<?xml version="1.0" encoding="UTF-8" ?> <taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd" version="2.0"> <description>JSTL 1.1 functions library</description> <display-name>JSTL functions</display-name> <tlib-version>1.1</tlib-version> <short-name>fn</short-name> <uri>http://java.sun.com/jsp/jstl/functions</uri> <function> <description> Tests if an input string contains the specified substring. </description> <name>contains</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>boolean contains(java.lang.String, java.lang.String)</function-signature> <example> <c:if test="${fn:contains(name, searchString)}"> </example> </function> <function> <description> Tests if an input string contains the specified substring in a case insensitive way. </description> <name>containsIgnoreCase</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>boolean containsIgnoreCase(java.lang.String, java.lang.String)</function-signature> <example> <c:if test="${fn:containsIgnoreCase(name, searchString)}"> </example> </function> <function> <description> Tests if an input string ends with the specified suffix. </description> <name>endsWith</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>boolean endsWith(java.lang.String, java.lang.String)</function-signature> <example> <c:if test="${fn:endsWith(filename, ".txt")}"> </example> </function> <function> <description> Escapes characters that could be interpreted as XML markup. </description> <name>escapeXml</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>java.lang.String escapeXml(java.lang.String)</function-signature> <example> ${fn:escapeXml(param:info)} </example> </function> <function> <description> Returns the index withing a string of the first occurrence of a specified substring. </description> <name>indexOf</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>int indexOf(java.lang.String, java.lang.String)</function-signature> <example> ${fn:indexOf(name, "-")} </example> </function> <function> <description> Joins all elements of an array into a string. </description> <name>join</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>java.lang.String join(java.lang.String[], java.lang.String)</function-signature> <example> ${fn:join(array, ";")} </example> </function> <function> <description> Returns the number of items in a collection, or the number of characters in a string. </description> <name>length</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>int length(java.lang.Object)</function-signature> <example> You have ${fn:length(shoppingCart.products)} in your shopping cart. </example> </function> <function> <description> Returns a string resulting from replacing in an input string all occurrences of a "before" string into an "after" substring. </description> <name>replace</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>java.lang.String replace(java.lang.String, java.lang.String, java.lang.String)</function-signature> <example> ${fn:replace(text, "-", "•")} </example> </function> <function> <description> Splits a string into an array of substrings. </description> <name>split</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>java.lang.String[] split(java.lang.String, java.lang.String)</function-signature> <example> ${fn:split(customerNames, ";")} </example> </function> <function> <description> Tests if an input string starts with the specified prefix. </description> <name>startsWith</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>boolean startsWith(java.lang.String, java.lang.String)</function-signature> <example> <c:if test="${fn:startsWith(product.id, "100-")}"> </example> </function> <function> <description> Returns a subset of a string. </description> <name>substring</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>java.lang.String substring(java.lang.String, int, int)</function-signature> <example> P.O. Box: ${fn:substring(zip, 6, -1)} </example> </function> <function> <description> Returns a subset of a string following a specific substring. </description> <name>substringAfter</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>java.lang.String substringAfter(java.lang.String, java.lang.String)</function-signature> <example> P.O. Box: ${fn:substringAfter(zip, "-")} </example> </function> <function> <description> Returns a subset of a string before a specific substring. </description> <name>substringBefore</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>java.lang.String substringBefore(java.lang.String, java.lang.String)</function-signature> <example> Zip (without P.O. Box): ${fn:substringBefore(zip, "-")} </example> </function> <function> <description> Converts all of the characters of a string to lower case. </description> <name>toLowerCase</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>java.lang.String toLowerCase(java.lang.String)</function-signature> <example> Product name: ${fn:toLowerCase(product.name)} </example> </function> <function> <description> Converts all of the characters of a string to upper case. </description> <name>toUpperCase</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>java.lang.String toUpperCase(java.lang.String)</function-signature> <example> Product name: ${fn:UpperCase(product.name)} </example> </function> <function> <description> Removes white spaces from both ends of a string. </description> <name>trim</name> <function-class>org.apache.taglibs.standard.functions.Functions</function-class> <function-signature>java.lang.String trim(java.lang.String)</function-signature> <example> Name: ${fn:trim(name)} </example> </function> </taglib>
使用方法
上述是http://java.sun.com/jsp/jstl/functions的源代码 用来弥补JSTL在处理字符串上的缺陷 使用的方式 一、 <%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %> 二、 在WEB-INF目录下创建functions.ltd 然后将上述代码拷进去 <%@ taglib prefix="fn" uri="/WEB-INF/functions.tld" %> 或则 <%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %> 区别在于说这样的话即使不联网也可以使用
函数说明
fn:contains 判断字符串是否包含另外一个字符串 <c:if test="${fn:contains(name, searchString)}"> fn:containsIgnoreCase 判断字符串是否包含另外一个字符串(大小写无关) <c:if test="${fn:containsIgnoreCase(name, searchString)}"> fn:endsWith 判断字符串是否以另外字符串结束 <c:if test="${fn:endsWith(filename, ".txt")}"> fn:escapeXml 把一些字符转成XML表示，例如<字符应该转为< ${fn:escapeXml(param:info)} fn:indexOf 子字符串在母字符串中出现的位置 ${fn:indexOf(name, "-")} fn:join 将数组中的数据联合成一个新字符串，并使用指定字符格开 ${fn:join(array, ";")} fn:length 获取字符串的长度，或者数组的大小 ${fn:length(shoppingCart.products)} fn:replace 替换字符串中指定的字符 ${fn:replace(text, "-", "•")} fn:split 把字符串按照指定字符切分 ${fn:split(customerNames, ";")} fn:startsWith 判断字符串是否以某个子串开始 <c:if test="${fn:startsWith(product.id, "100-")}"> fn:substring 获取子串 ${fn:substring(zip, 6, -1)} fn:substringAfter 获取从某个字符所在位置开始的子串 ${fn:substringAfter(zip, "-")} fn:substringBefore 获取从开始到某个字符所在位置的子串 ${fn:substringBefore(zip, "-")} fn:toLowerCase 转为小写 ${fn.toLowerCase(product.name)} fn:toUpperCase 转为大写字符 ${fn.UpperCase(product.name)} fn:trim 去除字符串前后的空格 ${fn.trim(name)}