java server pages technology introduction, how it works and how to create. java bean technology

1. JAVA SERVER PAGES
by Tanmoy Barman
cont:-
barmantanmoy.47@gmail.com

2. DISCUSSIONS
 Introduction
 JSP vs. ASP
 JSP life cycles
 JSP errors
 JSP comments
 JSP elements; Directives, Scripting, Actions
 JSP implicit objects
 Example of writing JSP
 Java Bean

3. INTRODUCTION
 JSP is a technology based in java which produces dynamic web
pages.
 JSP is a server side scripting language technology created by
sun micro systems.
 JSP files are html files which contains special tags where java
code is embedded into it.
 JSP have .jsp extension.

4. JSP VS. ASP
 JSP is technology introduced by Sun micro systems where as
ASP is a technology introduced y Microsoft.
 JSP is abbreviation of JAVA SERVER PAGES and ASP is
abbreviation of ACTIVE SERVER PAGES
 ASP pages can connect to my sql & ms Access databases and
also can connect to other database with the help of ADO
whereas JSP can connect to any database loading the
appropriate driver when needed.

5. JSP VS. ASP
 ASP runs on Microsoft IIS server which run on Microsoft
operating system where as JSP can run on any Linux based
server, IBM JBOSS as well as in Microsoft platform.
 ASP is an interpreted language, JSP can interpreted as well as
compiled.
 JSP is free of cost including JSP server where as ASP is free
but running ASP on Microsoft IIS server cost money.

6. JSP LIFE CYCLES
 JSP are deployed in the web server as servlet.
 The JSP page is compiled to servlet by JSP engine, eliminating
the html tags and putting them inside out.println() statements
and removing the jsp tags.
 Once it is translated into servlet then the servlet, then it
follows the servlet lifecycles.

7. JSP LIFE CYCLES

8. JSP ERRORS
 Three types of error can be evolved in JSP:-
 Jsp error; which occurs when jsp is translated to servlet.
 Java code error; occurs when the servlet is complied to java class.
 HTML error; occurs during the presentation of html pages in the
browser.

9. JSP ERRORS
 The first two errors (jsp error and java code error) is detected
by the application server.
 The HTML error is detected by the web browser.

10. JSP COMMENTS
 Comments can be include in the jsp page, follows:-
 <%-- --%>
 </* */>
 <!-- --!>

11. JSP ELEMENTS
 The elements in jsp contains the tags, each having special
meanings, containing java codes which tells the jsp engine
what/how dynamic output has to processed.
 There are three types of elements:-
 Directives
 Scripting
 Action

12. DIRECTIVES
 Directives:- This tag is used to convey special information
about the page to the jsp engine.
 Syntax:-
 <%@ %>
 Three kinds of Directives are available:-
 page
 include
 tag library

13. DIRECTIVES
 page directive ; this directive informs the jsp engine about the
headers and facilities that the page should get from the
environment.
 There can be any number of page directives in a jsp page.
 Declared usually at the top.
 Syntax:-
 <%@page attribute= %>
 Attributes can be; include, import, session, etc.
 Example; <%@page import=“package_name”%>

14. DIRECTIVES
 Include directive ; this is used to statically include one or
more resources to the jsp page.
 This allows the jsp developer to reuse the code.
 Syntax:-
 <%@include page=“”%>
 There is only on attribute named „page‟ in include directive.

15. SCRIPTING ELEMENTS
 Scripting Elements; contains embedded java code.
 There are three types:-
 Declarations
 Expression
 Scriplets

16. SCRIPTING ELEMENTS
 Declarations; this tag allows the developer to declare one or
multiple variable and methods.
 They do not produce any output.
 Syntax:-
 <%! %>
 Example:- <%! public String name;
public int age;
public void setDetail(name,age); %>

17. SCRIPTING ELEMENTS
 Expression; this tag allows the developer to embed single java
expression which is not terminated by a semi colon.
 Syntax:-
 <%= %>
 Example:- <%= new java.util.Date() %>

18. SCRIPTING ELEMENTS
 Scriplets; this tag allows the developer to embedded java code
inside it that can use the variable declared earlier.
 Syntax:-
 <% %>
 Example:- <% int sum=a+b;
system.out.println(sum);
%>

