[JAVA] CREATE WEB DOMAIN SERVER

URL link in Java, you can utilize the java.net.URL class, which represents a Uniform Resource Locator. Here's how you can work with URLs in Java:

1. Creating a URL Object:

You can create a URL object by providing a string representation of the URL.
Example:

Java

     try {
         URL url = new URL("http://www.example.com");
     } catch (MalformedURLException e) {
         // Handle the exception if the URL is invalid
         e.printStackTrace();
     }

It's recommended to use java.net.URI to parse or construct a URL instead of the deprecated URL constructors.

2. Connecting to the URL:

To establish a connection, use the openConnection() method of the URL object, which returns a URLConnection object.
Example:

Java

     try {
         URL url = new URL("http://www.example.com");
         URLConnection connection = url.openConnection();
         connection.connect(); // Initiates the connection
     } catch (MalformedURLException | IOException e) {
         e.printStackTrace();
     }

3. Reading Data from the URL:

You can read data from the URL using the getInputStream() method of the URLConnection object, which returns an InputStream.
Example:

Java

     try {
         URL url = new URL("http://www.example.com");
         URL page2URL = new URL(url, "page2.html");

URLConnection connection = url.openConnection();
         InputStream inputStream = connection.getInputStream();
         BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
         String line;
         while ((line = reader.readLine()) != null) {
             System.out.println(line);
         }
         reader.close();
         inputStream.close();
     } catch (MalformedURLException | IOException e) {
         e.printStackTrace();
     }

4. Sending HTTP Requests:

For more advanced interactions like sending HTTP GET or POST requests, use HttpURLConnection.
Example:

Java

     try {
         URL url = new URL("http://www.example.com/api");
         HttpURLConnection connection = (HttpURLConnection) url.openConnection();
         connection.setRequestMethod("GET"); // Or "POST"
         int responseCode = connection.getResponseCode();
         if (responseCode == HttpURLConnection.HTTP_OK) {
             // Read response
         }
         connection.disconnect();
     } catch (MalformedURLException | IOException e) {
         e.printStackTrace();
     }

Set request properties using setRequestProperty() and handle the response accordingly.

5. Other URL Operations:

You can obtain different parts of the URL such as the protocol, host, port, and file using methods like getProtocol(), getHost(), getPort(), and getFile().
You can also extract the reference part (fragment) of the URL using getRef().

6. Working with Local Files:

To use a local file as a URL, you can create a URL object using the file path.
Example:

Java

     try {
         URL fileUrl = new URL("file:///path/to/your/file.txt");
     } catch (MalformedURLException e) {
         e.printStackTrace();
     }

Be mindful of path separators and character escaping when dealing with local files.

Important Considerations:

Remember to handle MalformedURLException when creating URL objects, and IOException when connecting to or reading from URLs.
Consider using libraries like Apache HttpClient for more robust HTTP interactions.
When working with server-side applications, web servers like Apache Tomcat can be used to handle requests.