jstl标签库的配置
jstl标签库的配置
* 将jstl.jar和standard.jar拷贝到WEB-INF/lib下（如果使用el表达式，不用拷贝这两个jar）
注意：jstl必须在能够支持j2ee1.4/servlet2.4/jsp2.0版本上的容器才能运行，这个环境
是目前较为常用的环境
标签库的使用
* 采用taglib指令引入
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>
自定义函数库：
1、定义类和方法（方法必须是public static）
2、编写自定义tld文件，并且将此文件放到WEB-INF或WEB-INF任意子目录下
3、在jsp中采用taglib指令引入自定义函数库
4、采用 前缀+冒号+函数名 调用即可
Use.java
Group.java
JstlElAction.java
jstl_el.jsp
JstlCoreAction.java
jstl_core.jsp
JstlFmtAction.java
jstl_fmt.jsp
JstlFnAction.java
MyFunctions.java
MyFunctions.tld
struts-config.xml
Web.xml
jstl_fn.jsp
* 将jstl.jar和standard.jar拷贝到WEB-INF/lib下（如果使用el表达式，不用拷贝这两个jar）
注意：jstl必须在能够支持j2ee1.4/servlet2.4/jsp2.0版本上的容器才能运行，这个环境
是目前较为常用的环境
标签库的使用
* 采用taglib指令引入
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>
自定义函数库：
1、定义类和方法（方法必须是public static）
2、编写自定义tld文件，并且将此文件放到WEB-INF或WEB-INF任意子目录下
3、在jsp中采用taglib指令引入自定义函数库
4、采用 前缀+冒号+函数名 调用即可
Use.java
package com.bjsxt.struts;
public class User {
private String username1;
private int age;
private Group group;
public String getUsername() {
return username1;
}
public void setUsername(String username) {
this.username1 = username;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public Group getGroup() {
return group;
}
public void setGroup(Group group) {
this.group = group;
}
}
Group.java
package com.bjsxt.struts;
public class Group {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
JstlElAction.java
package com.bjsxt.struts;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
/**
* 测试EL表达式
* @author Administrator
*
*/
public class JstlElAction extends Action {
@Override
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
//普通字符串
request.setAttribute("hello", "hello world");
//结构
Group group = new Group();
group.setName("尚学堂");
User user = new User();
user.setUsername("张三");
user.setAge(18);
user.setGroup(group);
request.setAttribute("user", user);
//map
Map mapValue = new HashMap();
mapValue.put("key1", "value1");
mapValue.put("key2", "value2");
request.setAttribute("mapvalue", mapValue);
//字符串数组
String[] strArray = new String[]{"a", "b", "c"};
request.setAttribute("strarray", strArray);
User[] users = new User[10];
for (int i=0; i<10; i++) {
User u = new User();
u.setUsername("U_" + i);
users[i] = u;
}
request.setAttribute("users", users);
List userList = new ArrayList();
for (int i=0; i<10; i++) {
User uu = new User();
uu.setUsername("UU_" + i);
userList.add(uu);
}
request.setAttribute("userlist", userList);
//empty
request.setAttribute("value1", null);
request.setAttribute("value2", "");
request.setAttribute("value3", new ArrayList());
request.setAttribute("value4", "123456");
return mapping.findForward("success");
}
}
jstl_el.jsp
<%@ page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB18030">
<title>测试EL表达式</title>
</head>
<body>
<h1>测试EL表达式</h1><br>
<hr>
<li>普通字符串</li><br>
hello(jsp脚本):<%=request.getAttribute("hello") %><br>
hello(el表达式,el表达式的使用方法$和{}):${hello }<br>
hello(el表达式,el的隐含对象pageScope,requestScope,sessionScope,applicationScope,<br> 如果未指定scope,它的搜索顺序为pageScope~applicationScope):${requestScope.hello }<br>
hello(el表达式,scope=session):${sessionScope.hello }<br>
<p>
<li>结构,采用.进行导航，也称存取器</li><br>
姓名：${user.username }<br>
年龄：${user.age }<br>
所属组：${user.group.name }<br>
<p>
<li>输出map,采用.进行导航，也称存取器</li><br>
mapvalue.key1:${mapvalue.key1 }<br>
mapvalue.key2:${mapvalue.key2 }<br>
<p>
<li>输出数组,采用[]和下标</li><br>
strarray[2]:${strarray[1] }<br>
<p>
<li>输出对象数组,采用[]和下标</li><br>
