将数据转化为xml

private String toXml(List<NameValuePair> params) {        StringBuilder sb = new StringBuilder();        sb.append("<xml>");        for (int i = 0; i < params.size(); i++) {            sb.append("<"+params.get(i).getName()+">");            sb.append(params.get(i).getValue());            sb.append("</"+params.get(i).getName()+">");        }        sb.append("</xml>");        Log.e("orion",sb.toString());        return sb.toString();    }