struts2学习笔记一------struts2标签学习

struts2标签

      终于把struts2标签看的差不多了,不过还有好多还不是很熟悉,我是结合Max的struts2教程和struts自带的reference文档学习的!笔记中有好多都是从Max的博客中搬来的。不过也没有办法,咱水平还不行,也只能站在人家的肩膀上学习一下了!!

      if,elseif, else标签

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'tags.jsp' starting page</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
  </head>
  
  <body>
  	<!-- 
  		小技巧:#parameters.country[1]可以这样取值!原来Struts2是将URL传的参数封装 成一个数组的,
  		也就是说你可以在一个URL传两个同名的参数(即?name=a&name=b);
  	 -->
  	<%request.setCharacterEncoding("utf-8");%>
  	(request获取方式)country=<%=request.getParameter("country") %><br>
  	<s:if test="#parameters.country[1] == 'www'">中国</s:if>
    <s:elseif test="#parameters.country[0] == '美国'">美国</s:elseif>
    <s:else >其他国籍的人</s:else>
  	<br>
  	
  	<!-- 为某个属性赋值 -->
  	<s:set name="country" value="#parameters.country[1]"></s:set>
  	country=<s:property value="#country" /> <br> 	
    <s:if test="#country == 'www'">中国</s:if>
    <s:elseif test="#country == '美国'">美国</s:elseif>
    <s:else >其他国籍的人</s:else>
    <br>
  </body>
</html>

  

这里面有个小常识,就是通过url传递参数的时候:Struts2是将URL传的同名参数封装成一个数组,也就是说我们可以在一个URL传两个同名的参数(即?name=a&name=b);获取的时候直接#parameters.name[0], parameters.name[1]就可以分别取出两个参数的值。

      include标签

  被包含页面:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s"%>
this is the include page!!!

  包含页面:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s"%>
<%
	String path = request.getContextPath();
	String basePath = request.getScheme() + "://"
			+ request.getServerName() + ":" + request.getServerPort()
			+ path + "/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
	<head>
		<base href="<%=basePath%>">
		<title>My JSP 'includea.jsp' starting page</title>
		<meta http-equiv="pragma" content="no-cache">
		<meta http-equiv="cache-control" content="no-cache">
		<meta http-equiv="expires" content="0">
		<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
		<meta http-equiv="description" content="This is my page">
		<!--
	<link rel="stylesheet" type="text/css" href="styles.css" mce_href="styles.css">
	-->
	</head>
	<body>
		This is my JSP1 page.
		<br>
		<s:include value="include.jsp">
			<!-- 提交表单时才会获得value的值 -->
			<s:param name="value1">test1</s:param>
			<s:param name="value2" value="user"></s:param>
		</s:include>
	</body>
</html> 

当然struts的include标签静态动态页面都能包含的!

      i18n标签
描述:加载资源包到值堆栈。它可以允许text标志访问任何资源包的信息,而不只当前action相关联的资源包。

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'tags3.jsp' starting page</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css" mce_href="styles.css">
	-->
  </head>
  
  <body>
  	 <!-- <s:text>标签没弄明白 --> 
     <s:i18n name="I18N">
   		The i18n value is <s:text name="hi!!"></s:text>
	 </s:i18n>
	 <br>
	 <s:debug></s:debug>
  </body>
</html> 

  

      iterator标签   

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'tags2.jsp' starting page</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css" mce_href="styles.css">
	-->
  </head>  
  <% 
  	List<String> strs = new ArrayList<String>();
  	strs.add("a");
  	strs.add("b");
  	strs.add("c");
  	strs.add("d");
  	strs.add("e");  	
  	request.setAttribute("strs", strs);
  %>
  <body>
    <s:iterator value="#request.strs" var="strs">
    	<s:property value="#strs"/>
    </s:iterator>	
    <s:debug></s:debug>
  </body>
</html>

  

这个标签挺容易理解的。

      param标签

struts2的<s: param>标签问我觉得比较复杂的。struts2的s:param标签主要有两个属性name与value, 若想在value属性中输入直接量,则可以这样写:<s:param name="some" value="%{'user'}"/>,  也可以这样写:<s:param name="some">user</s:param>。 但如果直接赋值,这个值不是由Action动态生成的,而是自己指定的一个字符串,则只能用后者。

param页面代码:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'param.jsp' starting page</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css" mce_href="styles.css">
	-->
  </head>
  
  <body>
  	<!-- struts2的s:param标签主要有两个属性name与value, 
  	若想在value属性中输入直接量,则可以这样写:<s:param name="some" value="%{'user'}"/>, 
  	也可以这样写:<s:param name="some">user</s:param>。
  	但如果直接赋值,这个值不是由Action动态生成的,而是自己指定的一个字符串,则只能用后者。 -->
	<s:url value="paramAction.jsp" id="href">
		<s:param name="value1">hello!!</s:param>
		<s:param name="valu2" value="%{'HELLO!'}"></s:param>
	</s:url>
	<s:a href="%{href}" mce_href="%{href}">paramAction</s:a>
	<s:debug></s:debug>
  </body>
</html>

