Document Information

Preface

Part I Introduction

1.  Overview

2.  Using the Tutorial Examples

Part II The Web Tier

3.  Getting Started with Web Applications

4.  Java Servlet Technology

5.  JavaServer Pages Technology

6.  JavaServer Pages Documents

7.  JavaServer Pages Standard Tag Library

8.  Custom Tags in JSP Pages

The Example JSP Pages

Using Scripting

Disabling Scripting

JSP Declarations

Initializing and Finalizing a JSP Page

JSP Scriptlets

JSP Expressions

Programming Tags That Accept Scripting Elements

TLD Elements

Tag Handlers

How Is a Classic Tag Handler Invoked?

Tags with Bodies

Tag Handler Does Not Manipulate the Body

Tag Handler Manipulates the Body

Cooperating Tags

Tags That Define Variables

10.  JavaServer Faces Technology

11.  Using JavaServer Faces Technology in JSP Pages

12.  Developing with JavaServer Faces Technology

13.  Creating Custom UI Components

14.  Configuring JavaServer Faces Applications

15.  Internationalizing and Localizing Web Applications

Part III Web Services

16.  Building Web Services with JAX-WS

17.  Binding between XML Schema and Java Classes

18.  Streaming API for XML

19.  SOAP with Attachments API for Java

Part IV Enterprise Beans

20.  Enterprise Beans

21.  Getting Started with Enterprise Beans

22.  Session Bean Examples

23.  A Message-Driven Bean Example

Part V Persistence

24.  Introduction to the Java Persistence API

25.  Persistence in the Web Tier

26.  Persistence in the EJB Tier

27.  The Java Persistence Query Language

Part VI Services

28.  Introduction to Security in the Java EE Platform

29.  Securing Java EE Applications

30.  Securing Web Applications

31.  The Java Message Service API

32.  Java EE Examples Using the JMS API

33.  Transactions

34.  Resource Connections

35.  Connector Architecture

Part VII Case Studies

36.  The Coffee Break Application

37.  The Duke's Bank Application

Part VIII Appendixes

A.  Java Encoding Schemes

B.  About the Authors

Index

 

Chapter 9

Scripting in JSP Pages

JSP scripting elements allow you to use Java programming language statements in your JSP pages. Scripting elements are typically used to create and access objects, define methods, and manage the flow of control. Many tasks that require the use of scripts can be eliminated by using custom tag libraries, in particular the JSP Standard Tag Library. Because one of the goals of JSP technology is to separate static data from the code needed to dynamically generate content, very sparing use of JSP scripting is recommended. Nevertheless, there may be some circumstances that require its use.

There are three ways to create and use objects in scripting elements:

  • Instance and class variables of the JSP page’s servlet class are created in declarations and accessed in scriptlets and expressions.

  • Local variables of the JSP page’s servlet class are created and used in scriptlets and expressions.

  • Attributes of scope objects (see Using Scope Objects) are created and used in scriptlets and expressions.

This chapter briefly describes the syntax and usage of JSP scripting elements.