To create a web server in Golang, use the `net/http` package. Define your handler functions and use `http.ListenAndServe` to start the server.

Creating a web server in Golang is an exciting way to get started with web development using this powerful language. Golang’s net/http package makes it easy to set up a web server and define routes for handling requests. In this guide, we’ll walk through the steps to create a simple web server.

1. Importing Required Packages

• Begin by importing the net/http package along with the fmt package for formatting output:

  import (
      "fmt"
      "net/http"
  )
  

2. Defining Handler Functions

• A handler function is responsible for processing incoming HTTP requests. Define a handler function that takes http.ResponseWriter and *http.Request as parameters:

  func helloHandler(w http.ResponseWriter, r *http.Request) {
      fmt.Fprintf(w, "Hello, World!")
  }
  

• This function writes a simple response to the client when they visit the corresponding route.

3. Setting Up Routes

• Use the http.HandleFunc function to map URL paths to handler functions:

  func main() {
      http.HandleFunc("/", helloHandler)
  }
  

• This sets the root path ("/") to call the helloHandler function.

4. Starting the Web Server

• Use the http.ListenAndServe function to start the web server. Provide a port number and the handler functions:

  func main() {
      http.HandleFunc("/", helloHandler)
      fmt.Println("Server starting on :8080")
      http.ListenAndServe(":8080", nil)
  }
  

• This will start the server on port 8080. You can access it by visiting http://localhost:8080 in your web browser.

5. Adding More Routes

• To add more routes, simply define additional handler functions and map them to paths:

  func goodbyeHandler(w http.ResponseWriter, r *http.Request) {
      fmt.Fprintf(w, "Goodbye, World!")
  }
  
  func main() {
      http.HandleFunc("/", helloHandler)
      http.HandleFunc("/goodbye", goodbyeHandler)
  }
  

• This allows users to access different responses based on the URL.

6. Handling Query Parameters

• You can access query parameters from the URL in your handler functions:

  func queryHandler(w http.ResponseWriter, r *http.Request) {
      name := r.URL.Query().Get("name")
      if name == "" {
          name = "World"
      }
      fmt.Fprintf(w, "Hello, %s!", name)
  }
  

• With this function, users can customize their greeting by providing a name parameter, e.g., http://localhost:8080/query?name=Alice.

7. Conclusion Creating a web server in Golang is simple and powerful. With just a few lines of code, you can set up routes, define handler functions, and start serving requests. Explore Golang’s net/http package further to create more complex web applications and APIs.