@Named
@ViewScoped
public class DataTableController implements Serializable {

    private static final long serialVersionUID = 20111020L;

    private List<Message> messages;
    private List<Message> filteredMessages;
    private String newSubject = "my subject";
    private String newText = "my text";

    public DataTableController() {
        if (messages == null) {
            messages = new ArrayList<>();

            for (int i = 0; i < 100; i++) {
                final Message message = new Message();
                message.setSubject("subject " + i);
                message.setText("text " + i);
                messages.add(message);
            }
        }
    }

    public List<Message> getMessages() {
        return messages;
    }

    public void setMessages(final List<Message> messages) {
        this.messages = messages;
    }

    public List<Message> getFilteredMessages() {
        return filteredMessages;
    }

    public void setFilteredMessages(final List<Message> filteredMessages) {
        this.filteredMessages = filteredMessages;
    }

    public String getNewSubject() {
        return newSubject;
    }

    public void setNewSubject(final String newSubject) {
        this.newSubject = newSubject;
    }

    public String getNewText() {
        return newText;
    }

    public void setNewText(final String newText) {
        this.newText = newText;
    }

    public String addMessage() {
        doSomething();

        final Message message = new Message();
        message.setSubject(newSubject);
        message.setText(newText);
        messages.add(0, message);

        newSubject = "";
        newText = "";

        final FacesContext fc = FacesContext.getCurrentInstance();
        fc.addMessage(null,
                    new FacesMessage(FacesMessage.SEVERITY_INFO, "New message has been added successfully", null));

        return null;
    }

    public void doSomething() {
        try {
            // simulate a long running request
            Thread.sleep(1500);
        }
        catch (final Exception e) {
            // Restore interrupted state...
            Thread.currentThread().interrupt();
        }
    }

    public class Message implements Serializable {

        private static final long serialVersionUID = 1L;

        private String subject;
        private String text;
        private long time;

        public Message() {
            time = System.currentTimeMillis() + (long) (Math.random() * 10);
        }

        public final String getSubject() {
            return subject;
        }

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

        public final String getText() {
            return text;
        }

        public final void setText(final String text) {
            this.text = text;
        }

        public long getTime() {
            return time;
        }

        public void setTime(final long time) {
            this.time = time;
        }
    }
}