Receiving Parameters in the Applet

You have to do something in your Java program to retrieve the parameters on the web page or they will be ignored. The getParameter() method of the JApplet class retrieves a parameter from a param tag on a web page. The parameter name, which is specified with the name attribute on the page, is used as an argument to getParameter(). The following is an example of getParameter() in action:

String display1 = getParameter("headline1");

The getParameter() method returns all parameters as strings, so you have to convert them to other types as needed. If you want to use a parameter as an integer, you could use statements such as the following:

int speed;
String speedParam = getParameter("speed");
if (speedParam != null) {
 speed = Integer.parseInt(speedParam);

This example sets the speed variable by using the speedParam string. You have to test for null strings before setting speed because the parseInt() method cannot work with a null string. When you try to retrieve a parameter with getParameter() that was not included on a web page with the param tag, it will be sent as null, which is the value of an empty string.