JSF Generic entity converter is not ThreadSafe - jsf-2

I have been using the famouse entityConverter for a long time, but today I realised that this is not thread safe and it can generate concurrences errors.
If one thread adds a element in the Hash, and another reads the hash at the same time, a java.util.ConcurrentModificationException exception will be threw
Somebody can confirm this problem? Thanks
The converter code : taken from BalusC post Generic JSF entity converter
#FacesConverter(value="entityConverter")
public class EntityConverter implements Converter {
private static Map<Object, String> entities = new WeakHashMap<Object, String>();
#Override
public String getAsString(FacesContext context, UIComponent component, Object entity) {
synchronized (entities) {
if (!entities.containsKey(entity)) {
String uuid = UUID.randomUUID().toString();
entities.put(entity, uuid);
return uuid;
} else {
return entities.get(entity);
}
}
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String uuid) {
for (Entry<Object, String> entry : entities.entrySet()) {
if (entry.getValue().equals(uuid)) {
return entry.getKey();
}
}
return null;
}
}

Related

spring-data-elastic Id field not populated on reads when using CustomEntityMapper

Elasticversion - 1.7.6
springboot - 1.3.5
Using spring-data-elasticsearch I have created a custom JSON mapping as advised elsewhere in order to support Java8 new datetime fields.
This works fine - but breaks reading entities from the repository as the id field no longer gets populated.
CustomConfig:
#Bean
#Autowired
public ElasticsearchTemplate elasticsearchTemplate(Client client) {
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.registerModule(new JavaTimeModule());
return new ElasticsearchTemplate(client, new CustomEntityMapper(objectMapper));
}
public class CustomEntityMapper implements EntityMapper {
private ObjectMapper objectMapper;
public CustomEntityMapper(ObjectMapper objectMapper) {
this.objectMapper = objectMapper;
objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
objectMapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
}
#Override
public String mapToString(Object object) throws IOException {
return objectMapper.writeValueAsString(object);
}
#Override
public <T> T mapToObject(String source, Class<T> clazz) throws IOException {
return objectMapper.readValue(source, clazz);
}
}
Sample Entity :
#Document(indexName = "scanner", type = "Entry")
#Data
#Builder
#NoArgsConstructor
#AllArgsConstructor
public class Entry {
#Id
private String id;
#Field(type= FieldType.String)
private String path;
#Field(type = FieldType.Date, format = DateFormat.date_time )
private OffsetDateTime created;
}
Note - that when I remove the CustomEntityMapper the id field is returned. I have traced the spring-data-elasticsearch code,
and identified that it fails to resolve the Id field from the elastic response in DefaultResultMapper.setPersistentId since
the mappingContext is null.
private <T> void setPersistentEntityId(T result, String id, Class<T> clazz) {
if (mappingContext != null && clazz.isAnnotationPresent(Document.class)) {
PersistentProperty<ElasticsearchPersistentProperty> idProperty = mappingContext.getPersistentEntity(clazz).getIdProperty();
// Only deal with String because ES generated Ids are strings !
if (idProperty != null && idProperty.getType().isAssignableFrom(String.class)) {
Method setter = idProperty.getSetter();
if (setter != null) {
try {
setter.invoke(result, id);
} catch (Throwable t) {
t.printStackTrace();
}
}
}
}
}
Has anyone experienced this issue? How can I support a CustomEntityMapper without breaking the Id resolution?
upgrading to spring boot 1.4.1-RELEASE resolved the issue

Add attribute dynamically to component in converter?

