Java Newworking questions Part1

1. What is the difference between URL instance and URLConnection instance?
A URL instance represents the location of a resource, and a URLConnection instance represents a link for accessing or communicating with the resource at the location.
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2. How do I make a connection to URL?
You obtain a URL instance and then invoke openConnection on it. URLConnection is an abstract class, which means you can't directly create instances of it using a constructor. We have to invoke openConnection method on a URL instance, to get the right kind of connection for your URL. Eg. URL url;
URLConnection connection;
try{ url = new URL("...");
connection = url.openConnection();
}catch (MalFormedURLException e) { }
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3. What Is a Socket?
A socket is one end-point of a two-way communication link between two programs running on the network. A socket is bound to a port number so that the TCP layer can identify the application that data is destined to be sent. Socket classes are used to represent the connection between a client program and a server program. The java.net package provides two classes--Socket and ServerSocket--which implement the client side of the connection and the server side of the connection, respectively.
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4. What information is needed to create a TCP Socket?
The Local System?s IP Address and Port Number. And the Remote System's IPAddress and Port Number.
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