void foo() {
        System.out.println("foo");
    }
}

 MessageWrapper.aj文件：

public aspect MessageWrapper {
    private String prefix;
    private String suffix;

    public void setPrefix(String prefix) {
        this.prefix = prefix;
    }

    public String getPrefix() {
        return this.prefix;
    }

    public void setSuffix(String suffix) {
        this.suffix = suffix;
    }

    public String getSuffix() {
        return this.suffix;
    }

    pointcut doWriting() :
        execution(*
           com.apress.prospring5.ch5.MessageWriter.writeMessage());

    before() : doWriting() {
        System.out.println(prefix);
    }

    after() : doWriting() {
        System.out.println(suffix);
    }
}
import org.springframework.context.support.GenericXmlApplicationContext;

public class AspectJDemo {
    public static void main(String... args) {
        GenericXmlApplicationContext ctx = new GenericXmlApplicationContext();
        ctx.load("classpath:spring/app-context-xml.xml");
        ctx.refresh();

        MessageWriter writer = new MessageWriter();
        writer.writeMessage();
        writer.foo();
    }
}

 

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