这是我的工作：
首先，一个参数解析器：
public class AnnotationServletModelAttributeResolver extends ServletModelAttributeMethodProcessor { private ConcurrentMap<Class<?>, Map<String, String>> definitionsCache = Maps.newConcurrentMap(); public AnnotationServletModelAttributeResolver(boolean annotationNotRequired) { super(annotationNotRequired); } @Override public boolean supportsParameter(MethodParameter parameter) { if (parameter.getParameterType().isAnnotationPresent(SupportsAnnotationParameterResolution.class)) { return true; } return false; } @Override protected void bindRequestParameters(WebDataBinder binder, NativeWebRequest request) { ServletRequest servletRequest = request.getNativeRequest(ServletRequest.class); ServletRequestDataBinder servletBinder = (ServletRequestDataBinder) binder; bind(servletRequest, servletBinder); } @SuppressWarnings("unchecked") public void bind(ServletRequest request, ServletRequestDataBinder binder) { Map<String, ?> propertyValues = parsePropertyValues(request, binder); MutablePropertyValues mpvs = new MutablePropertyValues(propertyValues); MultipartRequest multipartRequest = WebUtils.getNativeRequest(request, MultipartRequest.class); if (multipartRequest != null) { bindMultipart(multipartRequest.getMultiFileMap(), mpvs); } // two lines copied from ExtendedServletRequestDataBinder String attr = HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE; mpvs.addPropertyValues((Map<String, String>) request.getAttribute(attr)); binder.bind(mpvs); } private Map<String, ?> parsePropertyValues(ServletRequest request, ServletRequestDataBinder binder) { // similar to WebUtils.getParametersStartingWith(..) (prefixes not supported) Map<String, Object> params = Maps.newTreeMap(); Assert.notNull(request, "Request must not be null"); Enumeration<?> paramNames = request.getParameterNames(); Map<String, String> parameterMappings = getParameterMappings(binder); while (paramNames != null && paramNames.hasMoreElements()) { String paramName = (String) paramNames.nextElement(); String[] values = request.getParameterValues(paramName); String fieldName = parameterMappings.get(paramName); // no annotation exists, use the default - the param name=field name if (fieldName == null) { fieldName = paramName; } if (values == null || values.length == 0) { // Do nothing, no values found at all. } else if (values.length > 1) { params.put(fieldName, values); } else { params.put(fieldName, values[0]); } } return params; } private Map<String, String> getParameterMappings(ServletRequestDataBinder binder) { Class<?> targetClass = binder.getTarget().getClass(); Map<String, String> map = definitionsCache.get(targetClass); if (map == null) { Field[] fields = targetClass.getDeclaredFields(); map = Maps.newHashMapWithExpectedSize(fields.length); for (Field field : fields) { CommandParameter annotation = field.getAnnotation(CommandParameter.class); if (annotation != null && !annotation.value().isEmpty()) { map.put(annotation.value(), field.getName()); } } definitionsCache.putIfAbsent(targetClass, map); return map; } else { return map; } } protected void bindMultipart(Map<String, List<MultipartFile>> multipartFiles, MutablePropertyValues mpvs) { for (Map.Entry<String, List<MultipartFile>> entry : multipartFiles.entrySet()) { String key = entry.getKey(); List<MultipartFile> values = entry.getValue(); if (values.size() == 1) { MultipartFile value = values.get(0); if (!value.isEmpty()) { mpvs.add(key, value); } } else { mpvs.add(key, values); } } }}然后使用后处理器注册参数解析器。它应该注册为
<bean>：
public class AnnotationHandlerMappingPostProcessor implements BeanPostProcessor { @Override public Object postProcessAfterInitialization(Object bean, String arg1) throws BeansException { return bean; } @Override public Object postProcessBeforeInitialization(Object bean, String arg1) throws BeansException { if (bean instanceof RequestMappingHandlerAdapter) { RequestMappingHandlerAdapter adapter = (RequestMappingHandlerAdapter) bean; List<HandlerMethodArgumentResolver> resolvers = adapter.getCustomArgumentResolvers(); if (resolvers == null) { resolvers = Lists.newArrayList(); } resolvers.add(new AnnotationServletModelAttributeResolver(false)); adapter.setCustomArgumentResolvers(resolvers); } return bean; }}
