What difference between <%%> and <%!%>

Question

I try to find that in JSP people use several different tags like <% %> and<%! %> when add Java code to page, but can anyone tell me what is the main difference between this two tags.

Thanks.

Answer 1

So, there are a number of different jsp scripting elements, each with different usages. These are:

• <% %>: Scriptlets
  • Evaluates a Java expression. Does not display any result in the HTML produced. Variables declared have only local scope, so cannot be accessed from elsewhere in the .jsp
• <%! %> : Declarations
  • Allows the declaration of methods or variables, which can then be accessed elsewhere in the .jsp
• <%@ %>: Directives
  • Specifies page-dependent attributes, such as the scripting language used, or "include" statements
• <%= %>: Expressions
  • Evaluates a Java expression. Inserts the result (as a string) into the HTML in the .jsp
• <%-- --%>: Comments
  • JSP comment tags. These will not show up in the page source, unlike HTML comments

For full documentation, see: http://docs.oracle.com/cd/B14099_19/web.1012/b14014/genlovw.htm

Answer 2

<!% %> Tag is declare java method(function) in JSP page

<% %> Tag is write Statement in JSP page

JSP look like a java class

over!