CREATE [OR REPLACE] PROCEDURE procedure_name (<Argument> {IN, OUT, IN OUT}    <Datatype>,…)  
IS 
  Declaration section<variable, constant> ; 
BEGIN 
  Execution section 
EXCEPTION 
  Exception section  
END

CREATE [OR REPLACE] FUNCTION function_name [parameters]  
 RETURN return_datatype;  {IS, AS} 
 Declaration_section <variable,constant> ;
 BEGIN   
    Execution_section 
    Return return_variable;   
 EXCEPTION 
   exception section   
    Return return_variable;  
 END;

import javax.servlet.http.*;
import java.io.*;

public class ConstructorServlet extends HttpServlet
{
  String str1, str2, str3;
  public ConstructorServlet()
  {
    str1 = "Constructor";
  }
  public void init()
  {
    str2 = "init() method";
  }
  public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
  {
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();

    str3 = " service() method";

    out.println("<h3>"+ str1 + "<br>" + str2 + "<br>" + str3 + "</h3>"); 
    out.close();
  }
}