userarray[3].username:${users[2].username }<br>
<p>
<li>输出list,采用[]和下标</li><br>
userlist[5].username:${userlist[4].username }<br>
<p>
<li>el表达式对运算符的支持</li><br>
1+2=${1+2 }<br>
10/5=${10/5 }<br>
10 div 5=${10 div 5 }<br>
10%3=${10 % 3 }<br>
10 mod 3=${10 mod 3 }<br>
<!--
==/eq
!=/ne
</lt
>/gt
<=/le
>=/ge
&&/and
||/or
!/not
//div
%/mod
-->
<li>测试empty</li><br>
value1:${empty value1 }<br>
value2:${empty value2 }<br>
value3:${empty value3 }<br>
value4:${empty value4 }<br>
value4:${!empty value4 }<br>
</body>
</html>
JstlCoreAction.java
package com.bjsxt.struts;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
/**
* 测试jstl核心库
* @author Administrator
*
*/
public class JstlCoreAction extends Action {
@Override
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
//普通属性
request.setAttribute("hello", "Hello World");
//测试条件控制标签
request.setAttribute("v1", 1);
request.setAttribute("v2", 2);
request.setAttribute("v3", new ArrayList());
request.setAttribute("v4", "test");
//html文本
request.setAttribute("bj", "<font color='red'>北京欢迎您</font>");
//测试c:forEach
Group group = new Group();
group.setName("尚学堂");
List userList = new ArrayList();
for (int i=0; i<10; i++) {
User user = new User();
user.setUsername("user_" + i);
user.setAge(18+i);
user.setGroup(group);
userList.add(user);
}
request.setAttribute("userlist", userList);
//测试循环输出map
Map map = new HashMap();
map.put("k1", "v1");
map.put("k2", "v2");
request.setAttribute("mapvalue", map);
//测试c:forTokens
request.setAttribute("strTokens", "1,2,3,4,5,6");
return mapping.findForward("success");
}
}
jstl_core.jsp
<%@ page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB18030">
<title>测试jstl核心库</title>
</head>
<body>
<h1>测试jstl核心库</h1>
<hr>
<li>测试c:out</li><br>
hello(default):<c:out value="${hello}"/><br>
hello(el表达式):${hello }<br>
hello(default="123"):<c:out value="${abc}" default="123"/><br>
hello(default="123"):<c:out value="${abc}">123</c:out><br>
bj(defalut):<c:out value="${bj}"/><br>
bj(escapeXml="true"):<c:out value="${bj}" escapeXml="true"/><br>
bj(escapeXml="false"):<c:out value="${bj}" escapeXml="false"/><br>
bj(el表达式):${bj }<br>
<p>
<li>测试c:set和c:remove</li><br>
<c:set value="123" var="temp"/>
temp:${temp }<br>
<c:remove var="temp"/>
temp:${temp }<br>
<p>
<li>测试条件控制标签c:if</li><br>
<c:if test="${v1 lt v2}" var="v">
v1小于v2<br>v=${v }<br>
</c:if>
<c:if test="${empty v3}">
v3为空<br>
</c:if>
<c:if test="${empty v4}">
v4为空<br>
</c:if>
<p>
<li>测试条件控制标签c:choose,c:when,c:otherwise</li><br>
<c:choose>
<c:when test="${v1 lt v2}">
v1小于v2<br>
</c:when>
<c:otherwise>
v1大于v2<br>
</c:otherwise>
</c:choose>
<c:choose>
<c:when test="${empty v4}">
v4为空<br>
</c:when>
<c:otherwise>
v4不为空<br>
</c:otherwise>
</c:choose>
<p>
<li>测试循环控制标签c:forEach</li><br>
<table border="1">
<tr>
<td>姓名</td>
<td>年龄</td>
<td>所属组</td>
</tr>
<c:choose>
<c:when test="${empty userlist}">
<tr>
<td colspan="3">没有符合条件的数据!</td>
</tr>
</c:when>
<c:otherwise>
<c:forEach items="${userlist}" var="u">
<tr>
<td>${u.username }</td>
<td>${u.age }</td>
<td>${u.group.name }</td>
</tr>
</c:forEach>
</c:otherwise>
</c:choose>
</table>
<p>
<li>测试循环控制标签c:forEach,varstatus</li><br>
<table border="1">
<tr>
<td>姓名</td>
<td>年龄</td>
<td>所属组</td>
</tr>
<c:choose>
<c:when test="${empty userlist}">
<tr>
<td colspan="3">没有符合条件的数据!</td>
</tr>
</c:when>
<c:otherwise>
<c:forEach items="${userlist}" var="user" varStatus="vs">
<c:choose>
<c:when test="${vs.count % 2 == 0}">
<tr bgcolor="red">
</c:when>
<c:otherwise>
<tr>
</c:otherwise>
</c:choose>
