spring mvc @ResponseStatus 和 ResponseEntity

@ResponseStatus 是标记一个方法或异常类在返回时响应的http状态。其代码注释如下：

* * <p>The status code is applied to the HTTP response when the handler * method is invoked and overrides status information set by other means, * like {@code ResponseEntity} or {@code "redirect:"}. * * <p><strong>Warning</strong>: when using this annotation on an exception * class, or when setting the {@code reason} attribute of this annotation, * the {@code HttpServletResponse.sendError} method will be used. * * <p>With {@code HttpServletResponse.sendError}, the response is considered * complete and should not be written to any further. Furthermore, the Servlet * container will typically write an HTML error page therefore making the * use of a {@code reason} unsuitable for REST APIs. For such cases it is * preferable to use a {@link org.springframework.http.ResponseEntity} as * a return type and avoid the use of {@code @ResponseStatus} altogether. * * <p>Note that a controller class may also be annotated with * {@code @ResponseStatus} and is then inherited by all {@code @RequestMapping} * methods.

@ResponseStatus 可以结合 @ResponseBody 一起使用。

@RequestMapping("/testResponseBody") @ResponseBody public Map<String, String> testResponseBody(){ return ImmutableMap.of("key", "value"); } @RequestMapping("/testResponseBodyFaild") @ResponseBody @ResponseStatus(HttpStatus.NOT_IMPLEMENTED) public Map<String, String> testResponseBodyFaild(){ return ImmutableMap.of("key", "faild"); }

这两个handler method返回的http status code(http状态码) 分别是200 和 501。

ResponseEntity 是在 org.springframework.http.HttpEntity 的基础上添加了http status code(http状态码)，用于RestTemplate以及@Controller的HandlerMethod。它在Controoler中或者用于服务端响应时，作用是和@ResponseStatus与@ResponseBody结合起来的功能一样的。用于RestTemplate时，它是接收服务端返回的http status code 和 reason的。 代码注释如下：

* Extension of {@link HttpEntity} that adds a {@link HttpStatus} status code. * Used in {@code RestTemplate} as well {@code @Controller} methods. * * <p>In {@code RestTemplate}, this class is returned by * {@link org.springframework.web.client.RestTemplate#getForEntity getForEntity()} and * {@link org.springframework.web.client.RestTemplate#exchange exchange()}: * <pre class="code"> * ResponseEntity&lt;String&gt; entity = template.getForEntity("http://example.com", String.class); * String body = entity.getBody(); * MediaType contentType = entity.getHeaders().getContentType(); * HttpStatus statusCode = entity.getStatusCode(); * </pre> * * <p>Can also be used in Spring MVC, as the return value from a @Controller method: * <pre class="code"> * &#64;RequestMapping("/handle") * public ResponseEntity&lt;String&gt; handle() { * URI location = ...; * HttpHeaders responseHeaders = new HttpHeaders(); * responseHeaders.setLocation(location); * responseHeaders.set("MyResponseHeader", "MyValue"); * return new ResponseEntity&lt;String&gt;("Hello World", responseHeaders, HttpStatus.CREATED); * } * </pre> * Or, by using a builder accessible via static methods: * <pre class="code"> * &#64;RequestMapping("/handle") * public ResponseEntity&lt;String&gt; handle() { * URI location = ...; * return ResponseEntity.created(location).header("MyResponseHeader", "MyValue").body("Hello World"); * } * </pre>

ResponseEntity 和 @ResponseStatus 一起使用是无效的

@RequestMapping("/testResponseEntity") public ResponseEntity<Map<String, String>> testResponseEntity(){ Map<String, String> map = ImmutableMap.of("key", "value"); return ResponseEntity.ok(map); } @RequestMapping("/testResponseEntityFaild") @ResponseStatus(HttpStatus.NOT_IMPLEMENTED) public ResponseEntity<Map<String, String>> testResponseEntityFaild(){ Map<String, String> map = ImmutableMap.of("key", "faild"); return ResponseEntity.ok(map); } @RequestMapping("/testResponseEntityFaild2") public ResponseEntity<Map<String, String>> testResponseEntityFaild2(){ return ResponseEntity.badRequest().body(ImmutableMap.of("key", "faild")); }

这三个handler method返回的http status code(http状态码) 分别是200 、 200 和 400。

完整的TestController代码

import com.google.common.collect.ImmutableMap; import org.springframework.http.HttpStatus; import org.springframework.http.ResponseEntity; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import org.springframework.web.bind.annotation.ResponseStatus; import org.springframework.web.bind.annotation.RestController; import java.util.Map; /** * Created by saleson on 2017/5/5. */ @RestController @RequestMapping("/test") public class TestController { @RequestMapping("/testResponseEntity") public ResponseEntity<Map<String, String>> testResponseEntity(){ Map<String, String> map = ImmutableMap.of("key", "value"); return ResponseEntity.ok(map); } @RequestMapping("/testResponseEntityFaild") @ResponseStatus(HttpStatus.NOT_IMPLEMENTED) public ResponseEntity<Map<String, String>> testResponseEntityFaild(){ Map<String, String> map = ImmutableMap.of("key", "faild"); return ResponseEntity.ok(map); } @RequestMapping("/testResponseEntityFaild2") public ResponseEntity<Map<String, String>> testResponseEntityFaild2(){ return ResponseEntity.badRequest().body(ImmutableMap.of("key", "faild")); } @RequestMapping("/testResponseBody") @ResponseBody public Map<String, String> testResponseBody(){ return ImmutableMap.of("key", "value"); } @RequestMapping("/testResponseBodyFaild") @ResponseBody @ResponseStatus(HttpStatus.NOT_IMPLEMENTED) public Map<String, String> testResponseBodyFaild(){ return ImmutableMap.of("key", "faild"); } }

返回的http status code截图: