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Validation Error: Value is not valid
(3 answers)
Closed 7 years ago.
I got this error many time.. i am using two h:selectonemenu in my JSF page, mediaList and Unitlist. while selecting any Media . my UnitList populate automatically, but some time it gives Validation Error: value is not valid;
My JSF code
<h:selectOneMenu id="media" value="#{workOrderMbean.selectedMedia}" converter="MediaConverter" onchange="submit()" valueChangeListener="#{workOrderMbean.onChangeMediaCombo}" immediate="true">
<f:selectItems value="#{workOrderMbean.mediaCombo}"/>
</h:selectOneMenu>
<h:selectOneMenu id="hUnit" value="#{workOrderMbean.selectedHeightUnit}" converter="UnitConverter" >
<f:selectItems value="#{workOrderMbean.unitCombo}"/>
</h:selectOneMenu>
onchane event of Mediacombo is
public void onChangeMediaCombo(ValueChangeEvent e) throws SearchBLException {
if (e.getNewValue() != null) {
Media media = (Media) e.getNewValue();
if (unitCombo != null && !unitCombo.isEmpty()) {
unitCombo.clear();
seclectedWidthUnit=new Unit();
selectedHeightUnit=new Unit();
}
unitCombo = ComboLoader.getUnitsComboByMediaid(media.getMediaId());
}
else
{
if (unitCombo != null && !unitCombo.isEmpty()) {
unitCombo.clear();
seclectedWidthUnit=null;
selectedHeightUnit=null;
}
unitCombo = ComboLoader.getUnitsComboByMediaid(-1);
}
}
i am also using converter for 'Unit'
my media converter is
#FacesConverter(value = "MediaConverter")
public class MediaConverter implements Converter{
MediaDAO mediadao=new MediaDAOImpl();
public Object getAsObject(FacesContext context, UIComponent component, String value) {
Media media=null;
try {
media=mediadao.getMedia(Integer.parseInt(value));
} catch (SearchBLException ex) {
Logger.getLogger(MediaConverter.class.getName()).log(Level.SEVERE, null, ex);
}
return media;
}
public String getAsString(FacesContext context, UIComponent component, Object value) {
String str = "";
if (value instanceof Media) {
str = "" + ((Media) value).getMediaId();
}
return str;
}
}
The problem is most likely in your converter and model class (Media).
You don't show how you exactly do the conversion, but I guess you're converting to String by returning the Media's Id, and converting back to Media by getting a new instance from some place like a DB?
In that case, your Media class needs to implement a custom equals and hashcode method.
JSF compares if the value send by the user corresponds with the values in the list you bind to the selectitems. It uses equals for that, which by default compares object Ids (kind of memory references). Unless you have the exact same instances, this will always be false.
Instead of defining an equals method, you can alternatively let your converter get the model object you need from the same list as the selectitems come from. There was an article on http://jdevelopment.nl a while back about this.
Related
I am creating a web application, where you have to read a list of objects / entities from a DB and populate it in a JSF <h:selectOneMenu>. I am unable to code this. Can someone show me how to do it?
I know how to get a List<User> from the DB. What I need to know is, how to populate this list in a <h:selectOneMenu>.
<h:selectOneMenu value="#{bean.name}">
...?
</h:selectOneMenu>
Based on your question history, you're using JSF 2.x. So, here's a JSF 2.x targeted answer. In JSF 1.x you would be forced to wrap item values/labels in ugly SelectItem instances. This is fortunately not needed anymore in JSF 2.x.
Basic example
To answer your question directly, just use <f:selectItems> whose value points to a List<T> property which you preserve from the DB during bean's (post)construction. Here's a basic kickoff example assuming that T actually represents a String.
<h:selectOneMenu value="#{bean.name}">
<f:selectItems value="#{bean.names}" />
</h:selectOneMenu>
with
#ManagedBean
#RequestScoped
public class Bean {
private String name;
private List<String> names;
#EJB
private NameService nameService;
#PostConstruct
public void init() {
names = nameService.list();
}
// ... (getters, setters, etc)
}
Simple as that. Actually, the T's toString() will be used to represent both the dropdown item label and value. So, when you're instead of List<String> using a list of complex objects like List<SomeEntity> and you haven't overridden the class' toString() method, then you would see com.example.SomeEntity#hashcode as item values. See next section how to solve it properly.
