Struts Bean标签库中的标签可以访问已存在的JavaBean以及它们的属性，还可以定义新的Bean，把它存放在page范围内或用户指定的范围内，供网页其他元素访问。Bean标签库大概分为三类：
用于访问HTTP请求信息或JSP隐含对象的Bean标签
用于访问Web应用资源的Bean标签
用于定义或者输出JavaBean的Bean标签
访问HTTP请求信息或JSP隐含对象
<bean:cookie>:访问Cookie信息
<bean:header>:访问HTTP请求中的Header信息
<bean:parameter>；访问请求参数。
<bean:page>:访问JSP隐含对象。
1.<bean:cookie>标签
该标签可以检索保存在浏览器中的Cookie，具有属性id,name,multiple,value，id是对cookie在该页面中的唯一标识，在页面其它地方可以通过id进行引用。相当于用cookie直接引用。Name是相应的cookie名称。Multiple可以赋予任意值，如果设置了该属性，可以检索出所有和Cookie名字匹配的Cookie名字匹配的Cookie，此时，id属性定义了一个Cookie数组类型的变量，而不是单个Cookie类型的变量。例如：
<bean:cookie id="myCookie" name="tags/cookiedemo" value="ddddddddd"/>
<bean:write name="myCookie" property="name"/>
<bean:write name="myCookie" property="value"/>
<%
String names=myCookie.getName();
String value=myCookie.getValue();
out.println("this cookie name is "+names+",value is "+value+"");
%>
2.<bean:header>标签
该标签用于检索HTTP请求中的Header信息。如果没有指定multiple属性则依据刚取回的值创建一个String类型的bean。如果指定了multiple属性则依据刚取回的值创建一个String[]类型的数组。例如：
<logic:present header="User-Agent">
<!-- 其它标签通过绑定到page作用域中的属性使用该值 -->
您的浏览器是<bean:header id="userAgent" name="User-Agent"/>
<bean:write name="userAgent" /><br/>
<!-- JSP脚本通过scripting变量使用该值 -->
<%
out.println("您的浏览器是"+userAgent+"。<br/>");
%>
</logic:present>
<%
String id = "userAgent";
String name = "User-Agent";
String value = ((HttpServletRequest)pageContext.getRequest()).getHeader(name);
out.println("============="+value);
%>
3.<bean:parameter>标签
该标签用于检索HTTP请求参数，具有以下属性：
id属性：定义一个java.lang.String类型的变量，这个变量存放在page范围内。
name属性：指定请求参数名。
value属性：请求指定参数的默认值
如果没有指定multiple属性则依据刚取回的值创建一个String类型的bean。如果指定了multiple属性则依据刚取回的值创建一个String[]类型的数组。例如：
<html:link page="/parameter2.jsptestString=this+is+a+test&testInt=123456">
请求参数
</html:link>
<bean:parameter id="test1" name="testString" value="" />
The first test is: <bean:write name="test1" />
<bean:parameter id="test2" name="testInt" value=""/>
The second test is:<bean:write name="test2"/>
4.<bean:page>标签
该标签用于检索获取JSP隐含对象，如session、request和response等，具有以下属性：
id属性：定义了一个引用隐含对象的变量，这个变量存放在page范围
property属性：指定隐含对象的名字，可选值包括application,config,request,response,session 例如：
<bean:page id="mySession" property="session"/>
<%
out.println("Session time:"+mySession.getCreationTime());
%>
<bean:message>:显示Resource Bundle中的消息。
<bean:resource>；把Web资源装载到一个JavaBean中。
<bean:struts>；访问Struts的内在配置对象。
<bean:include>;包含一个web资源。
1.<bean:include>标签
该标签用语将其他web资源包含进当前页面中，和标准的JSP标签<jsp:include>很类似，都可以用来包含其他Web资源的内容，区别在于<bean:include>标签把其他的Web资源的内容存放在一个对象中，而不是直接显示到网页，<bean:include>标签的id属性定义一个代表其他Web资源的变量。
<bean:include id="value" page="/index.jsp"/> //在当前资源中
<bean:write name="value" filter="false"/><br/>
// filter为true则为原文件
<%
out.println(value);
%>
2.<bean:message>标签 国际化
该标签用与显示资源文件中的消息文本。该标签有一个bundle属性，它和struts-config.xml文件中的messsge-resources标记内的key属性对应。
<message-resources parameter="com.resources" key="beanmessage">
//struts-config
message1=this is a test!
message2=this is a test too!
