JSTL `II8n` Tag LibraryS2C Home « JSTL `II8n` Tag Library

In our third lesson on JSTL tag libraries we look at the II8n tag library. The II8n tag library consists of actions that allow us to format and internationalise currencies, numbers, percentages, dates and times.

Each II8n action can have mandatory attributes that have to be populated and each attribute may also allow a run-time expression to be used. If a run-time expression is allowed for an attribute this can be populated using a static string or more interestingly a dynamic value which can be an EL or Java expression or a value set using the <jsp:attribute> standard action. If no run-time expression is allowed for an attribute then you can only populate that attribute using a static string.

Number `II8n` ActionsTop

There are two number II8n actions for formatting and parsing numbers, these being <fmt:formatNumber> which allows us to format a currency, number or percentage to our specifications and <fmt:parseNumber> which allows us to parse a string representation of currency, number or percentage.

Action / Attribute Name	Mandatory	Run-time Expression?	Default Value	Object Type	Description
`<fmt:formatNumber>`
`value`	Yes	Yes	None	`String` or `Number`	Numeric value to be formatted.
`type`	No	Yes	number	`String`	Specify whether `value` is to be formatted as a number, currency or percent.
`pattern`	No	Yes	None	`String`	Custom pattern for formatting.
`currencyCode`	No	Yes	None	`String`	`ISO 4217 ¹` currency code which is only applicable when `type` attribute is 'currency', otherwise this attribute is ignored.
`currencySymbol`	No	Yes	None	`String`	`ISO 4217 ¹` currency symbol which is only applicable when `type` attribute is 'currency', otherwise this attribute is ignored.
`groupingUsed`	No	Yes	true	`boolean`	Specifies whether formatted output will contain grouping separators.
`maxIntegerDigits`	No	Yes	None	`int`	Maximum number of digits in integer portion of the formatted output.
`minIntegerDigits`	No	Yes	None	`int`	Minimum number of digits in integer portion of the formatted output.
`maxFractionDigits`	No	Yes	None	`int`	Maximum number of digits in fractional portion of the formatted output.
`minFractionDigits`	No	Yes	None	`int`	Minimum number of digits in fractional portion of the formatted output.
`var`	No	No	None	`String`	Name of exported scoped variable to hold expression value. The type of scoped variable is `String`.
`scope`	No	No	page	`String`	Scope that the created scoped variable `var` exists in.
`<fmt:parseNumber>`
`value`	No	Yes	None	`String`	String value to be parsed.
`type`	No	Yes	number	`String`	Specify whether `value` is to be formatted as a number, currency or percent.
`pattern`	No	Yes	None	`String`	Custom pattern for formatting string value held within the `value` attribute.
`parseLocale`	No	Yes	None	`String`	Locale whose default formatting pattern is to be used during the parse operation, or to which the pattern specified via `pattern` attribute is applied.
`integerOnly`	No	Yes	true	`boolean`	Specifies whether just the integer portion of the given value should be parsed.
`var`	No	No	None	`String`	Name of exported scoped variable to hold expression value. The type of scoped variable is `Number`.
`scope`	No	No	page	`String`	Scope that the created scoped variable `var` exists in.

1: For a full list of valid ISO 4217 codes follow this wikipedia link.

`<fmt:formatNumber>`Top

The <fmt:formatNumber> tag formats a numeric value in a locale-sensitive or customized manner as a number, currency, or percentage.

The numeric value to be formatted can be specified using the value attribute or when omitted read from <fmt:formatNumber> tag’s body content. The formatting pattern may be specified via the pattern attribute and if present takes precedence over the type attribute and must adhere to the pattern syntax rules spcifed in the java.text.DecimalFormat class.

Formatted results using the <fmt:formatNumber> tag are output to the current JspWriter object, unless the var attribute is specified, in which case formatted results are stored in the named scoped variable.

The following code snippets shows the two variants of the <fmt:formatNumber> tag where the square brackets indicate optional attributes and the curly bracers indicate a choice of options within them where the default is underlined.


