MongoDB connection refused, port 3001 reactjs - reactjs

Question

MongoDB connection is being refused at port connection 3001, it was working before but suddenly it stopped working. My database is on MongoDB atlas. I am connected through mongoDB compass and I have the connection link in my code. I followed a mern tutorial exactly but am still facing this issue: https://www.youtube.com/watch?v=I7EDAR2GRVo. Does anyone have any idea why this would happen?
import "./App.css";
import { useState, useEffect } from "react";
import Axios from "axios";
function App() {
const [listOfUsers, setListOfUsers] = useState([]);
const [name, setName] = useState("");
const [age, setAge] = useState(0);
const [username, setUsername] = useState("");
useEffect(() => {
Axios.get("http://localhost:3001/getUsers").then((response) => {
setListOfUsers(response.data);
});
}, []);
const createUser = () => {
Axios.post("http://localhost:3001/createUser", {
name,
age,
username,
}).then((response) => {
setListOfUsers([
...listOfUsers,
{
name,
age,
username,
},
]);
});
};
return (
<div className="App">
<div className="usersDisplay">
{listOfUsers.map((user) => {
return (
<div>
<h1>Name: {user.name}</h1>
<h1>Age: {user.age}</h1>
<h1>Username: {user.username}</h1>
</div>
);
})}
</div>
<div>
<input
type="text"
placeholder="Name..."
onChange={(event) => {
setName(event.target.value);
}}
/>
<input
type="number"
placeholder="Age..."
onChange={(event) => {
setAge(event.target.value);
}}
/>
<input
type="text"
placeholder="Username..."
onChange={(event) => {
setUsername(event.target.value);
}}
/>
<button onClick={createUser}> Create User </button>
</div>
</div>
);
}
export default App;
const express = require("express");
const app = express();
const mongoose = require("mongoose");
const UserModel = require("./models/Users");
const cors = require("cors");
app.use(express.json());
app.use(cors());
mongoose.connect("mongodb+srv://username:password#cluster0.md4aag2.mongodb.net/merntutorial?retryWrites=true&w=majority");
app.get("/getUsers", (req, res) => {
UserModel.find({}, (err, result) => {
if (err) {
res.json(err);
} else {
res.json(result);
}
})
});
app.post("/createUser", async (req, res) => {
const user = req.body;
const newUser = new UserModel(user);
await newUser.save();
res.json(user);
});
app.listen(3001, () => {
console.log("SERVER RUNS PERFECTLY!");
});

Answer 1

Search services.msc in your device and click start to run the MongoDB server.
After start or restart running MongoDB server, you will be able to run your program