大数据正式29
大数据正式29
Spring中的AOP
- 代理模式
- 特点
- 具备和被代理者相同的方法
- 代理者不仅要做目标对象的方法，而且还要做额外的一些方法
- 操作
- 事务
- 权限控制
- 统计每个方法的执行时间
- 分类
- 静态代理
- 之前
- 代理
- 之前
- 动态代理
- 之前
- 代理
- 之前
- 静态代理
- 特点
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代理模式的来源
- 之前的service层耦合了事务的控制等操作--耦合度太高
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解决的小案例（静态代理）
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pojo
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BigBoss
package com.peng.pojo; import org.springframework.stereotype.Component; @Component(value = "bigboss") public class BigBoss implements SellInterface { @Override public void sellAction() { System.out.println("boss sell home!"); } } -
LinkHome
package com.peng.pojo; import org.springframework.stereotype.Component; @Component(value = "bigboss") public class BigBoss implements SellInterface { @Override public void sellAction() { System.out.println("boss sell home!"); } } -
Manager
package com.peng.pojo; import org.springframework.stereotype.Component; @Component(value = "bigboss") public class BigBoss implements SellInterface { @Override public void sellAction() { System.out.println("boss sell home!"); } } -
SellInterface
package com.peng.pojo; import org.springframework.stereotype.Component; @Component(value = "bigboss") public class BigBoss implements SellInterface { @Override public void sellAction() { System.out.println("boss sell home!"); } }
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test
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Test
package com.peng.test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.peng.pojo.LinkHome; public class Test { @org.junit.Test public void Test_Agent() { ApplicationContext context = new ClassPathXmlApplicationContext( "applicationContext.xml"); LinkHome linkhome = (LinkHome) context.getBean("linkhome"); linkhome.sellAction(); } }
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配置文件
- applicationContext.xml
- applicationContext.xml
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MVC的静态代理
- 项目结构
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代码示例
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dao
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PersonDao
package com.peng.dao; import com.peng.pojo.Person; public interface PersonDao { void savePerson(Person p); } -
PersonDaoImpl
package com.peng.dao; import com.peng.pojo.Person; public interface PersonDao { void savePerson(Person p); }
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service
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PersonService
package com.peng.dao; import com.peng.pojo.Person; public interface PersonDao { void savePerson(Person p); } -
PersonServiceImpl
package com.peng.service; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Service; import com.peng.dao.PersonDao; import com.peng.pojo.Person; @Service(value = "serviceImpl") public class PersonServiceImpl implements PersonService { @Autowired @Qualifier(value = "personDao") private PersonDao dao; @Override public void savePerson(Person p) { if (null != dao) { dao.savePerson(p); } } }
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web
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PersonServlet
package com.peng.web; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Controller; import com.peng.pojo.Person; import com.peng.service.PersonService; @Controller(value = "personServlet") public class PersonServlet { @Autowired @Qualifier(value = "personserviceproxy") private PersonService proxy; public void doSomething(Person p) { proxy.savePerson(p); } }
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proxy
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PersonServiceProxy
package com.peng.web; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Controller; import com.peng.pojo.Person; import com.peng.service.PersonService; @Controller(value = "personServlet") public class PersonServlet { @Autowired @Qualifier(value = "personserviceproxy") private PersonService proxy; public void doSomething(Person p) { proxy.savePerson(p); } }
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manager
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Manager
package com.peng.web; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Controller; import com.peng.pojo.Person; import com.peng.service.PersonService; @Controller(value = "personServlet") public class PersonServlet { @Autowired @Qualifier(value = "personserviceproxy") private PersonService proxy; public void doSomething(Person p) { proxy.savePerson(p); } }
