JSTL基础

下载： 从Apache标准标记库和解压的压缩文件。

 

JSTL全名为JavaServer Pages Standard Tag Library。JSTL是由JCP(Java Community Process)所制定的标准规范，它主要提供给Java Web开发人员一个标准通用的标签函数库。

 

标签引用：

1、以classPath中，加入jar包：  standard-1.1.2.jar ，  jstl-1.1.2.jar

2、在相目\WEB-INF\tld\文件夹中放入常用的tld文件：c.tld，fmt.tld

3、在jsp文件的顶部加入以下内容：

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

 

核心JSTL标签：

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

功能上分为4类：
1.表达式控制标签：out、set、remove、catch
2.流程控制标签：if、choose、when、otherwise
3.循环标签：forEach、forTokens
4.URL操作标签：import、url、redirect

demo:

<c:out value="&lt要显示的数据对象（未使用转义字符）&gt" escapeXml="true" default="默认值"></c:out>  
<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<jsp:useBean id="person" class="lihui.Person"></jsp:useBean>
  <c:set value="张三" var="name1" scope="session"></c:set>
<c:if test="条件1" var="name" [scope="page|request|session|application"]></c:if>

 

语法1：迭代一集合对象之所有成员

<c:forEach [var="varName"] items="collection" [varStatus="varStatusName"] [begin="begin"] [end="end"] [step="step"]>
本体内容
</c:forEach>

语法2：迭代指定的次数

<c:forEach [var="varName"] [varStatus="varStatusName"] begin="begin" end="end" [step="step"]>
本体内容
</c:forEach>

 <c:forEach> 遍历 List列表：

 对于一个基本类型的数组，当前元素将作为相应包装类（Integer、Float等等）的一个实例提供。

<c:forEach items="${domainList }" var="item">  
<tr>  
  <td align="center" valign="middle">${item["domain"]==null?"&nbsp;":item["domain"]}</td>  
  <td align="center" valign="middle"><fmt:formatDate value="${item['bind_date']}" pattern="yyyy-MM-dd HH:mm:ss"/></td>  
  <td align="center" valign="middle">  
    <c:if test="${item['domain']!=null}">  
    <a href="javascript:;" id="${item['domain']}" class="del">&nbsp;</a>  
    </c:if>  
    </td>  
</tr>    
</c:forEach> 

 <c:forEach> 遍历Map:

 对于一个java.util.Map，当前元素则作为一个java.util.Map.Entry提供。

<c:if test="${!empty permissionMap}">    
<c:forEach items="${permissionMap}" var="item">  
<tr>  
    <td>${item.value.id}</td>  
    <td>${item.value.urlOnClass}</td>  
    <td>${item.value.urlOnMethod}</td>  
</tr>  
</c:forEach>  
</c:if>    

 

<c:forTokens items="stringOfTokens" delims="delimiters" [var="varName"]  
[varStatus="varStatusName"] [begin="begin"] [end="end"] [step="step"]>  
本体内容  
</c:forTokens>  

 

 

<c:import> 把其他静态或动态文件包含到 JSP 页面。与<jsp:include>的区别是后者只能包含同一个web应用中的文件，前者可以包含其他web应用中的文件，甚至是网络上的资源

<c:import url="url" [context="context"] [value="value"] [scope="..."] [charEncoding="encoding"]></c:import>

<c:redirect url="url" [context="context"]>
            <c:param name="name1" value="value1">
       </c:redirect>

 

 

格式化标签：

使用JSTL格式标签来格式化和显示文本，日期，时间和数字的，国际化的网站。以下是在您的JSP的语法，包括格式化库：

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

以下是格式化JSTL标签列表：

Tag Description

<fmt:formatNumber>	To render numerical value with specific precision or format.
<fmt:parseNumber>	Parses the string representation of a number, currency, or percentage.
<fmt:formatDate>	Formats a date and/or time using the supplied styles and pattern
<fmt:parseDate>	Parses the string representation of a date and/or time
<fmt:bundle>	Loads a resource bundle to be used by its tag body.
<fmt:setLocale>	Stores the given locale in the locale configuration variable.
<fmt:setBundle>	Loads a resource bundle and stores it in the named scoped variable or the bundle configuration variable.
<fmt:timeZone>	Specifies the time zone for any time formatting or parsing actions nested in its body.
<fmt:setTimeZone>	Stores the given time zone in the time zone configuration variable
<fmt:message>	To display an internationalized message.
<fmt:requestEncoding>	Sets the request character encoding

