1) 使用HiddenField

2) 使用自定义 WebSession 对象:

2) use a custom WebSession object:

public class MySession extends WebSession{
    public Mysession(Request request){super(request);}
    private boolean completedRegistration;

    public boolean hasCompletedRegistration() {
        return completedRegistration;
    }

    public void setCompletedRegistration(boolean completedRegistration) {
        this.completedRegistration = completedRegistration;
    }
}