Start up a plain text editor and type in the source code. It's important that you use a plain ASCII text editor (such as "Notepad" on Windows, "SimpleText" on Mac, or "vi" or "emacs" on UNIX) to enter the source code; don't use a word processing application (such as "WordPerfect" or "Word") since they use a proprietary format for files. If you don't want to do any typing, you can download the source file. Save the file as DrawingLines.java. It's important that the filename match the class name in the source code

When you write a Java program, you must keep in mind the distinction Java makes between an application and an applet. An application is a stand-along program that must have a main method/procedure; it is executed by invoking the Java interpreter within the general computing context. An applet is a module that is run within the context of a browser or other program that has an integral Java interpreter that provides the context for the applet. An applet is, thus, normally invoked as a result of an applet tag included within an html document that is accessed by a Java-capable browser

This site is meant to be a quick-and-dirty introduction to writing Java applets. A set of example applets are given to be used as exercises. Feel free to download the source code herein, try it out on your own machine, and modify it. Designers and artists: this tutorial emphasizes visual and interactive aspects of applets. It was made especially for people wishing to create small, graphical, expressive forms with Java. However, if you have no programming experience at all, you'll probably need additional learning resources. Please see the note below for first-time programmers.

The datagram communication protocol, known as UDP (user datagram protocol), is a connectionless protocol, meaning that each time you send datagrams, you also need to send the local socket descriptor and the receiving socket's address. As you can tell, additional data must be sent each time a communication is made

The stream communication protocol is known as TCP (transfer control protocol). Unlike UDP, TCP is a connection-oriented protocol. In order to do communication over the TCP protocol, a connection must first be established between the pair of sockets. While one of the sockets listens for a connection request (server), the other asks for a connection (client). Once two sockets have been connected, they can be used to transmit data in both (or either one of the) directions