关于js的一个低不低，高不高的应用

大家知道，后台程序通常情况下无法与js进行交互，而我们一般通过组成XML的形式来传递我们想要的数据，或者说用ajax，dwr等，这里只是介绍其中的一种方法，可能不是最好的，但至少能很快的解决问题：
1.所需要取到的数据结构形为：
var object={
"strArr1":[{
"brandId":"1"},{"brandName":"三星"},{"childs":[{"phoneType":"N870"},{}]
}],
"strArr2":[{},{}]
}
2.明白了我们想要的数据结构，之后我们将在Action中对所要的数据进行拼凑，在action中我们可以建立一个Map对象：Map<Brand,List<ClientSoft>> map=new HashMap<Brand,List<ClientSoft>>
拼凑：

public String execute() throws Exception {
		Map<Brand, List<ClientSoft>> clientSoftMap = clientSoftManager
				.getClientSoftInfo();
		Iterator it = clientSoftMap.entrySet().iterator();
		StringBuffer sb = new StringBuffer();
		sb.append("var str={\"strArr\":[");
		while (it.hasNext()) {
			Map.Entry entry = (Map.Entry) it.next();
			Object key = entry.getKey();
			/* 对键进行处理 */
			Brand brand = (Brand) key;
			Long brandId = brand.getBrandId();
			String brandName = brand.getBrandName();
			String brandUrl = brand.getImageUrl();

			Object value = entry.getValue();
			/* 对值进行处理:子型号，版本号，手机图片，标识软件版本号，软件下载地址，大小，版本，Release号，软件描述，下载次数 */
			List<ClientSoft> liCs = (List<ClientSoft>) value;

			System.out.println("键:" + key + ";" + "值:" + value);
			
			sb.append("{");
			sb.append("\"brandName\":" + "\"" +brandName+"\"");
			sb.append(",");
			sb.append("\"brandId\":" +"\""+ brandId + "\"");
			sb.append(",");
			sb.append("\"brandUrl\":" + "\"" + brandUrl +"\"");
			sb.append(",");
			sb.append("\"childs\":");
			sb.append("[");
			if (liCs.size() != 0) {
				for (ClientSoft clientSoft : liCs) {
					sb.append("{");
					sb.append("\"phoneType\":" + "\""
							+ clientSoft.getPhoneType() + "\"");
					sb.append(",");
					sb.append("\"ua\":" + "\"" + clientSoft.getUa() + "\"");
					sb.append(",");
					sb.append("\"imageUrl\":" + "\"" + clientSoft.getImageUrl()
							+ "\"");
					sb.append(",");
					sb.append("\"clientUa\":" + "\"" + clientSoft.getClientUa()
							+ "\"");
					sb.append(",");
					sb.append("\"URL\":" + "\"" + clientSoft.getUrl() + "\"");
					sb.append(",");
					sb.append("\"softSize\":" + "\"" + clientSoft.getSoftSize()
							+ "\"");
					sb.append(",");
					sb.append("\"version\":" + "\"" + clientSoft.getVersion()
							+ "\"");
					sb.append(",");
					sb.append("\"release\":" + "\"" + clientSoft.getRelease()
							+ "\"");
					sb.append(",");
					sb.append("\"description\":" + "\""
							+ clientSoft.getDescription() + "\"");
					sb.append(",");
					sb.append("\"createDate\":" + "\""
							+ clientSoft.getCreateDate() + "\"");
					sb.append(",");
					sb.append("\"downloadCount\":" + "\""
							+ clientSoft.getDownloadCount() + "\"");
					sb.append("},");
				}
				sb = new StringBuffer(sb.toString().substring(0,
						sb.length() - 1));
			}
			sb.append("]");
			sb.append("},");
		}
		sb=new StringBuffer(sb.substring(0, sb.length() - 1));
		sb.append("]}");
		String str=sb.toString();
		ServletActionContext.getRequest().setAttribute("str",
				str);
		return SUCCESS;
	}

4.到页面执行

function initBrand(){
	var strTmp='${requestScope.str}';
	eval(strTmp);
	phoneStr=str;
	for(var o = 0; o < str.strArr.length; o++){
		var op = document.createElement("OPTION");
		op.text=str.strArr[o].brandName;
		op.value=o;
		document.getElementById("vendor").options.add(op);
		}
	${"brandSelId"}.value=0;
}