// No body content
<fmt:formatNumber value="numericValue" [type="{number|currency|percent}"] [pattern="customPattern"]
        [currencyCode="currencyCode"] [currencySymbol="currencySymbol"] [groupingUsed="{true|false}"] 
        [maxIntegerDigits="maxIntegerDigits"] [minIntegerDigits="minIntegerDigits"] 
        [maxFractionDigits="maxFractionDigits"] [minFractionDigits="minFractionDigits"] 
        [var="varName"] [scope="{page|request|session|application}"]>

// Body content specifying numeric value to be formatted
<fmt:formatNumber [type="{number|currency|percent}"] [pattern="customPattern"]
        [currencyCode="currencyCode"] [currencySymbol="currencySymbol"] [groupingUsed="{true|false}"] 
        [maxIntegerDigits="maxIntegerDigits"] [minIntegerDigits="minIntegerDigits"] 
        [maxFractionDigits="maxFractionDigits"] [minFractionDigits="minFractionDigits"] 
        [var="varName"] [scope="{page|request|session|application}"] >
    numeric value to be formatted
</fmt:formatNumber>

`<fmt:parseNumber>`Top

The <fmt:parseNumber> tag parses the string representation of numbers, currencies, and percentages that were formatted in a locale-sensitive or customized manner.

The numeric value to be parsed can be specified using the value attribute or when omitted read from <fmt:parseNumber> tag’s body content. The formatting pattern may be specified via the pattern attribute and if present takes precedence over the type attribute and must adhere to the pattern syntax rules spcifed in the java.text.DecimalFormat class.

Formatted results using the <fmt:parseNumber> tag are output to the current JspWriter object using java.lang.Number.toString(), unless the var attribute is specified, in which case formatted results are stored in the named scoped variable.

The following code snippets shows the two variants of the <fmt:parseNumber> tag where the square brackets indicate optional attributes and the curly bracers indicate a choice of options within them where the default is underlined.


// No body content
<fmt:parseNumber value="numericValue" [type="{number|currency|percent}"] [pattern="customPattern"]
        [parseLocale="parseLocale"] [integerOnly="{true|false}"] 
        [var="varName"] [scope="{page|request|session|application}"]>

// Body content specifying numeric value to be parsed
<fmt:parseNumber [type="{number|currency|percent}"] [pattern="customPattern"]
        [parseLocale="parseLocale"] [integerOnly="{true|false}"] 
        [var="varName"] [scope="{page|request|session|application}"] >
    numeric value to be parsed
</fmt:parseNumber>

Number `II8n` ExamplesTop

The following code shows examples of using general purpose tags within the Core tag library.


<%@taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>

<%-- Output formatted number --%>
Number: <fmt:formatNumber value="123456789"><br>
<%-- Output formatted number with maximum fraction digits --%>
Maximum Fraction Number: <fmt:formatNumber value="123456789" maxIntegerDigits="6"><br>
<%-- Output formatted number with minimum digits --%>
Minimum Digits Number: <fmt:formatNumber value="123456789" minFractionDigits="3"><br>
<%-- Output formatted number using a pattern --%>
Pattern Number: <fmt:formatNumber value="123456.789" pattern="#,#00.0#"><br>
<%-- Output formatted number with default currency type --%>
Default Currency: <fmt:formatNumber value="12345" type="currency"><br>
<%-- Output formatted number with Japanese currency type --%>
Japanese Currency: <fmt:formatNumber value="12345" type="currency" currencyCode="JPY"><br>
<%-- Output precentage number--%>
Percentage: <fmt:formatNumber value="45" type="percent"><br>

The following screnshot shows the results of running the above JSP code.

Date `II8n` ActionsTop

There are two date II8n actions for formatting and parsing dates, these being <fmt:formatDate> which allows us to format a dates to our specifications and <fmt:parseDate> which allows us to parse a string representation of a date and time in locale-sensitive format.

Action / Attribute Name	Mandatory	Run-time Expression?	Default Value	Object Type	Description
`<fmt:formatDate>`
`value`	Yes	Yes	None	`java.util.Date`	Date and/or time to be formatted.
`type`	No	Yes	date	`String`	Specify whether `value` is to be formatted as a date or time or both.
`dateStyle`	No	Yes	default	`String`	Predefined formatting style for dates that follow the semantics defined in `java.text.DateFormat`.
`timeStyle`	No	Yes	default	`String`	Predefined formatting style for times that follow the semantics defined in `java.text.DateFormat`.
`pattern`	No	Yes	None	`String`	Custom pattern for formatting dates and times.
`timeZone`	No	Yes	None	`String` or `java.util.TimeZone`	The time zone used to represent the time.
`var`	No	No	None	`String`	Name of exported scoped variable to hold expression value. The type of scoped variable is `String`.
`scope`	No	No	page	`String`	Scope that the created scoped variable `var` exists in.
`<fmt:parseDate>`
`value`	Yes	Yes	None	`java.util.Date`	Date and/or time to be formatted.
`type`	No	Yes	date	`String`	Specify whether `value` is to be formatted as a date or time or both.
`dateStyle`	No	Yes	default	`String`	Predefined formatting style for dates that follow the semantics defined in `java.text.DateFormat`.
`timeStyle`	No	Yes	default	`String`	Predefined formatting style for times that follow the semantics defined in `java.text.DateFormat`.
`pattern`	No	Yes	None	`String`	Custom pattern for formatting dates and times.
`timeZone`	No	Yes	None	`String` or `java.util.TimeZone`	The time zone used to represent the time.
`parseLocale`	No	Yes	None	`String` or `java.util.Locale`	Locale whose predefined formatting styles are to be used during the parse operation, or to which any present `pattern` attribute is applied.
`var`	No	No	None	`String`	Name of exported scoped variable to hold expression value. The type of scoped variable is `String`.
`scope`	No	No	page	`String`	Scope that the created scoped variable `var` exists in.

