The following syntax allows you to declare variables and methods for the page. These are placed in the generated servlet outside the _jspService() method; in other words, variables declared here will be instance variables of the servlet. Declarations don't produce any output.
This is an example of declaring a variable:
<%! String message; %>
The following code declares a variable and initializes it:
<%! String message = "variable declarared"; %>
You can define a method for use on the global page like so:
<%! public String showMessage() { return message; } %>
Declaration tags are mainly used in conjunction with scriptlets.