springmvc对请求参数进行预处理HandlerMethodArgumentResolver

蔚落 2023-02-14 10:38 117阅读 0赞

@Override
        public boolean supportsParameter(MethodParameter methodParameter) {
            return true;
        }
    
        @Override
        public Object resolveArgument(MethodParameter methodParameter, ModelAndViewContainer modelAndViewContainer, NativeWebRequest nativeWebRequest,
            WebDataBinderFactory webDataBinderFactory) throws InstantiationException, IllegalAccessException, NoSuchMethodException, InvocationTargetException {
            HttpServletRequest httpServletRequest = nativeWebRequest.getNativeRequest(HttpServletRequest.class);
    
            // 处理get请求
            if ("GET".equals(httpServletRequest.getMethod())) {
                return getRequestHandle(methodParameter, nativeWebRequest);
            }
    
            return postRequestHandle(methodParameter, nativeWebRequest);
        }
    
        /**
         * 处理get请求
         */
        private Object getRequestHandle(MethodParameter methodParameter, NativeWebRequest nativeWebRequest)
            throws IllegalAccessException, InstantiationException, NoSuchMethodException, InvocationTargetException {
            Class<?> parameterType = methodParameter.getParameterType();
            String parameter = nativeWebRequest.getParameter(methodParameter.getParameterName());
    
            if (parameterType == String.class) {
                return parameter;
            }
    
            if (parameterType.isPrimitive()) {
                return JSON.parseObject(parameter, parameterType);
            }
    
            Object instance = parameterType.newInstance();
            Iterator<String> parameterNames = nativeWebRequest.getParameterNames();
            while (parameterNames.hasNext()) {
                String attrName = parameterNames.next();
                String attrValue = nativeWebRequest.getParameter(attrName);
                Class attrType = getAttrClassType(parameterType, attrName);
                Method setterMethod = parameterType.getMethod(getSetterName(attrName), attrType);
    
                if (attrType.isPrimitive()) {
                    setterMethod.invoke(instance, JSON.parseObject(attrValue, attrType));
                    continue;
                }
                setterMethod.invoke(instance, attrValue);
            }
    
            return instance;
        }
    
        /**
         * 处理宝武基座转发的请求
         */
        private Object postRequestHandle(MethodParameter methodParameter, NativeWebRequest nativeWebRequest) {
            // 宝武基座转发数据从data中获取
            String data = nativeWebRequest.getParameter("data");
            // 得到参数的类型
            Class<?> parameterType = methodParameter.getParameterType();
            // 基本数据类型
            if (parameterType.isPrimitive() || parameterType == String.class) {
                JSONObject jsonObject = JSON.parseObject(data);
                String parameterName = methodParameter.getParameterName();
                Object parameterValue = jsonObject.get(parameterName);
    
                if (parameterValue == null) {
                    log.error("参数丢失, 缺少->" + parameterName + "参数。完整请求数据->" + data);
                }
    
                return parameterValue;
                // 包装类
            } else {
                return JSON.parseObject(data, parameterType);
            }
        }
    
        /**
         * 根据参数名称获取set方法名
         */
        private String getSetterName(String attrName) {
            String firstLetter = attrName.substring(0, 1);
            firstLetter = firstLetter.toUpperCase();
    
            return "set" + firstLetter + attrName.substring(1, attrName.length());
        }
    
        /**
         * 获取类中某个属性的类型
         */
        private Class getAttrClassType(Class classType, String attrName) {
            Field[] fields = classType.getDeclaredFields();
            for (Field field : fields) {
                field.setAccessible(true);
                if (field.getName().equals(attrName)) {
                    return field.getType();
                }
            }
    
            log.error("类->" + classType.getName() + "中没有名称为->" + attrName + "的属性");
            return null;
        }

上面实现的功能是：当请求方式为post请求时，将body里的请求参数进行解体；

请求数据格式：![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0NDY4MTc0_size_16_color_FFFFFF_t_70][]

解析后传入控制层方法时的数据格式：dataItem:CWS2\_LargePool

相当于去掉了data这一层

list类型时："list":["a","b","c"]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0NDY4MTc0_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200602144101677.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0NDY4MTc0,size_16,color_FFFFFF,t_70