Java: lectura de una URL usando la clase URLConnection

Java

// Java Program to Illustrate Reading and Writing
// in URLConnection Class
  
// Importing required classes
import java.io.*;
import java.net.*;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
  
// Class
// URLConnectionclass
class GFG {
    // main driver method
    public static void main(String[] args)
    {
  
        // Try block to check for exceptions
        try {
  
            // Fetching URL by creating
            URL url = new URL(
                "https://www.geeksforgeeks.org/java");
  
            // Opening the connection to the above URL
            URLConnection urlcon = url.openConnection();
  
            // Executing the below line would print the
            // value of
            // Allow User Interaction field.
            // System.out.println(urlcon.getAllowUserInteraction());
  
            // Executing the below line would print
            // the value of Content Type field.
            // System.out.println(urlcon.getContentType());
  
            // Executing the below line would print the
            // value
            // of URL of the given connection.
            // System.out.println(urlcon.getURL());
  
            // Executing the below line would
            // print the value of Do Input field.
            // System.out.println(urlcon.getDoInput());
  
            // Executing the below line would
            // print the value of Do Output field.
            // System.out.println(urlcon.getDoOutput());
  
            // Executing the below line would
            // print the value of Last Modified field.
            // System.out.println(new
            // Date(urlcon.getLastModified()));
  
            // Executing the below line would
            // print the value of Content Encoding field.
            // System.out.println(urlcon.getContentEncoding());
  
            // To get a map of all the fields of http header
            Map<String, List<String> > header
                = urlcon.getHeaderFields();
  
            // Printing all the fields along with their
            // value
            for (Map.Entry<String, List<String> > mp :
                 header.entrySet()) {
                System.out.print(mp.getKey() + " : ");
                System.out.println(
                    mp.getValue().toString());
            }
  
            System.out.println();
            System.out.println(
                "Complete source code of the URL is-");
            System.out.println(
                "---------------------------------");
  
            // Getting the inputstream of the open
            // connection
            BufferedReader br
                = new BufferedReader(new InputStreamReader(
                    urlcon.getInputStream()));
            String i;
  
            // Printing the source code line by line
            while ((i = br.readLine()) != null) {
  
                System.out.println(i);
            }
        }
  
        // Catch block to handle exceptions
        catch (Exception e) {
  
            // Displaying exceptions
            System.out.println(e);
        }
    }
}