在NestJS中實現基於請求頭的版本檢測——使用中間件實現

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import { Injectable, NestMiddleware } from "@nestjs/common";
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import { Request, Response, NextFunction } from "express";
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@Injectable()
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export class VersionMiddleware implements NestMiddleware {
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  private readonly latestVersion = "2.0.0"; // 設定最新版本號
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  use(req: Request, res: Response, next: NextFunction) {
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    const version = req.headers["version"] as string; // 從header中獲取版本號
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    res.on("finish", () => {
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      if (version && this.needsUpdate(version)) {
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        // 如果需要更新，則修改響應數據
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        const originalSend = res.send;
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        res.send = (body: any) => {
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          let modifiedBody = body;
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          try {
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            modifiedBody = JSON.parse(body);
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          } catch (err) {}
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          const updateInfo = {
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            updateAvailable: true,
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            updateUrl: "xxxx", // 更新地址
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            latestVersion: this.latestVersion,
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            message: "A new version is available, please update.",
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          };
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          const updatedBody = { ...modifiedBody, ...updateInfo };
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          return originalSend.call(res, JSON.stringify(updatedBody));
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        };
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      }
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    });
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    next();
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  }
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  // 版本比較邏輯
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  private needsUpdate(clientVersion: string): boolean {
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    return clientVersion < this.latestVersion;
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  }
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}

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import { MiddlewareConsumer, Module, NestModule } from "@nestjs/common";
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import { AppController } from "./app.controller";
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import { VersionMiddleware } from "./version.middleware";
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@Module({
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  controllers: [AppController],
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})
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export class AppModule implements NestModule {
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  configure(consumer: MiddlewareConsumer) {
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    consumer.apply(VersionMiddleware).forRoutes("*"); // 對所有路由應用中間件
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  }
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}

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{
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  "data": "Here is your data",
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  "updateAvailable": true,
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  "latestVersion": "2.0.0",
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  "message": "A new version is available, please update."
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}

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{
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  "data": "Here is your data"
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}