How to make HTTP requests in java

what is HTTP request in javascript?

In JavaScript, an HTTP request refers to the process of sending a request from a client (such as a web browser) to a server over the HTTP protocol, typically to retrieve or send data. An HTTP request is initiated by the client and includes a method (such as GET, POST, PUT, or DELETE), a URL, and optional headers and data.

To make an HTTP request in JavaScript, you can use the XMLHttpRequest object or the fetch API. The XMLHttpRequest object is an older method that has been around for a long time, while the fetch API is a newer, more modern method that offers a simpler and more flexible way to make HTTP requests.

Once the HTTP request is sent, the server processes the request and returns a response to the client. The response typically includes a status code (such as 200 for success or 404 for not found), headers, and optional data. The client can then use the response data to update the user interface or perform other actions as needed. 

How http request works in java?

In Java, you can make HTTP requests using the built-in java.net.HttpURLConnection or java.net.URL classes, or using third-party libraries such as Apache HttpComponents or OkHttp.

Here's an example of how to use HttpURLConnection to make a GET request:

java

Code:-

URL url = new URL("https://example.com/api/data");

HttpURLConnection con = (HttpURLConnection) url.openConnection();

con.setRequestMethod("GET");

int responseCode = con.getResponseCode();

if (responseCode == HttpURLConnection.HTTP_OK) {

    BufferedReader in = new BufferedReader(

            new InputStreamReader(con.getInputStream()));

    String inputLine;

    StringBuffer response = new StringBuffer();

    while ((inputLine = in.readLine()) != null) {

        response.append(inputLine);

    }

    in.close();

    System.out.println(response.toString());

} else {

    System.out.println("HTTP GET request failed with error code: " + responseCode);

}

This code creates a URL object with the desired endpoint, creates an HttpURLConnection object, sets the request method to GET, and sends the request by calling getResponseCode(). If the response code is HTTP_OK (which is 200), the response is read using a BufferedReader and stored in a StringBuffer, which is then printed to the console.

You can modify this code to make other types of HTTP requests (such as POST, PUT, or DELETE) by changing the setRequestMethod() method and including any necessary request data in the request body.

How do I make an HTTP request in Javascript?

To make an HTTP request in Javascript, you can use the built-in XMLHttpRequest object or the newer fetch API. Here's an example of how to use each:

Using XMLHttpRequest:

javascript

code:-

const xhr = new XMLHttpRequest();

xhr.open('GET', 'https://example.com/api/data');

xhr.onload = () => {

  if (xhr.status === 200) {

    console.log(xhr.response);

  } else {

    console.error('Request failed. Returned status of', xhr.status);

  }

};

xhr.send();

//Complete 

Using fetch:

javascript

fetch('https://example.com/api/data')

  .then(response => response.json())

  .then(data => console.log(data))

  .catch(error => console.error(error));

Both of these methods can be used to make GET, POST, PUT, DELETE, and other HTTP requests. For more advanced requests or for working with APIs that require authentication, you may need to use a library like axios or fetch-mock.