struts2中的默认选项

//...
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=“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="Select Search Engines"
		list="searchEngine"
		name="yourSearchEngine"
		value="defaultSearchEngine" />

在这个例子中，下拉框将自动选择“yahoo.com”作为默认选项。