Spring方法拦截器MethodInterceptor

布满荆棘的人生 2023-02-25 07:13 3阅读 0赞

实现MethodInterceptor 接口，在调用目标对象的方法时，就可以实现在调用方法之前、调用方法过程中、调用方法之后对其进行控制。

MethodInterceptor 接口可以实现MethodBeforeAdvice接口、AfterReturningAdvice接口、ThrowsAdvice接口这三个接口能够所能够实现的功能，但是应该谨慎使用MethodInterceptor 接口，很可能因为一时的疏忽忘记最重要的MethodInvocation而造成对目标对象方法调用失效，或者不能达到预期的设想。

实例1：

public class AdviseMethodInterceptor implements MethodInterceptor \{  
    @Override  
    public Object invoke(MethodInvocation methodInvocation) throws Throwable \{  
        System.out.println("方法执行之前：" + methodInvocation.getMethod().toString());  
        Object result = methodInvocation.proceed();  
        System.out.println("方法执行之后：" + methodInvocation.getMethod().toString());  
        return result;  
    \}  
\}  
   
public class BeforeAdvice implements MethodBeforeAdvice \{  
    public void before(Method method, Object\[\] args, Object target) throws Throwable \{  
        System.out.println("前置增强====================》");  
    \}  
\}  
   
public class AfterAdvice implements AfterReturningAdvice \{  
    public void afterReturning(Object returnValue, Method method, Object\[\] args, Object target) throws Throwable \{  
        System.out.println("后置增强==================》");  
    \}  
\}  
   
public class ExceptionAdvice implements ThrowsAdvice \{  
   
    public void afterThrowing(Method method, Object\[\] args, Object target, Exception ex) \{  
        System.out.println("异常====================》");  
    \}  
\}  
   
   
public  class User \{  
    public void helloWorld() \{  
        System.out.println("你好！");  
    \}  
    public void Error() \{  
        throw new RuntimeException("Error");  
    \}  
\}  
   
   
public class Main \{  
   
    public static void main(String\[\] args) \{  
   
   
        ProxyFactory proxyFactory = new ProxyFactory();  
   
        proxyFactory.setTarget(new User());  
   
        proxyFactory.addAdvice(new AdviseMethodInterceptor());  
        proxyFactory.addAdvice(new BeforeAdvice());  
        proxyFactory.addAdvice(new AfterAdvice());  
        proxyFactory.addAdvice(new ExceptionAdvice());  
   
        User proxyUser = (User) proxyFactory.getProxy();  
        proxyUser.helloWorld();  
        proxyUser.Error();  
    \}  
\}  
结果：

方法执行之前：public void www.User.helloWorld()  
前置增强====================》  
你好！  
后置增强==================》  
方法执行之后：public void www.User.helloWorld()  
   
方法执行之前：public void www.User.Error()  
前置增强====================》  
异常====================》  
Exception in thread "main" java.lang.RuntimeException: Error

[https://blog.csdn.net/hong10086/article/details/91554901][https_blog.csdn.net_hong10086_article_details_91554901]

[https_blog.csdn.net_hong10086_article_details_91554901]: https://blog.csdn.net/hong10086/article/details/91554901