Comments on: Finding selected checkbox items in a JSF dataTable

By: Anshul

Anshul — Thu, 15 Dec 2011 08:47:33 +0000

(refering to comment no. 18)

Novino,
i have also got the same problem, i am working on it…if anyone else knows the solution then please help.

This is Exception:
Dec 15, 2011 1:53:31 PM javax.faces.event.MethodExpressionActionListener processAction
SEVERE: Received ‘java.lang.NullPointerException’ when invoking action listener ‘#{Shop.submitSelections}’ for component ‘j_id_jsp_1988918580_18′
Dec 15, 2011 1:53:31 PM javax.faces.event.MethodExpressionActionListener processAction
SEVERE: java.lang.NullPointerException
at com.Shop.submitSelections(Shop.java:26)
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 org.apache.el.parser.AstValue.invoke(AstValue.java:172)
at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276)
at org.apache.jasper.el.JspMethodExpression.invoke(JspMethodExpression.java:68)
at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:99)
at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88)
at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:771)
at javax.faces.component.UICommand.broadcast(UICommand.java:372)
at org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:321)
at org.ajax4jsf.component.AjaxViewRoot.broadcastEvents(AjaxViewRoot.java:296)
at org.ajax4jsf.component.AjaxViewRoot.processPhase(AjaxViewRoot.java:253)
at org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:466)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:265)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)

And This is my Shop.java
package com;

import java.util.ArrayList;

import javax.faces.event.ActionEvent;
import javax.faces.model.DataModel;

public class Shop {

private DataModel selectableItems;
ArrayList items;
ArrayList selectedItems;

public String addToCart()
{

items = (ArrayList)selectableItems.getWrappedData();

selectedItems = new ArrayList();

for (ProductModel item : items) {
if (item.getChecked()) {
selectedItems.add(item);
System.out.print(“\n\nproduct added to cart=”+item.desc+”\n\n”);
}
else{
selectedItems.remove(item);
System.out.print(“\n\nproduct removed from cart=”+item.desc+”\n\n”);
}
}
return “add_to_cart”;
}
public ArrayList getSelectedItems() {
return selectedItems;
}
public void setSelectedItems(ArrayList selectedItems) {
this.selectedItems = selectedItems;
}

}

By: zeeshan Akhter

zeeshan Akhter — Wed, 02 Nov 2011 10:11:09 +0000

its really good ……..
but i want to delete and update selected items from database using in

By: Sirisha

Sirisha — Thu, 16 Jun 2011 15:57:43 +0000

Hi,

When i tried to add items to javax.faces.model.ListDataModel object, it is showing a compile time error saying ‘add’ method is not supported.

Can you please let me know how can items be added to ListDataModel object.

Thanks

By: Neha

Neha — Wed, 16 Mar 2011 09:57:51 +0000

I really liked the example. It helped me a lot when i was stuck in that piece of code

By: Butterfly07

Butterfly07 — Wed, 08 Sep 2010 07:55:17 +0000

How to get the jar com.stevideter.manager.DomainManager?????

By: Sathish

Sathish — Mon, 28 Jun 2010 06:00:44 +0000

Thanks to all articles and comments , it is very much useful for fresh developers and most of others

thanks a lot , keep posting like wise articles

By: Anonymous Coward

Anonymous Coward — Tue, 15 Jun 2010 22:45:46 +0000

Thank you! Saved me probably 25 minutes of thinking.

By: stevi

stevi — Tue, 15 Jun 2010 17:03:47 +0000

novino,
I’d look at your UserBean.java file at line 298 and figure out why it’s throwing a null pointer exception.

By: novino

novino — Tue, 15 Jun 2010 14:49:58 +0000

Hi Stevi,

I tried the same but I’m getting following Exception. Do you have any suggestion on this.

Thanks.

java.lang.NullPointerException
at com.geae.empis.bean.UserBean.deletePan(UserBean.java:298)
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:585)
at org.apache.el.parser.AstValue.invoke(AstValue.java:131)
at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276)
at org.apache.jasper.el.JspMethodExpression.invoke(JspMethodExpression.java:68)
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
at javax.faces.component.UICommand.broadcast(UICommand.java:387)
at org.ajax4jsf.component.AjaxViewRoot.processEvents(AjaxViewRoot.java:184)
at org.ajax4jsf.component.AjaxViewRoot.broadcastEvents(AjaxViewRoot.java:162)
at org.ajax4jsf.component.AjaxViewRoot.processApplication(AjaxViewRoot.java:350)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:265)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:141)
at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:281)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:228)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:216)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:634)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:445)
at java.lang.Thread.run(Thread.java:595)

By: Geraldo Luiz

Geraldo Luiz — Thu, 14 Jan 2010 21:01:17 +0000

I use a similar aproach. But, like you, I’m also not very fond of messing with my domain objects, introducing an artificial atribute that doesn’t belong there.

Maybe it’s possible to extend the DataModel abstract class as a MultipleSelectionEntityDataModel or something like that. The default DataModel (and its derived concrete classes) models a single selection collection, so we must add methods to get and set the selected rows indexes, and the implementation of the getRowIndex() and setRowIndex() abstract methods may return, for example, the first selected one.

It’s just a thought. I will play with this idea, when I have a spare time, and I inform here if I have any success sith this aproach.