//resource中
<bean:message bundle="beanmessage" key="message1"/>
//jsp中
3.<bean:resource>标签
该标签用于检索、获得Web资源内容，如：网页的源代码。该标签的属性有：id有其他标签一样，name指定Web资源的路径，input如果没有设置，则id属性默认为一个字符类型对象，如果给input赋值yes，则id属性所定义的对象为java.IputStream。例如：
<bean:resource id="indexpage" name="/index.jsp" input="yes"/>
<bean:write name="indexpage" filter="false"/>
4.<bean:struts>标签
该标签用于获取Struts框架内的一些对象，如AationForm和ActionForward等。。<bean:struts>标签的id属性定义一个page范围的变量，用来引用Struts框架的内在对象，必需设置formbean,forward,mapping属性中的一个属性，来指定被引用的Struts内在对象。
formbean属性：指定ActionFormBean对象，和struts配置文件的<form-bean>元素匹配。
forward属性；指定ActionForward对象，和配置文件的<global-forwards>元素的<forward>子元素匹配。
mapping属性：指定ActionMapping对象，和配置文件的<action>元素匹配
例如：
<bean:struts id="listFormBean" formBean="listForm"/>
name:<bean:write name="listFormBean" property="name"/><br/>
type:<bean:write name="listFormBean" property="type"/><br/>
dynamic:<bean:write name="listFormBean" property="dynamic"/><br/>
<bean:define>：用于定义一个变量。
<bean:write>： 显示JavaBean属性的内容。
<bean:size>： 获得集合对象或数组对象的长度。
1.<bean:define>标签
该标签用于定义一个变量，id属性指定变量的名字，toScope属性指定这个变量的存放范围，如果没有设置，则这个变量存放在page范围内，给id属性定义的变量赋值有三种方式：
第一种是，通过value属性直接赋值；
第二种是，通过name和porperty共同指定一个变量来给id所定义的变量，name——bean，porperty——属性；
第三种是，通过type属性和name联合指定id所定义的变量类型，type——id定义变量的完整类型，name——存在的javaBean。例如：
<bean:define id="string" value="this is a test"/>
<bean:write name="string"/>--%>
<%
Date d = new Date();
pageContext.setAttribute("currDate",d);
%>
<bean:define id="milliseconds" name="currDate" property="time"/>
当前时间距离1970年1月1日的毫秒数为：<bean:write name="milliseconds"/>
2.<bean:size>标签
该标签用于获取集合或者数组的长度。
id属性定义一个Integer类型的变量，那么属性指定已经存在的Map，Collection或数组变量，id属性定义的变量值为Map，collection或数组的长度。
name属性为对象名字。例如：
<%
ArrayList testlist=new ArrayList();
testlist.add(new Integer(1));
testlist.add(new Integer(2));
testlist.add(new Integer(3));
pageContext.setAttribute("listforcount",testlist);
%>
<bean:size id="size" name="listforcount"/>
长度为：<bean:write name="size"/>
3.<bean:write>标签
该标签用于输出各种类型的对象，有点类似与System.out.println（）。例如：
<%
String a = "string for test";
pageContext.setAttribute("test",a);
%>
<bean:write name="test"/>
标签logic的示例用法。
LogicCompare.jsp
<%@ page language="java" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<%@ page import="logictaglibs.SomeBean" %>
<html:html>
<head>
<title>Logic Compare sample code</title>
</head>
<body bgcolor="white">
<h3>Logic Compare sample code</h3>
<p>This page provides examples of the following Struts LOGIC tags:<br>
<ul>
<li><logic:equal></li>
<li><logic:lessEqual></li>
<li><logic:lessThan></li>
<li><logic:greaterEqual></li>
<li><logic:greaterThan></li>
<li><logic:notEqual></li>
</ul>
<%
Cookie c = new Cookie("username", "Linda");
c.setComment("A test cookie");
c.setMaxAge(3600); //60 seconds times 60 minutes
response.addCookie(c);
%>
<logic:equal cookie="username" value="Linda" >
UserName in Cookie is Linda <p>
</logic:equal>
<logic:equal header="Accept-Language" value="zh-cn" >
Client?¡¥s language is: zh-cn. <p>
</logic:equal>
<logic:greaterThan parameter="arg1" value="100" >
The first request parameter is greater than 100 <p>
</logic:greaterThan >
<%
request.setAttribute("intBean",new Integer(100));
%>
<logic:equal name="intBean" value="100" >
The value of intBean is "100".<p>
</logic:equal >
<%
SomeBean bean=new SomeBean();
bean.setName("Linda");
request.setAttribute("someBean",bean);
%>
