Reactjs 无法从localhost:3000将请求/api/用户代理到http://localhost:3000/

我是新来的。我不知道从哪里开始。尝试发布时出现以下错误：代理错误：无法从localhost:3000向代理请求/api/user。 [1] 有关更多信息，请参阅（EconReset）

这是我的server.js文件：

var cors = require("cors");
var express = require("express");
var bodyParser = require("body-parser");
var methodOverride = require("method-override");
var PORT = process.env.PORT || 3001;
var app = express();
var Sequelize = require("Sequelize");
var passport = require("passport");
var session = require("express-session");
var env = require("dotenv").load();
const routes = require("./routes");

// Requiring our models for syncing
var db = require("./models");

// Add routes, both API and view
app.use(routes);

// Creates connection with Sequelize
const connection = new Sequelize("live_work_chill_db", "root", "password", {
  host: "localhost",
  dialect: "mysql",
  operatorsAliases: false
});

// Create instance of cors with Express
app.use(cors());
app.use(bodyParser.json());

app.use(express.static(process.cwd() + "/public"));
app.use(bodyParser.urlencoded({ extended: false }));
app.use(methodOverride("_method"));

// Initialize passport, express session and passport session
app.use(
  session({
    secret: process.env.PASSPORT_SECRET,
    resave: true,
    saveUninitialized: true
  })
); // session secret
app.use(passport.initialize());
app.use(passport.session()); // persistent login sessions

// // Routes - Import our auth.js file
// var authRoute = require('./controllers/auth.js')(app,passport); // Added passport as an argument to pass its functionality to auth.js

// load passport strategies
require("./config/passport/passport.js")(passport, db.Users);

// Syncing our sequelize models and then starting our express app
db.sequelize.sync({ force: false }).then(function() {
  app.listen(PORT, function() {
    console.log("App listening on PORT " + PORT);
  });
});

这是我的package.json文件：

{
  "name": "mern",
  "version": "1.0.0",
  "description": "",
  "main": "server.js",
  "scripts": {
    "start": "if-env NODE_ENV=production && npm run start:prod || npm run start:dev",
    "start:prod": "node server.js",
    "start:dev": "concurrently \"nodemon server.js\" \"npm run client\"",
    "client": "cd client && npm run start",
    "install": "cd client && npm install",
    "build": "cd client && npm run build",
    "heroku-postbuild": "npm run build"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "concurrently": "^4.1.0",
    "nodemon": "^1.18.7"
  },
  "dependencies": {
    "axios": "^0.18.0",
    "bcrypt-nodejs": "^0.0.3",
    "cors": "^2.8.5",
    "express": "^4.16.3",
    "express-session": "^1.15.6",
    "if-env": "^1.0.4",
    "method-override": "^3.0.0",
    "mysql2": "^1.6.4",
    "passport": "^0.4.0",
    "passport-local": "^1.0.0",
    "react": "^16.8.1",
    "react-router-dom": "^4.3.1",
    "react-scripts": "^2.1.3",
    "sequelize": "^4.42.0"
  }
}

---

尝试将其添加到package.json中

"proxy": "http://localhost:3000",

---

尝试将其添加到package.json中

"proxy": "http://localhost:3000",