`<fmt:formatDate>`Top

The <fmt:formatDate> tag allows us to which allows us to format a dates to our specifications or to locale-sensitive formats.

If the scope attribute is specified the var attribute must also be specified. If the value attribute is null or empty, nothing is written to the current JspWriter object and any scoped variable specified is removed. If the timeZone attribute is null or empty, it is handled as if it wasn't specified.

If the <fmt:formatDate> tag fails to determine a formatting locale, it uses java.util.Date.toString() for formatting any output.

The following code snippet shows the syntax of the <fmt:formatDate> tag where the square brackets indicate optional attributes and the curly bracers indicate a choice of options within them where the default is underlined.


// Format a date
<fmt:formatDate value="date" [type="{date|time|both}"] 
        [dateStyle="{default|short|medium|long|full}"]
        [timeStyle="{default|short|medium|long|full}"]
        [pattern="customPattern"] [timezone="timezone"]
        [var="varName"] [scope="{page|request|session|application}"]>

`<fmt:parseDate>`Top

The <fmt:parseDate> tag is used to parse the string representation of dates and times that were formatted in a locale-sensitive or customized manner.

If the date string to be parsed is null or empty, the scoped variable defined by var and scope are removed, allowing "empty" input to be distinguished from "invalid" input, which causes an exception. If the timeZone attribute is null or empty, it is handled as if it wasn't specified. If the parseLocale attribute is null or empty, it is handled as if it wasn't specified. If an exception occurs during parsing of the value, it must be caught and rethrown as a JspException.

If the <fmt:formatDate> tag fails to determine a formatting locale, it uses java.util.Date.toString() for formatting any output.

There are two variants of the <fmt:parseDate> tag, with or without a body, as shown in the code snippets below:


// No body content
<fmt:parseDate value="dateString" [type="{date|time|both}"]
        [dateStyle="{default|short|medium|long|full}"]
        [timeStyle="{default|short|medium|long|full}"]
        [pattern="customPattern"] [timezone="timezone"] [parseLocale="parseLocale"]
        [var="varName"] [scope="{page|request|session|application}"]>

// Body content specifying date value to be parsed
<fmt:parseDate [type="{date|time|both}"]
        [dateStyle="{default|short|medium|long|full}"]
        [timeStyle="{default|short|medium|long|full}"]
        [pattern="customPattern"] [timezone="timezone"] [parseLocale="parseLocale"]
        [var="varName"] [scope="{page|request|session|application}"] >
    numeric value to be parsed
</fmt:parseDate>

Date `II8n` ExamplesTop

The following code shows examples of using general purpose tags within the Core tag library.


<%@taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>

<%-- Get current date and time --%>
<jsp:useBean id="now" class="java.util.Date">
<%-- Output formatted date --%>
Current Date: <fmt:formatDate value="${now}"><br>
<%-- Output formatted time --%>
Current Time: <fmt:formatDate value="${now}" type="time"><br>
<%-- Output formatted date and time --%>
Current Date and Time: <fmt:formatDate value="${now}" type="both"><br>
<%-- Output long date --%>
Current Long Date: <fmt:formatDate value="${now}" dateStyle="long"><br>
<%-- Output full time --%>
Current Full Time: <fmt:formatDate value="${now}" type="time" timeStyle="full"><br>

The following screnshot shows the results of running the above JSP code.

Time Zone `II8n` ActionsTop

There are two time zone II8n actions, these being <fmt:timeZone> action which allows us to specify the time zone in which time information is to be formatted or parsed in its body content and the <fmt:setTimeZone> action which allows us to store the specified time zone in either a scoped variable or the time zone configuration variable.

