Java Server Pages

subduedjourneyΛογισμικό & κατασκευή λογ/κού

28 Οκτ 2013 (πριν από 3 χρόνια και 8 μήνες)

52 εμφανίσεις

Java server pages is a technology for developing portable java web
applications that runs on a java web server.

Main motivation behind developing JSP was to develop a technology so
that a non
-
java programmer or a person with little knowledge of java
could write web applications for java plaform.

Initially JSP was developed to replace servlet but now common practice
is to use servlet and jsp together using MVC(model
-
view
-
controller)
pattern.

JSP allows developer to write html (static content),jsp action tags and
java (dynamic content) code in the same page.

JSPs are compiled into java servlets by a jsp compiler, thus internally jsp
page is converted into servlet, it is must to understand java servlet
technology throughly for becoming a good jsp programmer.

Java Server Pages


JSP enables you to separate the dynamic content of a web page from its
presentation. It caters to different types of developes.

Web designers, who are responsible for the graphical design of the page

Java developers, who write the code to generate dynamic content.



Java Server Pages

JSP life cycle includes following steps/phases:


JSP page translation


generate servlet source code


The translation occurs only when jsp page has to serve its first request.
Translation does not have to happen again unless the page is updated.

JSP page compilation


compile generated code into byte code

Load class

Create instance

Call the jspInit method

Call the _jspService method
-

for each request

Call the jspDestroy method

JSP Life Cycle

User don’t need to register jsp pages in deployment descriptor file web.xml. Just
place them in the accessible area of a web application directory structure and
user can access them.

How ever you can register a jsp page same way as a servlet. You even use the
<servlet> element with one vital difference


where the <servlet
-
class> would
apper,you substitute <jsp
-
file> instead.

<servlet>


<servlet
-
name>JspName1<servlet
-
name>


<jsp
-
file>/instanceCheck.jsp</jsp
-
file>

</servlet>

<servlet
-
mapping>


<servlet
-
name>JspName1</servlet
-
name>


<url
-
pattern>/jspName2</url
-
pattern>

</servlet
-
mapping>

Deploying JSP

Now you can access jsp page in following two ways

http://localhost:8080/myapp/instanceCheck.jsp

OR

http://localhost:8080/myapp/jspName2

if you want to supress direct access to jsp , locate jsp page under

WEB
-
INF directory.


Deploying JSP

Translated JSP Servlet implements javax.serlvet.jsp.HttpJspPage
interface, which is a sub interface of javax.servlet.jsp.JspPage.

The javax.servlet.jsp.JspPage interface contains two methods:

1. public void jspInit()
-

This method is invoked when the JSP is
initialized and the page authors are free to provide initialization of the
JSP by implementing this method in their JSPs.

2. public void jspDestroy()
-

This method is invoked when the JSP is
about to be destroyed by the container. Similar to above, page authors
can provide their own implementation.

The javax.servlet.jsp.HttpJspPage interface contains one method:

public void _jspService(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException

This method generated by the JSP container is invoked, every time a
request comes to the JSP. The request is processed and the JSP generates
appropriate response. This response is taken by the container and passed
back to the client.

JSP API

JSP Elements


Directives


Scripting Elements


JSP Actions


Templates



Java Server Pages

There are four types of scripting elements defined

Declaration

Expression

Scriptlets

Comments


JSP Scripting Elements

Declares a variable or method valid in the scripting language used in the JSP
page.

JSP Syntax



<%! declaration; [ declaration; ]+ ... %>

XML Syntax



<jsp:declaration>






code fragment

[ declaration; ]+ ...



</jsp:declaration>

Examples



<%! int i = 0; %>



<%! int a, b, c; %>



<%! Circle a = new Circle(2.0); %>

Declaration

A declaration declares one or more variables or methods that you can use
in Java code later in the JSP page. You must declare the variable or
method
before

you use it in the JSP page.

You can declare any number of variables or methods within one
declaration element, as long as you end each declaration with a
semicolon. The declaration must be valid in the Java programming
language.

You can use declaration to write anything that would be placed in the
generated servlet outside of the _jspService method.

You can place in your declaration any code that can appear in a servlet
soure file; instance methods, static methods, inner classes . You can also
use declarations to override some methods that appear further up in the
jsp servlet hierarchy


namely jspInit and jspDestroy.

Declaration

Contains an expression valid in the scripting language used in the JSP page.

