无法实例化bean类[com.github.dandelion.datatables.core.ajax.DatatablesCriterias]：未找到默认构造函数

Question

你知道为什么我会收到这个错误吗？

SEVERE: Servlet.service() for servlet [enemr] in context with path [/enemr] threw exception [Request processing failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.github.dandelion.datatables.core.ajax.DatatablesCriterias]: No default constructor found; nested exception is java.lang.NoSuchMethodException: com.github.dandelion.datatables.core.ajax.DatatablesCriterias.<init>()] with root cause
java.lang.NoSuchMethodException: com.github.dandelion.datatables.core.ajax.DatatablesCriterias.<init>()

我从这里换了我的控制器

@RequestMapping(value = "/results", method = RequestMethod.GET)
    public @ResponseBody DatatablesResponse<Results> findAllForDataTables(HttpServletRequest request) {

        DatatablesCriterias dataTableCriterias = DatatablesCriterias.getFromRequest(request);
        DataSet<Results> results = this.resultsServiceimpl.findResultsWithDatatablesCriterias(dataTableCriterias);
        return DatatablesResponse.build(results, dataTableCriterias);
    }

要这样做：

@RequestMapping(value = "/results", method = RequestMethod.GET)
    public @ResponseBody 
    DatatablesResponse<Results> findAllForDataTables(@DatatablesParams DatatablesCriterias criterias) {

        DataSet<Results> results = this.resultsServiceimpl.findResultsWithDatatablesCriterias(criterias);
        return DatatablesResponse.build(results, criterias);
    }

突然停止工作

任何帮助我都会非常感谢。

我使用的是Spring3.2和dandelion datatables 1.1.0

Answer 1

当您将控制器更改为使用DatatablesParams注释时，您需要启用一个解析器，它将实例化DatatablesCriterias对象。由于Spring3.2正在使用中，因此需要启用DatatablesCriteriasMethodArgumentResolver：

通过xml：

     <!-- Add support for @DatatablesParams annotations in controller's methods -->
   <mvc:annotation-driven>
      <mvc:argument-resolvers>
         <bean class="com.github.dandelion.datatables.extras.spring3.ajax.DatatablesCriteriasMethodArgumentResolver" />
      </mvc:argument-resolvers>
   </mvc:annotation-driven>

或java config：

   @Configuration
   @EnableWebMvc
   public class MyWebConfig extends WebMvcConfigurerAdapter {
      @Override
      public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
         argumentResolvers.add(new DatatablesCriteriasMethodArgumentResolver());
      }
   }