5Spring AOP的几种通知（xml）

Posted 2020-08-28

1、前置、后置、返回、异常和环绕

 1 public interface Calculator {
 2 
 3     int add(int a, int b);
 4 
 5     int sub(int a, int b);
 6 }
 7 
 8 public class CalculatorImpl implements Calculator {
 9 
10     @Override
11     public int add(int a, int b) {
12         return a + b;
13     }
14 
15     @Override
16     public int sub(int a, int b) {
17         try {
18             int i = 1 / 0;
19         } catch (Exception e) {
20         }
21         return a - b;
22     }
23 
24 }

 1 public void before(JoinPoint joinPoint) {
 2         System.out.println("前置通知。。。");
 3         String joinPointName = joinPoint.getSignature().getName();
 4         System.out.println("开始执行 " + joinPointName + " 方法。。。参数: " + Arrays.toString(joinPoint.getArgs()));
 5     }
 6 
 7     public void after(JoinPoint joinPoint) {
 8         System.out.println("后置通知。。。");
 9         String joinPointName = joinPoint.getSignature().getName();
10         System.out.println(joinPointName + " 方法执行完毕。。。");
11     }
12 
13     public void afterReturning(JoinPoint joinPoint, Object result) {
14         System.out.println("返回通知。。。");
15         String joinPointName = joinPoint.getSignature().getName();
16         System.out.println(joinPointName + " 方法执行完毕。。。\n返回值是: " + result);
17     }
18     
19     public void afterThrowing(JoinPoint joinPoint, Exception e) {
20         System.out.println("异常通知。。。");
21         String joinPointName = joinPoint.getSignature().getName();
22         System.out.println(joinPointName + " 方法抛出异常。。。\n异常信息: " + e.getMessage());
23     }
24     
25     public Object around(ProceedingJoinPoint pJoinPoint) {
26         System.out.println("环绕通知。。。");
27         String joinPointName = pJoinPoint.getSignature().getName();
28         Object[] args = pJoinPoint.getArgs();
29         System.out.println("开始执行 " + joinPointName + " 方法。。。参数: " + Arrays.toString(args));
30         Object result = null;
31         try {
32             result = pJoinPoint.proceed();
33 //            result = pJoinPoint.proceed(args);
34         } catch (Throwable e) {
35             e.printStackTrace();
36         }
37         
38         System.out.println(joinPointName + " 方法执行完毕。。。");
39         
40         return result;
41     }

  配置：

 1 <bean id="calculator" class="demo.CalculatorImpl" />
 2 
 3     <bean id="calculatorLoggingAspect" class="demo.CalculatorLoggingAspect" />
 4     
 5     <aop:config>
 6         <aop:pointcut id="pointCut" expression="execution(* demo.*.add(..))" />
 7         <aop:aspect id="logging" ref="calculatorLoggingAspect">
 8             <!-- <aop:before method="before" pointcut-ref="pointCut" /> -->
 9             <!-- <aop:after method="after" pointcut-ref="pointCut" /> -->
10             <!-- <aop:after-returning method="afterReturning" returning="result" pointcut-ref="pointCut"/> -->
11             <!-- <aop:after-throwing method="afterThrowing" throwing="e" pointcut-ref="pointCut" /> -->
12             <aop:around method="around" pointcut-ref="pointCut"/>
13         </aop:aspect>
14     </aop:config>

2、引入通知

 1 public interface MinCalculator {
 2 
 3     int min(int a, int b);
 4     
 5 }
 6 
 7 public class MinCalculatorImpl implements MinCalculator{
 8 
 9     @Override
10     public int min(int a, int b) {
11         return a < b ? a : b;
12     }
13 
14 }

  配置：

1 <aop:declare-parents types-matching="demo.*"
2                 implement-interface="demo.MinCalculator" default-impl="demo.MinCalculatorImpl" />

3、测试

1 Object obj = ctx.getBean("calculator");
2 Calculator cal = (Calculator) obj;
3 int r = cal.add(1, 1);
4 System.out.println(r);
5         
6 MinCalculator min = (MinCalculator)obj;
7 r = min.min(1, 3);
8 System.out.println(r);