Struts2 <s:select>下拉框例子

<s:select label="what's your favor search engine" 
		headerkey="-1" headervalue="select search engines"
		list="searchengine" 
		name="yoursearchengine" />

产生下面的html代码...

<td class="tdlabel">
   <label for="resultaction_yoursearchengine" class="label">
       what's your favor search engine:
   </label>
</td> 
<td>
<select name="yoursearchengine" id="resultaction_yoursearchengine"> 
    <option value="-1">select search engines</option> 
    <option value="google.com">google.com</option> 
    <option value="bing.com">bing.com</option> 
    <option value="yahoo.com">yahoo.com</option> 
    <option value="baidu.com">baidu.com</option> 
</select> 
</td>

其语法不需要太多解释，只不过是“headerkey”和“headervalue”。“headerkey”是一个在下拉列表中项用来表示键，而“headervalue”是在下拉列表中的项目表示值。

要自动选择下拉框中的默认值，看看这篇文章：自动选择struts2下拉框的值

struts 2 <s:select> 示例

一个通过<s:select>创建下拉框完整的struts2的例子，和填充通过java列表，ognl列表中选择选项，保存所选的值，并在另一页显示。

1. 动作 - action

action类来生成并按住选定的下拉框中选项。
selectaction.java

package com.h3.common.action;

import java.util.arraylist;
import java.util.list;

import com.opensymphony.xwork2.actionsupport;

public class selectaction extends actionsupport{

	private list<string> searchengine;

	private string yoursearchengine;
	private string yourmonth;
	
	public string getyourmonth() {
		return yourmonth;
	}

	public void setyourmonth(string yourmonth) {
		this.yourmonth = yourmonth;
	}

	public list<string> getsearchengine() {
		return searchengine;
	}

	public void setsearchengine(list<string> searchengine) {
		this.searchengine = searchengine;
	}

	public string getyoursearchengine() {
		return yoursearchengine;
	}

	public void setyoursearchengine(string yoursearchengine) {
		this.yoursearchengine = yoursearchengine;
	}

	public string getdefaultsearchengine() {
		return "yahoo.com";
	}
	
	public selectaction(){
		
		searchengine = new arraylist<string>();
		searchengine.add("google.com");
		searchengine.add("bing.com");
		searchengine.add("yahoo.com");
		searchengine.add("baidu.com");
	}

	public string execute() {
		return success;
	}
	
	public string display() {
		return none;
	}
	
}

2. 结果页面

渲染下拉框中通过“<s:select>”标签，并填充通过java列表，ognl列表中的选择选项

select.jsp

<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
</head>

<body>
<h1>struts 2 drop down box example</h1>

<s:form action="resultaction" namespace="/">

<h2>
	<s:select label="what's your favor search engine" 
		headerkey="-1" headervalue="select search engines"
		list="searchengine" 
		name="yoursearchengine" 
		value="defaultsearchengine" />
</h2> 

<h2>
	<s:select label="select a month" 
		headerkey="-1" headervalue="select month"
		list="#{'1':'jan', '2':'feb', '3':'mar', '4':'apr'}" 
		name="yourmonth" 
		value="2" />
</h2> 

<s:submit value="submit" name="submit" />
	
</s:form>

</body>
</html>

result.jsp

<%@ taglib prefix="s" uri="/struts-tags" %>
<html>

<body>
<h1>struts 2 drop down box example</h1>

<h2>
  favor search engine : <s:property value="yoursearchengine"/>
</h2> 

<h2>
  selected month : <s:property value="yourmonth"/>
</h2> 

</body>
</html>

3. struts.xml

<?xml version="1.0" encoding="utf-8" ?>
<!doctype struts public
"-//apache software foundation//dtd struts configuration 2.0//en"
"http://struts.apache.org/dtds/struts-2.0.dtd">
 
<struts>

 <constant name="struts.devmode" value="true" />
 	
<package name="default" namespace="/" extends="struts-default">
		
   <action name="selectaction" 
         class="com.h3.common.action.selectaction" method="display">
	<result name="none">/pages/select.jsp</result>
   </action>
		
   <action name="resultaction" class="com.h3.common.action.selectaction">
	<result name="success">/pages/result.jsp</result>
   </action>
  </package>
	
</struts>

5. 运行实例

http://localhost:8080/strut2selectdropdown/selectaction.action

http://localhost:8080/strut2selectdropdown/resultaction.action

参考

struts 2 select 文档

下载代码 – http://pan.baidu.com/s/1eqgzqho