CODEWITHSUNDEEP
jsf-2el
Mr.J4mes
Mr.J4mes

Reputation: 9266

javax.el.ELException: Can't set property 'propertyName' on class 'com.example.MrBean' to value 'null'

In my .xhtml file, I have the following SelectOneMenu component:

<ui:define name="formContent">
    <h:selectOneMenu value="#{mrBean.itemCategoryID}">
        <f:ajax render="abc def" execute="@this" listener="#{mrBean.getListOfItems}"></f:ajax> 
        <f:selectItem itemLabel="Choose one .." itemValue="0" noSelectionOption="true" />
        <f:selectItems value="#{mrBean.itemCategories}" var="ic"
                       itemLabel="#{ic.name}" itemValue="#{ic.id}" />
    </h:selectOneMenu>

<h:panelGrid id="abc" columns="3" border="1">
    <h:outputText style="font-weight: bold" value="Name"/> 
    <h:outputText style="font-weight: bold" value="Producer" />
    <h:outputText />
</h:panelGrid>    

<h:panelGroup id="def" >
    <ui:repeat value="#{mrBean.items}" var="i">
        <h:form id="BuyItemForm">
            <h:panelGrid columns="3" border="1">
                <h:outputText style="font-weight: normal" value="#{i.name}" /> 
                <h:outputText style="font-weight: normal" value="#{i.producer.name}" /> 
                <h:commandButton value="Buy" actionListener="#{mrBean.buyItem}" >
                    <f:param name="itemID" value="#{i.id}" />
                </h:commandButton> 

            </h:panelGrid>
        </h:form>
    </ui:repeat>
</h:panelGroup>
</ui:define>

When I open the page, it can load normally with the menu populated properly. However, when I choose 1 of the option, I ran into the following error:

SEVERE: javax.faces.component.UpdateModelException: javax.el.ELException: /partner/BuyItem.xhtml @53,81 value="#{mrBean.itemCategoryID}": Can't set property 'itemCategoryID' on class 'managedBean.MrBean' to value 'null'.
... 
Caused by: javax.el.ELException: /partner/BuyItem.xhtml @53,81 value="#{mrBean.itemCategoryID}": Can't set property 'itemCategoryID' on class 'managedBean.MrBean' to value 'null'.
    at com.sun.faces.facelets.el.TagValueExpression.setValue(TagValueExpression.java:139)
    at javax.faces.component.UIInput.updateModel(UIInput.java:818)
    ... 47 more
Caused by: java.lang.IllegalArgumentException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at javax.el.BeanELResolver.setValue(BeanELResolver.java:381)
    at com.sun.faces.el.DemuxCompositeELResolver._setValue(DemuxCompositeELResolver.java:255)
    at com.sun.faces.el.DemuxCompositeELResolver.setValue(DemuxCompositeELResolver.java:281)
    at com.sun.el.parser.AstValue.setValue(AstValue.java:197)
    at com.sun.el.ValueExpressionImpl.setValue(ValueExpressionImpl.java:286)
    at com.sun.faces.facelets.el.TagValueExpression.setValue(TagValueExpression.java:131)
    ... 48 more

EDIT: this is my bean with getListOfItems function:

@ManagedBean
@ViewScoped
public class MrBean {
    @EJB
    private PartnerBeanLocal partnerBean;

    @ManagedProperty(value="0")
    private long    itemCategoryID;
    private List<ItemState> items;

    ...
    public void getListOfItems() {
        try {
            System.out.println(itemCategoryID); // I never saw this line printed out
            ArrayList data = partnerBean.getInfo(Constants.GET_LIST_OF_ITEMS, itemCategoryID);

            int result = ((Integer) data.get(0)).intValue();
            if (result == Constants.STATUS_SUCCESSFUL) items = (List<ItemState>) data.get(1);
            else if (result == Constants.STATUS_NOT_FOUND) FacesContext.getCurrentInstance().getExternalContext().redirect("HomePage.xhtml");

        } catch (IOException ex) {
            Logger.getLogger(MrBean.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    ...

    // Getters and Setters
    ...
    public long getItemCategoryID() {
        return itemCategoryID;
    }

    public void setItemCategoryID(long itemCategoryID) {
        this.itemCategoryID = itemCategoryID;
    }

    public List<ItemState> getItems() {
        return items; 
    }

    public List<ItemState> setItems(List<ItemState> items) {
        this.items = items; 
    }
    ...
}

I'd be very grateful if someone could give me an advice on how to tackle this problem.

EDIT 2: Thanks everyone for helping me! The problem was that I stupidly forgot to put the <f:ajax> tag inside a <h:form> tag.

Upvotes: 1

Views: 12777

Answers (4)

S&#252;leyman &#220;nl&#252;
S&#252;leyman &#220;nl&#252;

Reputation: 1

I had the same issue and it was resolved by changing my variable type boolean to Boolean

Upvotes: 0

Mr.J4mes
Mr.J4mes

Reputation: 9266

The <f:ajax> tag need to be wrapped inside a <h:form> tag.

Upvotes: 1

kgautron
kgautron

Reputation: 8283

Seems like some of your item values are null. If you want to accept null, use Long instead of long.

Upvotes: 0

Bhesh Gurung
Bhesh Gurung

Reputation: 51030

Here is what I tried:

@ManagedBean
@ViewScoped
public class MrBean implements Serializable {
    @ManagedProperty(value="0")
    private long itemCategoryID;
    private List<ItemCategory> itemCategories;

    @PostConstruct
    public void init() {
        this.itemCategories = new ArrayList<ItemCategory>();
        this.itemCategories.add(new ItemCategory("Item1", 1));
        this.itemCategories.add(new ItemCategory("Item2", 2));
        this.itemCategories.add(new ItemCategory("Item3", 3));
    }

    public void getListOfItems() {
        System.out.println(Thread.currentThread().getStackTrace()[1]);
        System.out.println("itemCategoryID: " + this.itemCategoryID);
    }

    public List<ItemCategory> getItemCategories() {
        return itemCategories;
    }

    public void setItemCategories(List<ItemCategory> itemCategories) {
        this.itemCategories = itemCategories;
    }

    public long getItemCategoryID() {
        return itemCategoryID;
    }

    public void setItemCategoryID(long itemCategoryID) {
        this.itemCategoryID = itemCategoryID;
    }
}

with:

<h:form>
    <h:selectOneMenu value="#{mrBean.itemCategoryID}">
        <f:ajax execute="@this" listener="#{mrBean.getListOfItems}"></f:ajax> 
        <f:selectItem itemLabel="Choose one .." itemValue="0" noSelectionOption="true" />
        <f:selectItems value="#{mrBean.itemCategories}" var="ic"
                           itemLabel="#{ic.name}" itemValue="#{ic.id}" />
    </h:selectOneMenu>
</h:form>

And it works without any problem.

Might be the version of JSF (EL) you have, or you have problem somewhere else.

Upvotes: 1

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