JSP Syntax

<%=
expression

%>

XML Syntax

<jsp:expression>

expression

</jsp:expression>

Description

An expression element contains a scripting language expression that is
evaluated, converted to a String, and inserted into the response where the
expression appears in the JSP page. Because the value of an expression is
converted to a String, you can use an expression within a line of text,
whether or not it is tagged with HTML, in a JSP page.

Example

Welcome, <%=userName%>

Output:

Welcome, James

Expression

<%= new java.util.Date()%>

When this is generated into servlet code, the resulting java stmt will
probably look like this:

out.print(new java.util.Date());

Out is an instance of javax.servlet.http.jsp.JspWriter and it is associated
with the response for the generated servlet.

Cotents of your jsp expression are used directly as the parameter to the
print() method.so it must not end with semicolon.



Expression

Contains a code fragment valid in the page scripting language.

Scriptlets allows you to include a series of java statements inside the
_jspService method that are executed on every request to the page.these
java stmts are incorporated into _jspService method as it is.so you must
terminate them with semicolon.

JSP Syntax

<%
code fragment

%>


OR

<jsp:scriptlet>

code fragment

</jsp:scriptlet>


Script lets

Examples

<%

String name = null;




if (request.getParameter("name") == null) { %>




<%@ include file="error.html" %>

<%

}



else {



userObject.setName(request.getParameter("name"));



}

%>

Scriptlets

To denote any lines you want to be completely ignored by the JSP
translation process.

Example

<%
--

Author: James Gosling
--
%>


Comments

Directives are instructions to jsp compiler. Those intructions
tell the compiler that some action needs to be taken.

General syntax for directives is:

<%@ Directive
-
name attribute
-
value pairs %>

There are three main directives defined in jsp

Page

Include

Taglib

JSP Directives

Page Directive
-

Defines attributes that apply to an entire JSP page.

JSP Syntax


<%@ page

language="
java
" import="{
package.class

|
package.*
},
..."

,





session="
true
|false"

%>




OR


<jsp:directive.page pageDirectiveAttrList />


where
pageDirectiveAttrList

is the same as the list in the JSP syntax.

XML Syntax


<jsp:directive.page pageDirectiveAttrList /> where
pageDirectiveAttrList

is the same as the list in the JSP syntax.


Examples


<%@ page import="java.util.*, java.lang.*" %>



<%@ page buffer="5kb" autoFlush="false" %>


<jsp:directive.page errorPage="error.jsp" />

Page Directive

Description

The page directive applies to an entire JSP page and any of its
static
include files
, which together are called a
translation unit
. A static include file
is a file whose content becomes part of the calling JSP page. The page
directive does not apply to any dynamic resources; see
<jsp:include>

for
more information.

You can use the page directive more than once in a translation unit, but
you can only use each attribute, except import, once. Because the import
attribute is similar to the import statement in the Java programming
language, you can use a page directive with import more than once in a
JSP page or translation unit.

No matter where you position the page directive in a JSP page or
included files, it applies to the entire translation unit. However, it is often
good programming style to place it at the top of the JSP page.

Page Directive

Attributes

language="
java
"


The scripting language used in scriptlets, declarations, and
expressions in the JSP page and any included files. In v2.0, the only
allowed value is java.

extends="
package.class
"


The fully qualified name of the superclass of the Java class this JSP
page will be compiled to. Use this attribute cautiously, as it can limit
the JSP container's ability to provide a specialized superclass that
improves the quality of the compiled class.

Page Directive

import="{
package.class

|
package.*
}, ..."


A comma
-
separated list of Java packages that the JSP page should
import. The packages (and their classes) are available to scriptlets,
expressions, and declarations within the JSP page. If you want to
import more than one package, you can specify a comma
-
separated
list after import or you can use import more than once in a JSP page.


The following packages are implicitly imported, so you don't need to
specify them with the import attribute:


java.lang.*


javax.servlet.*


javax.servlet.jsp.*


javax.servlet.http.*


You must place the import attribute before the element that calls the
imported class.


Page Directive

isThreadSafe="
true
|false"


Whether thread safety is implemented in the JSP page. The default
value is true, which means that the JSP container can send multiple,
concurrent client requests to the JSP page. You must write code in the
JSP page to synchronize the multiple client threads. If you use false,
the JSP container sends client requests one at a time to the JSP page.

info="
text
"


A text string that is incorporated verbatim into the compiled JSP
page. You can later retrieve the string with the Servlet.getServletInfo()
method.

errorPage="
relativeURL
"


A pathname to a JSP page that this JSP page sends exceptions to. If
the pathname begins with a /, the path is relative to the JSP
application's document root directory and is resolved by the web
server. If not, the pathname is relative to the current JSP page.

