URL Class in Java with Examples
Last Updated :
18 Apr, 2022
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URL known as Uniform Resource Locator is simply a string of text that identifies all the resources on the Internet, telling us the address of the resource, how to communicate with it, and retrieve something from it.
Components of a URL
A URL can have many forms. The most general however follows a three-components system as proposed below:
- Protocol: HTTP is the protocol here
- Hostname: Name of the machine on which the resource lives.
- File Name: The pathname to the file on the machine.
- Port Number: Port number to which to connect (typically optional).
URL Class
The URL class is the gateway to any of the resources available on the internet. A Class URL represents a Uniform Resource Locator, which is a pointer to a “resource” on the World Wide Web. A resource can point to a simple file or directory, or it can refer to a more complicated object, such as a query to a database or to a search engine.
Constructors of the URL class
- URL(String address) throws MalformedURLException: It creates a URL object from the specified String.
- URL(String protocol, String host, String file): Creates a URL object from the specified protocol, host, and file name.
- URL(String protocol, String host, int port, String file): Creates a URL object from protocol, host, port, and file name.
- URL(URL context, String spec): Creates a URL object by parsing the given spec in the given context.
- URL(String protocol, String host, int port, String file, URLStreamHandler handler):
Creates a URL object from the specified protocol, host, port number, file, and handler. - URL(URL context, String spec, URLStreamHandler handler):
Creates a URL by parsing the given spec with the specified handler within a specified context.
Important Methods used in URL class
| Method | Action Performed |
|---|---|
| getAuthority() | Returns the authority part of URL or null if empty |
| getDefaultPort() | Returns the default port used |
| getFile() | Returns the file name. |
| getHost() | Return the hostname of the URL in IPv6 format |
| getPath() | Returns the path of the URL, or null if empty |
| getPort() | Returns the port associated with the protocol specified by the URL |
| getProtocol() | Returns the protocol used by the URL |
| getQuery() | the Returns the query part of URL. A query is a part after the ‘?’ in the URL. Whenever logic is used to display the result, there would be a query field in the URL. It is similar to querying a database. |
| getRef() | Returns the reference of the URL object. Usually, the reference is the part marked by a ‘#’ in the URL. You can see the working example by querying anything on Google and seeing the part after ‘#’ |
| toString() | As in any class, toString() returns the string representation of the given URL object. |
Example:
Java
// Java program to demonstrate working of URL // Importing required classes import java.net.MalformedURLException; import java.net.URL; // Main class // URL class public class GFG { // Main driver method public static void main(String[] args) throws MalformedURLException { // Creating a URL with string representation URL url1 = new URL( + "WK26I4fT8gfth6CACg#q=geeks+for+geeks+java"); // Creating a URL with a protocol,hostname,and path URL url2 = new URL("http", "www.geeksforgeeks.org", "/jvm-works-jvm-architecture/"); URL url3 = new URL( + "q=gnu&rlz;=1C1CHZL_enIN71" + "4IN715&oq;=gnu&aqs;=chrome..69i57j6" + "9i60l5.653j0j7&sourceid;=chrome&ie;=UTF" + "-8#q=geeks+for+geeks+java"); // Printing the string representation of the URL System.out.println(url1.toString()); System.out.println(url2.toString()); System.out.println(); System.out.println( "Different components of the URL3-"); // Retrieving the protocol for the URL System.out.println("Protocol:- " + url3.getProtocol()); // Retrieving the hostname of the url System.out.println("Hostname:- " + url3.getHost()); // Retrieving the default port System.out.println("Default port:- " + url3.getDefaultPort()); // Retrieving the query part of URL System.out.println("Query:- " + url3.getQuery()); // Retrieving the path of URL System.out.println("Path:- " + url3.getPath()); // Retrieving the file name System.out.println("File:- " + url3.getFile()); // Retrieving the reference System.out.println("Reference:- " + url3.getRef()); } } |
Output:
https://www.google.co.in/?gfe_rd=cr&ei=ptYqWK26I4fT8gfth6CACg#q=geeks+for+geeks+java https://www.geeksforgeeks.org/jvm-works-jvm-architecture/ Different components of the URL3- Protocol:- https Hostname:- www.google.co.in Default port:- 443 Query:- q=gnu&rlz=1C1CHZL_enIN714IN715&oq=gnu&aqs=chrome..69i57j69i60l5.653j0j7&sourceid=chrome&ie=UTF-8 Path:- /search File:- /search?q=gnu&rlz=1C1CHZL_enIN714IN715&oq=gnu&aqs=chrome..69i57j69i60l5.653j0j7&sourceid=chrome&ie=UTF-8 Reference:- q=geeks+for+geeks+java