Also note that the bean for <f:selectItems> value does not necessarily need to be the same bean as the bean for <h:selectOneMenu> value. This is useful whenever the values are actually applicationwide constants which you just have to load only once during application's startup. You could then just make it a property of an application scoped bean.
<h:selectOneMenu value="#{bean.name}">
<f:selectItems value="#{data.names}" />
</h:selectOneMenu>
Complex objects as available items
Whenever T concerns a complex object (a javabean), such as User which has a String property of name, then you could use the var attribute to get hold of the iteration variable which you in turn can use in itemValue and/or itemLabel attribtues (if you omit the itemLabel, then the label becomes the same as the value).
Example #1:
<h:selectOneMenu value="#{bean.userName}">
<f:selectItems value="#{bean.users}" var="user" itemValue="#{user.name}" />
</h:selectOneMenu>
with
private String userName;
private List<User> users;
#EJB
private UserService userService;
#PostConstruct
public void init() {
users = userService.list();
}
// ... (getters, setters, etc)
Or when it has a Long property id which you would rather like to set as item value:
Example #2:
<h:selectOneMenu value="#{bean.userId}">
<f:selectItems value="#{bean.users}" var="user" itemValue="#{user.id}" itemLabel="#{user.name}" />
</h:selectOneMenu>
with
private Long userId;
private List<User> users;
// ... (the same as in previous bean example)
Complex object as selected item
Whenever you would like to set it to a T property in the bean as well and T represents an User, then you would need to bake a custom Converter which converts between User and an unique string representation (which can be the id property). Do note that the itemValue must represent the complex object itself, exactly the type which needs to be set as selection component's value.
<h:selectOneMenu value="#{bean.user}" converter="#{userConverter}">
<f:selectItems value="#{bean.users}" var="user" itemValue="#{user}" itemLabel="#{user.name}" />
</h:selectOneMenu>
with
private User user;
private List<User> users;
// ... (the same as in previous bean example)
and
#ManagedBean
#RequestScoped
public class UserConverter implements Converter {
#EJB
private UserService userService;
#Override
public Object getAsObject(FacesContext context, UIComponent component, String submittedValue) {
if (submittedValue == null || submittedValue.isEmpty()) {
return null;
}
try {
return userService.find(Long.valueOf(submittedValue));
} catch (NumberFormatException e) {
throw new ConverterException(new FacesMessage(String.format("%s is not a valid User ID", submittedValue)), e);
}
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object modelValue) {
if (modelValue == null) {
return "";
}
if (modelValue instanceof User) {
return String.valueOf(((User) modelValue).getId());
} else {
throw new ConverterException(new FacesMessage(String.format("%s is not a valid User", modelValue)), e);
}
}
}
(please note that the Converter is a bit hacky in order to be able to inject an #EJB in a JSF converter; normally one would have annotated it as #FacesConverter(forClass=User.class), but that unfortunately doesn't allow #EJB injections)
Don't forget to make sure that the complex object class has equals() and hashCode() properly implemented, otherwise JSF will during render fail to show preselected item(s), and you'll on submit face Validation Error: Value is not valid.
public class User {
private Long id;
#Override
public boolean equals(Object other) {
return (other != null && getClass() == other.getClass() && id != null)
? id.equals(((User) other).id)
: (other == this);
}
#Override
public int hashCode() {
return (id != null)
? (getClass().hashCode() + id.hashCode())
: super.hashCode();
}
}
Complex objects with a generic converter
Head to this answer: Implement converters for entities with Java Generics.
Complex objects without a custom converter
The JSF utility library OmniFaces offers a special converter out the box which allows you to use complex objects in <h:selectOneMenu> without the need to create a custom converter. The SelectItemsConverter will simply do the conversion based on readily available items in <f:selectItem(s)>.
<h:selectOneMenu value="#{bean.user}" converter="omnifaces.SelectItemsConverter">
<f:selectItems value="#{bean.users}" var="user" itemValue="#{user}" itemLabel="#{user.name}" />
</h:selectOneMenu>
See also:
Our <h:selectOneMenu> wiki page
View-Page
<h:selectOneMenu id="selectOneCB" value="#{page.selectedName}">
<f:selectItems value="#{page.names}"/>
</h:selectOneMenu>
Backing-Bean
List<SelectItem> names = new ArrayList<SelectItem>();
//-- Populate list from database
names.add(new SelectItem(valueObject,"label"));
//-- setter/getter accessor methods for list
To display particular selected record, it must be one of the values in the list.
