【增强的类型】
1.前置增强:org.springframework.aop.BeforeAdvice。
由于Spring只支持方法级别的增强,所以MethodBeforeAdvice是目前可用的前置增强,表示在目标方法执行前执行前置增强,BeforeAdvice是为了将来版本扩展需要而定义的。
2.后置增强:org.springframework.aop.AfterReturningAdvice。
表示在目标方法执行后执行增强。
3.环绕增强:org.aopalliance.intercept.MethodInterceptor。
表示在目标方法执行前后执行增强。
4.异常抛出增强:org.springframework.aop.ThrowsAdvice。
表示在目标方法抛出异常时执行增强。
5.引介增强:org.springframework.aop.IntroductionInterceptor。
在目标类中添加一些新的属性和方法。
【前置、后置、环绕增强整个工程】
【车子接口 Car.java】
package com.Higgin.part1; /** * 车子接口 */ public interface Car { public void drive(); }
【具体奔驰车类:BenzCar.java】
package com.Higgin.part1; /** * 奔驰车类 * 我们希望测试奔驰车在执行drive()方法前、后、前后增强的情况 */ public class BenzCar implements Car{ @Override public void drive() { System.out.println("【业务方法】奔驰车在行驶...."); } }
【前置增强类】
package com.Higgin.part1; import java.lang.reflect.Method; import org.springframework.aop.MethodBeforeAdvice; /** * 前置增强类 * 实现的是:MethodBeforeAdvice接口 */ public class DriveBeforeAdvice implements MethodBeforeAdvice{ /** * method:目标类的方法 * args:目标类方法的参数 * obj:目标类的实例 */ @Override public void before(Method method, Object[] args, Object obj)throws Throwable { System.out.println("【前置增强】开车前自动放音乐~~~"); } }
【测试前置增强类1:TestBeforeAdvice】
package com.Higgin.part1.Test; import org.springframework.aop.BeforeAdvice; import org.springframework.aop.framework.ProxyFactory; import com.Higgin.part1.BenzCar; import com.Higgin.part1.Car; import com.Higgin.part1.DriveBeforeAdvice; /** * 测试 前置增强 */ public class TestBeforeAdvice{ public static void main(String[] args) { Car benz=new BenzCar(); //目标对象 BeforeAdvice driveBeforeAdvice=new DriveBeforeAdvice(); //前置增强 ProxyFactory pf=new ProxyFactory(); //1.Spring代理工厂 pf.setTarget(benz); //2.设置代理目标对象 pf.addAdvice(driveBeforeAdvice); //3.为代理对象添加增强 Car carProxy=(Car) pf.getProxy(); //4.生成代理实例 carProxy.drive(); } }
[ 运行结果 ]
【测试前置增强类2:用Spring的xml配置文件方式:TestBeforeAdviceXml.java】
package com.Higgin.part1.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.Higgin.part1.Car; public class TestBeforeAdviceXml { public static void main(String[] args) { ApplicationContext context=new ClassPathXmlApplicationContext("part1.xml"); Car car=(Car) context.getBean("benzCar1"); car.drive(); } }
【测试前置增强类2:用Spring的xml配置文件方式的配置文件:part1.xml】
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:p="http://www.springframework.org/schema/p" xmlns:util="http://www.springframework.org/schema/util" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:cache="http://www.springframework.org/schema/cache" xsi:schemaLocation=" http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.1.xsd http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache-3.1.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd"> <!-- 要增强的目标对象 --> <bean id="target" class="com.Higgin.part1.BenzCar"/> <!-- 前置增强的类 --> <bean id="driveBeforeAdvice" class="com.Higgin.part1.DriveBeforeAdvice" /> <!-- Spring代理工厂的成员变量配置(前置增强)--> <bean id="benzCar1" class="org.springframework.aop.framework.ProxyFactoryBean" p:proxyInterfaces="com.Higgin.part1.Car" p:interceptorNames="driveBeforeAdvice" p:target-ref="target" /> </beans>
[ 运行结果 ]
【后置增强类:DriveAfterAdvice.java】
package com.Higgin.part1; import java.lang.reflect.Method; import org.springframework.aop.AfterReturningAdvice; /** * 后置增强类 * 实现的是:AfterReturningAdvice */ public class DriveAfterAdvice implements AfterReturningAdvice{ @Override public void afterReturning(Object returnObj, Method method, Object[] args, Object obj) throws Throwable { System.out.println("【后置增强】停车后自动关闭音乐~~~"); } }
【测试后置增强类1:TestAfterAdvice.java】
package com.Higgin.part1.Test; import org.springframework.aop.AfterReturningAdvice; import org.springframework.aop.BeforeAdvice; import org.springframework.aop.framework.ProxyFactory; import com.Higgin.part1.BenzCar; import com.Higgin.part1.Car; import com.Higgin.part1.DriveAfterAdvice; import com.Higgin.part1.DriveBeforeAdvice; public class TestAfterAdvice { public static void main(String[] args) { Car benz=new BenzCar(); //目标对象 BeforeAdvice driveBeforeAdvice=new DriveBeforeAdvice(); //前置增强 AfterReturningAdvice driveAfterAdvice=new DriveAfterAdvice(); //后置增强 ProxyFactory pf=new ProxyFactory(); //1.Spring代理工厂 pf.setTarget(benz); //2.设置代理目标 pf.addAdvice(driveBeforeAdvice); //3.为代理对象添加 前 置增强 pf.addAdvice(driveAfterAdvice); //3.为代理对象添加 后 置增强 Car carProxy=(Car) pf.getProxy(); //4.生成代理实例 carProxy.drive(); } }
【运行结果】
