JavaServer Pages, 3/e

Summary

JavaServer Pages (JSP) has built a huge following since the release of JSP 1.0 in 1999, providing Enterprise Java developers with a flexible tool for the development of dynamic web sites and web applications. While new point releases over the years, along with the introduction of the JSP Standard Tag Library (JSTL), have incrementally improved the rough areas of the first version of the JSP specification, JSP 2.0 takes this technology to new heights.

JavaServer Pages, Third Edition, is completely revised and updated to cover the JSP 2.0 and JSTL 1.1 specifications. It includes detailed coverage of the Expression Language (EL) incorporated into JSP 2.0, the JSTL 1.1 tag libraries and the new function library, the new tag file format that enables custom tag library development without Java code, the simplified Java tag library API, improvements in the JSP XML syntax, and more. Further, it details setup of the Apache Tomcat server, JSP and JSTL syntax and features, error handling and debugging, authentication and personalization, database access, XML processing, and internationalization.

This book recognizes the different needs of the two groups of professionals who want to learn JSP: page authors interested in using JSP elements in web pages, and programmers concerned with learning the JSP API and using JSP effectively as a part of an enterprise application. If you're in the first group, you'll learn from the practical web application examples in the second part of the book. If you're in the latter group, you'll appreciate the detailed coverage of advanced topics in the third part, such as how to integrate servlets and JavaBeans components with JSP using the popular Apache Struts MVC framework, and how to develop custom tag libraries using the JSP API, with realistic examples that you can use as a springboard for your own libraries.

"Hans Bergsten, a JSP expert group veteran and one of our most active contributors, has thoroughly and accurately captured the new features of JSP 2.0 and JSTL 1.1 in a way that is well-organized and easy to understand. With excellent, to-the-point examples, this book is a 'must have' for any serious JSP 2.0 developer."
--Mark Roth, JSP 2.0 Specification Lead, Sun Microsystems, Inc.

Hans Bergsten is the founder of Gefion Software, a company focused on Java services and products based on J2EE technologies. Hans has been an active participant in the working groups for both the servlet and JSP specifications since their inception and contributes to other related JCP specifications, such as JSP Standard Tag Library (JSTL) and JavaServer Faces (JSF), and, as one of the initial members of the Apache Jakarta Project Management Committee, helped develop the Apache Tomcat reference implementation for the servlet and JSP specifications.

Table of Contents

Preface

Part I. JSP Application Basics

1. Introducing JavaServer Pages

     What Is JavaServer Pages?

     Why Use JSP?

     What You Need to Get Started

2. HTTP and Servlet Basics

     The HTTP Request/Response Model

     Servlets

3. JSP Overview

     The Problem with Servlets

     The Anatomy of a JSP Page

     JSP Processing

     JSP Application Design with MVC

4. Setting Up the JSP Environment

     Installing the Java Software Development Kit

     Installing the Tomcat Server

     Testing Tomcat

     Installing the Book Examples

     Example Web Application Overview

Part II. JSP Application Development

5. Generating Dynamic Content

     Creating a JSP Page

     Installing a JSP Page

     Running a JSP Page

     Using JSP Directive Elements

     Using Template Text

     Using JSP Action Elements

6. Using JavaBeans Components in JSP Pages

     What Is a Bean?

     Declaring a Bean in a JSP Page

     Reading Bean Properties

     Setting Bean Properties

7. Using Custom Tag Libraries and the JSP Standard Tag Library

     What Is a Custom Tag Library?

     Installing a Custom Tag Library

     Declaring a Custom Tag Library

     Using Actions from a Tag Library

8. Processing Input and Output

     Reading Request Parameter Values

     Validating User Input

     Formatting HTML Output

9. Error Handling and Debugging

     Dealing with Syntax Errors

     Debugging a JSP Application

     Dealing with Runtime Errors

10. Sharing Data Between JSP Pages, Requests, and Users

     Passing Control and Data Between Pages

     Sharing Session and Application Data

     Online Shopping

     Memory Usage Considerations

11. Developing Custom Tag Libraries as Tag Files

     Creating and Using a Tag File

     Accessing Attribute Values

     Processing the Action Body

     Processing Fragment Attributes

     Exposing Data to the Calling Page Through Variables

     Aborting the Page Processing

     Packaging Tag Files for Easy Reuse

12. Accessing a Database

     Accessing a Database from a JSP Page

     Validating Complex Input Without a Bean

     Using Transactions

     Application-Specific Database Actions

13. Authentication and Personalization

     Container-Provided Authentication

     Application-Controlled Authentication

     Other Security Concerns

14. Internationalization

     How Java Supports Internationalization and Localization
     Generating Localized Output