I wonder if should be possible to add an attribute to a component inside a converter? So inside the getAsString I would use uiComponent.addAttribute(). This seems to work 50% for me, the initial value is set, but when the converter is called later setting a new value the initial value is still retrieved.
you should not do it this way since it breaks separation of duties. you should use a bean or a scope attribute instead.
but maybe this suits:
<h:inputText value="#{bean.someValue}" converter="#{bean}">
<f:attribute name="attrName" value="#{bean.attrValue}"/>
</h:inputText>
and
#ManagedBean
public class Bean implements Converter
{
private String someValue;
private String attrValue;
#Override
public String getAsString(FacesContext context, UIComponent component, Object value)
{
attrValue = "uppercase";
return someValue.toUpperCase();
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value)
{
attrValue = "lowercase";
return value.toLowerCase();
}
public String getSomeValue()
{
return someValue;
}
public void setSomeValue(String someValue)
{
this.someValue = someValue;
}
public String getAttrValue()
{
return attrValue;
}
public void setAttrValue(String attrValue)
{
this.attrValue = attrValue;
}
}

selectOneMenu with complex objects, is a converter necessary? [duplicate]

This question already has answers here:
Conversion Error setting value for 'null Converter' - Why do I need a Converter in JSF?
(2 answers)
Closed 7 years ago.
Is a Converter necessary for a <h:selectOneMenu> or <p:selectOneMenu> with arbitrary user-created classes as its values? I mean, is the following code supposed to work without a converter?
<p:selectOneMenu value="#{bean.language}">
<f:selectItems value="#{bean.allLanguages}" />
</p:selectOneMenu>
and
#Named(value = "bean")
#ConversationScoped
public class Bean {
private Language language; // appropriate getter and setter are present
public List<SelectItem> getAllLanguages() {
// populates a list of select items with Strings as item labels and Languages as item values
}
}
I have a similar code with an enum as the type (Language) and it works perfectly. But when I replace the type with a normal java class, I get a conversion error.
You need a converter here, as JSF will assume strings by default, that is the way you coded it. JSF has no idea how to convert your pseudo entities to strings and vice versa.
Some notes:
1 . Your getAsString method defines your identifier for your entities/POJOs, not what the JSF (or whatever) select gets as itemLabel.
2 . Your converter can dig into the DB for real entities using this infamous article:
http://balusc.blogspot.de/2011/09/communication-in-jsf-20.html#ConvertingAndValidatingGETRequestParameters
You can also use CDI annotations with that "pattern".
3 . Your value = "bean"is redundant and the CDI scope of choice is usually #ViewScoped. However, you have to keep in mind that CDI #Named + JSF #ViewScoped isn't working together without using Seam 3 or Apache MyFaces CODI.
You do not need a converter, if you use this little class that I wrote :-) It can back selectOne and selecteMany components. It requires that your class's toString() provides a one-to-one unique representation of your object. If you like, you could substitute a method name other than toString(), like toIDString()
To use ListBacker in your ManagedBean, use ListBacker<Type> wherever you would have used List<Type>
#ManagedBean
#RequestScoped
public class BackingBean {
private ListBacker<User> users; // +getter +setter
#PostConstruct
public void init() {
// fill it up from your DAO
users = new ListBacker<User>(userDAO.find());
}
// Here's the payoff! When you want to use the selected object,
// it is just available to you, with no extra database hits:
User thisOneIsSelected = users.getSelectedItemAsObject();
// or for multi-select components:
List<User> theseAreSelected = users.getSelectedItemsAsObjects();
}
In your xhtml file:
<p:selectOneMenu value="#{backingBean.users.selectedItem}">
<f:selectItems value="#{backingBean.users.contents}" var="item" itemValue="#{item.value}" itemLabel="#{item.label}" />
</p:selectOneMenu>
The ListBacker class:
public class ListBacker<T extends AbstractEntityBase> {
// Contains the String representation of an Entity's ID (a.k.a.
// primary key) and the associated Entity object
Map<String, T> contents = new LinkedHashMap<String, T>(); // LinkedHashMap defaults to insertion-order iteration.
// These hold values (IDs), not labels (descriptions).
String selectedItem; // for SelectOne list
List<String> selectedItems; // for SelectMany list
public class ListItem {
private String value;
private String label;
public ListItem(String value, String label) {
this.value = value;
this.label = label;
}
public String getValue() {
return value;
}
public String getLabel() {
return label;
}
}
public ListBacker() {}
public ListBacker(List<T> lst) {
put(lst);
}
public void clear() {
contents.clear();
selectedItem = null;
if(selectedItems != null) {
selectedItems.clear();
}
}
public List<ListItem> getContents() {
return convert(contents);
}
public String getSelectedItem() {
return selectedItem;
}
public void setSelectedItem(String selectedItem) {
this.selectedItem = selectedItem;
}
public List<String> getSelectedItems() {
return selectedItems;
}
public void setSelectedItems(List<String> selectedItems) {
this.selectedItems = selectedItems;
}
public T getSelectedItemAsObject() {
return convert(selectedItem);
}
public List<T> getSelectedItemsAsObjects() {
return convert(selectedItems);
}
public void put(T newItem) {
contents.put(newItem.toString(), newItem);
}
public void put(List<T> newItems) {
for (T t : newItems) {
put(t);
}
}
// PROTECTED (UTILITY) METHODS
protected List<ListItem> convert(Map<String, T> maps) {
List<ListItem> lst = new ArrayList<ListItem>();
for (Entry<String, T> e : maps.entrySet()) {
lst.add(new ListItem(e.getKey(), e.getValue().desc()));
}
return lst;
}
protected List<T> convert(List<String> ids) {
List<T> lst = new ArrayList<T>();
for (String id : ids) {
lst.add(convert(id));
}
return lst;
}
protected T convert(String id) {
return contents.get(id);
}
}
I have two toString() implementations, one for JPA entities:
public abstract class AbstractEntityBase {
#Override
public final String toString() {
return String.format("%s[id=%s]", getClass().getSimpleName(), getIdForToString().toString());
}
/**
* Return the entity's ID, whether it is a field or an embedded ID class..
* #return ID Object
*/
protected abstract Object getIdForToString();
}
and one for JPA EmbeddedId's:
public abstract class CompositeKeyBase {
#Override
public final String toString() {
return String.format("%s[id=%s]", getClass().getSimpleName(), getIdForToString());
}
/**
* Supports the class's toString() method, which is required for ListBacker.
* Compile a string of all ID fields, with this format:
* fieldName=StringVALUE,field2=STRINGvAlUE2,...,fieldx=stringvalue <br />
* Recommended: start with Eclipse's "generate toString()" utility and move it to getIdForToString()
* #return a 1-to-1 String representation of the composite key
*/
public abstract String getIdForToString();
}
An example implementation of getIdForToString(), for an entity that has one Id field:
#Override
public Object getIdForToString() {
return userID;
}
An example implementation of getIdForToString(), for an EmbeddedId that has two fields:
#Override
public String getIdForToString() {
return "userID=" + userID + ",roleID=" + roleID;
}

