Java 构建在Spring3（m3）上的REST全注释服务的最小配置是什么？

我试图公开一个REST完整服务（由Tomcat托管），但无法确定Spring3（M3）需要什么配置

这是（示例）服务的外观：

@Controller
@Scope("prototype")
public class UsersController
{
    @RequestMapping(value="/users/hello", method=RequestMethod.GET)
    public String hello()
    {
        return "hello, user!";
    }
}

我的Spring配置如下所示（为了简单起见，我省略了完整的类名）：

令我沮丧的是，我在日志文件中看到的不是“hello，user！”的回复，而是以下错误：

09:54:45,140 DEBUG RequestContextListener:69 - Bound request context to thread: org.apache.catalina.connector.RequestFacade@19299f5
09:54:45,140 DEBUG DispatcherServlet:834 - DispatcherServlet with name 'dispatcher' determining Last-Modified value for [/myserver/services/users/hello]
09:54:45,156 DEBUG DefaultAnnotationHandlerMapping:178 - Mapping [/users/hello] to handler 'com.symantec.repserver.myserver.UsersController@21447f'
09:54:45,171 DEBUG DispatcherServlet:850 - Last-Modified value for [/myserver/services/users/hello] is: -1
09:54:45,171 DEBUG DispatcherServlet:683 - DispatcherServlet with name 'dispatcher' processing GET request for [/myserver/services/users/hello]
09:54:45,218 DEBUG HandlerMethodInvoker:148 - Invoking request handler method: public java.lang.String com.symantec.repserver.myserver.UsersController.hello()
09:54:45,218 DEBUG DefaultListableBeanFactory:1366 - Invoking afterPropertiesSet() on bean with name 'hello, user!'
09:54:45,218 DEBUG DispatcherServlet:1060 - Rendering view [org.springframework.web.servlet.view.InternalResourceView: name 'hello, user!'; URL [hello, user!]] in DispatcherServlet with name 'dispatcher'
09:54:45,234 DEBUG InternalResourceView:237 - Forwarding to resource [hello, user!] in InternalResourceView 'hello, user!'
09:54:45,250 DEBUG DispatcherServlet:834 - DispatcherServlet with name 'dispatcher' determining Last-Modified value for [/myserver/services/users/hello, user!]
09:54:45,250 DEBUG DispatcherServlet:842 - No handler found in getLastModified
09:54:45,250 DEBUG DispatcherServlet:683 - DispatcherServlet with name 'dispatcher' processing GET request for [/myserver/services/users/hello, user!]
09:54:45,250  WARN PageNotFound:959 - No mapping found for HTTP request with URI [/myserver/services/users/hello, user!] in DispatcherServlet with name 'dispatcher'
09:54:45,250 DEBUG DispatcherServlet:643 - Successfully completed request
09:54:45,250 DEBUG DispatcherServlet:643 - Successfully completed request
09:54:45,250 DEBUG RequestContextListener:89 - Cleared thread-bound request context: org.apache.catalina.connector.RequestFacade@19299f5

正如您所注意到的，我的当前配置正在尝试将此请求作为新请求重新路由：

/myserver/services/users/hello, user!

你知道怎么了吗？我遗漏了什么？

问题是您的hello（）方法被注释为Spring的handlerMethod，根据@RequestMapping文档，handler方法可以返回任意数量的对象，但如果它返回字符串，则：

解释为视图名称的字符串值，模型通过命令对象和带ModelAttribute注释的引用数据访问器方法隐式确定。handler方法还可以通过声明ModelMap参数以编程方式丰富模型（请参见上文）

因此，它基本上是在寻找您返回的字符串“hello，user”的映射，该字符串不存在。您可以让您的方法返回void，并在方法内部自己将其写入HttpServletResponse

进一步答复:

@RequestMapping(value="/users/hello", method=RequestMethod.GET) 
public void hello(Writer w) { 
   w.write("hello, user!"); 
   w.flush(); 
   return; 
} 

