INTRODUCTION TO JSP SCRIPTLETS

  <%
  //java codes
   %>

JSP Scriptlets begins with <% and ends %> .We can embed any amount of java code in the JSP Scriptlets. JSP Engine places these code in the _jspService() method. Variables available to the JSP Scriptlets are:

• request:
  request represents the clients request and is a subclass of HttpServletRequest. Use this variable to retrieve the data submitted along the request.
  Example:
    <%
    //java codes
     String userName=null;
     userName=request.getParameter("userName");
     %>
  
• response:
  response is subclass of HttpServletResponse.
   
• session:
  session represents the HTTP session object associated with the request.
   
• out:
  out is an object of output stream and is used to send any output to the client.

INTRODUCTION TO JSP EXPRESSIONS

Syntax of JSP Expressions are:

  <%="Any thing"   %>

JSP Expressions start with 

Syntax of JSP Scriptles are with <%= and ends with  %>. Between these this you can put anything and that will converted to the String and that will be displayed.

Example:
  <%="Hello World!" %>
Above code will display 'Hello World!'.