使用前置通知进行访问控制：通过方法参数决定是否可以访问该方法,分别使用基于XML的声明式AspectJ和基于注解的声明式AspectJ来实现。

1,基于XML的声明式AspectJ来实现
TestDao.java:

package dynamic.jdk;public interface TestDao {
 public void save(String t);
}
TestDaoImpl.java:package dynamic.jdk;public class TestDaoImpl implements TestDao {
 @Override
 public void save(String t) {
  System.out.println("你好");
 }}

MyAspect.java:

package aspectj.xml;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
public class MyAspect {
 public void before(JoinPoint jp) {
  Object[] args=jp.getArgs();
  if(args[0]=="agree") {
   System.out.println("访问成功");
  }else {
   
   System.out.println("访问失败");
   System.exit(-1);
      
   }

  }}

applicationContext.xml:

<?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: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"><!-- 定义目标对象 -->
    <bean id="testDao" class="dynamic.jdk.TestDaoImpl"/>
    <!-- 定义切面 -->
    <bean id="myAspect" class="aspectj.xml.MyAspect"/>
    <!-- AOP配置 -->
    <aop:config>
    <!-- 配置切面 -->
    <aop:aspect ref="myAspect">
    <!-- 配置切入点，通知增强哪些方法 -->
    <aop:pointcut expression="execution(* dynamic.jdk.*.*(..))" id="myPointCut"/>
    <!-- 将通知与切入点关联 -->
    <!-- 关联前置通知 -->
    <aop:before method="before" pointcut-ref="myPointCut"/>
    </aop:aspect>
    </aop:config>
    </beans> 

XMLAspectJTest:

package aspectj.xml;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import dynamic.jdk.TestDao;
public class XMLAspectJTest {
 public static void main(String[] args) {
  ApplicationContext appCon=new ClassPathXmlApplicationContext("/aspectj/xml/applicationContext.xml");
  //从容器中获取增强后的目标对象
  TestDao testDaoAdvice=(TestDao)appCon.getBean("testDao");
  //执行方法
  testDaoAdvice.save("agree");
  testDaoAdvice.save("disagree");
 }}

**2,基于注解声明式AspectJ来实现

AspectJ来实现MyAspect.java:

package aspectj.annotation;**
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;
@Aspect
@Component
public class MyAspect {
  @Pointcut("execution(* dao.*.*(..))")
     private void myPointCut() {
         
     }
  @Before("myPointCut()")
  public void before(JoinPoint jp) {
   Object[] args=jp.getArgs();
   if(args[0]=="agree") {
    System.out.println("访问成功");
   }else {    
    System.out.println("访问失败");
    System.exit(-1);
       
    }
  }
}

applicationContext.xml:

<?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:aop="http://www.springframework.org/schema/aop"
    xmlns:context="http://www.springframework.org/schema/context"
    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
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">
    <!-- 指定要需要扫描的包，使注解生效 -->
    <context:component-scan base-package="aspectj.annotation"/>
    <context:component-scan base-package="dynamic.jdk"/>
    <!-- 启动基于注解的AspectJ支持 -->
    <aop:aspectj-autoproxy/>
    </beans>

Aspectjannotationtest.java:

package aspectj.annotation;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import dynamic.jdk.TestDao;
public class Aspectjannotationtest {
 public static void main(String[] args) {
  ApplicationContext appCon=new ClassPathXmlApplicationContext("/aspectj/xml/applicationContext.xml");
  //从容器中获取增强后的目标对象
  TestDao testDaoAdvice=(TestDao)appCon.getBean("testDao");
  //执行方法
  testDaoAdvice.save("agree");
  testDaoAdvice.save("disagree");
 }
}