     A Brief History of Bits

     Handling Localized Input

15. Working with XML Data

     Generating an XML Response

     Transforming XML into HTML

     Transforming XML into a Device-Dependent Format

     Processing XML Data

16. Using Scripting Elements

     Using page Directive Scripting Attributes

     Implicit JSP Scripting Objects

     Using Scriptlets

     Using Expressions

     Using Declarations

     Mixing Action Elements and Scripting Elements

     Dealing with Scripting Syntax Errors

17. Bits and Pieces

     Buffering

     Including Page Segments

     Global Configuration Options

     Mixing Client-Side and Server-Side Code

     Precompiling JSP Pages

     Preventing Caching of JSP Pages

     Writing JSP Pages as XML Documents

     How URIs Are Interpreted

Part III. JSP in J2EE and JSP Component Development

18. Web Application Models

     The Java 2 Enterprise Edition Model

     The MVC Design Model

     Scalability

19. Combining JSP and Servlets

     Servlets, Filters, and Listeners

     Picking the Right Component Type for Each Task

     Initializing Shared Resources Using a Listener

     Access Control Using a Filter

     Centralized Request Processing Using a Servlet

     Using a Common JSP Error Page

20. Developing JavaBeans Components for JSP

     Beans as JSP Components

     JSP Bean Examples

     Unexpected <jsp:setProperty> Behavior

21. Developing Custom Tag Libraries Using Java

     Developing Simple Tag Handlers

     Developing Classic Tag Handlers

     Developing Tag Library Functions

     Creating the Tag Library Descriptor

     Packaging and Installing a Tag Library

22. Advanced Custom Tag Library Features

     Developing Cooperating Actions

     Validating Syntax

     Using a Listener in a Tag Library

     Dynamic Attribute Values and Types

23. Integrating Custom Code with JSTL

     Setting and Using Configuration Variables

     Integrating Custom Conditional Actions

     Integrating Custom Iteration Actions

     Integrating Custom I18N Actions

     Integrating Custom Database Actions

     Using JSTL Tag Library Validators

24. Database Access Strategies

     JDBC Basics

     Using Connections and Connection Pools

     Making a Connection Pool Available to Application Components

     Using a Generic Database Bean

     Developing Application-Specific Database Components

Part IV. Appendixes

A. JSP Elements Reference

B. JSTL Actions and API Reference

C. JSP Expression Language Reference

D. JSP API Reference

E. Book Example Custom Actions and API Reference

F. Web Application Structure and Deployment Descriptor Reference

Index

摘要

自從1999年JSP 1.0版本發布以來，JavaServer Pages (JSP)已經建立了一個龐大的追隨者群，為企業級Java開發人員提供了一個靈活的工具，用於開發動態網站和Web應用程序。多年來的新版本發布以及JSP標準標籤庫（JSTL）的引入，逐步改進了JSP規範的初版中的問題，而JSP 2.0則將這項技術推向了新的高度。

JavaServer Pages第三版完全修訂和更新，涵蓋了JSP 2.0和JSTL 1.1的規範。它詳細介紹了JSP 2.0中引入的表達式語言（EL），JSTL 1.1標籤庫和新的函數庫，以及無需Java代碼即可開發自定義標籤庫的新標籤文件格式，簡化的Java標籤庫API，JSP XML語法的改進等等。此外，它還詳細介紹了Apache Tomcat服務器的設置，JSP和JSTL語法和功能，錯誤處理和調試，身份驗證和個性化，數據庫訪問，XML處理和國際化。

本書認識到兩個對想要學習JSP的專業人士的不同需求：對在Web頁面中使用JSP元素感興趣的頁面作者，以及對學習JSP API並將JSP有效地作為企業應用程序的一部分的程序員。如果您屬於第一組，您將從本書第二部分的實用Web應用程序示例中學習。如果您屬於後一組，您將欣賞第三部分中關於高級主題的詳細介紹，例如如何使用流行的Apache Struts MVC框架將servlet和JavaBeans組件與JSP集成，以及如何使用JSP API開發自定義標籤庫，並提供實際的示例，可作為您自己庫的起點。

“Hans Bergsten是JSP專家組的老將之一，也是我們最活躍的貢獻者之一，他以井然有序且易於理解的方式全面而準確地捕捉到了JSP 2.0和JSTL 1.1的新功能。這本書具有優秀且直接的示例，對於任何嚴肅的JSP 2.0開發人員來說都是“必備品”。”
--Mark Roth，JSP 2.0規範負責人，Sun Microsystems, Inc.

Hans Bergsten是Gefion Software的創始人，該公司專注於基於J2EE技術的Java服務和產品。Hans自從servlet和JSP規範成立以來就一直是工作組的積極參與者，並對其他相關的JCP規範（如JSP標準標籤庫（JSTL）和JavaServer Faces（JSF））做出貢獻。作為Apache Jakarta項目管理委員會的最初成員之一，他還幫助開發了servlet和JSP規範的Apache Tomcat參考實現。

目錄

前言

第一部分. JSP應用程序基礎知識

1. 介紹JavaServer Pages

     什麼是JavaServer Pages？

     為什麼使用JSP？

     開始之前需要什麼？

2. HTTP和Servlet基礎知識

     HTTP請求/響應模型

     Servlets

3. JSP概述

     Servlet的問題

     JSP頁面的結構

     JSP處理

     使用MVC設計JSP應用程序

4. 設置JSP環境

     安裝Java軟件```