您可能希望获得整个HttpServletResponse，而不仅仅是编写器，这样您就可以设置适当的Http头

---

很抱歉，我下面的评论很混乱，我是这个网站的新手。

嗯。。。但是它打破了整个JAX-RS的想法，即将方法的返回值发送给请求方。有没有一种方法可以对我的方法进行注释，从而使上述要求成立？根据javadoc Is，您的方法接受一个参数OutputStream或Writer，RequestMapper将传入ServletOutputStream/Writer供您写入。我不确定这是否真的是最好的方法，但它会起作用@RequestMapping（value=“/users/hello”，method=RequestMethod.GET）public void hello（Writer w）{w.write（“hello，user！”）；w.flush（）；return；}您可能希望获取整个HttpServletResponse，而不仅仅是Writer，通过这种方式，您可以设置适当的Http头。您可以按照上面的建议将响应直接写入流，也可以返回执行此操作的ModelAndView对象。效果差不多。如果Spring3使用新的HttpMessageConverter模式来处理方法返回值，那就太好了，但实际上它们只适用于@RequestBody。方法返回值的解释仍然与Spring2.5中的解释相同，请记住SpringRESTMVC不是JAX-RS兼容的，这是他们做出的明确选择。JAX-RS不适合SpringMVC。看起来这在某种程度上已经被解决了。您可以实现ModelAndViewResolver接口，并将bean添加到您的上下文中，它将能够解析字符串“视图名称”，并将其写入您的响应中。它还没有准备好被称为JAX-RS兼容，因为它从未打算被称为JAX-RS兼容。它是SpringMVC的扩展。SpringSource已经说过，已经有至少3个JAX-RS实现了，他们不想再增加第四个。

09:54:45,140 DEBUG RequestContextListener:69 - Bound request context to thread: org.apache.catalina.connector.RequestFacade@19299f5
09:54:45,140 DEBUG DispatcherServlet:834 - DispatcherServlet with name 'dispatcher' determining Last-Modified value for [/myserver/services/users/hello]
09:54:45,156 DEBUG DefaultAnnotationHandlerMapping:178 - Mapping [/users/hello] to handler 'com.symantec.repserver.myserver.UsersController@21447f'
09:54:45,171 DEBUG DispatcherServlet:850 - Last-Modified value for [/myserver/services/users/hello] is: -1
09:54:45,171 DEBUG DispatcherServlet:683 - DispatcherServlet with name 'dispatcher' processing GET request for [/myserver/services/users/hello]
09:54:45,218 DEBUG HandlerMethodInvoker:148 - Invoking request handler method: public java.lang.String com.symantec.repserver.myserver.UsersController.hello()
09:54:45,218 DEBUG DefaultListableBeanFactory:1366 - Invoking afterPropertiesSet() on bean with name 'hello, user!'
09:54:45,218 DEBUG DispatcherServlet:1060 - Rendering view [org.springframework.web.servlet.view.InternalResourceView: name 'hello, user!'; URL [hello, user!]] in DispatcherServlet with name 'dispatcher'
09:54:45,234 DEBUG InternalResourceView:237 - Forwarding to resource [hello, user!] in InternalResourceView 'hello, user!'
09:54:45,250 DEBUG DispatcherServlet:834 - DispatcherServlet with name 'dispatcher' determining Last-Modified value for [/myserver/services/users/hello, user!]
09:54:45,250 DEBUG DispatcherServlet:842 - No handler found in getLastModified
09:54:45,250 DEBUG DispatcherServlet:683 - DispatcherServlet with name 'dispatcher' processing GET request for [/myserver/services/users/hello, user!]
09:54:45,250  WARN PageNotFound:959 - No mapping found for HTTP request with URI [/myserver/services/users/hello, user!] in DispatcherServlet with name 'dispatcher'
09:54:45,250 DEBUG DispatcherServlet:643 - Successfully completed request
09:54:45,250 DEBUG DispatcherServlet:643 - Successfully completed request
09:54:45,250 DEBUG RequestContextListener:89 - Cleared thread-bound request context: org.apache.catalina.connector.RequestFacade@19299f5

/myserver/services/users/hello, user!

@RequestMapping(value="/users/hello", method=RequestMethod.GET) 
public void hello(Writer w) { 
   w.write("hello, user!"); 
   w.flush(); 
   return; 
}