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test
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Test
package com.peng.test; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.peng.pojo.Person; import com.peng.web.PersonServlet; public class Test { @org.junit.Test public void trest1() { ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext( "applicationContext.xml"); System.out.println("=================懒加载在此之后================="); Person person = (Person) ac.getBean("person"); PersonServlet servlet = (PersonServlet) ac.getBean("personServlet"); servlet.doSomething(person); ac.close(); } }
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pojo
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Person
package com.peng.pojo; import javax.annotation.PostConstruct; import javax.annotation.PreDestroy; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Lazy; import org.springframework.context.annotation.Scope; import org.springframework.stereotype.Component; @Scope(value = "singleton") @Lazy(value = true) @Component(value = "person") public class Person { @Value(value = "张三") private String name; @Value(value = "12") private Integer age; private Person() { super(); System.out.println("============构造函数==========="); } private Person(String name, Integer age) { super(); this.name = name; this.age = age; } @Override public String toString() { return "名称：" + name + "，年龄：" + age; } @PostConstruct public void init() { System.out.println("=====Person=====init=========="); } @PreDestroy public void destory() { System.out.println("=====Person=====destory=========="); } }
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配置文件
- applicationContext.xml
- applicationContext.xml
- 执行结果
十二月 20, 2017 10:26:03 上午 org.springframework.context.support.AbstractApplicationContext prepareRefresh INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@dfe491: startup date [Wed Dec 20 10:26:03 CST 2017]; root of context hierarchy 十二月 20, 2017 10:26:03 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions INFO: Loading XML bean definitions from class path resource [applicationContext.xml] 十二月 20, 2017 10:26:04 上午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@cb855e: defining beans [personDao,manager,person,personserviceproxy,serviceImpl,personServlet,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; root of factory hierarchy =================懒加载在此之后================= ============构造函数=========== =====Person=====init========== start................ 保存了~~名称：张三，年龄：12 commit................ 十二月 20, 2017 10:26:05 上午 org.springframework.context.support.AbstractApplicationContext doClose INFO: Closing org.springframework.context.support.ClassPathXmlApplicationContext@dfe491: startup date [Wed Dec 20 10:26:03 CST 2017]; root of context hierarchy 十二月 20, 2017 10:26:05 上午 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry destroySingletons INFO: Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@cb855e: defining beans [personDao,manager,person,personserviceproxy,serviceImpl,personServlet,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; root of factory hierarchy =====Person=====destory==========
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静态代理的优缺点
- 优点
- 解耦
- 缺点
- 一个代理只服务一个被代理者，重复代码太多
动态代理
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JDK的动态代理方式
- 优点：
- 继承静态代理的优点
- 一个代理类可以为多个目标类服务
- 实现了代码的分离
- 实现了代码的复用，before和after可以根据不同场景来指定不同的操作
- 缺点：
- 只能处理事务，不具有通用性
- 必须实现接口，否则创建不了对象
- 目标类的每个方法都经过判断，降低性能
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关键代码
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DynamicProxy
package com.peng.proxy; import java.lang.reflect.InvocationHandler; import java.lang.reflect.Method; import java.lang.reflect.Proxy; public abstract class DynamicProxy { public Object getProxy(final Object obj) { Object proxy_ob = Proxy.newProxyInstance(obj.getClass() .getClassLoader(), obj.getClass().getInterfaces(), new InvocationHandler() { @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { /* 被代理的对象的方法任意执行的这里都执行 */ // 执行before方法 before(); // 执行目标方法 Object result = method.invoke(obj, args); // 执行after方法 after(); return result; } }); return proxy_ob; } protected abstract void before(); protected abstract void after(); } -
PersonDynamicProxy
