我想strategy design pattern
在 Spring Boot 应用程序中实现。我BeanPostProcessor
为构造 创建strategy resolver
:
@Component
public class HandlerInAnnotationBeanPostProcessor implements BeanPostProcessor {
private final UnpHandlersResolver unpHandlersResolver;
public HandlerInAnnotationBeanPostProcessor(UnpHandlersResolver unpHandlersResolver) {
this.unpHandlersResolver = unpHandlersResolver;
}
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
Annotation[] annotations = bean.getClass().getAnnotations();
for (Annotation annotation : annotations) {
if (annotation instanceof HandlerIn) {
if (bean.getClass() != UnpHandler.class)
throw new RuntimeException("Not UnpHandler bean annotated by HandlerIn");
SmevMessageType[] type = ((HandlerIn) annotation).type();
for (SmevMessageType smevMessageType : type) {
unpHandlersResolver.setHandler(smevMessageType, (UnpHandler) bean);
}
}
}
return bean;
}
}
我创建解析器:
@Slf4j
@Component
public class UnpHandlersResolverImpl implements UnpHandlersResolver {
private Map<SmevMessageType, UnpHandler> map = new HashMap<>();
@Override
public void setHandler(SmevMessageType messageType, UnpHandler unpHandler) {
map.put(messageType, unpHandler);
}
@Override
public UnpHandler getUnpHandler(SmevMessageType type) {
UnpHandler sendRequestHandler = map.get(type);
if (sendRequestHandler == null)
throw new IllegalArgumentException("Invalid SendRequestHandler type: " + type);
return sendRequestHandler;
}
}
我BeanPostProcessor
扫描所有带有注释的beanHandlerIn
并添加到解析器的mup中。我认为这样做是错误的:
unpHandlersResolver.setHandler(smevMessageType, (UnpHandler) bean);
但我不明白如何将查找 bean 添加到解析器。@Postconstruct
在此实现之前,我在以下方法中找到了bean resolver
:
context.getBeansWithAnnotation(HandlerIn.class);
但在这个解决方案中,我有context
,resolver
我认为很糟糕。
告诉我如何正确实现我想要的?简而言之,我想要一组实现不同行为的类。以及控制它们的类。给班级一个参数,以便他选择正确的策略并将其提供给我。像这样:
Handler handler = handlersResolver.getHandler(messageType);
Result result = handler.somthing(param);