如何在 NestJS 中处理异常？

NestJS 提供了强大的异常处理机制。可以通过 @Catch() 装饰器创建自定义异常过滤器来捕获和处理异常。例如：

typescript复制代码

import { ExceptionFilter, Catch, ArgumentsHost, HttpException, HttpStatus } from '@nestjs/common';
import { Request, Response } from 'express';

@Catch(HttpException)
export class HttpExceptionFilter implements ExceptionFilter {
  catch(exception: HttpException, host: ArgumentsHost) {
    const ctx = host.switchToHttp();
    const response = ctx.getResponse<Response>();
    const request = ctx.getRequest<Request>();
    const status = exception.getStatus();

    response.status(status).json({
      statusCode: status,
      timestamp: new Date().toISOString(),
      path: request.url,
      message: exception.message,
    });
  }
}

在模块中全局注册异常过滤器：

typescript复制代码

import { Module, APP_FILTER } from '@nestjs/common';
import { APP_INTERCEPTOR } from '@nestjs/core';
import { HttpExceptionFilter } from './http-exception.filter';

@Module({
  providers: [
    {
      provide: APP_FILTER,
      useClass: HttpExceptionFilter,
    },
  ],
})
export class AppModule {}

这样，所有未捕获的 HttpException 都会被 HttpExceptionFilter 处理，返回统一的错误响应格式。