How do I do a HTTP GET in Java?

java

http-requests

okhttp

httpurlconnection

byNikita Barsukov·Feb 12, 2025

Here's a barebones example of an HTTP GET request with Java's HttpURLConnection:

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class SimpleHttpGet {

    public static void main(String[] args) throws Exception {
        URL url = new URL("http://example.com"); // Ahoy, internet!
        HttpURLConnection con = (HttpURLConnection) url.openConnection();
        con.setRequestMethod("GET"); // Ready to GET us some data!

        BufferedReader reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
        String line;
        StringBuilder result = new StringBuilder();

        while ((line = reader.readLine()) != null) { // slurping the data
            result.append(line);
        }
        reader.close(); // Bye, reader!

        System.out.println(result); // Data, glorious data!
    }
}

With this code, you create a connection, set the request method to "GET", and read the response with a BufferedReader. This is GETting exciting!

Hang on, there's more. To handle data and parameters in HTTP GET requests, you can:

append parameters directly to the URL string.
use URL encoding for parameter values to handle special characters.
set request headers with conn.setRequestProperty("header-name", "header-value");.
remember to clean up your toys; i.e., con.disconnect() when you're done.

Navigating the labyrinth of GET requests

Where there's a library, there's a way

HttpURLConnection is good for simple requests, but when things get feisty, libraries like Apache HttpClient or OkHttp can provide:

Fluent APIs to build requests without going insane
Connection pooling for better performance
Automatic retry policies because computers fail
Easier response handling with automatic JSON parsing because who has the time?

Here's a code snippet using OkHttp:

OkHttpClient client = new OkHttpClient(); // Call me HttpClient... OkHttpClient
Request request = new Request.Builder()
  .url("http://example.com") // I want my data from here
  .build(); // All set, Cap'n!

Response response = client.newCall(request).execute(); // Executing order 66... ummm... GET request
String responseBody = response.body().string(); // What do we have here?

Beyond happy paths – error handling

Every superhero needs a plan B. And so does your program. Here's how you can save the day:

Wrap network operations with try-catch blocks to catch IOException.
Use specific catch blocks for MalformedURLException or ProtocolException.
Check HttpURLConnection.getResponseCode() to handle HTTP status 404... and the other ones.

Attention: Secure your requests

When it's about HTTPS, not Hand-Tossed Pizza Service:

Verify the certificate with SSLContext and TrustManager because security first!
Ensure that URL starts with "https://". That 'S' matters.
When in doubt, consider libraries like Apache HttpClient with built-in HTTPS support.