请问JAVA FTP下传的一个有关问题

 /**     * @Title: connect     * @Description: 连接FTP客户端     * @param client     *            客户端     * @throws IOException     * @throws SocketException     */    private FTPClient connectServer() throws SocketException, IOException {        FTPSClient client = init();                client.connect(server, port);                if (!client.login(userName, password)) {            client.logout();            client.disconnect();            client = null;            return client;        }        client.enterLocalPassiveMode();        client.setBufferSize(1024);        client.setConnectTimeout(10000);        client.setFileType(FTPClient.BINARY_FILE_TYPE);        client.setControlEncoding("GBK");        client.enterLocalPassiveMode();        SocketFactory factory=null;          factory= SSLSocketFactory.getDefault();          client.setSocketFactory(factory);        int replyCode = client.getReplyCode();        if (!FTPReply.isPositiveCompletion(replyCode)) {            close(client);            client = null;            throw new IOException("服务器连接失败！username:" + userName + " password:" + password);        }        return client;    }

org.apache.commons.net.ftp.FTPConnectionClosedException: Connection closed without indication.    at org.apache.commons.net.ftp.FTP.__getReply(FTP.java:313)    at org.apache.commons.net.ftp.FTP.__getReply(FTP.java:290)    at org.apache.commons.net.ftp.FTP._connectAction_(FTP.java:396)    at org.apache.commons.net.ftp.FTPClient._connectAction_(FTPClient.java:796)    at org.apache.commons.net.ftp.FTPSClient._connectAction_(FTPSClient.java:203)    at org.apache.commons.net.SocketClient.connect(SocketClient.java:172)    at org.apache.commons.net.SocketClient.connect(SocketClient.java:192)    at service.ftp.client.FileClient.connectServer(FileClient.java:78)    at service.ftp.client.FileClient.handle(FileClient.java:103)    at service.ftp.client.FileClient.main(FileClient.java:142)