<tr>
<td>
<c:out value="${user.username}"/>
</td>
<td>
<c:out value="${user.age}"/>
</td>
<td>
<c:out value="${user.group.name}"/>
</td>
</tr>
</c:forEach>
</c:otherwise>
</c:choose>
</table>
<p>
<li>测试循环控制标签c:forEach,begin,end,step</li><br>
<table border="1">
<tr>
<td>姓名</td>
<td>年龄</td>
<td>所属组</td>
</tr>
<c:choose>
<c:when test="${empty userlist}">
<tr>
<td colspan="3">没有符合条件的数据!</td>
</tr>
</c:when>
<c:otherwise>
<c:forEach items="${userlist}" var="user" begin="2" end="8" step="2">
<tr>
<td>${user.username}</td>
<td>${user.age}</td>
<td>${user.group.name }</td>
</tr>
</c:forEach>
</c:otherwise>
</c:choose>
</table>
<p>
<li>测试循环控制标签c:forEach，普通循环</li><br>
<c:forEach begin="1" end="10">
a<br>
</c:forEach>
<p>
<li>测试循环控制标签c:forEach，输出map</li><br>
<c:forEach items="${mapvalue}" var="v">
${v.key }=${v.value }<br>
</c:forEach>
<p>
<li>测试循环控制标签c:forTokens</li><br>
<c:forTokens items="${strTokens}" delims="," var="v">
${v }<br>
</c:forTokens>
<p>
<li>测试c:catch</li><br>
<%
try {
Integer.parseInt("asdfsdf");
}catch(Exception e) {
out.println(e.getMessage());
}
%>
<p>
<c:catch var="exinfo">
<%
Integer.parseInt("asdfsdf");
%>
</c:catch>
${exinfo }<br>
<p>
<li>测试c:import</li><br>
<c:import url="http://localhost:8080/struts_login"/>
<p>
<li>测试c:url和c:param</li><br>
<c:url value="http://localhost:8080/drp/sysmgr/user_add.jsp" var="v">
<c:param name="username" value="Jack"/>
<c:param name="age" value="20"/>
</c:url>
${v }<br>
<li>测试:redirect</li><br>
<c:redirect context="/struts_login" url="/index.jsp"/>
</body>
</html>
JstlFmtAction.java
package com.bjsxt.struts;
import java.util.Date;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
/**
* 测试jstl格式化库
* @author Administrator
*
*/
public class JstlFmtAction extends Action {
@Override
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
request.setAttribute("today", new Date());
request.setAttribute("n", 123456.123);
request.setAttribute("p", 0.12345);
return mapping.findForward("success");
}
}
jstl_fmt.jsp
<%@ page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB18030">
<title>测试jstl格式化库</title>
</head>
<body>
<h1>1983测试jstl格式化库</h1>
<hr>
<li>测试日期的格式化</li><br>
today(default):<fmt:formatDate value="${today}"/><br>
today(type="date"):<fmt:formatDate value="${today}" type="date"/><br>
today(type="time"):<fmt:formatDate value="${today}" type="time"/><br>
today(type="both"):<fmt:formatDate value="${today}" type="both"/><br>
today(dateStyle="short"):<fmt:formatDate value="${today}" dateStyle="short"/><br>
today(dateStyle="medium"):<fmt:formatDate value="${today}" dateStyle="medium"/><br>
today(dateStyle="long"):<fmt:formatDate value="${today}" dateStyle="long"/><br>
today(dateStyle="full"):<fmt:formatDate value="${today}" dateStyle="full"/><br>
today(pattern="yyyy/MM/dd HH:mm:ss"):<fmt:formatDate value="${today}" pattern="yyyy/MM/dd HH:mm:ss"/><br>
today(pattern="yyyy/MM/dd HH:mm:ss"):<fmt:formatDate value="${today}" pattern="yyyy/MM/dd HH:mm:ss" var="d"/><br>
${d }<br>
<p>
<li>测试数字的格式化</li><br>
n(default):<fmt:formatNumber value="${n}"/><br>
n(pattern="###,###.##"):<fmt:formatNumber value="${n}" pattern="###,###.##"/><br>
n(pattern="###,###.0000"):<fmt:formatNumber value="${n}" pattern="###,###.0000"/><br>
n(groupingUsed="false"):<fmt:formatNumber value="${n}" groupingUsed="false"/><br>
n(minIntegerDigits="10"):<fmt:formatNumber value="${n}" minIntegerDigits="10"/><br>
n(type="currency"):<fmt:formatNumber value="${n}" type="currency"/><br>
