Chapter 11

Most of the information on this and other chapters refers directly to material in Wilson, L.B. and Clark, R.G., Comparative Programming Languages (Third Edition, updated by R.G. Clark), Addison-Wesley, September 2000, ISBN 0-201-71012-9.

The material is intended to supplement the textbook by providing further examples and discussion. It is not self-standing, but assumes that you have a copy of the book to hand.

Section 11.2 Process synchronisation and communication

Monitors

An outline Java program to implement the producer/consumer problem is given and discussed on pages 268 to 272. An applet that executes this program can be run from here.
There have been minor addition to Producer and Consumer. The run method of Producer now produces a sequence of integer values as fast as it can while Consumer waits for 1 second before it takes each item. The consumer then displays what it has taken.
From the values ouput, we see that no items are lost and so the rate of production by Producer is controlled by how fast Buffer is able to accept the items. That, in turn, is controlled by the rate at which Consumer takes items from Buffer.

Section 11.3 Internet programming

Animating web pages

Page 279 lists a simple HTML file that includes a Java applet. The applet merely implements the "Hello World" program.
The HTML file is held here.

Using URLs

Page 280 describes how we can get the host and the filename from a URL object. The listing of a simple program that will take the string representing a URL and split it into host and filename is available here.

Common Gateway Interface

On page 281, there is a listing of how a form can be implemented within an HTML document. The idea is that you enter your name in the form and that a CGI program will then generate a new HTML document that will appear on your screen. The simple CGI program is written in Perl and is listed on page 282. It handles the data and creates the new page.
You can run the example from here.