试图在springboot中访问模型中的ConversionControl,没有运气.
@Component
public class CityHelperService {
@Autowired
ConversionService conversionService;// = ConversionServiceFactory.registerConverters();
public City toEntity(CityDTO dto){
City entity = conversionService.convert(dto,City.class);
return entity;
}
public CityDTO toDTO(City entity){
CityDTO dto = conversionService.convert(entity,CityDTO.class);
return dto;
}
}
它显示以下错误：
Injection of autowired dependencies failed;
nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.lumiin.mytalk.model.CityModel com.lumiin.mytalk.controllers.CityController.cityModel;
nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'cityModel' defined in file : Unsatisfied dependency expressed through constructor argument with index 1 of type [com.lumiin.mytalk.dao.CityHelperService]: : Error creating bean with name 'cityHelperService': Injection of autowired dependencies failed;
nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: org.springframework.core.convert.ConversionService com.lumiin.mytalk.dao.CityHelperService.conversionService;
nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.core.convert.ConversionService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)};
nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'cityHelperService': Injection of autowired dependencies failed;
nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: org.springframework.core.convert.ConversionService com.lumiin.mytalk.dao.CityHelperService.conversionService;
nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.core.convert.ConversionService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
显然,没有ConversionService bean可用,从最后一个嵌套异常判断：
org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.core.convert.ConversionService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency.
查看Spring documentation会发现,您应该声明一个ConversionService bean.在XML配置中,它看起来像这样：
因为你正在使用Spring Boot,我假设你是以编程方式创建上下文,所以你应该创建一个用@Bean注释的方法,它返回一个ConverstionService,就像这样(explained here)：
@Bean(name="conversionService")
public ConversionService getConversionService() {
ConversionServiceFactoryBean bean = new ConversionServiceFactoryBean();
bean.setConverters(...); //add converters
bean.afterPropertiesSet();
return bean.getObject();
}
