web service-Cannot create a secure XMLInputFactory

Cannot create a secure XMLInputFactory

public static String postData1(String urlAddress, String encodedType,Map params) {

try {

URL url = new URL(urlAddress);

URLConnection conn = url.openConnection();
conn.setRequestProperty("accept", "*/*");
conn.setRequestProperty("connection", "Keep-Alive");
conn.setRequestProperty("user-agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");

        conn.setDoOutput(true);  
        conn.setDoInput(true);  
        conn.setUseCaches(false); // Post請求不用設置緩存  

        conn.getOutputStream();

        // 獲取返回數據  
        BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "utf-8"));  
        String line = null;  
        StringBuffer sb = new StringBuffer();  
        while ((line = in.readLine()) != null) {  
            sb.append(line);  
        }  
        in.close(); // 關閉流  
        return sb.toString();  
    } catch (Exception e) {  
        e.printStackTrace();  
    }  
    return "";  
}  
    使用上述的代碼訪問webservice，如果不加conn.getOutputStream()，返回soap協議正確，如果加上這一句，報錯500，服務器那邊顯示錯誤：不能創建一個安全的xmlInputFactory：java.lang.RuntimeException: Cannot create a secure XMLInputFactory。
    這是什麼原因呢？在線等待，大家幫幫忙......

最佳回答：

http://blog.csdn.net/fengcheqidong/article/details/40423517
終於解決了！！！