Getting nullpointer exception on orderlist in primefaces

Question

 Error Rendering View[test.xhtml]
                                 java.lang.NullPointerException
    at org.primefaces.component.orderlist.OrderListRenderer.encodeOptions(OrderListRenderer.java:149)
    at org.primefaces.component.orderlist.OrderListRenderer.encodeList(OrderListRenderer.java:108)
    at org.primefaces.component.orderlist.OrderListRenderer.encodeMarkup(OrderListRenderer.java:79)
    at org.primefaces.component.orderlist.OrderListRenderer.encodeEnd(OrderListRenderer.java:49)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:519)
    at org.apache.myfaces.shared_impl.renderkit.RendererUtils.renderChild(RendererUtils.java:543)
    at org.apache.myfaces.shared_impl.renderkit.html.HtmlGridRendererBase.renderChildren(HtmlGridRendererBase.java:315)
    at org.apache.myfaces.shared_impl.renderkit.html.HtmlGridRendererBase.encodeEnd(HtmlGridRendererBase.java:150)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:519)
    at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:60)
    at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:44)
    at org.primefaces.component.dialog.DialogRenderer.encodeContent(DialogRenderer.java:174)
    at org.primefaces.component.dialog.DialogRenderer.encodeMarkup(DialogRenderer.java:103)
    at org.primefaces.component.dialog.DialogRenderer.encodeEnd(DialogRenderer.java:41)
    at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:519)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:626)
    at javax.faces.component.UIComponent.encodeAll(UIComponent.java:622)
    at org.primefaces.component.accordionpanel.AccordionPanelRenderer.encodeEnd(AccordionPanelRenderer.java:60)

@FacesConverter("contactConverter") public class ContactConverter implements Converter{

@Override
public Object getAsObject(FacesContext arg0, UIComponent arg1, String arg2)
        throws ConverterException {
    // TODO Auto-generated method stub
    TestBean tb= new TestBean();
    tb.setName(arg2);
    return tb;
}

@Override
public String getAsString(FacesContext arg0, UIComponent arg1, Object arg2)
        throws ConverterException {
    // TODO Auto-generated method stub
    return arg2.toString();
}

I was working with primefaces orderlist example. But I am facing this null pointer exception. After googling i found that this issue is some thing related to conveter, but I am not sure.can anyone help me with the simple primeface orderlist with the converter.

It'd be helpful if you mention the exact PrimeFaces version, so that we (or you ...) can just look in the source code for the exact cause. — BalusC
@BalusC: I have read your many blogs related to Jsf2 and I found very useful and I was able to resolve many issues. Primefaces 3.4 is what I am using and I am trying out simple orderlist example. — shreekanth
<p:orderList styleClass="resultBox" style="color: #263F6A;" var="user" value="#{testBean.contacts}" itemValue="#{user}" controlsLocation="none" converter="contactConverter"> </p:orderList> — shreekanth

BalusC BalusC · Accepted Answer · 2013-02-13T12:54:29

java.lang.NullPointerException
    at org.primefaces.component.orderlist.OrderListRenderer.encodeOptions(OrderListRenderer.java:149)
    at org.primefaces.component.orderlist.OrderListRenderer.encodeList(OrderListRenderer.java:108)

From the PrimeFaces 3.4 OrderListRenderer source code:

90     protected void encodeList(FacesContext context, OrderList ol) throws IOException {
...
108        encodeOptions(context, ol, (List) ol.getValue());
...
115    }
...
143    @SuppressWarnings("unchecked")
144    protected void encodeOptions(FacesContext context, OrderList old, List model) throws IOException {
145        ResponseWriter writer = context.getResponseWriter();
146        String var = old.getVar();
147        Converter converter = old.getConverter();
148
149        for(Iterator it = model.iterator(); it.hasNext();) {

Thus, the model is null and thus this exception will occur when <p:orderList value> is null and thus your #{testBean.contacts} has returned null. Make sure that it's not null. Note that this can also happen when #{testBean} cannot be found in the scope.

Getting nullpointer exception on orderlist in primefaces

1 Answers