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SpringMVC @ExceptionHandler 典型用法

news 2025/7/11 5:37:34

处理单个异常类型

当 getUser() 方法抛出 UserNotFoundException 时，会自动调用 handleUserNotFound() 方法进行处理。

@RestController
@RequestMapping("/users")
public class UserController {@GetMapping("/{id}")public User getUser(@PathVariable Long id) {// 可能抛出 UserNotFoundExceptionreturn userService.getUserById(id);}@ExceptionHandler(UserNotFoundException.class)public ResponseEntity<String> handleUserNotFound(UserNotFoundException ex) {return ResponseEntity.status(HttpStatus.NOT_FOUND).body(ex.getMessage());}
}

处理多个异常类型

一个 @ExceptionHandler 方法可以处理多个异常类型：

@ExceptionHandler({IllegalArgumentException.class, ResourceNotFoundException.class})
public ResponseEntity<String> handleClientErrors(RuntimeException ex) {return ResponseEntity.status(HttpStatus.BAD_REQUEST).body("客户端错误: " + ex.getMessage());
}

结合 @ResponseStatus 使用（返回指定状态码）

此时返回值直接作为响应体，HTTP 状态码由 @ResponseStatus 指定。

@ExceptionHandler(ResourceNotFoundException.class)
@ResponseStatus(HttpStatus.NOT_FOUND)
public String handleResourceNotFound(ResourceNotFoundException ex) {return ex.getMessage();
}

返回结构化错误信息（推荐做法）

@ExceptionHandler(UserNotFoundException.class)
public ResponseEntity<ErrorResponse> handleUserNotFound(UserNotFoundException ex) {ErrorResponse error = new ErrorResponse(HttpStatus.NOT_FOUND.value(), ex.getMessage(), LocalDateTime.now());return ResponseEntity.status(HttpStatus.NOT_FOUND).body(error);
}// ErrorResponse 示例类
@Data
@NoArgsConstructor
@AllArgsConstructor
public class ErrorResponse {private int status;private String message;private LocalDateTime timestamp;
}

捕获所有异常（兜底处理）

注意顺序：更具体的异常应放在前面，避免被 Exception.class 拦截。

@ExceptionHandler(Exception.class)
@ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
public ErrorResponse handleAllExceptions(Exception ex) {return new ErrorResponse(HttpStatus.INTERNAL_SERVER_ERROR.value(), "系统内部错误", ex.getMessage(), LocalDateTime.now());
}

不同返回类型

@ExceptionHandler 方法可以有多种返回类型，如 String, ResponseEntity, Map, 自定义 DTO 等。

@RestController
@RequestMapping("/users")
public class UserController {@GetMapping("/{id}")public User getUser(@PathVariable Long id) {if (id == null || id <= 0) {throw new IllegalArgumentException("用户 ID 不合法");}// ...}@ExceptionHandler(IllegalArgumentException.class)@ResponseStatus(HttpStatus.BAD_REQUEST)public String handleIllegalArgument(IllegalArgumentException ex) {return "参数错误：" + ex.getMessage();}@ExceptionHandler(UserNotFoundException.class)public ResponseEntity<ErrorResponse> handleUserNotFound(UserNotFoundException ex) {ErrorResponse error = new ErrorResponse(404, ex.getMessage(), LocalDateTime.now());return ResponseEntity.status(HttpStatus.NOT_FOUND).body(error);}@ExceptionHandler(Exception.class)@ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)public ErrorResponse handleAllExceptions(Exception ex) {return new ErrorResponse(500, "系统错误", ex.getMessage(), LocalDateTime.now());}
}