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Custom BeanELResolver using primefaces

I am using the dynamic columns feature, provided by primefaces library. Because I also have nested properties (such as bean.city.address), I made a custom BeanElResolver to deal with that:
public class ExtendedBeanELResolver extends BeanELResolver {
#Override
public Object getValue(ELContext context, Object base, Object property)
throws NullPointerException, PropertyNotFoundException, ELException
{
if (property == null || base == null || base instanceof ResourceBundle || base instanceof Map || base instanceof Collection) {
return null;
}
String propertyString = property.toString();
if (propertyString.contains(".")) {
Object value = base;
for (String propertyPart : propertyString.split("\\.")) {
value = super.getValue(context, value, propertyPart);
}
return value;
}
else {
return super.getValue(context, base, property);
}
}
It works fine for the bean properties, but when the page is rendered I'm getting PropertyNotFound Exception for some image in primefaces, that is not a bean property:
Servlet failed with an Exception -javax.el.PropertyNotFoundException: The class 'org.primefaces.application.PrimeResourceHandler' does not have the property 'primefaces- aristo:images/ui-bg_highlight-soft_100_c4c4c4_1x100.png'.
I think that is because I extended the BeanELResolver class and it somehow overrides the default ELResolver, that deals with all sorts of properties. I tried to make a CompositeELResolver class, to deal with other types of properties as well, but I can't figure out how. Any ideas?

h:selectOneMenu : validation error

I defined the following drop down box in my page:
...
<td>
<h:selectOneMenu id="bootenvironment1" value="#{detailModel.selectedBootenvironment1}"
disabled="#{detailModel.mode == detailModel.viewMode}">
<f:selectItems value="#{detailModel.availableBootenvironments}"/>
</h:selectOneMenu>
</td>
In my model I have:
...
private Map<String, Bootenvironment> availableBootenvironments;
public DefinitionDetailModel()
{
super();
}
public String getSelectedBootenvironment1()
{
if (((Definition) getAfterObject()).getBootenvironment1() != null)
{
return ((Definition) getAfterObject()).getBootenvironment1().getEnvironmentName();
}
return "--Please select one--";
}
public void setSelectedBootenvironment1( String selectedBootenvironment )
{
((Definition) getAfterObject()).setBootenvironment1(availableBootenvironments.get(selectedBootenvironment));
}
...
And in the controller I set the availableBootenvironments map:
private void fetchBootenvironments()
{
...
#SuppressWarnings( "unchecked" )
List<Bootenvironment> bootenvironments = (List<Bootenvironment>) ...
Map<String, Bootenvironment> availableBootenvironments = new HashMap<String, Bootenvironment>();
availableBootenvironments.put("--Please select one--", null);
for(Bootenvironment bootenvironment : bootenvironments)
{
availableBootenvironments.put(bootenvironment.getEnvironmentName(), bootenvironment);
}
((DefinitionDetailModel) detailModel).setAvailableBootenvironments(availableBootenvironments);
}
The problem is that when I click a button in the page (which is bound to an action), I get the error:
detailForm:bootenvironment1: Validation error: value is not valid.
I don't understand where the error is; the value for selectItems is a map with the object's name-field(so a string) as key and the object itself as value. Then the value for the default selected (value="#{detailModel.selectedBootenvironment1}") is a string too as you can see in the getter/setter method of the model.
Another problem (maybe related to the previous one) is that when the page first loads, the default selected value should be --Please select one--- as the getBootenvironment1() returns null, but this does not happen: another one from the list is selected.
Can you please help me understanding what/where am I doing wrong?
EDIT
I implemented the Converter as you said:
#FacesConverter( forClass = Bootenvironment.class )
public class BootenvironmentConverter implements Converter
{
#Override
public String getAsString( FacesContext context, UIComponent component, Object modelValue ) throws ConverterException
{
return String.valueOf(((Bootenvironment) modelValue).getDbId());
}
#Override
public Object getAsObject( FacesContext context, UIComponent component, String submittedValue ) throws ConverterException
{
List<Bootenvironment> bootenvironments = ... (get from DB where dbid=submittedValue)
return bootenvironments.get(0);
}
}
But now I have the following error:
java.lang.ClassCastException: java.lang.String cannot be cast to
ch.ethz.id.wai.bootrobot.bo.Bootenvironment

