作为spring框架的另外的重点AOP的介绍（详细篇）

package com.zking.aop.biz;
public interface IBookBiz {
  // 购书
  public boolean buy(String userName, String bookName, Double price);
  // 发表书评
  public void comment(String userName, String comments);
}

package com.zking.aop.biz.impl;
import com.zking.aop.biz.IBookBiz;
import com.zking.aop.exception.PriceException;
public class BookBizImpl implements IBookBiz {
  public BookBizImpl() {
    super();
  }
  public boolean buy(String userName, String bookName, Double price) {
    // 通过控制台的输出方式模拟购书
    if (null == price || price <= 0) {
      throw new PriceException("book price exception");
    }
    System.out.println(userName + " buy " + bookName + ", spend " + price);
    return true;
  }
  public void comment(String userName, String comments) {
    // 通过控制台的输出方式模拟发表书评
    System.out.println(userName + " say:" + comments);
  }
}

package com.zking.aop.advice;
import org.springframework.aop.MethodBeforeAdvice;
import java.lang.reflect.Method;
import java.util.Arrays;
/**
 * 买书、评论前加系统日志
 * @author Administrator
 *
 */
public class MyMethodBeforeAdvice implements MethodBeforeAdvice {
  @Override
  public void before(Method arg0, Object[] arg1, Object arg2) throws Throwable {
    //在这里，可以获取到目标类的全路径及方法及方法参数，然后就可以将他们写到日志表里去
    String target = arg2.getClass().getName();
    String methodName = arg0.getName();
    String args = Arrays.toString(arg1);
    System.out.println("【前置通知：系统日志】："+target+"."+methodName+"("+args+")被调用了");
  }
}

package com.zking.aop.advice;
import org.springframework.aop.AfterReturningAdvice;
import java.lang.reflect.Method;
import java.util.Arrays;
/**
 * 买书返利
 * @author Administrator
 *
 */
public class MyAfterReturningAdvice implements AfterReturningAdvice {
  @Override
  public void afterReturning(Object arg0, Method arg1, Object[] arg2, Object arg3) throws Throwable {
    String target = arg3.getClass().getName();
    String methodName = arg1.getName();
    String args = Arrays.toString(arg2);
    System.out.println("【后置通知：买书返利】："+target+"."+methodName+"("+args+")被调用了，"+"该方法被调用后的返回值为："+arg0);
  }
}

package com.zking.aop.advice;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import java.util.Arrays;
/**
 * 环绕通知
 *  包含了前置和后置通知
 * 
 * @author Administrator
 *
 */
public class MyMethodInterceptor implements MethodInterceptor {
  @Override
  public Object invoke(MethodInvocation arg0) throws Throwable {
    String target = arg0.getThis().getClass().getName();
    String methodName = arg0.getMethod().getName();
    String args = Arrays.toString(arg0.getArguments());
    System.out.println("【环绕通知调用前：】："+target+"."+methodName+"("+args+")被调用了");
//    arg0.proceed()就是目标对象的方法
    Object proceed = arg0.proceed();
    System.out.println("【环绕通知调用后：】：该方法被调用后的返回值为："+proceed);
    return proceed;
  }
}