jsp jstl 功能标签库

 

要使用到jstl里某些功能，如获取list的长度等这些就可以使用jstl里的功能标签库，首先得先引用这两个jstl库

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions"%>

 

具体这个功能标签库里哪些功能可以参考以下的库配置文件，里面每个功能都有功能说明，最重要的还有使用例子，里面大多数是类型string里的方法，

如果以下的标签都不合用

涉及到格式化可以使用

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

<?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>
      &lt;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>
      &lt;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>
      &lt;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, "-", "&#149;")}
    </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>
      &lt;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>