You will get this error when the selected item value doesn't pass the equals() test on any of the available item values.
And indeed, you've there a list of Bootenvironment item values, but you've bound the property to a String which indicates that you're relying on the Bootenvironment#toString() value being passed as submitted value and that you aren't using a normal JSF Converter at all. A String can never return true on an equals() test with an Bootenvironment object.
You'd need to provide a Converter which converts between Bootenvironment and its unique String representation. Usually, the technical ID (such as the autogenerated PK from the database) is been used as the unique String representation.
#FacesConverter(forClass=Bootenvironment.class)
public class BootenvironmentConverter implements Converter {
#Override
public void getAsString(FacesContext context, UIComponent component, Object modelValue) throws ConverterException {
// Write code to convert Bootenvironment to its unique String representation. E.g.
return String.valueOf(((Bootenvironment) modelValue).getId());
}
#Override
public void getAsObject(FacesContext context, UIComponent component, Object submittedValue) throws ConverterException {
// Write code to convert unique String representation of Bootenvironment to concrete Bootenvironment. E.g.
return someBootenvironmentService.find(Long.valueOf(submittedValue));
}
}
Finally, after implementing the converter accordingly, you should be able to fix the selectedBootenvironment1 property to be a normal property without any mess in getter/setter:
private Bootenvironment selectedBootenvironment1;
public Bootenvironment getSelectedBootenvironment1() {
return selectedBootenvironment1;
}
public void setSelectedBootenvironment1(Bootenvironment selectedBootenvironment1) {
this.selectedBootenvironment1 = selectedBootenvironment1;
}

#FacesConverter prevents method call of p:selectOneMenu and p:ajax

I have a weird problem with a custom #FacesConverter with JBoss-7.1.0.CR1b during an AJAX call in p:selectOneMenu (Primefaces 3.0).
The simplified Converter looks like this, there are no NPE or other exceptions in this class
#FacesConverter("MyConverter")
public class MyConverter implements Converter
{
public Object getAsObject(FacesContext fc, UIComponent uic, String value)
{
logger.debug("getAsObject value: "+value);
if (submittedValue.trim().equals("")) {return null;}
else
{
MyEjb ejb = new MyEjb();
ejb.setId(Long.parseLong(value()));
return ejb; //**** alternative with return null; ****
}
}
public String getAsString(FacesContext fc, UIComponent uic, Object value)
{
if (value == null || value.equals("")) {return "";}
else
{
MyEjb ejb = (MyEjb)value;
return ""+ejb.getId();
}
}
}
The converter is used in a p:selectOneMenu:
<h:form>
<p:selectOneMenu value="#{clientBean.selected}" converter="MyConverter">
<f:selectItems value="#{clientBean.all}" var="my"
itemLabel="#{my.name}" itemValue="#{my}"/>
<p:ajax listener="#{clientBean.changed}" />
</p:selectOneMenu>
</h:form>
That's not rocket engineering, the changed method simply makes a debug:
public void changed()
{
logger.info("changed() "+selected);
}
But now the annoying part: The changed() is never called with the code like above, but I get the converter invoked three times:
12:37:51,500 DEBUG getAsObject value: 35
12:37:51,502 DEBUG getAsObject value:
12:37:51,503 DEBUG getAsObject value:
If I change the p:selectOneMenu value="#{clientBean.selectedId}" to a long selectedId and don't use the Converter the method is called once. Even if I return null in getAsObject()the changed() is called (once). I don't assume it's Primefaces related, because I have the same behavior if I use h:selectOneMenu and f:ajax.

You should have a <p:messages />, <p:growl /> or <h:messages /> which is been ajax-updated in your view. You should also pay attention to warnings in server logs about possible missing faces messages. The chance is big that you're seeing the infamous Validation error: Value not valid validation error.
After conversion, JSF will validate if the submitted object is one of the available items as part of safeguard against tampered/hacked requests. JSF will do that by submittedObject.equals(oneOfAvailableObjects) for each of the available objects as you have there in <f:selectItems>. If nothing matches, then JSF will display this validation error.
In your particular case, the MyEjb class has apparently no equals() method or its implementation is broken. See also Right way to implement equals contract.

Java Beans, BeanUtils, and the Boolean wrapper class

I'm using BeanUtils to manipulate Java objects created via JAXB, and I've run into an interesting issue. Sometimes, JAXB will create a Java object like this:
public class Bean {
protected Boolean happy;
public Boolean isHappy() {
return happy;
}
public void setHappy(Boolean happy) {
this.happy = happy;
}
}
The following code works just fine:
Bean bean = new Bean();
BeanUtils.setProperty(bean, "happy", true);
However, attempting to get the happy property like so:
Bean bean = new Bean();
BeanUtils.getProperty(bean, "happy");
Results in this exception:
Exception in thread "main" java.lang.NoSuchMethodException: Property 'happy' has no getter method in class 'class Bean'
Changing everything to a primitive boolean allows both the set and get call to work. I don't have this option, however, since these are generated classes. I assume this happens because the Java Bean libraries only consider an is<name> method to represent a property if the return type is a primitive boolean, and not the wrapper type Boolean. Does anyone have a suggestion as to how to access properties like these through BeanUtils? Is there some kind of workaround I can use?