Page Directive

isErrorPage="true|
false
"


Whether the JSP page displays an error page. If set to true, you can use the
exception object in the JSP page. If set to false (the default value), you cannot
use the exception object in the JSP page.


contentType="
mimeType

[; charset=
characterSet

]" |



"
text/html;charset=ISO
-
8859
-
1
"


The MIME type and character encoding the JSP page uses for the response.
You can use any MIME type or character set that are valid for the JSP
container. The default MIME type is text/html, and the default character set is
ISO
-
8859
-
1.


pageEncoding="
characterSet

|
ISO
-
8859
-
1
"


The character encoding the JSP page uses for the response. The default
character set is ISO
-
8859
-
1.


Page Directive

Includes a static file in a JSP page, parsing the file's JSP elements.

JSP Syntax


<%@ include file="
relati veURL
" %> OR


<jsp:direct ive.include file="
relati veURL
" />

XML Syntax

<jsp:direct ive.include file="
relati veURL
" />

Examples

include.jsp:

<html>

<head>

<title>An Include Test</title>

</head>


<body bgcolor="white">


<font color="blue">

The current date and time are <%@ include file="date.jsp" %>

</font> </body> </html>



Include Directive

date.jsp


<%@ page import="java.util.*" %>

<%= (new java.util.Date() ).toLocaleString() %>

Displays in the page: The current date and time are Aug 30, 1999
2:38:40

Description

An include directive inserts a file of text or code in a JSP page at
translation time, when the JSP page is compiled. When you use the
include directive, the include process is
static
. A static include means
that the text of the included file is added to the JSP page. The
included file can be a JSP page, HTML file, XML document, or text
file. If the included file is a JSP page, its JSP elements are translated
and included (along with any other text) in the JSP page. Once the
included file is translated and included, the translation process
resumes with the next line of the including JSP page.

Include Directive

Attributes

file="
relativeURL
"


The pathname to the included file, which is always a relative URL. A
relative URL is just the path segment of an URL, without a protocol,
port, or domain name, like this:


"error.jsp" "/templates/onlinestore.html" "/beans/calendar.jsp"


If the relative URL starts with /, the path is relative to the JSP
application's context, which is a javax.servlet.ServletContext object
that is in turn stored in the application object. If the relative URL starts
with a directory or file name, the path is relative to the JSP page.



Include Directive

Defines a tag library and prefix for the custom tags used in the JSP
page.

JSP Syntax

<%@ taglib {uri="
URI
" | tagdir="/WEB
-
INF/tags[/
subdir
]+"}
prefix="
tagPrefix
" %>

Examples

<%@ taglib uri="http://www.jspcentral.com/tags" prefix="public" %>


<public:loop>

... </public:loop>

Description

The taglib directive declares that the JSP page uses custom tags, names
the tag library that defines them, and specifies their tag prefix.

You must use a taglib directive
before

you use the custom tag in a JSP
page. You can use more than one taglib directive in a JSP page, but the
prefix defined in each must be unique.

taglib directive


Attributes

uri
="
URI
"
-


The Uniform Resource Identifier (URI) that uniquely locates the TLD
that describes the set of custom tags associated with the named tag
prefix.

Prefix
=‘tagprefix’

The prefix that precedes the custom tag name, for example, public in
<public:loop>. Empty prefixes are illegal.


If you are developing or using custom tags, you cannot use the tag
prefixes jsp, jspx, java, javax, servlet, sun, and sunw, as they are reserved
by Sun Microsystems.

taglib Directive

Servlet container provides many built in functionality to ease the
development of the applications


Programmers

can use these functions in JSP applications. The JSP
Actions tags enables the programmer to use these functions. The JSP
Actions are XML tags that can be used in the JSP page.

Here is the list of JSP Actions:

jsp:include


The
jsp:include

action work as a subroutine, the Java servlet temporarily
passes the request and response to the specified JSP/Servlet. Control is
then returned back to the current JSP page.



jsp:param


The
jsp:param

action is used to add the specific parameter to current
request. The jsp:param tag can be used inside a jsp:include, jsp:forward
or jsp:params block.



jsp:forward


The
jsp:forward

tag is used to hand off the request and response to
another JSP or servlet. In this case the request never return to the calling
JSP page.




