异常处理

通常一个 web 开发中，有大量需要处理的异常。比如业务异常，权限不足，数据库异常等等。前端通过弹出提示信息的方式告诉用户出了什么错误。通常情况下我们用 try ...... catch... 对异常进行捕获，但是在实际项目中业务模块进行异常捕获，会造成代码的冗余，不够优雅，我们希望代码中只有业务相关的操作，所有的异常通过一个类 GlobalExceptionMiddleware中间件的形式进行集中处理。全局异常就是对框架所有异常进行统一管理。这样我们的代码就很简洁了。

如何使用

/// <summary>
/// 登录验证
/// </summary>
/// <param name="loginBody"></param>
/// <returns></returns>
public SysUser Login(LoginBodyDto loginBody)
{
    SysUser user = SysLogininfoRepository.Login(loginBody);
    if (user == null)
    {
        throw new CustomException(ResultCode.LOGIN_ERROR ,"用户名或密码错误");
    }
    return user;
}

当我们登录输入错误的用户名或密码时将返回以下结果

{
  "msg": "用户名或密码错误",
  "code": 105
}

CustomException 重载方法

public CustomException(string msg) : base(msg)
{
}
public CustomException(int code, string msg) : base(msg)
{
		Code = code;
		Msg = msg;
}

public CustomException(ResultCode resultCode, string msg) : base(msg)
{
		Code = (int)resultCode;
}

/// <summary>
/// 自定义异常
/// </summary>
/// <param name="resultCode"></param>
/// <param name="msg"></param>
/// <param name="errorMsg">用于记录详细日志到输出介质</param>
public CustomException(ResultCode resultCode, string msg, object errorMsg) : base(msg)
{
		Code = (int)resultCode;
		LogMsg = errorMsg.ToString();
}

更多用法

throw new CustomException("使用默认code");
throw new CustomException(100, "自定义code");
throw new CustomException(ResultCode.LOGIN_ERROR ,"固定code值");
throw new CustomException(ResultCode.FAIL, "出错了", "记录日志使用,打印出更详细的日志内容");

ResultCode 自带 code 值

public enum ResultCode
{
		[Description("success")]
		SUCCESS = 200,

		[Description("没有更多数据")]
		NO_DATA = 210,

		[Description("参数错误")]
		PARAM_ERROR = 101,

		[Description("验证码错误")]
		CAPTCHA_ERROR = 103,

		[Description("登录错误")]
		LOGIN_ERROR = 105,

		[Description("操作失败")]
		FAIL = 1,

		[Description("服务端出错啦")]
		GLOBAL_ERROR = 500,

		[Description("自定义异常")]
		CUSTOM_ERROR = 110,

		[Description("非法请求")]
		INVALID_REQUEST = 116,

		[Description("授权失败")]
		OAUTH_FAIL = 201,

		[Description("未授权")]
		DENY = 401,

		[Description("授权访问失败")]
		FORBIDDEN = 403,

		[Description("Bad Request")]
		BAD_REQUEST = 400
}