Download What is JSP

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

page
1
page
2
page
3
page
4
page
5
page
6
page
7
page
8
page
9
page
10
page
11
page
12
page
13
page
14
page
15
page
16
page
17
page
18
page
19
page
20
page
21
page
22
page
23
page
24
Document related concepts
no text concepts found
Transcript 
Internet Applications, Lecture 4
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Java Server Pages™
A technology for serving dynamic web content
Summary
Stanisław Osiński, [email protected]
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
Agenda
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
•
•
•
•
•
•
•
•
What is JSP ?
Elements of a JSP document
JavaBeans and JSP
Exception handling
Custom Tags, JSP Standard Tag Library
JSP and Java Servlets
JSP v2.0 – new features
Summary
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
What is JSP ?
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
„The JavaServer Pages technology
provides the means for textual
specification of the creation of a
dynamic response to a request”
(JSP Spec. v1.2)
JSP v2.0
Summary
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
What is JSP ?
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP is a textual specification of the creation of a
dynamic response to a request (JSP Spec. v1.2)
/** */
public class SomeServlet extends HttpServlet
{
/** */
protected void doGet(...)
{
// ...
out.println(„<HTML><TITLE>Title</TITLE>”);
out.println(„<BODY><P>Today is:”);
JSP v2.0
out.println(new java.util.Date().toString());
Summary
out.println(„</P></BODY>”);
out.println(„</HTML>”);
out.close();
}
}
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
What is JSP ?
What is JSP ?
Elements of a
JSP document
JSP is a textual specification of the creation of a
dynamic response to a request (JSP Spec. v1.2)
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
<HTML>
<TITLE>Title</TITLE>;
<BODY>
<P>
Today is:
<%= new java.util.Date().toString() %>
JSP v2.0
Summary
</P>
</BODY>
</HTML>
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
Elements of a JSP document
Comment not copied to
the output document
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
<%-- An example JSP page --%>
Directives
page – JSP document
properties
<%@page import=„java.util.*"
contentType="text/html"
session="true" %>
Static content
written verbatim to
the output document
<HTML>
<TITLE>Title</TITLE>
<BODY>
<P>
Today is:
Declarations of global
variables and methods
Java code ("scriptlets")
executed on request time
Expressions evaluated on
request time
Actions executed on
request time
<%! String date; %>
<%
date = new Date().toString();
%>
<%= date %>
</P>
<jsp:include page="logo.jsp"/>
</BODY>
</HTML>
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
Implicit Objects
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
In every JSP document a number of implicit
objects can be accessed:
•
•
•
•
•
•
•
application (javax.servlet.ServletContext)
config (javax.servlet.ServletConfig)
out (javax.servlet.jsp.JspWriter)
request (javax.servlet.ServletRequest)
response (java.servlet.ServletResponse)
session (javax.servlet.http.HttpSession)
exception (java.lang.Throwable)
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
JavaBeans in JSP (1)
package org.stachoodev.examples.*;
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
/** */
public class Login
{
/** */
private String userId, password;
/** */
public void setUserId(String userId) {
this.userId = userId;
}
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
/** */
public void setPassword(String password) {
this.password = password;
}
JSP v2.0
Summary
/** */
public boolean isLoginCorrect() {
return userId.equals(password);
}
}
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
JavaBeans in JSP (2)
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
<%@page import="org.stachoodev.examples.*"
contentType="text/html" %>
<HTML>
<TITLE>Login</TITLE>
<BODY>
<P>
<%
Login login = new Login();
login.setUserId(request.getParameter("userId”));
login.setPassword(request.getParameter("password”));
%>
<% if (login.isLoginCorrect()) { %>
Login successful.
<% } else { %>
Login failed.
<% } %>
</P>
</BODY>
</HTML>
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
JavaBeans in JSP (3)
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
<%@page import="org.stachoodev.examples.*"
contentType="text/html" %>
<jsp:useBean id="login" scope="page" class="Login"/>
<HTML>
<TITLE>Login</TITLE>
<BODY>
<P>
<%
login.setUserId(request.getParameter("userId"));
login.setPassword(request.getParameter("password"));
%>
<% if (login.isLoginCorrect()) { %>
Login successful.
<% } else { %>
Login failed.
<% } %>
</P>
</BODY>
</HTML>
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
JavaBean instance scope
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
The scope parameter of the jsp:useBean action
determines the "visibility" of a JavaBean
instance:
• page – the bean is visible only within the JSP
page containing its declaration
• request – the bean is visible in any JSP page
processing the same request
• session – the instance is accessible across the
current user session
• application – any JSP page can access the
JavaBean instance
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
JavaBeans in JSP (4)
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
<%@page import="org.stachoodev.examples.*"
contentType="text/html" %>
<jsp:useBean id="login" scope="page" class="Login" />
<jsp:setProperty name="login" property="userId"
value="<%= request.getParameter("userId") %>" />
<jsp:setProperty name="login" property="passowrd"
value="<%= request.getParameter("password") %>" />
<HTML>
<TITLE>Login</TITLE>
<BODY>
<P>
<% if (login.isLoginCorrect()) { %>
Login successful.
