在传统的开发过程中，我们的控制CONTROLL层通常需要转向一个JSP视图；但随着WEB2.0相关技术的崛起，我们很多时候只需要返回数据即可，而不是一个JSP页面。
SPRING MVC3的@ResponseBody使Controller直接返回数据，而不是直接指向具体的视图；同时通过
MessageConverter和produces（如produces="text/plain;charset=UTF-8"）可以返回各种格式的数据（XML，json，RSS，TEXT，字节流等),本章只介绍最简单的使用；
见代码：
@ResponseBody可以直接返回结果，
而ResponseEntity 可以定义返回的HttpHeaders和HttpStatus，见文章最后的两张图
- @RequestMapping(value="/response", method=RequestMethod.GET)
- public class ResponseController {
- //http://127.0.0.1:8010/response/annotation
- @RequestMapping("/annotation")
- public @ResponseBody String responseBody() {
- return "The String ResponseBody";
- }
- @RequestMapping("/charset/accept")
- public @ResponseBody String responseAcceptHeaderCharset() {
- return "\u3053\u3093\u306b\u3061\u306f\u4e16\u754c\uff01 (\"Hello world!\" in Japanese)";
- }
- //http://127.0.0.1:8010/response/charset/produce
- @RequestMapping(value="/charset/produce", produces="text/plain;charset=UTF-8")
- public @ResponseBody String responseProducesConditionCharset() {
- return "\u3053\u3093\u306b\u3061\u306f\u4e16\u754c\uff01 (\"Hello world!\" in Japanese)";
- }
- //http://127.0.0.1:8010/response/entity/status
- @RequestMapping("/entity/status")
- public ResponseEntity<String> responseEntityStatusCode() {
- return new ResponseEntity<String>("The String ResponseBody with custom status code (403 Forbidden)",
- HttpStatus.FORBIDDEN);
- }
- //http://127.0.0.1:8010/response/entity/headers
- @RequestMapping("/entity/headers")
- public ResponseEntity<String> responseEntityCustomHeaders() {
- HttpHeaders headers = new HttpHeaders();
- headers.setContentType(MediaType.TEXT_PLAIN);
- return new ResponseEntity<String>("The String ResponseBody with custom header Content-Type=text/plain",
- headers, HttpStatus.OK);
- }
- }