Roll-your-own generic converter for complex objects as selected item
The Balusc gives a very useful overview answer on this subject. But there is one alternative he does not present: The Roll-your-own generic converter that handles complex objects as the selected item. This is very complex to do if you want to handle all cases, but pretty simple for simple cases.
The code below contains an example of such a converter. It works in the same spirit as the OmniFaces SelectItemsConverter as it looks through the children of a component for UISelectItem(s) containing objects. The difference is that it only handles bindings to either simple collections of entity objects, or to strings. It does not handle item groups, collections of SelectItems, arrays and probably a lot of other things.
The entities that the component binds to must implement the IdObject interface. (This could be solved in other way, such as using toString.)
Note that the entities must implement equals in such a way that two entities with the same ID compares equal.
The only thing that you need to do to use it is to specify it as converter on the select component, bind to an entity property and a list of possible entities:
<h:selectOneMenu value="#{bean.user}" converter="selectListConverter">
<f:selectItem itemValue="unselected" itemLabel="Select user..."/>
<f:selectItem itemValue="empty" itemLabel="No user"/>
<f:selectItems value="#{bean.users}" var="user" itemValue="#{user}" itemLabel="#{user.name}" />
</h:selectOneMenu>
Converter:
/**
* A converter for select components (those that have select items as children).
*
* It convertes the selected value string into one of its element entities, thus allowing
* binding to complex objects.
*
* It only handles simple uses of select components, in which the value is a simple list of
* entities. No ItemGroups, arrays or other kinds of values.
*
* Items it binds to can be strings or implementations of the {#link IdObject} interface.
*/
#FacesConverter("selectListConverter")
public class SelectListConverter implements Converter {
public static interface IdObject {
public String getDisplayId();
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
if (value == null || value.isEmpty()) {
return null;
}
return component.getChildren().stream()
.flatMap(child -> getEntriesOfItem(child))
.filter(o -> value.equals(o instanceof IdObject ? ((IdObject) o).getDisplayId() : o))
.findAny().orElse(null);
}
/**
* Gets the values stored in a {#link UISelectItem} or a {#link UISelectItems}.
* For other components returns an empty stream.
*/
private Stream<?> getEntriesOfItem(UIComponent child) {
if (child instanceof UISelectItem) {
UISelectItem item = (UISelectItem) child;
if (!item.isNoSelectionOption()) {
return Stream.of(item.getValue());
}
} else if (child instanceof UISelectItems) {
Object value = ((UISelectItems) child).getValue();
if (value instanceof Collection) {
return ((Collection<?>) value).stream();
} else {
throw new IllegalStateException("Unsupported value of UISelectItems: " + value);
}
}
return Stream.empty();
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
if (value == null) return null;
if (value instanceof String) return (String) value;
if (value instanceof IdObject) return ((IdObject) value).getDisplayId();
throw new IllegalArgumentException("Unexpected value type");
}
}
I'm doing it like this:
Models are ViewScoped
converter:
#Named
#ViewScoped
public class ViewScopedFacesConverter implements Converter, Serializable
{
private static final long serialVersionUID = 1L;
private Map<String, Object> converterMap;
#PostConstruct
void postConstruct(){
converterMap = new HashMap<>();
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object object) {
String selectItemValue = String.valueOf( object.hashCode() );
converterMap.put( selectItemValue, object );
return selectItemValue;
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String selectItemValue){
return converterMap.get(selectItemValue);
}
}
and bind to component with:
<f:converter binding="#{viewScopedFacesConverter}" />
If you will use entity id rather than hashCode you can hit a collision- if you have few lists on one page for different entities (classes) with the same id
Call me lazy but coding a Converter seems like a lot of unnecessary work. I'm using Primefaces and, not having used a plain vanilla JSF2 listbox or dropdown menu before, I just assumed (being lazy) that the widget could handle complex objects, i.e. pass the selected object as is to its corresponding getter/setter like so many other widgets do. I was disappointed to find (after hours of head scratching) that this capability does not exist for this widget type without a Converter. In fact if you supply a setter for the complex object rather than for a String, it fails silently (simply doesn't call the setter, no Exception, no JS error), and I spent a ton of time going through BalusC's excellent troubleshooting tool to find the cause, to no avail since none of those suggestions applied. My conclusion: listbox/menu widget needs adapting that other JSF2 widgets do not. This seems misleading and prone to leading the uninformed developer like myself down a rabbit hole.