Finally I've found legal confirmation:
8.3.2 Boolean properties
In addition, for boolean properties, we allow a getter method to match the pattern:
public boolean is<PropertyName>();
From JavaBeans specification. Are you sure you haven't came across JAXB-131 bug?

Workaround to handle Boolean isFooBar() case with BeanUtils
Create new BeanIntrospector
private static class BooleanIntrospector implements BeanIntrospector{
#Override
public void introspect(IntrospectionContext icontext) throws IntrospectionException {
for (Method m : icontext.getTargetClass().getMethods()) {
if (m.getName().startsWith("is") && Boolean.class.equals(m.getReturnType())) {
String propertyName = getPropertyName(m);
PropertyDescriptor pd = icontext.getPropertyDescriptor(propertyName);
if (pd == null)
icontext.addPropertyDescriptor(new PropertyDescriptor(propertyName, m, getWriteMethod(icontext.getTargetClass(), propertyName)));
else if (pd.getReadMethod() == null)
pd.setReadMethod(m);
}
}
}
private String getPropertyName(Method m){
return WordUtils.uncapitalize(m.getName().substring(2, m.getName().length()));
}
private Method getWriteMethod(Class<?> clazz, String propertyName){
try {
return clazz.getMethod("get" + WordUtils.capitalize(propertyName));
} catch (NoSuchMethodException e) {
return null;
}
}
}
Register BooleanIntrospector:
BeanUtilsBean.getInstance().getPropertyUtils().addBeanIntrospector(new BooleanIntrospector());

you can just create second getter with SET - sufix as workaround :)

JSF Validation Error While Using Custom Converter

I am setting up a form using JSF (I'm pretty new at this) and I am getting a Validation Error: Value is not valid message on one of the fields. This field is actually a separate object (as I will show below) that has a custom converter.
Here is what I have (with non-relevant code removed):
I have a Citation class:
#ManagedBean(name="citation")
public class Citation {
private int id;
private Status status;
// getters and setters
}
I also have a Status class that you see referenced in the Citation class:
#ManagedBean(name="status")
public class Status {
private int id;
private String name;
// getters and setters
public List<Status> getAllStatuses() {
Session session = HibernateUtil.getCurrentSession();
session.beginTransaction();
session.clear();
Query query = session.createQuery("from Status");
List<Status> statuses = query.list();
try {
session.getTransaction().commit();
} catch (HibernateException e) {
// TODO: handle exception
session.getTransaction().rollback();
}
return statuses;
}
#Override
public boolean equals(Object obj) {
if (obj == null) return false;
if (!(obj instanceof Status)) return false;
if (this.id == ((Status)obj).getId()) {
return true;
} else {
return false;
}
}
#Override
public int hashCode() {
return this.name.hashCode();
}
}
Then for my form, I have:
<h:selectOneMenu id="citation_status" value="#{citation.status}">
<f:selectItems value="#{status.allStatuses} var="s" itemValue="#{s.id}" itemLabel="#{s.name}" />
</h:selectOneMenu>
<h:message for="citation_status" />
Lastly, for my converter, I have:
#FacesConverter(forClass=Status.class)
public class StatusConverter implements Converter {
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
// uses Hibernate to get the Status object (using a breakpoint in Eclipse, I have verified that this works)
// I can post this code if needed, but just trying to keep it short :)
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
return String.valueOf(((Status) value).getId());
}
}
Now when I get to my form and submit, I get the Validation Error next to the Status. I'm pretty new at this and thanks to #BalusC, I'm this far along.
Any help is greatly appreciated.

Validation Error: Value is not valid
In case of <h:selectOneMenu>, you will get this when error whenever the selected item does not match any of the items available in the list. I.e. selectedItem.equals(selectItem) has never returned true for any of the items.
Since it's apparently a custom object (the Status class), did you implement its Object#equals() (and #hashCode()) properly? You can if necessary let the IDE (Eclipse/Netbeans) autogenerate them.
See also:
Overriding equals and hashCode in Java
How to implement equals() in beans/entities
Update: after having a closer look at your code, it turns out that you're actually submitting #{s.id} instead of #{s} (the whole Status object). Fix the itemValue accordingly and it should work (if equals() is still doing its job properly).