n(type="currency"):<fmt:formatNumber value="${n}" type="currency" currencySymbol="$"/><br>
n(type="percent"):<fmt:formatNumber value="${p}" type="percent" maxFractionDigits="2" minFractionDigits="2"/><br>
</body>
</html>
JstlFnAction.java
package com.bjsxt.struts;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
/**
* 测试jstl函数库
* @author Administrator
*
*/
public class JstlFnAction extends Action {
@Override
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
request.setAttribute("hello", "hello world");
List list = new ArrayList();
list.add("t1");
list.add("t2");
request.setAttribute("list", list);
request.setAttribute("name", "Tom");
return mapping.findForward("success");
}
}
MyFunctions.java
package com.bjsxt.struts;
public class MyFunctions {
/**
* 方法必须是public static
* @param name
* @return
*/
public static String sayHello(String name) {
return "Hello " + name;
}
}
MyFunctions.tld
<?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>my functions library</description>
<display-name>my functions</display-name>
<tlib-version>1.0</tlib-version>
<short-name>my</short-name>
<uri>http://www.bjsxt.com/functions</uri>
<function>
<name>sayHello</name>
<function-class>com.bjsxt.struts.MyFunctions</function-class>
<function-signature>java.lang.String sayHello(java.lang.String)</function-signature>
</function>
</taglib>
struts-config.xml
<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE struts-config PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 1.2//EN"
"http://jakarta.apache.org/struts/dtds/struts-config_1_2.dtd">
<struts-config>
<action-mappings>
<action path="/jstlel"
type="com.bjsxt.struts.JstlElAction"
>
<forward name="success" path="/jstl_el.jsp"/>
</action>
<action path="/jstlcore"
type="com.bjsxt.struts.JstlCoreAction"
>
<forward name="success" path="/jstl_core.jsp"/>
</action>
<action path="/jstlfmt"
type="com.bjsxt.struts.JstlFmtAction"
>
<forward name="success" path="/jstl_fmt.jsp"/>
</action>
<action path="/jstlfn"
type="com.bjsxt.struts.JstlFnAction"
>
<forward name="success" path="/jstl_fn.jsp"/>
</action>
</action-mappings>
</struts-config>
Web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
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-app_2_4.xsd">
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<!-- Standard Action Servlet Configuration (with debugging) -->
<servlet>
<servlet-name>action</servlet-name>
<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
<init-param>
<param-name>config</param-name>
<param-value>/WEB-INF/struts-config.xml</param-value>
</init-param>
<init-param>
<param-name>debug</param-name>
<param-value>2</param-value>
</init-param>
<init-param>
<param-name>detail</param-name>
<param-value>2</param-value>
</init-param>
<load-on-startup>2</load-on-startup>
</servlet>
<!-- Standard Action Servlet Mapping -->
<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
</web-app>
jstl_fn.jsp
<%@ page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030"%>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions"%>
<%@ taglib prefix="my" uri="http://www.bjsxt.com/functions"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB18030">
<title>测试jstl函数库</title>
</head>
<body>
<h1>测试jstl函数库</h1>
<hr>
hello.length=(jsp脚本):<%=((String)request.getAttribute("hello")).length() %><br>
hello.length(jstl函数库，函数调用必须在el表达式中 前缀+冒号+函数名):${fn:length(hello) }<br>
list.length:${fn:length(list) }<br>
<p>
<li>测试自定义函数库</li><br>
${my:sayHello(name) }<br>
</body>
</html>