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Applets use theApplet getParametermethod to get user-specified values for applet parameters. ThegetParametermethod is defined as follows:public String getParameter(String name)Your applet might need to convert the string that
getParameterreturns into another form, such as an integer. Thejava.langpackage provides classes such as Integer that you can use to help with converting strings to primitive types. Here's an example from theAppletButtonclass of converting a parameter's value into an integer:Note that if the user doesn't specify a value for theint requestedWidth = 0; . . . String windowWidthString = getParameter("WINDOWWIDTH"); if (windowWidthString != null) { try { requestedWidth = Integer.parseInt(windowWidthString); } catch (NumberFormatException e) { //Use default width. } }WINDOWWIDTHparameter, the above code uses a default value of 0, which the applet interprets as "use the window's natural size." It's important that you supply default values wherever possible.Besides using the
getParametermethod to get values of applet-specific parameters, you can also usegetParameterto get the values of attributes of the applet's<APPLET>tag. See The <APPLET> Tag for a list of<APPLET>tag attributes.
AppletButtonBelow is theAppletButtoncode that gets the applet's parameters. For more information onAppletButton, see the previous page.String windowClass; String buttonText; String windowTitle; int requestedWidth = 0; int requestedHeight = 0; . . . public void init() { windowClass = getParameter("WINDOWCLASS"); if (windowClass == null) { windowClass = "TestWindow"; } buttonText = getParameter("BUTTONTEXT"); if (buttonText == null) { buttonText = "Click here to bring up a " + windowClass; } windowTitle = getParameter("WINDOWTITLE"); if (windowTitle == null) { windowTitle = windowClass; } String windowWidthString = getParameter("WINDOWWIDTH"); if (windowWidthString != null) { try { requestedWidth = Integer.parseInt(windowWidthString); } catch (NumberFormatException e) { //Use default width. } } String windowHeightString = getParameter("WINDOWHEIGHT"); if (windowHeightString != null) { try { requestedHeight = Integer.parseInt(windowHeightString); } catch (NumberFormatException e) { //Use default height. } }
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