// Controller 示例
@GetMapping("/{id}")
public ResponseEntity<curse> getCursaById (@PathVariable("id") Long id) {
    curse c = curseService.findCurseById(id);
    return new ResponseEntity<>(c, HttpStatus.OK);
}

// 位于同一控制器內(nèi)的異常處理器
@ResponseStatus(HttpStatus.NOT_FOUND)
@ExceptionHandler(CursaNotFoundException.class)
public String noCursaFound(CursaNotFoundException ex) {
    return ex.getMessage();
}

// 自定義異常
public class CursaNotFoundException extends RuntimeException {
    public CursaNotFoundException(String s) {
        super(s);
    }
}

// ApiError.java
public class ApiError {
    private String message;
    private String code; // 可選，用于更精確地標(biāo)識錯誤類型

    public ApiError() {
    }

    public ApiError(String message, String code) {
        this.message = message;
        this.code = code;
    }

    // Getters and Setters
    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }
}

// GlobalExceptionHandler.java
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;

@ControllerAdvice
public class GlobalExceptionHandler {

    /**
     * 處理 CursaNotFoundException 異常
     * 當(dāng) CursaNotFoundException 被拋出時，返回 HTTP 404 NOT_FOUND 和 ApiError 對象
     */
    @ExceptionHandler(value = CursaNotFoundException.class)
    public ResponseEntity<ApiError> handleCursaNotFoundException(CursaNotFoundException ex) {
        ApiError error = new ApiError();
        error.setMessage(ex.getMessage());
        // 假設(shè) CursaNotFoundException 有一個 getCode() 方法，或者可以設(shè)置一個默認(rèn)的錯誤碼
        // 如果自定義異常沒有 getCode() 方法，可直接設(shè)置固定錯誤碼
        error.setCode("CURSA_NOT_FOUND"); 
        return new ResponseEntity<>(error, HttpStatus.NOT_FOUND);
    }

    /**
     * 處理所有未被特定 @ExceptionHandler 捕獲的通用異常
     * 當(dāng)其他任何 Exception 被拋出時，返回 HTTP 500 INTERNAL_SERVER_ERROR 和 ApiError 對象
     */
    @ExceptionHandler(value = Exception.class)
    public ResponseEntity<ApiError> handleGenericException(Exception ex) {
        ApiError error = new ApiError();
        // 生產(chǎn)環(huán)境中，通常不直接返回詳細(xì)異常信息，而是返回一個通用錯誤消息
        error.setMessage("An unexpected error occurred. Please try again later."); 
        error.setCode("GENERIC_ERROR");
        // 詳細(xì)異常信息應(yīng)記錄到日志中，例如：logger.error("Unhandled exception: ", ex);
        return new ResponseEntity<>(error, HttpStatus.INTERNAL_SERVER_ERROR);
    }

    // 可以根據(jù)業(yè)務(wù)需求添加更多針對特定異常的處理器
    // @ExceptionHandler(value = IllegalArgumentException.class)
    // public ResponseEntity<ApiError> handleIllegalArgumentException(IllegalArgumentException ex) {
    //     ApiError error = new ApiError(ex.getMessage(), "INVALID_ARGUMENT");
    //     return new ResponseEntity<>(error, HttpStatus.BAD_REQUEST);
    // }
}

// CursaNotFoundException.java (更新版本，可選)
public class CursaNotFoundException extends RuntimeException {
    private String code;

    public CursaNotFoundException(String message) {
        super(message);
        this.code = "CURSA_NOT_FOUND"; // 默認(rèn)錯誤碼
    }

    public CursaNotFoundException(String message, String code) {
        super(message);
        this.code = code;
    }

    public String getCode() {
        return code;
    }
}