SQL标签:

JSTL的SQL标签库标签可以交互关系型数据库（如Oracle，MySQL或Microsoft SQL Server的关系数据库管理系统）。

以下是在您的JSP语法包括JSTL SQL库：

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

以下是SQL JSTL标签的列表：

Tag Description

<sql:setDataSource>	Creates a simple DataSource suitable only for prototyping
<sql:query>	Executes the SQL query defined in its body or through the sql attribute.
<sql:update>	Executes the SQL update defined in its body or through the sql attribute.
<sql:param>	Sets a parameter in an SQL statement to the specified value.
<sql:dateParam>	Sets a parameter in an SQL statement to the specified java.util.Date value.
<sql:transaction >	Provides nested database action elements with a shared Connection, set up to execute all statements as one transaction.

XML 标签:

JSTL XML标记提供了一种创建和操作XML文档的JSP为中心的方式。以下是在您的JSP的语法包括JSTL XML库。

JSTL XML标记库具有自定义标签与XML数据交互。这包括XML解析，转换XML数据，流控制，基于XPath表达式。

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

在继续之前的例子中，将需要复制下面的两个XML和XPath相关的库到<Tomcat安装目录> 的\lib目录：

1. XercesImpl.jar: 下载地址 http://www.apache.org/dist/xerces/j/

2. xalan.jar: 下载地址 http://xml.apache.org/xalan-j/index.html

以下是XML JSTL标签列表：

Tag Description

<x:out>	Like <%= ... >, but for XPath expressions.
<x:parse>	Use to parse XML data specified either via an attribute or in the tag body.
<x:set >	Sets a variable to the value of an XPath expression.
<x:if >	Evaluates a test XPath expression and if it is true, it processes its body. If the test condition is false, the body is ignored.
<x:forEach>	To loop over nodes in an XML document.
<x:choose>	Simple conditional tag that establishes a context for mutually exclusive conditional operations, marked by <when> and <otherwise>
<x:when >	Subtag of <choose> that includes its body if its expression evalutes to 'true'
<x:otherwise >	Subtag of <choose> that follows <when> tags and runs only if all of the prior conditions evaluated to 'false'
<x:transform >	Applies an XSL transformation on a XML document
<x:param >	Use along with the transform tag to set a parameter in the XSLT stylesheet

JSTL 函数:

JSTL包括一些标准功能，其中大部分是常见的字符串操作函数。以下是在JSP的语法包函JSTL函数库：

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

以下是JSTL函数列表：

 

Function Description

fn:contains()	Tests if an input string contains the specified substring.
fn:containsIgnoreCase()	Tests if an input string contains the specified substring in a case insensitive way.
fn:endsWith()	Tests if an input string ends with the specified suffix.
fn:escapeXml()	Escapes characters that could be interpreted as XML markup.
fn:indexOf()	Returns the index withing a string of the first occurrence of a specified substring.
fn:join()	Joins all elements of an array into a string.
fn:length()	Returns the number of items in a collection, or the number of characters in a string.
fn:replace()	Returns a string resulting from replacing in an input string all occurrences with a given string.
fn:split()	Splits a string into an array of substrings.
fn:startsWith()	Tests if an input string starts with the specified prefix.
fn:substring()	Returns a subset of a string.
fn:substringAfter()	Returns a subset of a string following a specific substring.
fn:substringBefore()	Returns a subset of a string before a specific substring.
fn:toLowerCase()	Converts all of the characters of a string to lower case.
fn:toUpperCase()	Converts all of the characters of a string to upper case.
fn:trim()	Removes white spaces from both ends of a string.

 

转自：http://elf8848.iteye.com/blog/245559