我正在使用Spring-Hateoas和Spring-Boot创建我的第一个RESTful API。到目前为止，一切看起来都很有希望，但是当我尝试使用toResource（）方法（通过调用http://localhost:8080/myVariable/greeting）扩展ResourceAssemblerSupport的类中创建资源时，我得到一个IllegalArgumentException告诉我
没有足够的变量值可用于根据原因扩展＆＃39; var＆＃39;]
只有在类级别引用@PathVariable时才会发生这种情况，据我所知应该支持。
我的ControllerClass：
@RestController
@ExposesResourceFor(GreetingResource.class)
@RequestMapping("/{var}")
public class GreetingController {
@Autowired
private BeanFactory beanFactory;
@Autowired
private GreetingAssembler greetingAssembler;
private static final String TEMPLATE = "Hello, %s!";
@ResponseStatus(HttpStatus.OK)
@RequestMapping("/greeting")
public GreetingResource greeting( @PathVariable("var") String var ) {
GreetingEntity greetingEntity = beanFactory.getBean(GreetingEntity.class, String.format(TEMPLATE, var));
GreetingResource greeting = greetingAssembler.toResource(greetingEntity);
greeting.add(linkTo(methodOn(GreetingController.class).greeting(var)).withSelfRel());
return greeting;
}
}
我的ResourceAssembler类似乎有问题
@Service
public class GreetingAssembler extends ResourceAssemblerSupport<GreetingEntity, GreetingResource> {
@Autowired
private BeanFactory beanFactory;
/**
* constructor must call super to define which controller to link to
* and to define the resource
*/
public GreetingAssembler() {
super(GreetingController.class, GreetingResource.class);
}
/**
* based on configuration, build the resource
*
* @param entity
* @return
*/
@Override
public GreetingResource toResource(GreetingEntity entity) {
GreetingResource resource = createResourceWithId( entity.getId(),
entity);
return resource;
}
/**
* same as the method in ResourceAssemblerSupport, overwritten to evaluate the problem
*
* @param id
* @param entity
* @param parameters
* @return
*/
@Override
protected GreetingResource createResourceWithId(Object id, GreetingEntity entity, Object... parameters) {
Assert.notNull(entity);
Assert.notNull(id);
GreetingResource instance = instantiateResource(entity);
ControllerLinkBuilder builder = linkTo(GreetingController.class, parameters);
builder = builder.slash(id);
Link link = builder.withSelfRel();
instance.add(link);
return instance;
}
/**
* overwrite the default method to be able to call the class from aplicationcontext with params
*
* @param entity
* @return
*/
@Override
protected GreetingResource instantiateResource(GreetingEntity entity) {
return beanFactory.getBean(GreetingResource.class, entity.getContent());
}
}
GreetingResource和GreetingEntity是简单的POJO。
整个源代码位于https://github.com/r0bse/Spring-Hateoas-ResourceAssemblerSupport-Problem，基于一个简单示例：https://github.com/spring-guides/gs-rest-hateoas
我的问题是：我做错了什么，这是一个错误，还是我理解一切如何一起工作不够好？