SpringBoot 统一异常处理

1. 首先定义一个统一管理所有异常的类，加上注解@RestControllerAdvice
2. 定义处理不同异常的方法，加上注解 @ExceptionHandler

3. @RestControllerAdvice
   public class GlobalExceptionHandler
   {
       private static final Logger log = LoggerFactory.getLogger(GlobalExceptionHandler.class);
   
       /**
        * 权限码异常
        */
       @ExceptionHandler(NotPermissionException.class)
       public AjaxResult handleNotPermissionException(NotPermissionException e, HttpServletRequest request)
       {
           String requestURI = request.getRequestURI();
           log.error("请求地址'{}',权限码校验失败'{}'", requestURI, e.getMessage());
           return AjaxResult.error(HttpStatus.FORBIDDEN, "没有访问权限，请联系管理员授权");
       }
   
       /**
        * 角色权限异常
        */
       @ExceptionHandler(NotRoleException.class)
       public AjaxResult handleNotRoleException(NotRoleException e, HttpServletRequest request)
       {
           String requestURI = request.getRequestURI();
           log.error("请求地址'{}',角色权限校验失败'{}'", requestURI, e.getMessage());
           return AjaxResult.error(HttpStatus.FORBIDDEN, "没有访问权限，请联系管理员授权");
       }
   
       /**
        * 请求方式不支持
        */
       @ExceptionHandler(HttpRequestMethodNotSupportedException.class)
       public AjaxResult handleHttpRequestMethodNotSupported(HttpRequestMethodNotSupportedException e, HttpServletRequest request)
       {
           String requestURI = request.getRequestURI();
           log.error("请求地址'{}',不支持'{}'请求", requestURI, e.getMethod());
           return AjaxResult.error(e.getMessage());
       }
   
       /**
        * 业务异常
        */
       @ExceptionHandler(ServiceException.class)
       public AjaxResult handleServiceException(ServiceException e, HttpServletRequest request)
       {
           log.error(e.getMessage(), e);
           Integer code = e.getCode();
           return StringUtils.isNotNull(code) ? AjaxResult.error(code, e.getMessage()) : AjaxResult.error(e.getMessage());
       }
   
       /**
        * 请求路径中缺少必需的路径变量
        */
       @ExceptionHandler(MissingPathVariableException.class)
       public AjaxResult handleMissingPathVariableException(MissingPathVariableException e, HttpServletRequest request)
       {
           String requestURI = request.getRequestURI();
           log.error("请求路径中缺少必需的路径变量'{}',发生系统异常.", requestURI, e);
           return AjaxResult.error(String.format("请求路径中缺少必需的路径变量[%s]", e.getVariableName()));
       }
   
       /**
        * 请求参数类型不匹配
        */
       @ExceptionHandler(MethodArgumentTypeMismatchException.class)
       public AjaxResult handleMethodArgumentTypeMismatchException(MethodArgumentTypeMismatchException e, HttpServletRequest request)
       {
           String requestURI = request.getRequestURI();
           String value = Convert.toStr(e.getValue());
           if (StringUtils.isNotEmpty(value))
           {
               value = EscapeUtil.clean(value);
           }
           log.error("请求参数类型不匹配'{}',发生系统异常.", requestURI, e);
           return AjaxResult.error(String.format("请求参数类型不匹配，参数[%s]要求类型为：'%s'，但输入值为：'%s'", e.getName(), e.getRequiredType().getName(), value));
       }
   
       /**
        * 拦截未知的运行时异常
        */
       @ExceptionHandler(RuntimeException.class)
       public AjaxResult handleRuntimeException(RuntimeException e, HttpServletRequest request)
       {
           String requestURI = request.getRequestURI();
           log.error("请求地址'{}',发生未知异常.", requestURI, e);
           return AjaxResult.error(e.getMessage());
       }
   
       /**
        * 系统异常
        */
       @ExceptionHandler(Exception.class)
       public AjaxResult handleException(Exception e, HttpServletRequest request)
       {
           String requestURI = request.getRequestURI();
           log.error("请求地址'{}',发生系统异常.", requestURI, e);
           return AjaxResult.error(e.getMessage());
       }
   
       /**
        * 自定义验证异常
        */
       @ExceptionHandler(BindException.class)
       public AjaxResult handleBindException(BindException e)
       {
           log.error(e.getMessage(), e);
           String message = e.getAllErrors().get(0).getDefaultMessage();
           return AjaxResult.error(message);
       }
   
       /**
        * 自定义验证异常
        */
       @ExceptionHandler(MethodArgumentNotValidException.class)
       public Object handleMethodArgumentNotValidException(MethodArgumentNotValidException e)
       {
           log.error(e.getMessage(), e);
           String message = e.getBindingResult().getFieldError().getDefaultMessage();
           return AjaxResult.error(message);
       }
   
       /**
        * 内部认证异常
        */
       @ExceptionHandler(InnerAuthException.class)
       public AjaxResult handleInnerAuthException(InnerAuthException e)
       {
           return AjaxResult.error(e.getMessage());
       }
   
       /**
        * 演示模式异常
        */
       @ExceptionHandler(DemoModeException.class)
       public AjaxResult handleDemoModeException(DemoModeException e)
       {
           return AjaxResult.error("演示模式，不允许操作");
       }
   }