Page 49 - The Definitive Guide to Building Java Robots

Preston_5564C02.fm Page 30 Wednesday, September 14, 2005 5:42 AM

30 CHAPTER 2 ■ SERIAL COMMUNICATION

■Note More about the setup of Tomcat can be found in Chapter 8: Advanced Topics.

Setup

The following setup represents my PC with my Java IDE (Eclipse). I have a wireless connection
to the Tomcat Servlet Engine running on my robot’s computer. (See Figure 2-4.)

Figure 2-4. Wireless WebSerialPort setup

Code Objective

The code objective is to extend the serial port so I can connect to it over my home’s wireless
connection using HTTP.

Code Discussion
The following example will be utilized in a Java Server Page residing on the web server.
The string, CMD_ACK, will be the acknowledge string returned from the webcom.jsp if
everything goes as planned and there are no errors.
The string, COMM_JSP, is the name of the JSP that will take the input and output request
from the client.
The READ_ONLY and DEFAULT_TIMEOUT variables are used to best calculate whether
the client should wait for the web server to respond with output from the serial port or make a
separate request for the output.