divesh saini's questions

我正在学习 GraphQL 并尝试使用 Express (v4) 设置 Apollo Server，但是在发出请求时不断收到以下错误/graphql：

req.body is not set; this probably means you forgot to set up the `json` middleware before the Apollo Server middleware.

这是我的服务器代码：

const express = require("express");
const { ApolloServer } = require('@apollo/server');
const { expressMiddleware } = require('@apollo/server/express4')
const cors = require('cors');

async function startServer() {
    const app = express();

    const server = new ApolloServer({
        typeDefs: `
            type Todo {
                id: ID!
                title: String!
                completed: Boolean!
            }
            
            type Query {
                getTodos: [Todo]
            }
        `,
        resolvers: {
            Query: {
                getTodos: () => []
            }
        }
    });

    await server.start();

    app.use('/graphql', cors(), express.json(), expressMiddleware(server));

    const PORT = process.env.PORT || 8000;
    await new Promise((resolve) => app.listen(PORT, resolve));
    console.log(`Server is running on port ${PORT}`);
}

startServer().catch((err) => {
    console.error('Error starting the server:', err);
});

我在 expressMiddleware 之前添加了 express.json()，但错误仍然存​​在。我在使用 Apollo Server 和 Express 4 中间件时是否遗漏了什么？

任何帮助都值得感激！