Spring-AOP简介

springAOP的各个概念、

说明：

    *  切面

        日志、安全性的框架、权限的检查等，总之和业务逻辑没有关系的都可以看做切面

    *  通知

        切面中的方法

    * 切入点

        只有符合切入点，才能把通知和目标方法结合在一起

    * 连接点

        客户端调用的方法

    * 代理对象的方法=通知+目标方法

    * aop:做到了代码块的重用

/** * 切面的总的接口 * @author Administrator * */public interface Interceptor {public void interceptor();}

每个切面实现interceptor的接口

public class Logger implements Interceptor{@Overridepublic void interceptor() {System.out.println("logging");}}

/** * 1、把日志、安全性框架、权限导入进去 * 2、把目标类导入进去 * 3、上述两类通过构造函数赋值 * @author Administrator * */public class SalaryInterceptor implements InvocationHandler{private Logger logger;private Security security;private Privilege privilege;private List<Interceptor> interceptorList;private Object target;public SalaryInterceptor(Logger logger,Security security,Privilege privilege,Object target,List<Interceptor> interceptorList){this.logger = logger;this.security = security;this.privilege = privilege;this.target = target;this.interceptorList = interceptorList;}@Overridepublic Object invoke(Object proxy, Method method, Object[] args)throws Throwable {// TODO Auto-generated method stub/** * 执行所有的切面中的通知 */for(Interceptor interceptor:interceptorList){interceptor.interceptor();}method.invoke(this.target, args);return null;}}

public class ProxyTest {@Testpublic void test(){Logger logger = new Logger();Privilege privilege = new Privilege();Security security = new Security();List<Interceptor> interceptorList = new ArrayList<Interceptor>();interceptorList.add(logger);interceptorList.add(privilege);interceptorList.add(security);SalaryManager target = new SalaryManagerImpl();SalaryInterceptor interceptor = new SalaryInterceptor(logger, security, privilege, target,interceptorList);/** * 1、目标类的类加载器 * 2、目标类的所有的接口 * 3、拦截器 */ SalaryManager proxy = (SalaryManager) Proxy.newProxyInstance(target.getClass().getClassLoader(), target.getClass().getInterfaces(), interceptor); proxy.showSalary();//代理对象的代理方法}}

aop举例

public class Person {private Long pid;private String pname;public Long getPid() throws Exception{return pid;}public void setPid(Long pid) {this.pid = pid;}public String getPname() {return pname;}public void setPname(String pname) {this.pname = pname;}@Testpublic void test() throws Exception{Method method = Person.class.getMethod("getPid");System.out.println(method.toString());}//public java.lang.Long cn.itcast.spring0909.aop.xml.Person.getPid() throws java.lang.Exception}

/** * 目标接口 * @author Administrator * */public interface PersonDao {public void savePerson();public void updatePerson();public void deletePerson();public List<Person> getPerson();}

public class PersonDaoImpl implements PersonDao{@Overridepublic void savePerson() {// TODO Auto-generated method stubSystem.out.println("save person");}@Overridepublic void updatePerson() {// TODO Auto-generated method stubSystem.out.println("update person");}@Overridepublic void deletePerson() {// TODO Auto-generated method stubSystem.out.println("delete person");}@Overridepublic List<Person> getPerson() {// TODO Auto-generated method stubPerson person = new Person();person.setPid(1L);person.setPname("aaa");List<Person> personList = new ArrayList<Person>();personList.add(person);for(Person person2:personList){System.out.println(person2.getPname());}return personList;}}

public class Transaction {public void beginTransaction(){System.out.println("begin transaction");}public void commit(){System.out.println("commit");}}

<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans"xmlns:aop="http://www.springframework.org/schema/aop"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beans           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd           http://www.springframework.org/schema/aop            http://www.springframework.org/schema/aop/spring-aop-2.5.xsd"><!-- 1、引入AOP的命名空间2、目标类3、切面4、拦截器  由spring内部实现5、aop的配置 --><bean id="personDao" class="cn.itcast.spring0909.aop.xml.PersonDaoImpl"></bean><bean id="transaction" class="cn.itcast.spring0909.aop.xml.Transaction"></bean><!-- aop的配置 --><aop:config><!-- 切入点表达式  expression     确定哪个类可以生成代理对象  id  唯一标识  --><aop:pointcut expression="execution(* cn.itcast.spring0909.aop.xml.PersonDaoImpl.*(..))" id="perform"/><!-- 切面 --> <aop:aspect ref="transaction"> <!--  前置通知  --> <aop:before method="beginTransaction" pointcut-ref="perform"/> <aop:after-returning method="commit" pointcut-ref="perform"/> </aop:aspect></aop:config></beans>

/** * 原理 *    *  加载配置文件，启动spring容器 *    *  spring容器为bean创建对象 *    *  解析aop的配置，会解析切入点表达式 *    *  看纳入spring管理的那个类和切入点表达式匹配，如果匹配则会为该类创建代理对象 *    *  代理对象的方法体的形成就是目标方法+通知 *    *  客户端在context.getBean时，如果该bean有代理对象，则返回代理对象，如果没有代理对象则返回原来的对象 * @author Administrator * */public class PersonTest extends SpringHelper{static{path = "cn/itcast/spring0909/aop/xml/applicationContext.xml";}@Testpublic void test(){PersonDao personDao = (PersonDao)context.getBean("personDao");personDao.updatePerson();}}

需要导入jar包