JSP ACTIONS

jsp:getProperty


The
jsp:getPropertyB
is used to get specified property from the
JavaBean object.




jsp:setProperty


The
jsp:setProperty

tag is used to set a property in the JavaBean
object.




jsp:useBean


The
jsp:useBean


tag is used to instantiate an object of Java Bean or
it can re
-
use existing java bean object.

JSP ACTIONS

<%@page contentType="text/html" import="java.util.*" %>


<html>

<body>

<p>&nbsp;</p><div align="center"><center>

<table border="0" cellpadding="0" cellspacing="0" width="460"
bgcolor="#EEFFCA">

<tr>

<td width="100%"><font size="6" color

="#008000">&nbsp;Date Example</font></td>

</tr>

<tr><td width="100%"><b>&nbsp;Current Date and time is:&nbsp;

<font color="#FF0000">

<%= new java.util.Date() %>

</font></b></td></tr></table></center></div></body></html>

Simple JSP Example

<html>

<head>

<title>Enter your name</title>

</head>

<body>

<p>&nbsp;</p>

<form method="POST" action="showname.jsp">


<p><font color="#800000" size="5">Enter your name:</font><input
type

="text" name="username" size="20"></p>


<p><input type="submit" value="Submit" name="B1"></p>

</form>

</body>

</html>

<%@page contentType="text/html" %>


<!
--

http://www.roseindia.net/jsp

--
>

<html>

<body>

<p><font size="6">Welcome :&nbsp;
<%=request.getParameter("username")%></font></p>

</body>

</html>

Forwards a request to a web resource.

JSP Syntax

<jsp:forward page="{
relativeURL

| <%=
expression

%>}" />




or


<jsp:forward page="{
relativeURL
| <%=
expression

%>}" >


<jsp:param name="
parameterName
"

value="{
parameterValue

| <%=
expression

%>}" />


</jsp:forward>

Examples

<jsp:forward page="/servlet/login" />

<jsp:forward page="/servlet/login">




<jsp:param name="username" value="jsmith" />


</jsp:forward>


jsp:forward

The <jsp:forward> element forwards the request object containing the client
request information from one JSP page to another resource. The target
resource can be an HTML file, another JSP page, or a servlet, as long as it is
in the same application context as the forwarding JSP page. The lines in the
source JSP page after the <jsp:forward> element are not processed.

You can pass parameter names and values to the target resource by using a
<jsp:param> clause. An example of this would be passing the parameter
name username (with name="username") and the value scott (with
value="scott") to a servlet as part of the request. If you use <jsp:param>, the
target resource should be a dynamic resource that can handle the
parameters.

Attributes

page="{
relativeURL

| <%=
expression

%>}"


A String or an expression representing the relative URL of the component to
which you are forwarding the request. The component can be another JSP
page, a servlet, or any other object that can respond to a request.


The relative URL looks like a path
--
it cannot contain a protocol name, port
number, or domain name. The URL can be absolute or relative to the current
JSP page. If it is absolute (beginning with a /), the path is resolved by your web
or application server.


jsp:forward

Includes a static file or the result from another web component.

JSP Syntax

<jsp:include page="{
relativeURL

| <%=

expression

%>}"

flush="true|
false" />




or


<jsp:include page="{
relativeURL

| <%=
expression

%>}"

flush="true|
false" >




<jsp:param
name="
parameterName
"

value="{
parameterValue

| <%=
expression

%>}" />


</jsp:include>

jsp:include

The <jsp:include> element allows you to include either a
static
or
dynamic

resource

in a JSP page. The results of including static and
dynamic resources are quite different. If the resource is static, its
content is included in the calling JSP page. If the resource is dynamic,
it acts on a request and sends back a result that is included in the JSP
page. When the include action is finished, the JSP container
continues processing the remainder of the JSP page.

You cannot always determine from a pathname if a resource is static
or dynamic. For example,
http://server:8080/index.html

might map to
a servlet through a server alias. The <jsp:include> element handles
both types of resources, so it is convenient to use when you don't
know whether the resource is static or dynamic.

If the included resource is dynamic, you can use a <jsp:param> clause
to pass the name and value of a parameter to the resource. As an
example, you could pass the string username and a user's name to a
login form that is coded in a JSP page.


jsp:include

Locates or instantiates a bean with a specific name and scope.