<% } else { %>
Login failed.
<% } %>
</P>
</BODY>
</HTML>
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
JavaBeans in JSP (5)
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
<%@page import="org.stachoodev.examples.*"
contentType="text/html" %>
<jsp:useBean id="login" scope="page" class="Login" />
<jsp:setProperty name="login" property="*" />
<HTML>
<TITLE>Login</TITLE>
<BODY>
<P>
<% if (login.isLoginCorrect()) { %>
Login successful.
<% } else { %>
Login failed.
<% } %>
</P>
</BODY>
</HTML>
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
Exception handling
<%@page contentType="text/html"
errorPage="error.jsp" %>
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
<HTML>
<TITLE>Test page</TITLE>
<BODY>
<P>
<%
((String)null).length();
%>
<%@page contentType="text/html"
</P>
isErrorPage="true" %>
</BODY>
</HTML>
<HTML>
<TITLE>Error</TITLE>
<BODY>
<P>
An error has occurred:
<%= exception.getMessage() %>
</P>
</BODY>
</HTML>
error.jsp
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
Including and forwarding
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
<%@page import="org.stachoodev.examples.*"
contentType="text/html" %>
<jsp:useBean id="login" scope="page" class="Login" />
<jsp:setProperty name="login" property="*" />
<%@include file="page_header.html" %>
<% if (login.isLoginCorrect()) { %>
<jsp:forward page="welcome.jsp" />
<% } else { %>
<jsp:include page="forgotten.jsp" />
<% } %>
<%@include file="page_footer.html" %>
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
Custom Tags (1)
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
<%@page import="org.stachoodev.examples.*"
contentType="text/html" %>
Exception
handling
<%@taglib prefix="util"
uri="util.tld" %>
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
<%@include file="page_header.html" %>
<util:login request="<%= request %>" />
<%@include file="page_footer.html" %>
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
Custom Tags (2)
To implement a Custom JSP Tag:
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
• Create the tag handler class (doStartTag(),
doEndTag(), ...)
• Create the class describing the variables
accesible within the Custom Tag (optional)
• Create the Tag Library Descriptor (TLD file)
JSP v2.0
Summary
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
JSP Standard Tag Library
A standardized library of JSP Custom Tags:
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
•
•
•
•
•
•
•
•
conditions, loops, enumerations
URL transformations
content localization
formatting of numbers and dates
SQL queries
XML processing
XSLT transformations
validation of JSP documents
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
JSP and Java Servlets
What is JSP ?
execution
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
Java Servlet
HTTP request
TagLibs, JSTL
JSP and Java
Servlets
User Agent (IE, Netscape, ...)
JSP Container
JSP v2.0
Summary
generation +
compilation
<%@page import="java.util.*" %>
<HTML>
<TITLE>Title</TITLE>;
<BODY>
<P>
Today is:
<%= new Date().toString() %>
</P>
</BODY>
</HTML>
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
JSP and Java Servlets
<%@page import=„java.util.*" %>
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
<HTML>
package org.apache.jsp;
<TITLE>JSP test</TITLE>
<BODY>
import java.util.*;
<P>
import javax.servlet.*;
<%! String date; %>
// ...
<%
date =
public class test$jsp extends HttpJspBase {
new Date().toString();
%>
// begin [file="/test.jsp";from=(8,9);to=(8,23)]
Today is:
String date;
<%= date %>
// end
</P>
</BODY>
public void _jspService(...) {
</HTML>
// ...
session = pageContext.getSession();
// HTML [file="/test.jsp";from=(2,36);to=(8,6)]
out.write("\r\n\r\n<HTML>\r\n<TITLE>JSP...");
// end
JSP v2.0
Summary
// begin [file="/test.jsp";from=(9,8);to=(11,6)]
date = new Date().toString();
// end
// begin [file="/test.jsp";from=(14,9);to=(14,15)]
out.print( date );
// end
}
}
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
JSP Specification v2.0
A lot of changes and improvements:
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
• Expression Language (EL) – scriptless JSP
• Tag Files
• based on Servlet Specification v2.4
• requires Java 2 Platform v1.4
• to be implemented in Tomcat 5.0
JSP v2.0
Summary
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
Summary
What is JSP ?
JSP vs. Java Servlets:
Elements of a
JSP document
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
• better, though still imperfect, codecontent separation
• Tag Libraries - extensibility and
component reuse
• faster development (less typing ;)
• development tools available
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
Summary
What is JSP ?
Elements of a
JSP document
JavaServer Pages Home
http://java.sun.com/jsp/
JavaBeans and
JSP
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
JSP Standard Templates Library
http://java.sun.com/products/jsp/jstl/
Tomcat – Reference Implementation
http://jakarta.apache.org/tomcat
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
What is JSP ?
Elements of a
JSP document
JavaBeans and
JSP
Thank you for your attention
Exception
handling
TagLibs, JSTL
JSP and Java
Servlets
JSP v2.0
Summary
Java Server Pages
A technology for serving dynamic web content
Stanisław Osiński, [email protected]
JSP – A technology for serving dynamic web content
Stanisław Osiński, 2002
Related documents