如何在文本中反映传入的GET请求？

Question

我使用Spring和Springboot (假设是最新版本)来安装一个简单的web服务，返回一些文本。

我想出了如何使用@RequestMapping和@PathVariable注释来显示一个URL路径变量作为服务器的响应(例如，如果用户转到./my_ user _id/在浏览器中，他们可以在浏览器中看到一些包含该user_id的文本.因为服务返回它作为响应)。

我需要帮助解决如何捕获用户浏览器发出的GET HTTP请求，然后将其以文本形式显示为浏览器中的响应(我希望以纯文本形式显示标题和请求正文)。

我做了一些研究，但是没有一个解决方案能正常工作。有人知道这里的正确方法/可行性吗？

我尝试过一种方法：

• http://www.mkyong.com/java/how-to-get-http-request-header-in-java/

当我尝试上述方法时，会得到一些关于错误的线程：

• Spring RestTemplate - how to enable full debugging/logging of requests/responses?
• http://forum.spring.io/forum/spring-projects/roo/84244-circular-view-path-resourcenotfound
• Circular view path
• How to avoid the "Circular view path" exception with Spring MVC test
• http://myshittycode.com/2014/01/17/mockmvc-circular-view-path-view-would-dispatch-back-to-the-current-handler-url-view-again/

关于Spring的更多信息，我正在大量使用它：

• http://docs.spring.io/spring/docs/current/spring-framework-reference/html/mvc.html

不管怎么说。当使用下面的@Controller时，我会得到一个错误：

@RestController
public class HelloController {

@RequestMapping("/")
public String index() {
    return "Welcome to your home directory";
}

@RequestMapping(value="/mydata/{userId}", method=RequestMethod.GET)
public String printTheUser(@PathVariable String userId) {
    return "The data for " + userId + " would live here";
}


@RequestMapping("/summary_data/")
public String index3() {
    return "All summary data would appear here";
}

private String server = "localhost";
private int port = 8080;

@RequestMapping("/request_mirror/**")
public @ResponseBody String mirrorRest(@RequestBody String body, HttpMethod method, HttpServletRequest request,
    HttpServletResponse response) throws URISyntaxException {
    URI uri = new URI("http", null, server, port, request.getRequestURI(), request.getQueryString(), null);

    RestTemplate restTemplate = new RestTemplate();

    ResponseEntity<String> responseEntity =
        restTemplate.exchange(uri, method, new HttpEntity<String>(body), String.class);

    return responseEntity.getBody();
    }
}

当运行此代码并导航到localhost:8080/request_镜像/stuff3 3/时，我得到以下错误：

Whitelabel Error Page.   This application has no explicit mapping for /error, so you are seeing this as a fallback.
Mon Feb 08 15:41:13 EST 2016
There was an unexpected error (type=Bad Request, status=400).
Required request body content is missing:    org.springframework.web.method.HandlerMethod$HandlerMethodParameter@a35a9b3f

现在，当我尝试另一种方法(另一个@Controller)时，代码如下所示：

@Controller
@RequestMapping("/site")
public class SecondController{

@Autowired
private HttpServletRequest request;

@RequestMapping(value = "/{input:.+}", method = RequestMethod.GET)
public ModelAndView getDomain(@PathVariable("input") String input) {

    ModelAndView modelandView = new ModelAndView("result");

    modelandView.addObject("user-agent", getUserAgent());
    modelandView.addObject("headers", getHeadersInfo());

    return modelandView;

}

//get user agent
private String getUserAgent() {
    return request.getHeader("user-agent");
}

//get request headers
private Map<String, String> getHeadersInfo() {

    Map<String, String> map = new HashMap<String, String>();

    Enumeration headerNames = request.getHeaderNames();
    while (headerNames.hasMoreElements()) {
        String key = (String) headerNames.nextElement();
        String value = request.getHeader(key);
        map.put(key, value);
    }

    return map;
}
}

对于上面的代码(SecondController)，(来源于http://www.mkyong.com/java/how-to-get-http-request-header-in-java/)，当我试图导航到本地主机时，我会得到以下错误:8080/site/stuff123456789.(但我可以在检查时看到Map中的请求中的头键和值.只是不知道如何将它们作为响应在浏览器中显示为文本)。

This application has no explicit mapping for /error, so you are seeing this as a fallback.

 Mon Feb 08 16:10:47 EST 2016
There was an unexpected error (type=Internal Server Error, status=500).
Circular view path [stuff123456789]: would dispatch back to the current handler URL [/site/stuff123456789] again. Check your ViewResolver setup! (Hint: This may be the result of an unspecified view, due to default view name generation.)

Answer 1

编辑:使用HttpEntity获取身体，以防它是空的。

我不知道你到底想达到什么目的，但我认为这可能是近在咫尺：

@RequestMapping(value="/echoRequest")
public @ResponseBody String echoRequest(HttpEntity<String> httpEntity, HttpServletRequest req) {
    String out = "";
    List<String> names = req.getHeaderNames();
    for (String name : names) {
        out += (name + ": " + req.getHeader(name) + "\n");
    }
    if (httpEntity.hasBody()) {
        out += httpEntity.getBody();
    }
    return out;
}