JAVA HTTP应用中的URL对象疑惑

  代码如下：
            URL url;
            url = new URL("http://sms.ha.unicom.local/servlet/test?telnum=13673399703&smscontext=您的接入认证密码是:108866); 
            HttpURLConnection urlConn;
            DataOutputStream outStream;
            DataInputStream inStream;
            BufferedReader buf;
            urlConn = (HttpURLConnection)url.openConnection(); 
            urlConn.setDefaultUseCaches(false);
            urlConn.setUseCaches(false);
            urlConn.setRequestProperty("charset","gb2312");
            urlConn.setRequestMethod("POST"); 
            urlConn.setDoOutput(true); 
            urlConn.setDoInput(true); 
            urlConn.setUseCaches(false); 
            urlConn.setAllowUserInteraction(false); 
            outStream = new DataOutputStream(urlConn.getOutputStream());             
            outStream.flush(); 
            outStream.close();
直接在浏览器的地址栏里输入 “http://sms.ha.unicom.local/servlet/test?telnum=13673399703&smscontext=您的接入认证密码是:108866 生成时间:2009-7-10 10:40:01” ，服务器有相应；url 如果是 “http://sms.ha.unicom.local/servlet/test?telnum=13673399703&smscontext=您的接入认证密码是:108866”，服务器就有相应；
url 如果是 “http://sms.ha.unicom.local/servlet/test?telnum=13673399703&smscontext=您的接入认证密码是:108866 生成时间:2009-7-10 10:40:01” ，服务器没有相应；请问这是为什么？ 似乎是后面的串里有空或或者冒号的特殊字符所致？ 如何解决？ 多谢