select optgroup

代码片段：

public class LoginAction extends BaseAction {

	private Map<Integer,String> usCiteis = new HashMap<Integer,String>();
	
	private Map<Integer,String> canadaCiteis = new HashMap<Integer,String>();
	
	private Map<Integer,String> mexicoCiteis = new HashMap<Integer,String>();

	public String method1() throws Exception {
		canadaCiteis.put(1, "Canada city 1");
		canadaCiteis.put(2, "Canada city 2");
		canadaCiteis.put(3, "Canada city 3");
		canadaCiteis.put(4, "Canada city 4");
		canadaCiteis.put(5, "Canada city 5");
		canadaCiteis.put(6, "Canada city 6");
		usCiteis.put(7, "US city 1");
		usCiteis.put(8, "US city 2");
		usCiteis.put(9, "US city 3");
		mexicoCiteis.put(10, "Mexico city 4");
		mexicoCiteis.put(11, "Mexico city 5");
		mexicoCiteis.put(12, "Mexico city 6");
		return SUCCESS;
	}

	public Map<Integer, String> getUsCiteis() {
		return usCiteis;
	}

	public void setUsCiteis(Map<Integer, String> usCiteis) {
		this.usCiteis = usCiteis;
	}

	public Map<Integer, String> getCanadaCiteis() {
		return canadaCiteis;
	}

	public void setCanadaCiteis(Map<Integer, String> canadaCiteis) {
		this.canadaCiteis = canadaCiteis;
	}

	public Map<Integer, String> getMexicoCiteis() {
		return mexicoCiteis;
	}

	public void setMexicoCiteis(Map<Integer, String> mexicoCiteis) {
		this.mexicoCiteis = mexicoCiteis;
	}
}

 HTML代码片段：

	<s:select name="city" label="City" list="#{'0':'choose one'}">
		<s:optgroup label="Canada" list="canadaCiteis"/>
		<s:optgroup label="US" list="usCiteis"/>
		<s:optgroup label="Mexico" list="mexicoCiteis"/>
	</s:select>

 其中，<s:select>标签里头的list属性是必填项。可以用它来做一个默认标题。