  

paramAction页面:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'paramAction.jsp' starting page</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css" mce_href="styles.css">
	-->
  </head>
  
  <body>
    value1的值:<%=request.getParameter("value1") %><br>
    value1的值:<s:property value="#parameters.value1" /><br>
    value2的值:<%=request.getParameter("value2") %><br/><!-- 获取不到值 -->
    value2的值:${#param.value2 }<!-- 获取不到值 -->
    <s:debug></s:debug>
  </body>
</html>

  

      经常用到的UI标签

<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<%@ taglib prefix="sx" uri="/struts-dojo-tags" %> 
<html>
<head>
    <title>UI Tags Example</title>
    <s:head />
     <sx:head parseContent="true"/>    
</head>
<body>
<s:actionerror/>
<s:actionmessage/>
<s:fielderror />
<s:form action="exampleSubmit" method="post" enctype="multipart/form-data" tooltipConfig="#{'jsTooltipEnabled':'true'}">
    <s:textfield 
            label="Name" 
            name="name"
            tooltip="Enter your Name here" />
	<s:date name="Select Your Birthday"/>	
	<!-- 在struts2.2.1中<sx:datetimepicker/>的标签使用有所变化,需要引入struts2-dojo-plugin-2.2.1.jar 
		 这个包。	
	-->
    <sx:datetimepicker
            tooltip="Select Your Birthday"
            label="Birthday"
            name="birthday" />
    <s:textarea
            tooltip="Enter your Biography"
            label="Biograph"
            name="bio"
            cols="20"
            rows="3"/>
    <s:select
            tooltip="Choose Your Favourite Color"
            label="Favorite Color"
            list="{'Red', 'Blue', 'Green'}"
            name="favoriteColor"
            emptyOption="true"
            headerKey="None"
            headerValue="None"/>
    <s:select
            tooltip="Choose Your Favourite Language"
            label="Favourite Language"
            list="#{'CN':'中文','EN':'英文','FR':'外文'}"
            name="favouriteLanguage"
            emptyOption="true"
            headerKey="None"
            headerValue="None"/>
    <s:checkboxlist
            tooltip="Choose your Friends"
            label="Friends"
            list="{'Patrick', 'Jason', 'Jay', 'Toby', 'Rene'}"
            name="friends"/>
    <s:checkbox
            tooltip="Confirmed that your are Over 18"
            label="Age 18+"
            name="legalAge"/>
    <s:doubleselect
            tooltip="Choose Your State"
            label="State"
            name="region" list="{'North', 'South'}"
            value="'South'"
            doubleValue="'Florida'"
            doubleList="top == 'North' ? {'Oregon', 'Washington'} : {'Texas', 'Florida'}" 
            doubleName="state"
            headerKey="-1"
            headerValue="---------- Please Select ----------"
            emptyOption="true" />
     <s:file
            tooltip="Upload Your Picture"
            label="Picture" 
            name="picture" />
            
    <s:optiontransferselect
            tooltip="Select Your Favourite Cartoon Characters"
            label="Favourite Cartoons Characters"
            name="leftSideCartoonCharacters" 
            leftTitle="Left Title"
            rightTitle="Right Title"
            list="{'Popeye', 'He-Man', 'Spiderman'}" 
            multiple="true"
            headerKey="headerKey"
            headerValue="--- Please Select ---"
            emptyOption="true"
            doubleList="{'Superman', 'Mickey Mouse', 'Donald Duck'}" 
            doubleName="rightSideCartoonCharacters"
            doubleHeaderKey="doubleHeaderKey"
            doubleHeaderValue="--- Please Select ---" 
            doubleEmptyOption="true"
            doubleMultiple="true" />
    
    <s:textarea
            label="Your Thougths"
            name="thoughts" 
            tooltip="Enter your thoughts here" />
            
    <s:submit onclick="alert('aaaa');" />
    <s:reset onclick="alert('bbbb');" />
</s:form>
    
</body>
</html>

  

这些代码是直接从Max的博文中copy过来的,本来这是一个完整的例子我只是把前台展示代码考过来了。在这里有一个要注意的地方,不过在代码中也有体现,这是struts2比较高级的版本和低版本之间的区别,具体从哪个 版本改的我也不是很清楚。这个不同的用法是关于<s: datetimepicker>的。在使用<s: datetimepicker>时,较高的版本中还必须引入struts2-dojo-plugin-2.2.1.jar,还得指明<%@ taglib prefix="sx" uri="/struts-dojo-tags" %> ,如果做实验不成功的可以考虑下是不是这个问题。

      struts-tags就算是复习到这里了,如果要是配合一个具体的项目的话就会更好了,继续努力!!!

                                                                                                                                                                 

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