java - Spring:委托(delegate)给自定义代理包装器进行接口(interface)注入(inject)

Question

在一个非常大的遗留应用程序中，我有一些接口(interface)和类不实现这些接口(interface)。

接口(interface)是基于类生成的，所以签名相同(除了接口(interface)在上面添加了另一个异常(exception))并且名称相似(因此很容易从接口(interface)名称中找到类名)。

为了实现接口(interface)，我们进行了一系列处理和记录调用，但基本上使用 java.lang.reflect.Proxy 委托(delegate)给类。简化后看起来像这样:

// This will create a proxy and invoke handler that calls HelloWorld.doSomething
HelloWorldInterface i = MyProxyUtil.getInstance(HelloWorldInterface.class);
i.doSomething();

public interface HelloWorldInterface {
    public void doSomething() throws Exception;  
}

public class HelloWorld {
    public void doSomething() {
     //something
    }
}

是否可以使用 Spring 注释处理，一般地 @Autowire 所有 *Interface 类型的字段，并让 spring 使用 MyProxyUtil.getInstance(*Interface.class ) 注入(inject)实现？

这样

@Autowire HelloWorldInterface a;

HelloWorldInterface b = MyProxyUtil.getInstance(HelloWorldInterface.class);

@Autowire AnotherInterface c;

AnotherInterface d = MyProxyUtil.getInstance(AnotherInterface.class);


a == b
c == d

Answer 1

是的，您需要实现一个AutowireCandidateResolver。

例如:

public class ProxyAutowiredCandidateResolver extends SimpleAutowireCandidateResolver {

    @Override
    public Object getSuggestedValue(DependencyDescriptor descriptor) {
        String dependencyClassName = descriptor.getDependencyType().getSimpleName();
        if (dependencyClassName.endsWith("Interface")) {
            return MyProxyUtil.getInstance(descriptor.getDependencyType());
        }

        return super.getSuggestedValue(descriptor);
    }

}

您可以使用 BeanFactoryPostProcessor 在应用程序上下文中配置它:

public class AutowireCandidateResolverConfigurer implements BeanFactoryPostProcessor {

    private AutowireCandidateResolver autowireCandidateResolver;

    public void postProcessBeanFactory(
            ConfigurableListableBeanFactory beanFactory) throws BeansException {
        DefaultListableBeanFactory  bf = (DefaultListableBeanFactory) beanFactory;
        bf.setAutowireCandidateResolver(autowireCandidateResolver);


    }

    public AutowireCandidateResolver getAutowireCandidateResolver() {
        return autowireCandidateResolver;
    }

    public void setAutowireCandidateResolver(

            AutowireCandidateResolver autowireCandidateResolver) {
        this.autowireCandidateResolver = autowireCandidateResolver;
    }

}

<bean id="autowireCandidateResolverConfigurer" class="AutowireCandidateResolverConfigurer">
        <property name="autowireCandidateResolver">
            <bean class="ProxyAutowiredCandidateResolver" />
        </property>
</bean>