If you're displaying static text on the page, just use the formatKey attribute of the <bean:write> tag. This specifies the name of an entry in your ApplicationResources.properties file that contains a mask for how you want to display the value. Here's an example:
ApplicationResources.properties
zerosuppress=###.##
JSP <bean:write name="myForm" property="myDouble" formatKey="zerosupress" />
If this is being displayed in an <html:text> box, It is strongly recommend that you not use data types other than
string for text input. This is mainly because it makes validation messy.
What you would need to do in this case is create a separate getter (e.g. getFormattedAmount) on your ActionForm that displays the double value as a String formatted the way you want. You also need to create a setter (e.g. setFormattedAmount) that accepts a String as input and converts it to a Double.