19. ACTION ELEMENT
 Functions provided like:-
 Use of java bean technology in jsp page.
 Browser independent support for applet.
 Transfers control among pages.
 Syntax:-
 <jsp: />

20. ACTION ELEMENT
 Standard action tag are:-
 useBean
 setProperty
 getProperty
 param
 include
 forward
 plugin

21. JSP IMPLICIT OBJECTS
 There are certain objects in jsp that can be used in jsp page without being
declared these are Implicit objects. There are nine implicit object in JSP:-
 application
 page
 pageContext
 config
 session
 exception
 request
 response
 out

22. EXAMPLE OF JSP
 A simple jsp program to show date using scriplets;” teddyTest.jsp”
<html>
<head>
</head>
<body>
<h1>JSP Page to show today Date </h1>
<% out.println(new java.util.Date()); %>
</body>
</html>

23. EXAMPLE OF JSP
 Now we will use the implicit object to get values from a html page.
 This is a html page to take user inputs “Impli.html”
<html>
<body>
<form ACTION=“ImpliShow.jsp”>
Name=<input type=“text” name=“nm”>
<input type=“submit”>
</form>
</body>
</html>

24. EXAMPLE OF JSP
 ImpliShow.jsp
<html>
<body>
<%
String nm=request.getParameter("usr");
String ag=request.getParameter("age");
out.println (“name:”+nm+””+age:”+ag);
%>
</body>
</html>

25. JAVA BEAN
 Java bean is a self contained class file in java which typically
contains;
 No argument constructor.
 Is seriliziable.
 Have getter and setter methods to get and set values of the
properties.
 According to java white papers java beans are reusable
component in java, and they combine various objects into a
single one which can be accessed by multiple user.

26. JAVA BEAN
 Jsp use three action tag for use of java bean technology:-
 useBean=used to locate or instantiate a bean class.
 setProperty=set the property value or values of a bean class.
 getProperty=get the property values of a bean class, first the
property values are converted into string and then added to the
request stream.

27. JAVA BEAN
 <jsp:useBean id= "instanceName" scope= "page | request |
session | application"
class= "packageName.className"
type= "packageName.className“
beanName=“ packgeName.className | <%= expression >" >
</jsp:useBean>

28. JAVA BEAN
 Example of useBean action tag in jsp:-
 Class student{
private String name;
Private int age;
public void setName(string n){
name=n;}
publci void setAge(int a){
age=n;}
}

29. JAVA BEAN
 A html page named bean.html
<html>
<body>
<form ACTION=“teddyBean.jsp”>
Name=<input type=“text” name=“nm”>
<input type=“submit”>
</form>
</body>
</html>

30. JAVA BEAN
 A jsp page named teddyBean.jsp
<html>
<body>
<jsp:useBean id=“obj” class=“student”>
<%
Sting n=request.getParameter(“name”);
obj.setName(n);
system.out.println(obj.getName());
%>
</body>
</html>

31. JAVA BEAN
 <jsp:setProperty name="instanceOfBean" property= "*" |
property="propertyName" param="parameterName" |
property="propertyName" value="{ string | <%= expression
%>}" />
 <jsp:getProperty name="instanceOfBean"
property="propertyName" />

32. JAVA BEAN
 <jsp:setProperty name=“obj" property="name" value="*" />
 To set all the values of the property.
 <jsp:setProperty name=“obj” property=“_property”
value=“_value” />
 To set a particular property with a value.

33. JAVA BEAN
 Example of setProperty and getProperty action tag:-
Package teddyPack
public class jB {
private String name;
private int age;
public void setAge(int age){this.age=age;}
public void setName(String name){this.name=name;}
public String getName(){return name;}
public int getAge(){ return age;}
}

34. JAVA BEAN
 A html page named “setGET.html”
<html>
<body>
<form ACTION=“setGet.jsp”>
Name:<input type=“text” name=“name”>
Age:<input type=“text” name=“age”>
<input type=“submit”>
</form>
</body></html>

35. JAVA BEAN
 A jsp page named “setGet.jsp”
<html>
<body>
<jsp:useBean id="ted" class="teddyPack.jB" />
<% String n=request.getParameter("name");%>
<jsp:setProperty name="ted" property="name" value="*" />
<b>HELLO</b><jsp:getProperty name="ted" property="name"/>; aged
<jsp:getProperty name=“ted” property=“age”/>
</body>
</html>

36. THANK YOU