Java HTTP 状态 500 - ... IllegalArgumentException：当我在 spring 控制器中使用 ResponseStatus 注释和返回值时返回值类型未知
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/27179875/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
HTTP Status 500 - ... IllegalArgumentException: Unknown return value type when I use ResponseStatus annotation and return value in spring controller
提问by gstackoverflow
I have wrote following controller method:
我编写了以下控制器方法：
@RequestMapping(value = "/member/createCompany/uploadImage1", method = RequestMethod.GET)
@ResponseStatus(HttpStatus.OK)
public Long handle() {
return 1l;
}
When I request this method in browser I see following:
当我在浏览器中请求此方法时，我看到以下内容：
HTTP Status 500 - Request processing failed; nested exception is java.lang.IllegalArgumentException: Unknown return value type [java.lang.Long]
type Exception report
message Request processing failed; nested exception is java.lang.IllegalArgumentException: Unknown return value type [java.lang.Long]
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalArgumentException: Unknown return value type [java.lang.Long]
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:948)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827)
javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)
javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118)
org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:154)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:150)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:199)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:110)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:50)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192)
org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:343)
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:260)
root cause
java.lang.IllegalArgumentException: Unknown return value type [java.lang.Long]
org.springframework.util.Assert.notNull(Assert.java:112)
org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:68)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:122)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827)
javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)
javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(Charac
.........
Did I implement server side wrong or is it client side problem?
我是否实现了服务器端错误还是客户端问题？
Updateto njjnex answer.
更新到 njjnex 答案。
What should I do if I want to realize following logic inside controller method:
如果我想在控制器方法中实现以下逻辑，我该怎么做：
if(someCondition){
return 1l;
}else{
//I want to return 500 or 400 http code
}
采纳答案by njjnex
Use @ResponseBodyannotation in this case. Without it Spring interpret your return value as a view name. But it cannot be long thats why you got error Unknown return value type
在这种情况下使用@ResponseBody注释。如果没有它，Spring 会将您的返回值解释为视图名称。但它不能很长，这就是为什么你出错的原因Unknown return value type
The @ResponseBody annotation is similar to @RequestBody. This annotation can be put on a method and indicates that the return type should be written straight to the HTTP response body (and not placed in a Model, or interpreted as a view name).
@ResponseBody 注释类似于@RequestBody。这个注解可以放在一个方法上，并指示返回类型应该直接写入 HTTP 响应主体（而不是放在模型中，或解释为视图名称）。
If you want to return error code from ResponseBody use:
如果要从 ResponseBody 返回错误代码，请使用：
return new ResponseEntity<String>(HttpStatus.BAD_REQUEST);
回答by Haritha Perera
@RestController is a specialized version of the controller. It includes the @Controller and @ResponseBody annotations and as a result, simplifies the controller implementation:
@RestController 是控制器的专用版本。它包括 @Controller 和 @ResponseBody 注释，因此简化了控制器实现：
@RestController
@RequestMapping("books-rest")
public class SimpleBookRestController {
@GetMapping("/{id}", produces = "application/json")
public Book getBook(@PathVariable int id) {
return findBookById(id);
}
private Book findBookById(int id) {
// ...
}
}
I thinked that case (Unknown return value type). i thinks You're applied @Controllerannotation in this class. if you want to repair it , you will want apply @Controllerinstead @RestControllerannotatan.
我认为这种情况（未知的返回值类型）。我认为你@Controller在这个类中应用了注释。如果你想修复它，你需要应用@Controller而不是 @RestControllerannotatan。
refer this link,
https://www.baeldung.com/spring-controller-vs-restcontroller
请参阅此链接，
https://www.baeldung.com/spring-controller-vs-restcontroller