【测试后置增强类2:用Spring的xml配置文件方式:TestAfterAdviceXml.java】
package com.Higgin.part1.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.Higgin.part1.Car; public class TestAfterAdviceXml { public static void main(String[] args) { ApplicationContext context =new ClassPathXmlApplicationContext("part1.xml"); Car benz=(Car) context.getBean("benzCar2"); benz.drive(); } }
【测试后置增强类2:用Spring的xml配置文件方式的配置文件:part1.xml】
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:p="http://www.springframework.org/schema/p" xmlns:util="http://www.springframework.org/schema/util" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:cache="http://www.springframework.org/schema/cache" xsi:schemaLocation=" http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.1.xsd http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache-3.1.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd"> <!-- 要增强的目标对象 --> <bean id="target" class="com.Higgin.part1.BenzCar"/> <!-- 前置增强的类 --> <bean id="driveBeforeAdvice" class="com.Higgin.part1.DriveBeforeAdvice" /> <!-- 后置增强的类 --> <bean id="dirveAfterAdvice" class="com.Higgin.part1.DriveAfterAdvice" /> <!-- Spring代理工厂的成员变量配置(后置增强+前置增强) --> <bean id="benzCar2" class="org.springframework.aop.framework.ProxyFactoryBean" p:proxyInterfaces="com.Higgin.part1.Car" p:interceptorNames="driveBeforeAdvice,dirveAfterAdvice" p:target-ref="target" /> </beans>
[ 运行结果 ]
【环绕增强类:DriveAroundAdvice.java】
package com.Higgin.part1; import org.aopalliance.intercept.MethodInterceptor; import org.aopalliance.intercept.MethodInvocation; /** * 环绕增强 * 实现的接口:MethodInterceptor * 注意:需要导入jar包:aopalliance-1.0.jar */ public class DriveAroundAdvice implements MethodInterceptor{ @Override public Object invoke(MethodInvocation invocation) throws Throwable { System.out.println("【前置增强】开车前自动打开音乐~~~"); Object obj=invocation.proceed(); //通过反射执行目标的业务方法 System.out.println("【后置增强】停车后自动关闭音乐~~~"); return obj; } }
【环绕增强测试类1:TestAroundAdvice.java】
package com.Higgin.part1.Test; import org.aopalliance.intercept.MethodInterceptor; import org.springframework.aop.framework.ProxyFactory; import com.Higgin.part1.BenzCar; import com.Higgin.part1.Car; import com.Higgin.part1.DriveAroundAdvice; public class TestAroundAdvice { public static void main(String[] args) { Car benzCar=new BenzCar(); MethodInterceptor driveAroundAdvice=new DriveAroundAdvice(); ProxyFactory pf=new ProxyFactory(); pf.setTarget(benzCar); pf.addAdvice(driveAroundAdvice); Car carProxy=(Car) pf.getProxy(); carProxy.drive(); } }
[ 运行结果 ]
【测试环绕增强类2:用Spring的xml配置文件方式:TestAroundAdviceXml.java】
package com.Higgin.part1.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.Higgin.part1.Car; public class TestAroundAdviceXml { public static void main(String[] args) { ApplicationContext context=new ClassPathXmlApplicationContext("part1.xml"); Car car=(Car) context.getBean("benzCar3"); car.drive(); } }
【测试环绕增强类2:用Spring的xml配置文件方式的配置文件:part1.xml】
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:p="http://www.springframework.org/schema/p" xmlns:util="http://www.springframework.org/schema/util" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:cache="http://www.springframework.org/schema/cache" xsi:schemaLocation=" http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.1.xsd http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache-3.1.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd"> <!-- 要增强的目标对象 --> <bean id="target" class="com.Higgin.part1.BenzCar"/> <!-- 环绕增强的类 --> <bean id="driveAroundAdvice" class="com.Higgin.part1.DriveAroundAdvice"/> <!-- Spring代理工厂的成员变量配置(环绕增强) --> <bean id="benzCar3" class="org.springframework.aop.framework.ProxyFactoryBean" p:proxyInterfaces="com.Higgin.part1.Car" p:interceptorNames="driveAroundAdvice" p:target-ref="target" /> </beans>
[ 运行结果 ]
【分析】
1.关于spring的xml配置文件的分析
其中的ProxyFactoryBean类是FactoryBean的实现类,
FactoryBean负责实例化一个Bean,
ProxyFactoryBean负责为其他Bean创建代理实例,它内部使用ProxyFactory来完成这一工作。
ProxyFactoryBean的几个可配置属性(成员变量)
target:代理的目标对象
proxyInterfaces:代理需要实现的接口,可以是多个接口。该属性该有一个别名interfaces。
interceptor:需要织入目标对象的Bean列表。采用Bean的名称指定。这些Bean必须是实现了org.aoplliance.interceptor.MethodInterceptor或者org.springframework.Advisor的Bean,配置中的顺序对应调用的顺序。
singleton:返回的代理是否是单例,默认单例。
optimize:为true时,强制使用Cglib代理,对于Singleton的代理,建议使用CGlib。对于其他作用域类型的代理,最好使用JDK代理。(CGLib创建代理时速度慢,而创建出来的代理对象运行效率高,JDK代理相反)
proxyTargetClass:是否对类进行代理(而不是对接口进行代理),设置为true时,使用CGLib代理。