JSF, Primefaces - 'Cannot format given Object as a Date' in case of an instructor call

Question

I'm very to to jsf and Primefaces. My problem is, if I do not comment currentLunch = new Lunch(...)in *IndexBean.java` out, I'll get the error message which I've append below.

Without this line of code, the code will run.

Why I do that?

I want to add a new lunch instance in case of a 'save' click. That's why the 'add'-form has an empty instance of a lunch object. Is this way okay?

I checked the following Stackoverflow posts but I think, their solution would not solve my problem

• JSF Cannot format given Object as a Date
• Java : Cannot format given Object as a Date

Error log

1100: JSF1073: java.lang.IllegalArgumentException caught during processing of RENDER_RESPONSE 6 : UIComponent-ClientId=, Message=Cannot format given Object as a Date

Code

Index.htmlx

<h:form id="newLunch">
        <h:panelGrid columns="2" style="width: 300px;">
            <h:outputLabel for="initiator" value="Initiator" />
            <p:inputText id="initiator" value="#{indexBean.currentLunch.initiator}"/>

            <h:outputLabel for="date" value="Date" />
            <p:calendar id="date" minHour="11" maxHour="13" stepMinute="15" value="#{indexBean.currentLunch.date}"/>

            <p:commandButton value="save" action="#{indexBean.onSaveLunch}" update=":lunches" />
        </h:panelGrid>
</h:form>

IndexBean.java

@ManagedBean
@SessionScoped
public class IndexBean
{
private List<Lunch> lunches;
private Lunch currentLunch;
public List<Lunch> getLunches() ...
public void setLunches(List<Lunch> lunches) ...
public Lunch getCurrentLunch() ...
public void setCurrentLunch(Lunch currentLunch) ...

public IndexBean()
{
    // Set attributes to a value whichs should work (as you can see one line below)
    currentLunch = new Lunch("Tobi", "Starbucks", new DateTime(2014, 5, 30, 12, 0, 0 ,0));

    // This works without any problems.
    lunches = new ArrayList<Lunch>();
    lunches.add(new Lunch("Tobi", "Starbucks", new DateTime(2014, 5, 30, 12, 0, 0 ,0)));
}

public void onSaveLunch() ...

}

Lunch.java

public class Lunch
{
    private String initiator;
    private String location;
    private DateTime date;

    public Lunch(String initiator, String location, DateTime date)
    {
        this.initiator = initiator != null ? initiator : "";
        this.location = location != null ? location : "";
        this.date = date != null ? date : DateTime.now();
    }

    // default getter / setter


    public String getFormattedDate()
    {
        if(date == null) return "";
        DateTimeFormatter fmt = DateTimeFormat.forPattern("hh:MM (dd.MM.yyyy)");
        return date.toString(fmt);
    }
}

Answer 1

This problem arise when you're not using java.util.Date. Check that the respective field in Lunch class has java.util.Date type and not java.sql.Date or another type.

Looks like you're using DateTime for Joda API. To solve this issue and not modify your current design, you may want to have a custom getter/setter for date field in your view. Just add this code to IndexBean:

public class IndexBean {
    //current code...
    public Date getDate() {
        if (currentLunch.getDate() != null) {
            return currentLunch.getDate().toDate();
        }
        return null;
    }
    public void setDate(Date date) {
        return currentLunch.setDate(new DateTime(date));
    }
}

And change the view to:

<!-- Note the expression language in value attribute -->
<p:calendar id="date" minHour="11" maxHour="13" stepMinute="15"
    value="#{indexBean.date}"/>

---

Not related to your current problem, but maybe @SessionScoped is a wider scope than you will need, probably the bean should be @ViewScoped.

Also, it is better to have any business logic associated to the bean initialization in a @PostConstruct annotated method:

public class IndexBean {
    public IntexBean() {
    }
    @PostConstruct
    public void init() {
        // Set attributes to a value whichs should work (as you can see one line below)
        currentLunch = new Lunch("Tobi", "Starbucks", new DateTime(2014, 5, 30, 12, 0, 0 ,0));
        // This works without any problems.
        lunches = new ArrayList<Lunch>();
        lunches.add(new Lunch("Tobi", "Starbucks", new DateTime(2014, 5, 30, 12, 0, 0 ,0)));
    }
    //rest of code...
}