ajax/json

JSP页面：

<select id="province" name="user.province" onchange="duplicateAddress()">
    <s:iterator value="provinceList" var="item">
        <option value="<s:property value='key'/>">
        <s:property value="value"/></option>
    </s:iterator>
</select>
<select id="city" name="user.city">
    <s:iterator value="cityList" id="citys">
        <option value="<s:property value='key'/>">
        <s:property value="value"/></option>
    </s:iterator>
</select>

JS：

function duplicateAddress() {
	var alterCity = $("#province").attr("value");
	$.ajax({
		async : false,
		type: "POST",
		url: "./alterAddress.action",
		data: "alterCity=" + alterCity,
		success: function(result){
			if (result != null) {
				var cityInfo = eval('('+result+')');
				var citySelect = $("#city");
				citySelect.children("option").remove();
				$("<option value='0'>不限</option>").appendTo(citySelect);
				for(var i=0;i<cityInfo.length;i++){
					$("<option value='"+cityInfo[i].value+"'>"+cityInfo[i].text+"</option>").appendTo(citySelect);
				}

			}

		}
	});
}

JAVA代码：

public String alterAddress(){
	StringBuffer result = new StringBuffer();
	StringBuffer buffer = new StringBuffer();
	result.append("[");
	//从xml中取得省、市放入map中传到前台
	List<Map<String, Object>> list = CityUtil.getCityList();
	//根据省找到对应市集合
	for (Map<String, Object> map : list) {
		//如果取得的省与前台选择的省相同
		if(((String) map.get("value")).equals(alterCity)){
			List<Map<String, String>> childList = (List<Map<String, String>>) map.get("children");
			for (Map<String, String> child : childList) {
				buffer.append("{")
				.append("value")
                                .append(":")
                                .append("'"+(String) child.get("value")+"'")
				.append(",")
				.append("text")
                                .append(":")
                                .append("'"+(String) child.get("name")+"'")
				.append("}")
				.append(",");
			}

			if (buffer.length() != 0) {
		            result.append(buffer.substring(0, buffer.length() - 1));
		        }
		        result.append("]");

			try {
				this.sendAjaxResponse(result.toString());
			} catch (Exception e) {
				e.printStackTrace();
				log.debug(e.getMessage());
			}
		}
	}
	return null;
}