SpringBoot接口获取参数的常用注解详解

// 获取单个参数
@GetMapping("/user/{id}")
public User getUserById(@PathVariable Long id) {
    return userService.findById(id);
}

// 获取多个参数
@GetMapping("/user/{id}/post/{postId}")
public String getInfo(
    @PathVariable Long id,
    @PathVariable Long postId
) {
    // ...
}

// 参数名不一致时指定
@GetMapping("/user/{userId}")
public User getUser(@PathVariable("userId") Long id) {
    return userService.findById(id);
}

// 获取所有路径变量（Map形式）
@GetMapping("/user/{id}/post/{postId}")
public String getInfo(@PathVariable Map<String, String> pathVariables) {
    return pathVariables.get("id");
}

// URL路径中的时间参数
@GetMapping("/events/date/{date}")
public List<Event> getEventsByPathDate(
    @PathVariable @DateTimeFormat(pattern = "yyyy-MM-dd") Date date) {
    return eventService.findByDate(date);
}

@GetMapping("/events/datetime/{datetime}")
public String getByDateTime(
    @PathVariable @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss") LocalDateTime datetime) {
    return "时间: " + datetime;
}

// 必填参数
@GetMapping("/users")
public List<User> getUsers(@RequestParam String name) {
    return userService.findByName(name);
}

// 可选参数
@GetMapping("/users")
public List<User> getUsers(
    @RequestParam(required = false) String name,
    @RequestParam(defaultValue = "1") int page,
    @RequestParam(defaultValue = "10") int size
) {
    return userService.findByName(name, page, size);
}

// 接收多个值
@GetMapping("/users")
public List<User> getUsers(@RequestParam List<Long> ids) {
    return userService.findByIds(ids);
}

// 获取所有查询参数（Map形式）
@GetMapping("/search")
public String search(@RequestParam Map<String, String> params) {
    return params.get("keyword");
}

// 查询参数中的时间
@GetMapping("/events")
public List<Event> getEventsByDate(
    @RequestParam @DateTimeFormat(pattern = "yyyy-MM-dd") Date date) {
    return eventService.findByDate(date);
}

// 多个时间参数
@GetMapping("/events/range")
public List<Event> getEventsByRange(
    @RequestParam @DateTimeFormat(pattern = "yyyy-MM-dd") Date startDate,
    @RequestParam @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME) LocalDateTime endTime) {
    return eventService.findByDateRange(startDate, endTime);
}

@PostMapping("/user")
public User createUser(@RequestBody User user) {
    return userService.save(user);
}

// 接收 Map 类型的请求体
@PostMapping("/data")
public String processData(@RequestBody Map<String, Object> data) {
    return data.toString();
}

// 使用 DTO 接收参数
@PostMapping("/register")
public ResponseEntity<?> register(@RequestBody RegisterDTO registerDTO) {
    // 处理注册逻辑
    return ResponseEntity.ok("注册成功");
}

// 绑定到对象
@PostMapping("/user")
public String createUser(@ModelAttribute User user) {
    userService.save(user);
    return "success";
}

// 绑定到 Map
@PostMapping("/user")
public String createUser(@ModelAttribute Map<String, Object> model) {
    return model.get("name").toString();
}

@GetMapping("/info")
public String getInfo(
    @RequestHeader("User-Agent") String userAgent,
    @RequestHeader(value = "Authorization", required = false) String auth,
    @RequestHeader Map<String, String> headers
) {
    return "User-Agent: " + userAgent;
}

@GetMapping("/profile")
public String getProfile(@CookieValue("sessionId") String sessionId) {
    return "Session ID: " + sessionId;
}

// 可选参数
@GetMapping("/profile")
public String getProfile(
    @CookieValue(value = "sessionId", defaultValue = "default") String sessionId
) {
    return "Session ID: " + sessionId;
}

@RestController
@RequestMapping("/api/upload")
public class UploadController {
    // 基础文件上传
    @PostMapping("/single")
    public String uploadSingle(@RequestPart("file") MultipartFile file) {
        return "Uploaded: " + file.getOriginalFilename();
    }

    // 多文件上传
    @PostMapping("/multiple")
    public String uploadMultiple(@RequestPart("files") MultipartFile[] files) {
        return "Uploaded " + files.length + " files";
    }

    // 文件 + JSON对象
    @PostMapping(value = "/upload", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
    public String uploadData(@RequestPart("file") MultipartFile file, 
                             @RequestPart("metadata") MyMetadata metadata) {
        // metadata 是自定义的 JSON 对象
        return "Uploaded file with metadata";
    }
    
    // 文件 + 表单字段
    @PostMapping(value = "/upload-with-data", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
    public ResponseEntity<?> uploadWithData(
                                            @RequestPart("file") MultipartFile file,
                                            @RequestParam("name") String name,
                                            @RequestParam("description") String description) {
        // 处理文件和文本数据
        return ResponseEntity.ok("上传成功");
    }
}

@PostMapping("/upload-simple")
public String uploadSimple(@RequestParam("file") MultipartFile file) {
    return "文件名称: " + file.getOriginalFilename();
}

@GetMapping("/dashboard")
public String dashboard(@SessionAttribute("user") User user) {
    return "欢迎 " + user.getUsername();
}

@GetMapping("/process")
public String process(@RequestAttribute("processedData") String data) {
    return "处理后的数据: " + data;
}

// URL: /cars;color=red;year=2023
@GetMapping("/cars")
public String getCar(@MatrixVariable String color) {
    return color;
}

@GetMapping("/config")
public String getConfig(@Value("${app.name}") String appName) {
    return "应用名称: " + appName;
}