首先，您应该遵循RESTful API的最佳实践。不要使用动词，而应使用名词作为URL
@GetMapping("/getOne")，因此您可以将其写为@GetMapping("/branch/{id}")。您可以参考此博客https://blog.mwaysolutions.com/2014/06/05/10-best-practices-for-better-restful-
api/
@ 2ndly，不返回泛型 吗？ ，您可以使用特定的类型（这里为 Branch） 并进行集中异常处理。以下代码段可以帮助您：
@GetMapping("/branch/{id}")public ResponseEntity<Branch> getBranch(@Pathvariable String id) {{ Branch branch = branchService.getOne(id); if(branch == null) { throw new RecordNotFoundException("Invalid Branch id : " + id); } return new ResponseEntity<Branch>(branch, HttpStatus.OK);}RecordNotFoundException.java
@ResponseStatus(HttpStatus.NOT_FOUND)public class RecordNotFoundException extends RuntimeException{ public RecordNotFoundException(String exception) { super(exception); }}CustomExceptionHandler.java
@ControllerAdvicepublic class CustomExceptionHandler extends ResponseEntityExceptionHandler{ @ExceptionHandler(Exception.class) public final ResponseEntity<Object> handleAllExceptions(Exception ex, WebRequest request) { List<String> details = new ArrayList<>(); details.add(ex.getLocalizedMessage()); ErrorResponse error = new ErrorResponse("Server Error", details); return new ResponseEntity(error, HttpStatus.INTERNAL_SERVER_ERROR); } @ExceptionHandler(RecordNotFoundException.class) public final ResponseEntity<Object> handleRecordNotFoundException(RecordNotFoundException ex, WebRequest request) { List<String> details = new ArrayList<>(); details.add(ex.getLocalizedMessage()); ErrorResponse error = new ErrorResponse("Record Not Found", details); return new ResponseEntity(error, HttpStatus.NOT_FOUND); }}ErrorResponse.java
public class ErrorResponse{ public ErrorResponse(String message, List<String> details) { super(); this.message = message; this.details = details; } private String message; private List<String> details; //Getter and setters}上面的类处理多个异常，包括RecordNotFoundException，您也可以为有效负载验证进行自定义。
测试用例 ：
1) HTTP GET /branch/1 [VALID]HTTP Status : 200{ "id": 1, "name": "Branch 1", ...}2) HTTP GET /branch/23 [INVALID]HTTP Status : 404{ "message": "Record Not Found", "details": [ "Invalid Branch id : 23" ]}