In the end I resisted coding a Converter and found through trial and error that if you set the widget value to a complex object, e.g.:
<p:selectOneListbox id="adminEvents" value="#{testBean.selectedEvent}">
... when the user selects an item, the widget can call a String setter for that object, e.g. setSelectedThing(String thingString) {...}, and the String passed is a JSON String representing the Thing object. I can parse it to determine which object was selected. This feels a little like a hack, but less of a hack than a Converter.
I'm creating a new message, by setting the indexers, like:
Iso8583 isoMsg = new Iso8583();
isoMsg[field] = value;
I noticed that I'm not receiving any exceptions; following the code I've seen that the validator is not running when I'm setting the fields this way; it only executes when unpacking a byte[] message. Do you think it would be possible to adapt the format and length validators to run also when setting a field?
Thanks in advance!
The validators are run on the fields when you call .Pack() on the message.
I guess you just set the value to one of the existing fields form the default template
When you create Iso8583() it uses the DefaultTemplate, which adds the set of default fields into the message instance on creation.
Indexer property is derived from AMessage class, which is Iso8583 class is inherited from.
public string this[int field]
{
get { return this.GetFieldValue(field); }
set { this.SetFieldValue(field, value); }
}
These methods:
protected string GetFieldValue(int field)
{
return this.bitmap[field] ? this.fields[field].Value : null;
}
protected void SetFieldValue(int field, string value)
{
if (value == null)
{
this.ClearField(field);
return;
}
this.GetField(field).Value = value;
}
So it seems that your code sets the value for one of the field from the default template
isoMsg[field] = value;
I'm using primefaces 3.5, with a glassfish server 3.1.2. I have a trivia question game that relies on the user to select answers. I have two tables which one is generated based on if it's a multi-select question, or if its mutlipile choice. While my multiple choice data table works beautifully, the other does not. I've followed the example on the show case, and when I select 2 of the table, and hit the next button on the wizard it is in, it deselects what I selected and keeps me on the same page. I made it stay on the same page on any exception, and the exception was a null pointer due to the fact that the "selected answers" where null. Here is my table.
<p:dataTable
id="multiQuestionTable"
value="#{triviaQuestionsBean.dataModel}"
var="answer"
selection="#{triviaQuestionsBean.selectAnswers}">
<p:column selectionMode="multiple" />
<p:column>
#{answer.answer.testAnswer}
</p:column>
</p:dataTable>
The setting and getter:
private QuestionAnswers[] selectAnswers;
public QuestionAnswers[] getSelectAnswers() {
return selectAnswers;
}
public void setSelectAnswers(QuestionAnswers[] selectAnswers) {
this.selectAnswers = selectAnswers;
}
The setter is never called, but the data model that is used works very well for the single select. If that is needed to figure out my issue let me know. Please assist if possible.
public class QuestionAnswersDataModel extends ListDataModel
implements SelectableDataModel {
/**
* This is the question answers data model used to allow for the sorting,
* and selection of items in a JSF dataTable. This is the basic no-arg
* constructor --Important-- This judges the data from the id, so if the ID
* has not been assigned, there will be unpredictable results.
*
*/
public QuestionAnswersDataModel() {
}
/**
* This is the question answers data model used to allow for the sorting,
* and selection of items in a JSF dataTable. This is the constructor where
* the list of elements are instantiated. --Important-- This judges the data
* from the id, so if the ID has not been assigned, there will be
* unpredictable results.
*
* #param data The list of QuestionAnswers to display in the table.
*/
public QuestionAnswersDataModel(List<QuestionAnswers> data) {
super(data);
}
/**
* This takes a "row key" and looks through the wrapped data to find the
* specific QuestionAnswers entity that matches the passed in row key
*
* #param rowKey The key to search with
* #return The QuestionAnswers entity that matches the criteria or null if
* nothing matches
*/
#Override
public QuestionAnswers getRowData(String rowKey) {
/**
* Get the wrapped data (If there was a lot of data you would use a
* query not just a list)
*/
List<QuestionAnswers> answers =
(List<QuestionAnswers>) getWrappedData();
//for each answer
for (QuestionAnswers answer : answers) {
//if the answer's unique identifier matches the row key:
if (answer.getQuestionAnswersId().toString().equals(rowKey)) {
//return it
return answer;
}
}
//if nothing matches return null
return null;
}
/**
* This takes a QuestionAnswers entity object and returns a key for the
* identification of this entity. As this one runs off of the ID of the
* answer, if nothing is assigned to the value, a null key will be returned.
