EmailData.java

public class EmailData {
    private final String recipient;
    private final String subject;
    private final String message;
    private final Set<EmailAttachment> emailAttachments;

    public EmailData() {
    }

    public String getRecipient() {
        return recipient;
    }

    public void setRecipient(String recipient) {
        this.recipient = recipient;
    }

    public String getSubject() {
        return subject;
    }

    public void setSubject(String subject) {
        this.subject = subject;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    // with toString, hashcode and equals overridden
}