Action / Attribute Name	Mandatory	Run-time Expression?	Default Value	Object Type	Description
`<fmt:timeZone>`
`value`	Yes	Yes	None	`String` or `java.util.TimeZone`	The time zone where a string value is interpreted as a time zone ID.
`<fmt:setTimeZone>`
`value`	Yes	Yes	None	`String` or `java.util.TimeZone`	The time zone where a string value is interpreted as a time zone ID.
`var`	No	No	None	`String`	Name of exported scoped variable to hold expression value. The type of scoped variable is `java.util.TimeZone`.
`scope`	No	No	page	`String`	Scope that the created scoped variable `var` exists in.

`<fmt:timeZone>`Top

The <fmt:timeZone> action allows us to specify the time zone in which time information is to be formatted or parsed in its body content.

The following code snippets shows the syntax of the <fmt:timeZone> tag.


// Specify time zone
<fmt:timeZone value="timeZone" >
    body content
</fmt:timeZone>

`<fmt:setTimeZone>`Top

The <fmt:setTimeZone> tag allows us to store the specified time zone in either a scoped variable or the time zone configuration variable.

The following code snippets shows the syntax of the <fmt:setTimeZone> tag.


// Store time zone
<fmt:setTimeZone value="timeZone" [var="varName"] [scope="{page|request|session|application}"]>

Time Zone `II8n` ExamplesTop

The following code shows examples of using general purpose tags within the Core tag library.


<%@taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>

<%-- Get time --%>
<jsp:useBean id="now" class="java.util.Date">
<%-- Specify time zone US Eastern Standard Time and output current date --%>
<fmt:timeZone value="EST" >
  Current Full Date and Time EST: <fmt:formatDate value="${now}" type="both" 
      dateStyle="full" timeStyle="full">
</fmt:timeZone>

The following screnshot shows the results of running the above JSP code.

Lesson 4 Complete

In our third lesson on JSTL tag libraries we looked at the Ii8n tag library.

What's Next?

In our fourth lesson on JSTL tag libraries we look at the Database tag library.

<< XML Tag library Database Tag library >>

Homepage Top

JSTL `II8n` Tag LibraryS2C Home « JSTL `II8n` Tag Library

Number `II8n` ActionsTop

`<fmt:formatNumber>`Top

`<fmt:parseNumber>`Top

Number `II8n` ExamplesTop

Date `II8n` ActionsTop

`<fmt:formatDate>`Top

`<fmt:parseDate>`Top

Date `II8n` ExamplesTop

Time Zone `II8n` ActionsTop

`<fmt:timeZone>`Top

`<fmt:setTimeZone>`Top

Time Zone `II8n` ExamplesTop

Lesson 4 Complete

What's Next?

JSP

EL

JSTL

Introduction to JSTL

`Core` Tag library

`XML` Tag library

`II8n` Tag library

Number `II8n` Actions

`<fmt:formatNumber>`

`<fmt:parseNumber>`

Number `II8n` Examples

Date `II8n` Actions

`<fmt:formatDate>`

`<fmt:parseDate>`

Date `II8n` Examples

Time Zone `II8n` Actions

`<fmt:timeZone>`

`<fmt:setTimeZone>`

Time Zone `II8n` Examples

`Database` Tag library

`Functions` Tag library

Creating Our Own Custom Tags

EL Functions

Tag Files

Other Tutorial Sites	© 2023, Server2Client.com
Java 8	Sitemap
JSP/Servlet Tutor	About Us
Learn JavaScript & jQuery	Contact Us
	Link To Us
	Privacy

JSTL II8n Tag LibraryS2C Home « JSTL II8n Tag Library

Number II8n ActionsTop

<fmt:formatNumber>Top

<fmt:parseNumber>Top

Number II8n ExamplesTop

Date II8n ActionsTop

<fmt:formatDate>Top

<fmt:parseDate>Top

Date II8n ExamplesTop

Time Zone II8n ActionsTop

<fmt:timeZone>Top

<fmt:setTimeZone>Top

Time Zone II8n ExamplesTop

Lesson 4 Complete

What's Next?

JSTL

JSTL `II8n` Tag LibraryS2C Home « JSTL `II8n` Tag Library

Number `II8n` ActionsTop

`<fmt:formatNumber>`Top

`<fmt:parseNumber>`Top

Number `II8n` ExamplesTop

Date `II8n` ActionsTop

`<fmt:formatDate>`Top

`<fmt:parseDate>`Top

Date `II8n` ExamplesTop

Time Zone `II8n` ActionsTop

`<fmt:timeZone>`Top

`<fmt:setTimeZone>`Top

Time Zone `II8n` ExamplesTop