Handling GET Requests in Node.js: 3 Examples

Introduction

Handling GET requests is a fundamental skill when building APIs with Node.js. A GET request fetches data from the server, and understanding how to implement this can greatly enhance your API development. In this article, we’ll walk through three diverse examples that illustrate how to handle GET requests effectively. Let’s dive in!

Example 1: Basic GET Request for User Data

Context

In this example, we will create a simple API endpoint that returns user data in JSON format. This is a common use case, especially for applications that require user profile information.

const express = require('express');
const app = express();
const PORT = 3000;

// Sample user data
const users = [
  { id: 1, name: 'Alice', email: 'alice@example.com' },
  { id: 2, name: 'Bob', email: 'bob@example.com' }
];

// GET request to fetch all users
app.get('/users', (req, res) => {
  res.json(users);
});

app.listen(PORT, () => {
  console.log(`Server is running on http://localhost:${PORT}`);
});

Notes

• The express framework simplifies the handling of HTTP requests.
• You can test this endpoint by visiting http://localhost:3000/users in your browser.

Example 2: GET Request with Query Parameters

Context

This example will demonstrate how to handle GET requests that include query parameters. We will create an endpoint to fetch a specific user by their ID.

const express = require('express');
const app = express();
const PORT = 3000;

const users = [
  { id: 1, name: 'Alice', email: 'alice@example.com' },
  { id: 2, name: 'Bob', email: 'bob@example.com' }
];

// GET request to fetch a user by ID
app.get('/users/:id', (req, res) => {
  const userId = parseInt(req.params.id);
  const user = users.find(u => u.id === userId);

  if (user) {
    res.json(user);
  } else {
    res.status(404).send('User not found');
  }
});

app.listen(PORT, () => {
  console.log(`Server is running on http://localhost:${PORT}`);
});

Notes

• This example uses URL parameters to dynamically retrieve user data.
• You can test this endpoint by visiting http://localhost:3000/users/1 or http://localhost:3000/users/2.

Example 3: GET Request with Error Handling

Context

In this final example, we’ll add basic error handling to our GET request. This is crucial for providing meaningful feedback to users when something goes wrong.

const express = require('express');
const app = express();
const PORT = 3000;

const users = [
  { id: 1, name: 'Alice', email: 'alice@example.com' },
  { id: 2, name: 'Bob', email: 'bob@example.com' }
];

// GET request with error handling
app.get('/users/:id', (req, res) => {
  const userId = parseInt(req.params.id);
  if (isNaN(userId)) {
    return res.status(400).send('Invalid user ID');
  }

  const user = users.find(u => u.id === userId);
  if (user) {
    res.json(user);
  } else {
    res.status(404).send('User not found');
  }
});

app.listen(PORT, () => {
  console.log(`Server is running on http://localhost:${PORT}`);
});

Notes

• This example includes a check for invalid user IDs, returning a 400 status code when necessary.
• Testing this endpoint with an invalid ID, like http://localhost:3000/users/abc, will now provide a clear error message.

Conclusion

These examples of handling GET requests in Node.js demonstrate how to create basic endpoints, manage query parameters, and implement error handling. Understanding these concepts will empower you to build robust APIs that can effectively respond to client requests.