package com.peng.proxy; import org.springframework.stereotype.Component; @Component(value = "persondynamicproxy") public class PersonDynamicProxy extends DynamicProxy { @Override protected void before() { System.out.println("person-------------------start"); } @Override protected void after() { System.out.println("person-------------------after"); } } -
Test
package com.peng.test; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.peng.pojo.Person; import com.peng.web.PersonServlet; public class Test { @org.junit.Test public void trest1() { ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext( "applicationContext.xml"); System.out.println("=================懒加载在此之后================="); Person person = (Person) ac.getBean("person"); PersonServlet servlet = (PersonServlet) ac.getBean("personServlet"); servlet.doSomething(person); ac.close(); } } -
。。。
- 执行结果
十二月 20, 2017 11:25:19 上午 org.springframework.context.support.AbstractApplicationContext prepareRefresh INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@dfe491: startup date [Wed Dec 20 11:25:19 CST 2017]; root of context hierarchy 十二月 20, 2017 11:25:19 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions INFO: Loading XML bean definitions from class path resource [applicationContext.xml] 十二月 20, 2017 11:25:19 上午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@cb855e: defining beans [personDao,manager,person,persondynamicproxy,serviceImpl,personServlet,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; root of factory hierarchy =================懒加载在此之后================= ============构造函数=========== =====Person=====init========== person-------------------start 保存了~~名称：张三，年龄：12 person-------------------after 十二月 20, 2017 11:25:19 上午 org.springframework.context.support.AbstractApplicationContext doClose INFO: Closing org.springframework.context.support.ClassPathXmlApplicationContext@dfe491: startup date [Wed Dec 20 11:25:19 CST 2017]; root of context hierarchy 十二月 20, 2017 11:25:19 上午 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry destroySingletons INFO: Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@cb855e: defining beans [personDao,manager,person,persondynamicproxy,serviceImpl,personServlet,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; root of factory hierarchy =====Person=====destory==========
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- 优点：
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Cglib方式的动态代理
- cglib是Spring中的动态代理
- 优点：
- 继承jdk动态代理的优点
- 不需要类必须有实现的接口
- 缺点：
- 过滤过于麻烦
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例子
package com.peng.proxy; import java.lang.reflect.Method; import org.springframework.cglib.proxy.Enhancer; import org.springframework.cglib.proxy.MethodInterceptor; import org.springframework.cglib.proxy.MethodProxy; public abstract class DynamicProxy { public Object getProxy(final Object obj) { // 创建一个增强器 Enhancer enhancer = new Enhancer(); // 设置父接口 enhancer.setInterfaces(obj.getClass().getInterfaces()); // 设置父类 enhancer.setSuperclass(obj.getClass()); // 设置接口 enhancer.setCallback(new MethodInterceptor() { @Override public Object intercept(Object arg0, Method arg1, Object[] arg2, MethodProxy arg3) throws Throwable { System.out.println("asdfghj"); Object result = arg1.invoke(obj, arg2); System.out.println("asdfghj"); return result; } }); return enhancer.create(); } protected abstract void before(); protected abstract void after(); }
Spring的AOP
- 优点
- 继承所有优点+过滤简单
- 原理
- 通过两种动态代理来实现，进行了封装
- AOP，是一种编程思想，可以实现把某些具体的功能放到一个切面（类），然后在改动原来的代码的基础上同时将切面插入到工程当中，实现最低限制的解耦
- SpringAOP的概念
- 切面（Aspect）：就是一个类：如事务的控制，权限控制类，日志输出切面类
- 连接点（JoinPoint）：具体的方法（之前，之后进行操作，所以这个目标类中的方法就是连接点）
- 通知（Advice）：切面中的方法
- 前置通知
- 后置通知
- 最终通知
- 环绕通知
- 异常通知
- 切入点（PointCut）：匹配连接点的断言，方法过滤的规则
- 步骤
- 导jar包，约束文件
- 事务切面类
- 配置文件
- 切入点：切入点标点时（一定在切面的上面）expression id
- 切面：ref
- 方法（前置，后置...）point-ref,method
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例子
- 流程
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切面类
package com.peng.aspect; import org.aspectj.lang.ProceedingJoinPoint; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Component; import com.peng.manager.Manager; /** * 切面 * * @author Administrator * */ @Component(value = "txaspect") public class TxAspect { @Autowired @Qualifier(value = "manager") Manager manager; // 此方法当代理对象执行方法的时候去执行 public Object around(ProceedingJoinPoint joinPoint) throws Throwable { manager.start();// 开始事务 // 执行目标方法 Object result = joinPoint.proceed(); manager.commit();// 提交事务 return result; } } - 配置文件
- 流程