JSP Syntax

<jsp:useBean
id="
beanInstanceName
"

scope="
page
|request|session|application"



{




class="
package.class
" [ type="
package.class
“ ]|





beanName="{
package.class

| <%=
expression

%>}“





type="
package.class
" |





}



{ /> | >
other elements

</jsp:useBean> }

jsp:useBean

Examples

<jsp:useBean id="cart" scope="session" class="session.Carts" />

<jsp:setProperty name="cart" property="*" />



<jsp:useBean id="checking" scope="session" class="bank.Checking"
>



<jsp:setProperty name="checking" property="balance" value="0.0"
/>

</jsp:useBean>

jsp:useBean

The <
jsp:useBean
> element locates or instantiates a JavaBeans
component. <
jsp:useBean
> first attempts to locate an instance
of the bean. If the bean does not exist, <
jsp:useBean
>
instantiates it from a class or serialized template.

To locate or instantiate the bean, <
jsp:useBean
> takes the following
steps, in this order:

Attempts to locate a bean with the scope and name you specify.

Defines an object reference variable with the name you specify.

If it finds the bean, stores a reference to it in the variable. If you
specified type, gives the bean that type.

If it does not find the bean, instantiates it from the class you specify,
storing a reference to it in the new variable.

If <
jsp:useBean
> has
instantiated

(rather than located) the bean, and
if it has body tags or elements (between <
jsp:useBean
> and
</
jsp:useBean
>), executes the body tags.


jsp:useBean

The body of a <jsp:useBean> element often contains a
<jsp:setProperty> element that sets property values in the bean. As
described in
Step

5
, the body tags are only processed if
<jsp:useBean> instantiates the bean. If the bean already exists and
<jsp:useBean> locates it, the body tags have no effect.

id="
beanInstanceName
"


A variable that identifies the bean in the scope you specify. You can
use the variable name in expressions or scriptlets in the JSP page.


The name is case sensitive and must conform to the naming
conventions of the scripting language used in the JSP page. If you use
the Java programming language, the conventions in the
Java
Language Specification
. If the bean has already been created by
another <jsp:useBean> element, the value of id must match the value
of id used in the original <jsp:useBean> element.


jsp:useBean

scope="
page
|request|session|application"


The scope in which the bean exists and the variable named in id is available.
The default value is page. The meanings of the different scopes are shown
below:


page

You can use the bean within the JSP page with the <jsp:useBean>
element or any of the page's static include files, until the page sends a
response back to the client or forwards a request to another resource.


request

You can use the bean from any JSP page processing the same
request, until a JSP page sends a response to the client or forwards the
request to another resource. You can use the request object to access the
bean, for example, request.getAttribute(
beanInstanceName
).


session

You can use the bean from any JSP page in the same session as the
JSP page that created the bean. The bean exists across the entire session, and
any page that participates in the session can use it. The page in which you
create the bean must have a page directive with session="true".


application

You can use the bean from any JSP page in the same application
as the JSP page that created the bean. The bean exists across an entire JSP
application, and any page in the application can use the bean.


jsp:useBean

class="
package.class
"


Instantiates a bean from a class, using the new keyword and the class
constructor. The class must not be abstract and must have a public,
no
-
argument constructor. The package and class name are case
sensitive.


type="
package.class
"


If the bean already exists in the scope, gives the bean a data type
other than the class from which it was instantiated. The value of type
must be a superclass of class or an interface implemented by class.


If you use type without class or beanName, no bean is instantiated.
The package and class name are case sensitive.


jsp:useBean

class="
package.class
" type="
package.class
"


Instantiates a bean from the class named in class and assigns the bean
the data type you specify in type. The value of type can be the same as
class, a superclass of class, or an interface implemented by class.


The class you specify in class must not be abstract and must have a
public, no
-
argument constructor. The package and class names you
use with both class and type are case sensitive.

jsp:useBean

Sets a property value or values in a bean.

JSP Syntax

<jsp:setProperty name="
beanInstanceName
"

{

property="*" |

property="
propertyName
" [
param="
parameterName
" ] |

property="
propertyName
"
value="{
stringLiteral
| <%=
expression
%>}" }


/>

Examples

<jsp:setProperty name="mybean" property="*" />

<jsp:setProperty name="mybean" property="username" />

<jsp:setProperty name="mybean" property="username"
value="Steve" />

jsp:setProperty

Description

The <
jsp:setProperty
> element sets the value of one or more properties
in a bean, using the bean's setter methods. You must declare the bean
with
<
jsp:useBean
>

before

you set a property value with
<jsp:setProperty>. Because <
jsp:useBean
> and <jsp:setProperty> work
together, the bean instance names they use must match (that is, the
value of name in <
jsp:setProperty
> and the value of id in <jsp:useBean>
must be the same).

