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工作示例

安装：

$ npm i --save @nestjs/microservices

main.ts

import { NestFactory } from '@nestjs/core';
import { Transport } from '@nestjs/microservices';import { AppModule } from './app.module';async function bootstrap() {const app = await NestFactory.create(AppModule);app.connectMicroservice({transport: Transport.TCP,});await app.startAllMicroservicesAsync();await app.listen(5000);
}
bootstrap();

app.controller.ts

import { Controller, Get, Query, UsePipes } from '@nestjs/common';
import {MessagePattern,Client,Transport,ClientProxy,
} from '@nestjs/microservices';
import { AppService } from './app.service';import { Observable, from } from 'rxjs';import { ValidationPipe } from './validation.pipe';@Controller()
export class AppController {@Client({ transport: Transport.TCP })client: ClientProxy;constructor(private readonly appService: AppService) {}@UsePipes(new ValidationPipe())@Get()getHello(@Query('data') data): Observable<number> {// const pattern = { cmd: 'sumObservable' };// const pattern = { cmd: 'sumAsync' };const pattern = { cmd: 'sum' };// 使用 send 调用微服务const r = this.client.send<number>(pattern, data);return r;}@MessagePattern({ cmd: 'sum' })sum(data: number[]): number {return data.reduce((acc, el) => acc + el);}// 返回promise异步响应@MessagePattern({ cmd: 'sumAsync' })sumAsync(data: number[]): Promise<number> {const result = data.reduce((acc, el) => acc + el) + 1;return Promise.resolve(result);}// 程序将响应3次@MessagePattern({ cmd: 'sumObservable' })sumObservable(data: number[]): Observable<number> {return from([1, 2, 3]);}
}

validation.pipe.ts

import {PipeTransform,Injectable,ArgumentMetadata,PayloadTooLargeException,BadRequestException,
} from '@nestjs/common';@Injectable()
export class ValidationPipe implements PipeTransform {transform(value: any, metadata: ArgumentMetadata) {if (metadata.type === 'query') {try {return JSON.parse(value);} catch (error) {throw new BadRequestException();}} else {throw new PayloadTooLargeException();}}
}

http://localhost:5000/?data=[1,2, 3] // 6