You can customize your applets by providing parameters at runtime in . But it is a good practice to always provide default values, when specific values for parameters are not provided.
You can do this by checking for null values and/or proper type checking (if you expect numeric or date values). Here is the code:
public class MyApplet extend Applet { public void init(){ // Get the Parameter String frameTitle = getParameter("FRAME_TITLE"); // Check for Null if (frameTitle == null) { // Provide Default value frameTitle = "Frame to Test Parameters"; } String frameWidthString = getParameter("FRAME_WIDTH"); int frameWidthInt = 0; try{ frameWidthInt = Integer.parseInt(frameWidthString); } catch(Exception ex){ // Catch Exception if frameWidthString is null or invalid value // Default value frameWidthInt = 100; } String frameHeightString = getParameter("FRAME_WIDTH"); int frameHeightInt = 0; try{ frameHeightInt = Integer.parseInt( frameHeightString ); } catch(Exception ex){ // Provide Default Value frameHeightString = 100; } Frame f = new Frame(frameTitle); f.setSize(frameWidthInt,frameHeightString); f.show(); }}