You can use <
jsp:setProperty
> to set property values in several ways:

By passing all of the values the user enters (stored as parameters in the
request object) to matching properties in the bean

By passing a specific value the user enters to a specific property in the
bean

By setting a bean property to a value you specify as either a String or an
expression that is evaluated at runtime

Each method of setting property values has its own syntax, as described
in the next section.

jsp:setProperty

Attributes and Usage

name="
beanInstanceName
"


The name of an instance of a bean that has already been created or
located with a <jsp:useBean> element. The value of name must match
the value of id in <jsp:useBean>. The <jsp:useBean> element must
appear before <jsp:setProperty> in the JSP page.


property="*"


Stores all of the values of request parameters in bean properties. The
names of the bean properties must match the names of the request
parameters. A bean property is usually defined by a variable
declaration with matching getter and setter methods

jsp:setProperty

property="
propertyName
" [ param="
parameterName
" ]


Sets one bean property to the value of one request parameter. In the syntax,
property specifies the name of the bean property and param specifies the
name of the request parameter by which data is being sent from the client to
the server.


If the bean property and the request parameter have different names, you
must specify both property and param. If they have the same name, you can
specify property and omit param.


If a parameter has an empty or null value, the corresponding bean property is
not set.

property="
propertyName
" value="{
string

| <%=
expression

%>}"


Sets one bean property to a specific value. The value can be a String or an
expression that is evaluated at runtime. If the value is a String, it is converted
to the bean property's data type according to the conversion rules shown
above in
TABLE 1
. If it is an expression, its value must have a data type that
matches the the data type of the value of the expression must match the data
type of the bean property.


jsp:setProperty

Inserts the value of a bean property into the result.

JSP Syntax

<
jsp:getProperty

name="
beanInstanceName
"
property="
propertyName
" />

XML Syntax

<
jsp:getProperty

name="
beanInstanceName
"
property="
propertyName
" />

Examples

<jsp:useBean id="calendar" scope="page"
class="employee.Calendar" /> <h2> Calendar of

<jsp:getProperty name="calendar" property="username" /> </h2>

jsp:getProperty

The <
jsp:getProperty
> element gets a bean property value using the
property's getter methods and inserts the value into the response.
You must create or locate a bean with
<
jsp:useBean
>

before

you use
<jsp:getProperty>.

jsp:getProperty

<
html
><
body
>

<
form

method=‘post’ action=‘usebeanexample.jsp’>

Name:<
input

type=‘text’ name=‘name’/><br>

Branch:<
input

type=‘text’ name=‘address’/><br>

RollNo:<
input

type=‘text’ name=‘rollNo’/><br>

Date of Birth:<
input

type=‘text’ name=‘dob’/><br>

<
input

type=‘submit’/><input type=‘reset’/>

</
form
>

</
body
></
html
>

jsp:useBean Example

public

class

Student{



String name,address,rollNo,dob;



public

Student(){}



String getName(){
return

name;}



String setName(String name){this.name=name;}



String geAddress(){
return

address;}



String setAddress(String
address){this.address=address;}



String getRollNo(){
return

rollNo;}



String setRollNo(String rollNo){this.rollNo=rollNo;}



String getDOB(){
return

dob;}



String setDOB(String dob){this.dob=dob;}




}

jsp:useBean Example

Usebeanexample.jsp

<%@page

language=‘java’ %>

<
jsp:useBean

id=‘stuobj’ class=“Student” scope=‘request’>



<
jsp:setProperty

name=‘stuobj’ property=‘name’/>



<
jsp:setProperty

name=‘stuobj’ property=‘address’/>



<
jsp:setProperty

name=‘stuobj’ property=‘rollNo’
param=‘rollNo’/>



<
jsp:setProperty

name=‘stuobj’ property=‘DOB’
param=‘dob’/>

</jsp:useBean>

<%

out.print(“student name is”+stuobj.getName());

%>





jsp:usebean Example

Object Name


Type

request



HttpServletRequest

response



HttpServletResponse


application


ServletContext


Session



HttpSession

page



Object

config



ServletConfig

pageContext


PageContext

Out



JspWriter

Exception


Throwable






JSP Implicit Objects

JSP session object