FTP无法在Verizon Android上连接

Question

我正在尝试使用Verizon LG Revolution Android智能手机上的URLConnection从我的服务器传输数据。下面的块适用于Sprint和MetroPCS的Android手机，但Verizon的Android手机似乎在使用ftp时遇到问题。在调用getInputStream（）之后捕获异常e3。

    try{
    URL url;
        try {
        url = new URL("ftp://myUsername:myPassword@myWebsite.com/myFile.txt");
            URLConnection urlCon = null;
            try {
                urlCon = url.openConnection();
                urlCon.setDoInput(true);          
                InputStream input = urlCon.getInputStream(); //This is the line that the exception below is caught
            } catch (Exception e3) {
            //Cannot connect to server; Unable to retrieve file: 425
            }
    } catch (MalformedURLException e2) {
    }

}catch(Exception e){
}