SpringBoot中controller深层详细讲解

@Data
public class ResponseData<T> {
    private Boolean status = true;
    private int code = 200;
    private String message;
    private T data;
    public static ResponseData ok(Object data) {
        return new ResponseData(data);
    }
    public static ResponseData ok(Object data,String message) {
        return new ResponseData(data,message);
    }
    public static ResponseData fail(String message,int code) {
        ResponseData responseData= new ResponseData();
        responseData.setCode(code);
        responseData.setMessage(message);
        responseData.setStatus(false);
        responseData.setData(null);
        return responseData;
    }
    public ResponseData() {
        super();
    }
    public ResponseData(T data) {
        super();
        this.data = data;
    }
    public ResponseData(T data,String message) {
        super();
        this.data = data;
        this.message=message;
    }
}

@AllArgsConstructor
@Data
public enum ResponseCode {
    SYS_FAIL(1, "操作失败"),
    SYS_SUCESS(200, "操作成功"),
    SYSTEM_ERROR_CODE_403(403, "权限不足"),
    SYSTEM_ERROR_CODE_404(404, "未找到请求资源"),
	；
	private int code;
    private String msg;
}

@RestControllerAdvice(basePackages = "com.example.demo")
public class ResponseAdvice implements ResponseBodyAdvice<Object> {
    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        // 如果不需要进行封装的，可以添加一些校验手段，比如添加标记排除的注解
        return true;
    }
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        // 提供一定的灵活度，如果body已经被包装了，就不进行包装
        if (body instanceof Result) {
            return body;
        }
        return Result.success(body);
    }
}

@RestController
@RequestMapping("/test")
public class TestController {
    private TestService testService;
	@Autowired
    public void setTestService(TestService prettyTestService) {
        this.testService = prettyTestService;
    }
    @GetMapping("/{num}")
    public Integer num(@PathVariable("num") @Min(1) @Max(20) Integer num) {
        return num * num;
    }
    @GetMapping("/email")
    public String email(@RequestParam @NotBlank @Email String email) {
        return email;
    }
}

@Data
public class TestDTO {
    @NotBlank
    private String userName;
    @NotBlank
    @Length(min = 6, max = 20)
    private String password;
    @NotNull
    @Email
    private String email;
}
@RestController
@RequestMapping("/test")
public class TestController {
    private TestService testService;
	@Autowired
    public void setTestService(TestService testService) {
        this.testService = testService;
    }
    @PostMapping("/testValidation")
    public void testValidation(@RequestBody @Validated TestDTO testDTO) {
        this.testService.save(testDTO);
    }
}

//自定义异常
public class ForbiddenException extends RuntimeException {
    public ForbiddenException(String message) {
        super(message);
    }
}
//自定义异常
public class BusinessException extends RuntimeException {
    public BusinessException(String message) {
        super(message);
    }
}
//统一拦截异常
@RestControllerAdvice(basePackages = "com.example.demo")
public class ExceptionAdvice {
    /**
     * 捕获 {@code BusinessException} 异常
     */
    @ExceptionHandler({BusinessException.class})
    public Result<?> handleBusinessException(BusinessException ex) {
        return Result.failed(ex.getMessage());
    }
    /**
     * 捕获 {@code ForbiddenException} 异常
     */
    @ExceptionHandler({ForbiddenException.class})
    public Result<?> handleForbiddenException(ForbiddenException ex) {
        return Result.failed(ResultEnum.FORBIDDEN);
    }
    /**
     * {@code @RequestBody} 参数校验不通过时抛出的异常处理
     */
    @ExceptionHandler({MethodArgumentNotValidException.class})
    public Result<?> handleMethodArgumentNotValidException(MethodArgumentNotValidException ex) {
        BindingResult bindingResult = ex.getBindingResult();
        StringBuilder sb = new StringBuilder("校验失败:");
        for (FieldError fieldError : bindingResult.getFieldErrors()) {
            sb.append(fieldError.getField()).append("：").append(fieldError.getDefaultMessage()).append(", ");
        }
        String msg = sb.toString();
        if (StringUtils.hasText(msg)) {
            return Result.failed(ResultEnum.VALIDATE_FAILED.getCode(), msg);
        }
        return Result.failed(ResultEnum.VALIDATE_FAILED);
    }
    /**
     * {@code @PathVariable} 和 {@code @RequestParam} 参数校验不通过时抛出的异常处理
     */
    @ExceptionHandler({ConstraintViolationException.class})
    public Result<?> handleConstraintViolationException(ConstraintViolationException ex) {
        if (StringUtils.hasText(ex.getMessage())) {
            return Result.failed(ResultEnum.VALIDATE_FAILED.getCode(), ex.getMessage());
        }
        return Result.failed(ResultEnum.VALIDATE_FAILED);
    }
    /**
     * 顶级异常捕获并统一处理，当其他异常无法处理时候选择使用
     */
    @ExceptionHandler({Exception.class})
    public Result<?> handle(Exception ex) {
        return Result.failed(ex.getMessage());
    }
}