Turn:
You can find it from the example that comes with the Apache official website, located at \velocity-tools-1.4-src\examples\showcase.
The examples that come with the Apache official website are as follows:
When using Velocity Tools, it must be specified in toolbox.xml, and then configured in the application's web.xml.
Here, regarding the reference to the jar package, a Velocity runtime exception is likely to occur, such as:
信息: Velocity [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /templates/context.vm [line 12,column 37] : $context is not a valid reference.
2008-4-23 9:41:45 org.apache.catalina.core.ApplicationContext log
信息: Velocity [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /templates/context.vm [line 16,column 37] : $context.keys is not a valid reference.
2008-4-23 9:41:45 org.apache.catalina.core.ApplicationContext log
信息: Velocity [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /templates/context.vm [line 20,column 37] : $context.toolbox is not a valid reference.
2008-4-23 9:41:45 org.apache.catalina.core.ApplicationContext log
信息: Velocity [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /templates/context.vm [line 24,column 37] : $context.values is not a valid reference.
The key is that there is a problem with the selection of the jar package, or it may be the jar package that does not add the specified tool.
Choose from several tools:
org.apache.velocity.tools.generic.ComparisonDateTool
The configuration in toolbox.xml looks like this:
<tool>
<key>date</key>
<scope>application</scope>
<class>org.apache.velocity.tools.generic.ComparisonDateTool</class>
<parameter name=”format” value=”yyyy-MM-dd”/>
<parameter name=”depth” value=”2″/>
<parameter name=”skip” value=”month”/>
</tool>
date is like a built-in object that you can always use in Velocity templates in .vm.
Regarding the date, it looks like this:
Example function to display the result
$date 2008-04-22
$date.long April 22, 2008
10:58:54 pm $date.medium_time 22:58:54
$date.full_date Tuesday, April 22, 2008
$date .yyyy 2008
$date.get('default','short') 2008-4-22 10:58 PM
$date.get('yyyy-Md H:m:s') 2008-4-22 22:58: 54
$date.whenIs('2008-04-20′) 2 days 22 hours ago
$date.whenIs('2008-04-20′).full 2 days 22 hours 58 minutes 54 seconds 484 milliseconds ago
$date.whenIs( '2008-04-20').days -2
$date.whenIs(’2008-04-20′) 22 hours 58 minutes ago
$date.whenIs(’2008-04-20′,’2008-04-20′) same time
$date.difference(’2008-04-20′, ’2008-04-20′) 2 days
$date.whenIs(’2008-04-20′).days -2
org.apache.velocity.tools.generic.MathTool
The configuration in toolbox.xml looks like this:
<tool>
<key>math</key>
<scope>application</scope>
<class>org.apache.velocity.tools.generic.MathTool</class>
</tool>
Regarding math, it looks like this:
函数举例显示结果$math.add(“10″,”4″) 14
$math.sub(“100″,”20″) 80
$math.mul(“11″,”7″) 77
$math.div(“100″,”5″) 20
$math.idiv(“100″,”5″) 20
$math.pow(“2″,”5″) 32
$math.mod(“13″,”5″) 3
$math.max(“99″,”16″) 99
$math.min(“99″,”16″) 16
$math.abs(“-99″) 99
$math.cell(“99.26″)
$math.cell(“99.26″)
$math.floor(“99.26″) 99
$math.random 0.7663665545444911
$math.random(“1″,”10″) 2
$math.roundTo(“2″,”5″) 5.0
$math.toInteger(“15″) 15
$math.toDouble(“15″) 15.0
$math.toNumber(“15″) 15
org.apache.velocity.tools.generic.NumberTool
The configuration in toolbox.xml looks like this:
<tool>
<key>number</key>
<scope>application</scope>
<class>org.apache.velocity.tools.generic.NumberTool</class>
<parameter name=”format” value=”#0.0″/>
</tool>
Regarding number, it looks like this:
Example of function display result $number org.apache.velocity.tools.generic.NumberTool@32c41c
$number.currency(“35″) ￥35.00
$number.format #0.0
$number.locale zh_CN
$number.format(“35″) 35.0
$number.integer(“35.47″) 35
$number.number(“35.47″) 35.47
$number.percent(“0.3547″) 35%
$number.toNumber(“35.47″) 35.47
org.apache.velocity.tools.generic.SortTool
The configuration in toolbox.xml looks like this:
<tool>
<key>sorter</key>
<scope>application</scope>
<class>org.apache.velocity.tools.generic.SortTool</class>
</tool>
Regarding the sorter, it looks like this:
Example of function display result
$sorter.sort(['d','a','b','c']) [a, b, c, d]
$sorter.sort([5,1,12,3] ) [1, 3, 5, 12]
The sorter tool can sort the specified collection, such as List, Array, Map and so on.
org.apache.velocity.tools.generic.EscapeTool
The configuration in toolbox.xml looks like this:
<tool>
<key>esc</key>
<scope>application</scope>
<class>org.apache.velocity.tools.generic.EscapeTool</class>
</tool>
Regarding esc, it looks like this:
Example of function display result $esc org.apache.velocity.tools.generic.EscapeTool@e09a07
$esc.b \
$esc.backslash \
$esc.d $
$esc.dollar $
$esc.e !
$esc.exclamation !
$ esc.h #
$esc.hash #
$esc.q "
$esc.quote "
\esc.s esc.s
$esc.singleQuote '
$esc.html("$esc.backslash") \
$esc.url(“shirdrn.org/users/index.vm?id=1&name=异域王者”) shirdrn.org%2Fusers%2Findex.vm%3Fid%3D1%26name%3D%E5%BC%82%E5%9F%9F%E7%8E%8B%E8%80%85
$esc.sql(“SELECT * FROM PERSON WHERE ID=’2008042319831′”) SELECT * FROM PERSON WHERE ID=”2008042319831”
\$esc.java() [说明]Escapes the characters in a String using Java String rules.
\$esc.javascript() [说明]Escapes the characters in a String using JavaScript String rules.
\$esc.xml() [说明]Escapes the characters in a String using XML entities.
\$esc.propertyKey() [说明]Escapes the characters in a String using java.util.Properties rules for escaping keys.
\$esc.propertyValue() [说明]Escapes the characters in a String using java.util.Properties rules for escaping values.