Spring Boot 3 构建统一的请求响应参数、异常处理、以及统一的异常状态码

在 Spring Boot 3 微服务中，构建统一的请求响应参数、异常处理、以及统一的异常状态码是标准化和提高可维护性的关键。以下是实现的最佳实践：

1. 统一请求响应结构

定义统一的响应结构
创建一个通用的响应包装类 ApiResponse：

public class ApiResponse<T> {private int code;         // 状态码private String message;   // 消息private T data;           // 数据public ApiResponse(int code, String message, T data) {this.code = code;this.message = message;this.data = data;}public static <T> ApiResponse<T> success(T data) {return new ApiResponse<>(200, "Success", data);}public static <T> ApiResponse<T> success(String message, T data) {return new ApiResponse<>(200, message, data);}public static <T> ApiResponse<T> error(int code, String message) {return new ApiResponse<>(code, message, null);}// Getters and Setters
}

统一返回格式的切面处理
使用 Spring 的 @ControllerAdvice 对所有 @RestController 返回的内容进行统一封装：

import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;@RestControllerAdvice
public class GlobalResponseHandler extends ResponseEntityExceptionHandler {@ExceptionHandler(Exception.class)@ResponseBodypublic ApiResponse<Object> handleException(Exception ex) {return ApiResponse.error(500, "Internal Server Error: " + ex.getMessage());}@ExceptionHandler(CustomException.class)@ResponseBodypublic ApiResponse<Object> handleCustomException(CustomException ex) {return ApiResponse.error(ex.getCode(), ex.getMessage());}
}

2. 统一异常处理

自定义异常类
创建一个通用的业务异常类 CustomException：

public class CustomException extends RuntimeException {private int code;public CustomException(int code, String message) {super(message);this.code = code;}public int getCode() {return code;}
}

全局异常处理
在 @RestControllerAdvice 中捕获自定义异常和其他常见异常：

import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;@RestControllerAdvice
public class GlobalExceptionHandler {@ExceptionHandler(CustomException.class)public ApiResponse<Object> handleCustomException(CustomException ex) {return ApiResponse.error(ex.getCode(), ex.getMessage());}@ExceptionHandler(IllegalArgumentException.class)public ApiResponse<Object> handleIllegalArgumentException(IllegalArgumentException ex) {return ApiResponse.error(400, "Invalid Argument: " + ex.getMessage());}@ExceptionHandler(Exception.class)public ApiResponse<Object> handleGeneralException(Exception ex) {return ApiResponse.error(500, "Internal Server Error: " + ex.getMessage());}
}

3. 统一状态码管理

定义状态码枚举
创建一个枚举类，管理所有可能的状态码：

public enum ApiStatus {SUCCESS(200, "Success"),BAD_REQUEST(400, "Bad Request"),UNAUTHORIZED(401, "Unauthorized"),FORBIDDEN(403, "Forbidden"),NOT_FOUND(404, "Not Found"),INTERNAL_SERVER_ERROR(500, "Internal Server Error"),CUSTOM_ERROR(1001, "Custom Business Error");private final int code;private final String message;ApiStatus(int code, String message) {this.code = code;this.message = message;}public int getCode() {return code;}public String getMessage() {return message;}
}

在 CustomException 中使用状态码

public class CustomException extends RuntimeException {private int code;public CustomException(ApiStatus status) {super(status.getMessage());this.code = status.getCode();}public int getCode() {return code;}
}

4. Controller 示例

在 Controller 中使用统一的返回结构和异常处理：

import org.springframework.web.bind.annotation.*;@RestController
@RequestMapping("/api")
public class UserController {@GetMapping("/user/{id}")public ApiResponse<User> getUser(@PathVariable Long id) {if (id <= 0) {throw new CustomException(ApiStatus.BAD_REQUEST);}// 模拟用户数据User user = new User(id, "John Doe", "john.doe@example.com");return ApiResponse.success(user);}
}