//...public class SelectAction extends ActionSupport{	private List<String> searchEngine;	private String yourSearchEngine;		//set default value	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");	}	//...}

<s:select>标记呈现HTML下拉框。value=http://www.mamicode.com/“defaultSearchEngine”将调用对应动作类的getDefaultSearchEngine()方法返回一个默认搜索引擎的值。

<s:select label="What‘s your favor search engine" 		headerKey="-1" headerValue="http://www.mamicode.com/Select Search Engines"		list="searchEngine" 		name="yourSearchEngine" 		value="http://www.mamicode.com/defaultSearchEngine" />

在这个例子中，下拉框将自动选择“yahoo.com”作为默认选项。

struts2中的<s:select>默认选项