next 微服务
Nestjs 微服务
文档
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