@GetMapping @PostMapping @DeleteMapping @PutMapping
在 Spring Boot（或 Spring MVC）中，@GetMapping、@PostMapping、@PutMapping 和 @DeleteMapping 是用于定义 RESTful 接口的 HTTP 方法专用注解，它们是对 @RequestMapping 的语义化封装，使代码更清晰、简洁。
| 注解 | HTTP 方法 | 用途 | 等价写法 | 参数 |
|---|---|---|---|---|
@GetMapping | GET | 获取资源（查询） | @RequestMapping(method = RequestMethod.GET) | @PathVariable, @RequestParam 单独使用 |
@PostMapping | POST | 创建资源 / 提交数据 | @RequestMapping(method = RequestMethod.POST) | @RequestBody |
@PutMapping | PUT | 全量更新 资源 | @RequestMapping(method = RequestMethod.PUT) | @PathVariable, @RequestBody 合用 |
@DeleteMapping | DELETE | 删除资源 | @RequestMapping(method = RequestMethod.DELETE) | @PathVariable |
@RestController @RequestMapping("/api/users")publicclassUserController{// GET /api/users/1@GetMapping("/{id}")publicUsergetUser(@PathVariable Long id){returnuserService.findById(id);}// GET /api/users?role=admin@GetMappingpublicList<User>getUsers(@RequestParam(required=false)String role){returnuserService.findByRole(role);}// POST /api/users （请求体为 JSON）@PostMappingpublicUsercreateUser(@RequestBody CreateUserRequest request){returnuserService.create(request);}// PUT /api/users/1 （全量更新）@PutMapping("/{id}")publicUserupdateUser(@PathVariable Long id,@RequestBody UpdateUserRequest request){returnuserService.updateFull(id,request);}// DELETE /api/users/1@DeleteMapping("/{id}")publicResponseEntity<Void>deleteUser(@PathVariable Long id){userService.delete(id);returnResponseEntity.noContent().build();// 返回 204 No Content}}@GetMapping
GET /api/example?a=1&b=2&c=3
方法1
@GetMapping("/example")publicStringhandleRequest(@RequestParam String a,@RequestParam Integer b,@RequestParam(required=false)String c// 可选参数){System.out.println("a="+a+", b="+b+", c="+c);return"OK";}方法二：封装到一个 POJO 对象中（适合参数多或复用）
publicclassQueryParams{privateString a;privateInteger b;privateString c;// 必须有 getter/setter（Lombok 可简化）publicStringgetA(){returna;}publicvoidsetA(String a){this.a=a;}publicIntegergetB(){returnb;}publicvoidsetB(Integer b){this.b=b;}publicStringgetC(){returnc;}publicvoidsetC(String c){this.c=c;}}@GetMapping("/example")publicStringhandleRequest(QueryParams params){System.out.println(params.getA()+", "+params.getB()+", "+params.getC());return"OK";}