*
* #param answer The answer to generate the key of
* #return The identifier for this object or null if the ID is null
*/
#Override
public Object getRowKey(QuestionAnswers answer) {
//if the answer is null, return null
if (answer == null) {
return null;
}
//else get the answer id
Long id = answer.getQuestionAnswersId();
//if it's null return null
if (id == null) {
return id;
}
//else return the String representation of the id
return id.toString();
}
I wrote an EnumConverter that is described in Use enum in h:selectManyCheckbox? Everything was fine until we recognize that this converter does not work properly in primefaces editable datatable. The problem is that although I added an attribute inside getAsString and getAsObject methods as following:
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
if (value instanceof Enum) {
component.getAttributes().put(ATTRIBUTE_ENUM_TYPE, value.getClass());
return ((Enum<?>) value).name();
} else {
throw new ConverterException(new FacesMessage("Value is not an enum: " + value.getClass()));
}
}
public Object getAsObject(FacesContext context, UIComponent component, String value) {
Class<Enum> enumType = (Class<Enum>) component.getAttributes().get(ATTRIBUTE_ENUM_TYPE);
try {
return Enum.valueOf(enumType, value);
} catch (IllegalArgumentException e) {
throw new ConverterException(new FacesMessage("Value is not an enum of type: " + enumType));
}
}
In the latter method(getAsObject) could not find the attribute that I gave to the components attribute map. But out of the pprimefaces editable datatable everything is fine. Is there any solution to achieve this?
This problem is caused because the custom component attribute was not saved in the row state of the PrimeFaces datatable (it works fine in standard h:dataTable).
We're going to need to store this information elsewhere. In the view scope along with the component ID would be one way.
In the getAsString():
context.getViewRoot().getViewMap().put(ATTRIBUTE_ENUM_TYPE + component.getId(), value.getClass());
And in the getAsObject():
Class<Enum> enumType = (Class<Enum>) context.getViewRoot().getViewMap().get(ATTRIBUTE_ENUM_TYPE + component.getId());
I have a f:convertDateTime with a pattern of mm/dd/yyyy. However, people are able to enter 2/19/78 and it would be 0078 rather then 1978 or 2078. I want to force people to enter in all 4 digits.
I tried using a regexPattern validator, but that is complaining because it wants a string and not a Date object. Seems that the converters fire first and validators validate the converted value?
I guess I could write a custom converter or validator, but this seems like such a simple thing I figure I'm doing something wrong.
The javadocs for the convertor say it is strict in matching the pattern, but I'm not seeing that?
Any ideas or suggestions?
thanks!
It's only strict for days/months, not for years. Here's an extract of relevance from SimpleDateFormat javadoc which <f:convertDateTime> is using under the covers:
For parsing, if the number of pattern letters is more than 2, the year is interpreted literally, regardless of the number of digits. So using the pattern "MM/dd/yyyy", "01/11/12" parses to Jan 11, 12 A.D.
It's by design indeed not possible to fire validators before converters. Essentially, this one should have thrown a ConverterException because the input is not in the proper format. I'd create a custom converter which validates the pattern beforehand. Something like this:
#FacesConverter("validatingPatternDateTimeConverter")
public class ValidatingPatternDateTimeConverter extends DateTimeConverter {
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
String regex = getMandatoryAttribute(component, "validateRegex");
String pattern = getMandatoryAttribute(component, "convertPattern");
if (value != null && !value.matches(regex)) {
throw new ConverterException(new FacesMessage(String.format("Invalid date, must be in pattern %s", pattern)));
}
setPattern(pattern);
return super.getAsObject(context, component, value);
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
setPattern(getMandatoryAttribute(component, "convertPattern"));
return super.getAsString(context, component, value);
}
private String getMandatoryAttribute(UIComponent component, String name) {
String value = (String) component.getAttributes().get(name);
if (value == null || value.isEmpty()) {
throw new IllegalArgumentException(String.format("<f:attribute name=\"%s\"> is missing.", name));
}
return value;
}
}
which is to be used as follows:
<h:inputText value="#{bean.date}">
<f:converter converterId="validatingPatternDateTimeConverter" />
<f:attribute name="validateRegex" value="\d{1,2}/\d{1,2}/\d{4}" />
<f:attribute name="convertPattern" value="MM/dd/yyyy" />
</h:inputText>