<logic:notEqual name="someBean" property="name" value="Tom" >
The name of someBean is not "Tom" <p>
</logic:notEqual >
<% request.setAttribute("number","100"); %>
<logic:equal name="number" value="100.0" >
"100" equals "100.0" <p>
</logic:equal >
<logic:lessThan name="number" value="100.0a" >
"100" is less than "100.0a" <p>
</logic:lessThan >
</body>
</html:html>
LogicForward.jsp
<%@ page language="java" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<html:html>
<head>
<title>Logic Forward sample code</title>
</head>
<body bgcolor="white">
<logic:forward name="index"/>
</body>
</html:html>
LogicIterate.jsp
<%@ page language="java" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<%@ page import="java.util.HashMap" %>
<%@ page import="java.util.Vector" %>
<html:html>
<head>
<title>Logic Iterate sample code</title>
</head>
<body bgcolor="white">
<h3>Logic Iterate sample code</h3>
<p>This page provides examples of the following Struts LOGIC tags:<br>
<ul>
<li><logic:iterate></li>
</ul>
<table border="1">
<tr>
<td>
<%--
Variables used on this page
--%>
<%
HashMap months = new HashMap();
months.put("Jan.", "January");
months.put("Feb.", "February");
months.put("Mar.", "March");
request.setAttribute("months", months);
%>
<%--
The following section shows iterate.
--%>
<logic:iterate id="element" indexId="ind" name="months">
<bean:write name="ind"/>.
<bean:write name="element" property="key"/>:
<bean:write name="element" property="value"/><BR>
</logic:iterate><P>
</td>
<td>
<%
HashMap h = new HashMap();
String vegetables[] = {"pepper", "cucumber"};
String fruits[] = {"apple","orange","banana","cherry","watermelon"};
String flowers[] = {"chrysanthemum","rose"};
String trees[]={"willow"};
h.put("Vegetables", vegetables);
h.put("Fruits", fruits);
h.put("Flowers", flowers);
h.put("Trees",trees);
request.setAttribute("catalog", h);
%>
<%--
The following section shows iterate.
--%>
<logic:iterate id="element" indexId="ind" name="catalog">
<bean:write name="ind"/>. <bean:write name="element" property="key"/><BR>
<logic:iterate id="elementValue" name="element" property="value" >
-----<bean:write name="elementValue"/><BR>
</logic:iterate>
</logic:iterate><P>
</td>
<td>
<%
Vector animals=new Vector();
animals.addElement("Dog");
animals.addElement("Cat");
animals.addElement("Bird");
animals.addElement("Chick");
request.setAttribute("Animals", animals);
%>
<logic:iterate id="element" name="Animals">
<bean:write name="element"/><BR>
</logic:iterate><p>
</td>
<td>
<logic:iterate id="element" indexId="index" name="Animals" offset="1" length="2">
<bean:write name="index"/>.<bean:write name="element"/><BR>
</logic:iterate><p>
</td>
<td>
<logic:iterate id="header" collection="<%= request.getHeaderNames() %>">
<bean:write name="header"/><BR>
</logic:iterate>
</td>
</tr>
<table>
</body>
</html:html>
LogicMatch.jsp
<%@ page language="java" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<%@ page import="java.util.Enumeration" %>
<html:html>
<head>
<title>Logic Match sample code</title>
</head>
<body bgcolor="white">
<h3>Logic Match sample code</h3>
<p>This page provides examples of the following Struts LOGIC tags:<br>
<ul>
<li><logic:match></li>
<li><logic:notMatch></li>
</ul>
<%--
Variables used on this page
--%>
<%
request.setAttribute("authorName", "LindaSun");
%>
<%--
The following section shows match and notMatch.
