FTP客户端类未连接

Question

FTPClient client = new FTPClient();
FileInputStream fis = null;


try {
    client.connect("32.178.10.121");
    client.login("XXX", "XXX");

    //
    // Create an InputStream of the file to be uploaded
    //
    String filename = "Touch.dat";
    fis = new FileInputStream(filename);

    //
    // Store file to server
    //
    client.storeFile(filename, fis);
    client.logout();
} catch (IOException e) {
    e.printStackTrace();
} finally {
    try {
        if (fis != null) {
            fis.close();
        }
        client.disconnect();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

I have tried this but each time it gives time out of bound exception and by other means of i am successfully getting connected but nt from here what could be reason.

this is the stacktrace:

java.net.ConnectException: Connection timed out: connect
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.PlainSocketImpl.doConnect(Unknown Source)
    at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at java.net.Socket.<init>(Unknown Source)
    at org.apache.commons.net.DefaultSocketFactory.createSocket(DefaultSocketFactory.java:53)
    at org.apache.commons.net.SocketClient.connect(SocketClient.java:162)
    at org.apache.commons.net.SocketClient.connect(SocketClient.java:250)
    at forTesting.FileUploadDemo.main(FileUploadDemo.java:15)

Answer 1

First try to set the proxy details like below

FTPClient ftp = new FTPHTTPClient(proxyHost, proxyPort, proxyUser, proxyPassword);

Then try to connect as you are doing and let me know if the error is gone.
If the error persists then check the firewall setting for the FTP server. Also try to connect from the System with some GUI tool like Filezilla to connect to the server.

Answer 2

You might want to try using PASV mode, if you're behind a firewall or proxy. Have a look here :

In situations where the client is behind a firewall and unable to accept incoming TCP connections, passive mode may be used. In this mode, the client uses the control connection to send a PASV command to the server and then receives a server IP address and server port number from the server, which the client then uses to open a data connection from an arbitrary client port to the server IP address and server port number received.