项目采用spring mvc 框架,spring封装的jdbc方式访问数据库,部分代码如下
@RequestMapping(value = "/xiangmu.html") public @ResponseBody ModelMap addWeiboComments(ModelMap modelMap, WeiboCommentsVO weiboCommentsVO) { //modelMap.clear(); /* 权限验证 */ if (this.user.get().getUid() <= 0) { return modelMap; } Map<String, String> map = getConditionParameters(this.request.get()); MultiValueMap<String, String> multiValueMap = mapToMultiValueMap(map); ModelMap repositoryAdd = restTemplate.postForObject(RestAPIURLConstant.WEIBOCOMMENTS, multiValueMap, ModelMap.class); ModelMap repositoryGet = restTemplate.getForObject(RestAPIURLConstant.WEIBOCOMMENTS, ModelMap.class, repositoryAdd.get(WebApplicationConstant.FLAG_RESULT)); modelMap.put(WebApplicationConstant.FLAG_STATUS, repositoryAdd.get(WebApplicationConstant.FLAG_STATUS)); modelMap.put(WebApplicationConstant.FLAG_RESULT, repositoryGet.get(WebApplicationConstant.FLAG_RESULT)); return modelMap; }
js里面 获取相应属性,但是报错:
严重: Servlet.service() for servlet chenming threw exception org.codehaus.jackson.map.JsonMappingException: No serializer found for class org.springframework.validation.DefaultMessageCodesResolver and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: org.springframework.validation.support.BindingAwareModelMap["org.springframework.validation.BindingResult.weiboCommentsVO"]->org.springframework.validation.BeanPropertyBindingResult["messageCodesResolver"]) at org.codehaus.jackson.map.ser.StdSerializerProvider$1.failForEmpty(StdSerializerProvider.java:89) at org.codehaus.jackson.map.ser.StdSerializerProvider$1.serialize(StdSerializerProvider.java:62) at org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:430) at org.codehaus.jackson.map.ser.BeanSerializer.serializeFields(BeanSerializer.java:175) at org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:142)
分析错误提示发现:jquery 获取异步返回的数据时候出现的问题,将modelmap.clear 去掉注释 后一切正常。
spring mvc 方式获取返回json数据时候,切记 方法里面加上 modelMap.clear();
但是要注意:jquery 获取返回数据时候,如果获取不到返回的属性 是不会报错的。所以问题还是出现在这个modelMap里面。