--%>
<logic:match name="authorName" scope="request" value="Linda">
<bean:write name="authorName"/> has the string 'Sun' in it.
</logic:match>
<logic:notMatch name="authorName" scope="request" value="Linda">
<bean:write name="authorName"/> doesn't have the string 'Linda' in it.
</logic:notMatch>
<BR>
<logic:match name="authorName" scope="request" value="Linda" location="start">
<bean:write name="authorName"/> starts with the string 'Linda'.
</logic:match>
<logic:notMatch name="authorName" scope="request" value="Linda" location="start">
<bean:write name="authorName"/> doesn't start with the string 'Linda'.
</logic:notMatch>
<BR>
<logic:match header="user-agent" value="Windows">
You're running Windows
</logic:match>
<logic:notMatch header="user-agent" value="Windows">
You're not running Windows
</logic:notMatch>
<BR>
</body>
</html:html>
LogicPresence.jsp
<%@ page language="java" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<%@ page import="java.util.HashMap" %>
<%@ page import="org.apache.struts.Globals" %>
<%@ page import="org.apache.struts.action.ActionMessage" %>
<%@ page import="org.apache.struts.action.ActionErrors" %>
<html:html>
<head>
<title>Logic Presence sample code</title>
</head>
<body bgcolor="white">
<h3>Logic Presence sample code</h3>
<p>This page provides examples of the following Struts LOGIC tags:<br>
<ul>
<li><logic:empty></li>
<li><logic:messagesPresent></li>
<li><logic:messagesNotPresent></li>
<li><logic:notEmpty></li>
<li><logic:notPresent></li>
<li><logic:present></li>
</ul>
<%--
Variables used on this page
--%>
<%
ActionErrors errors = new ActionErrors();
errors.add("totallylost", new ActionMessage("application.totally.lost"));
request.setAttribute(Globals.ERROR_KEY, errors);
request.setAttribute("myerrors", errors);
request.setAttribute("emptyString", "");
%>
<%--
The following section shows empty and notEmpty.
--%>
<logic:empty name="emptyString">
The variable named emptyString is empty!<P>
</logic:empty>
<logic:notEmpty name="emptyString">
The variable named emptyString is not empty!<P>
</logic:notEmpty>
<P>
<%--
The following section shows present and notPresent.
--%>
<logic:present name="noSuchBean" property="noSuchProperty">
Both noSuchBean and noSuchProperty exist!
</logic:present>
<logic:notPresent name="noSuchBean" property="noSuchProperty">
Either noSuchBean or noSuchProperty does not exist!
</logic:notPresent>
<P>
<logic:present name="emptyString" >
There is a JavaBean named "emptyString". <p>
</logic:present>
<logic:notPresent name="emptyString" property="noSuchProperty">
EmptyString doesn't have such a property named "noSuchProperty".
</logic:notPresent>
<P>
<logic:present header="user-agent">
Yep, we got a user-agent header.
</logic:present>
<logic:notPresent header="user-agent">
No, user-agent header does not exist.
</logic:notPresent>
<P>
<%--
The following section shows messagesPresent and messagesNotPresent.
--%>
<logic:messagesPresent>
Yes, there are errors.
</logic:messagesPresent><P>
<logic:messagesPresent name="myerrors">
Yes, there are errors in myerrors collection.
</logic:messagesPresent><P>
<logic:messagesNotPresent message="true" >
There are no normal messages.
</logic:messagesNotPresent><P>
<logic:messagesNotPresent property="noSuchError">
There is no error named "SuchError".
</logic:messagesNotPresent><P>
<logic:messagesPresent property="totallylost">
There is an error named "totallylost".
</logic:messagesPresent>
</body>
</html:html>
LogicRedirect.jsp
<%@ page language="java" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<html:html>
<head>
<title>Logic Redirect sample code</title>
</head>
<body bgcolor="white">
<logic:redirect href="http://www.apache.org"/>
</body>
</html:html>
package logictaglibs;
public class SomeBean{
public SomeBean(){}
private String name;
public void setName(String name){this.name=name;}
public String getName(){return this.name;}
}