struts2学习笔记一------struts2标签学习
原文链接：http://www.cnblogs.com/focusj/archive/2011/01/04/2057651.html#top
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！！！
