Java 如何使用ExposebeanaMeadvisors`

我需要找到我所代理的bean的名称。以下是一些背景：

我有以下xml配置，它使用BeanNameAutoProxyCreator，根据不同的bean的名称代理它们（使用NameMatchMethodPointcutAdvisor）：

我知道有一个ExposeBeanNameAdvisors类提供了一个方便的

getBeanName（MethodInvocation mi）

方法。然而，我不明白什么是“假设一个ExposeBeanNameAdvisor已经包含在拦截器链中。”（来自javadoc）你们能给我一个如何使用ExposeBeanNameAdvisor的例子吗

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谢谢

ExposebeanMeadvisors有两个

static

方法

createAdvisorWithoutIntroduction

和

createAdvisorPrintRoducingNamedBean

返回一个

Advisor

对象，该对象应添加到Advisor堆栈中

如果你看看其中一个的实现

private static class ExposeBeanNameInterceptor implements MethodInterceptor {

    private final String beanName;

    public ExposeBeanNameInterceptor(String beanName) {
        this.beanName = beanName;
    }

    public Object invoke(MethodInvocation mi) throws Throwable {
        if (!(mi instanceof ProxyMethodInvocation)) {
            throw new IllegalStateException("MethodInvocation is not a Spring ProxyMethodInvocation: " + mi);
        }
        ProxyMethodInvocation pmi = (ProxyMethodInvocation) mi;
        pmi.setUserAttribute(BEAN_NAME_ATTRIBUTE, this.beanName);
        return mi.proceed();
    }
}

您注意到bean名称作为属性添加到

MethodInvocation

，该属性被转换为

ProxyMethodInvocation

。这需要在定制advisor之前的代理调用堆栈中，以便您可以使用ExposeBeanNameAdvisors.getBeanName（）检索bean名称，否则会出现异常

public class MyAdvisor implements MethodInterceptor {
    public Object invoke(MethodInvocation methodInvocation) throws Throwable {
      // I want to be able to get the bean name of this method invocation here

      try {
          long startTime = System.nanoTime();
          log(startTime);

          return methodInvocation.proceed();
      }
      finally {
          long endTime = System.nanoTime();
          log(endTime);
      }
    }

}

private static class ExposeBeanNameInterceptor implements MethodInterceptor {

    private final String beanName;

    public ExposeBeanNameInterceptor(String beanName) {
        this.beanName = beanName;
    }

    public Object invoke(MethodInvocation mi) throws Throwable {
        if (!(mi instanceof ProxyMethodInvocation)) {
            throw new IllegalStateException("MethodInvocation is not a Spring ProxyMethodInvocation: " + mi);
        }
        ProxyMethodInvocation pmi = (ProxyMethodInvocation) mi;
        pmi.setUserAttribute(BEAN_NAME_ATTRIBUTE, this.beanName);
        return mi.proceed();
    }
}