FTPClient not serializable in Apache Wicket

Question

I am using Apache Wicket with Apache Commons Net. But when I define

new FTPClient(); //apache commons net library

I get an exception

org.apache.commons.net.ftp.FTPClient at.erpel.as2connector.testtool.protocols.FTP.client
[class=org.apache.commons.net.ftp.FTPClient] <----- field that is not serializable

What can I do?

Answer 1

Thank you for your suggestions!

I also have solved it with 2 possibilites:

1) you can make the field transient:

transient FTPClient() client;

2) Make a Singleton of parent class where FTPClient will be used

public class AnyClass implements Serializable {

    private static AnyClass instance;

    private AnyClass() {

    }

    public static AnyClass getInstance() {
        if (instance == null) {
            instance = new AnyClass();
        }
        return instance;
    }

    FTPClient client = new FTPClient();
    ...
}

3) As suggested by biziclop: Create an own Class only for FTP Communication.