AhmadLang / Java, How To Program, 2004

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Terminology

%\> escape sequence for %>

<!-- and --> XHTML comment delimiters

<%-- and --%> JSP comment delimiters

<% and %> scriptlet delimiters

<%! and %> declaration delimiters

<%= and %> JSP expression delimiters

<%@ and %> directive delimiters

<\% escape sequence for <% ${exp}

acceptChanges method of CachedRowSet autoFlush attribute of page directive beanName attribute of <jsp:useBean> action beforeFirst method of CachedRowSet buffer attribute of page directive

class attribute of <jsp:useBean> action comment

config implicit object

contentType attribute of page directive directive

dynamic content

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error page

errorPage attribute of page directive

execute method of CachedRowSet

expression

Expression Language

extends attribute of page directive file attribute of include directive fixed-template data

fixed-template text

flush attribute of <jsp:include> action forward a request

getParameterValues method of request object

id attribute of <jsp:useBean> action implicit object

implicit object scopes

import attribute of page directive include a resource

include directive

info attribute of page directive insertRow method of CachedRowSet isErrorPage attribute of page directive isThreadSafe attribute of page directive JavaBean

JavaServer Pages (JSPs) javax.servlet.jsp package

javax.servlet.jsp.tagext package

JSP action

<jsp:forward> action

<jsp:getProperty> action

<jsp:include> action

<jsp:param> action

<jsp:setProperty> action

<jsp:useBean> action

jspDestroy method

jspInit method

_jspService method

JspWriter (package javax.servlet.jsp) language attribute of page directive match request parameters

meta element

moveToCurrentRow method of CachedRowSet moveToInsertRow method of CachedRowSet

name attribute of <jsp:param>

name attribute of <jsp:setProperty> name-value pair

out implicit object

page attribute of <jsp:forward> page attribute of <jsp:include> page directive

page implicit object page scope

param attribute of <jsp:setProperty> property attribute of <jsp:setProperty> refresh interval

request implicit object request scope request-time error response implicit object

scope attribute of <jsp:useBean> scope of a bean

scripting element scriptlet

setCommand method of CachedRowSet

setPassword method of CachedRowSet setUrl method of CachedRowSet setUsername method of CachedRowSet specify attributes of a custom tag standard actions

translation-time error

type attribute of <jsp:plugin> type attribute of <jsp:useBean>

updateString method of CachedRowSet value attribute of <jsp:param>

value attribute of <jsp:setProperty>

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Self-Review Exercises

27.1 Fill in the blanks in each of the following statements:

a.Action __________ has the ability to match request parameters to properties of the same name in a bean by specifying "*" for attribute property.

b.There are four key components to JSPs: __________, __________,

__________ and __________.

c.The implicit objects have four scopes: __________, __________, __________

and. __________

d.The __________ directive is processed once at JSP translation time and causes content to be copied into the JSP.

e.Classes and interfaces specific to JavaServer Pages programming are located in packages __________ and __________ .

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f.JSPs normally execute as part of a Web server that is referred to as the

__________ .

g.JSP scripting components include __________, __________, __________,

__________ and __________ .

27.2 State whether each of the following is true or false. If false, explain why.

a.An object with page scope exists in every JSP of a particular Web application.

b.Directives specify global information that is not associated with a particular JSP request.

c.Action <jsp:include> is evaluated once at page translation time.

d.Like XHTML comments, JSP comments and script-language comments appear in the response to the client.

e.Objects with application scope are part of a particular Web application.

f.Each page has its own instances of the page-scope implicit objects.

g.Action <jsp:setProperty> has the ability to match request parameters to properties of the same name in a bean by specifying "*" for attribute property.

h.Objects with session scope exist for the client's entire browsing session.

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Answers to Self-Review Exercises

27.1 a) <jsp:setProperty>. b) directives, actions, scripting elements, tag libraries. c) application, page, request, session. d) include. e) javax.servlet.jsp, javax.servlet.jsp.tagext. f) JSP container. g) scriptlets, comments, expressions, declarations, escape sequences.

27.2 a) False. Objects with page scope exist only as part of the page in which they are used. b) True. c) False. Action <jsp:include> enables dynamic content to be included in a JavaServer Page. d) False. JSP comments and script-language comments are ignored and do not appear in the response. e) False. Objects with application scope are part of the JSP container application. f) True. g) True. h) True.

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Exercises

27.3Write a JSP page to output the string "Hello world!" ten times.

27.4Modify Exercise 26.6 to run as a JSP page.

27.5Rewrite Figure 27.15 to provide a form that allow users to select a book title and view the book's cover. Use a JSP expression instead of the getProperty JSP tag.

27.6Create a JSPand JDBC-based address book. Use the guest-book example of Fig. 27.20 through Fig. 27.24 as a guide. Your address book should allow the user to insert entries and search for entries. [Note: If you are not familiar with XHTML and CSS, refer to the chapters from our book Internet & World Wide Web HTP, 3/eIntroduction to XHTML: Part 1, Introduction to XHTML: Part 2 and Cascading Style Sheets (CSS), which are included as PDF documents on the CD that accompanies this book.]

27.7Reimplement the Web application of Fig. 26.21 (favorite animal survey) using JSPs. [Note: If you are not familiar with XHTML and CSS, refer to the chapters from our book Internet & World Wide Web HTP, 3/eIntroduction to XHTML: Part 1, Introduction to XHTML: Part 2 and Cascading Style Sheets (CSS), which are included as PDF documents on the CD that accompanies this book.]

27.8Modify your solution to Exercise 27.7 to allow the user to see the survey results without responding to the survey. [Note: If you are not familiar with XHTML and CSS, refer to the chapters from our book Internet & World Wide Web HTP, 3/eIntroduction to XHTML: Part 1, Introduction to XHTML: Part 2 and Cascading Style Sheets (CSS), which are included as PDF documents on the CD that accompanies this book.]

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Chapter 28. Formatted Output

All the news that's fit to print.

Adolph S. Ochs

What mad pursuit?What struggle to escape?

John Keats

Remove not the landmark on the boundary of the fields.

Amenehope

OBJECTIVES

In this chapter you will learn:

To understand input and output streams.

To use printf formatting.

To print with field widths and precisions.

To use formatting flags in the printf format string.

To print with an argument index.

To output literals and escape sequences.

To format output with class Formatter.

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Outline

28.1 Introduction

28.2 Streams

28.3 Formatting Output with printf

28.4 Printing Integers

28.5 Printing Floating-Point Numbers

28.6 Printing Strings and Characters

28.7 Printing Dates and Times

28.8 Other Conversion Characters

28.9 Printing with Field Widths and Precisions

28.10 Using Flags in the printf Format String

28.11 Printing with Argument Indices

28.12 Printing Literals and Escape Sequences

28.13 Formatting Output with Class Formatter

28.14 Wrap-Up

Summary

Terminology

Self-Review Exercises

Answers to Self-Review Exercises

Exercises

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28.1. Introduction

An important part of the solution to any problem is the presentation of the results. In this chapter, we discuss the formatting features of method printf and class Formatter (package java.util). Method printf formats and outputs data to the standard output streamSystem.out. Class Formatter formats and outputs data to a specified destination, such as a string or a file output stream.

Many features of printf were discussed earlier in the text. This chapter summarizes those features and introduces others, such as displaying date and time data in various formats, reordering output based on the index of the argument and displaying numbers and strings with various flags.