ENTITY object in the JSF SelectOneMenu is not working

I want to get the instance of the Entity from SelectOneMenu so i can assign the entity variables to some other method. But it is pointing to null.
xhtml code
<h:selectOneMenu value="#{statusReport.projectDetID}" converter="ObjectStringConv" onchange="#{statusReport.retrieveReport()}" >
<f:selectItems value="#{statusReport.listOfProjectDetail}"
var="projectDetail" itemLabel="#{projectDetail.project} #{projectDetail.startDate} - #{projectDetail.endDate}"
itemValue="#{projectDetail}" noSelectionValue="Select the Saved Project"/>
</h:selectOneMenu>
statusReport bean
public class StatusReport implements Serializable {
private ProjectDetail projectDetID;
private List<ProjectDetail> listOfProjectDetail;
public List<ProjectDetail> getListOfProjectDetail() {
listOfProjectDetail = projectDetailFacade.findAll();
return listOfProjectDetail;
}
public void setListOfProjectDetail(List<ProjectDetail> listOfProjectDetail) {
this.listOfProjectDetail = listOfProjectDetail;
}
public ProjectDetail getProjectDetID() {
return projectDetID;
}
public void setProjectDetID(ProjectDetail projectDetID) {
this.projectDetID = projectDetID;
}
public void retrieveReport(){
System.out.println(" Processing .....");
if ( projectDetID == null )
{
System.out.println("The object from Select null");
}
else
{
System.out.println("The object from Select menu" + projectDetID.toString());
}
System.out.println("Generated Data:Completed");
}}
ProjectDetail Entity Bean
package com.jira.entity;
import java.io.Serializable;
import javax.persistence.*;
import java.util.Date;
import java.util.List;
/**
* The persistent class for the PROJECT_DETAIL database table.
*
*/
#Entity
#Table(name="PROJECT_DETAIL",schema="weeklyrep")
public class ProjectDetail implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="projectdetail_seq")
#SequenceGenerator(name="projectdetail_seq",schema="weeklyrep",sequenceName="projectdetail_seq", allocationSize=1)
#Column(name="PDETAIL_ID")
private long pdetailId;
private Boolean completed;
#Temporal( TemporalType.DATE)
#Column(name="END_DATE")
private Date endDate;
private Long project;
#Temporal( TemporalType.DATE)
#Column(name="START_DATE")
private Date startDate;
//bi-directional many-to-one association to MajorEvent
#OneToMany(mappedBy="projectDetail",cascade=CascadeType.ALL)
private List<MajorEvent> majorEvents;
//bi-directional one-to-one association to ExecSummary
#OneToOne(mappedBy="projectDetailExec",cascade=CascadeType.ALL)
private ExecSummary execSummary;
public ProjectDetail() {
}
public long getPdetailId() {
return this.pdetailId;
}
public void setPdetailId(Long pdetailId) {
this.pdetailId = pdetailId;
}
public Boolean getCompleted() {
return this.completed;
}
public void setCompleted(Boolean completed) {
this.completed = completed;
}
public Date getEndDate() {
return this.endDate;
}
public void setEndDate(Date endDate) {
this.endDate = endDate;
}
public long getProject() {
return this.project;
}
public void setProject(long project) {
this.project = project;
}
public Date getStartDate() {
return this.startDate;
}
public void setStartDate(Date startDate) {
this.startDate = startDate;
}
public List<MajorEvent> getMajorEvents() {
return this.majorEvents;
}
public void setMajorEvents(List<MajorEvent> majorEvents) {
this.majorEvents = majorEvents;
}
public ExecSummary getExecSummary() {
return execSummary;
}
public void setExecSummary(ExecSummary execSummary) {
this.execSummary = execSummary;
}
}
Converter
I don't know if it needs converter, however i don't know how code it.
package com.weeklyreport.converters;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;
import javax.faces.convert.FacesConverter;
import com.jira.entity.ProjectDetail;
#FacesConverter(value="ObjectStringConv")
public class ObjectStringConv implements Converter {
#Override
public Object getAsObject(FacesContext context, UIComponent component, String svalue) {
System.out.print("String version of object is:" + svalue);
return "test";
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object ovalue) {
return ovalue.toString();
}
}
Please help me figure this out. Is there a way we get instance of the entity object like this?
Your converter needs to be written that way so that it can convert between ProjectDetail and String based on an unique identifier of ProjectDetail. Usually entities have an id. You need to use this as String value. Here's a kickoff example without any trivial checks like null and instanceof:
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
// Convert ProjectDetail to its unique String representation.
ProjectDetail projectDetail = (ProjectDetail) value;
String idAsString = String.valueOf(projectDetail.getId())
return idAsString;
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
// Convert unique String representation of ProjectDetail back to ProjectDetail object.
Long id = Long.valueOf(value);
ProjectDetail projectDetail = someProjectDetailService.find(id);
return projectDetail;
}
Note that using EJBs in JSF converters (and validators) needs some hackery. See also How to inject #EJB, #PersistenceContext, #Inject, #Autowired, etc in #FacesConverter?

Converter in Primefaces PickList

I'm using Primefaces' PickList and I can't make it work. My problem is Converter. I followed the directions of another post, but in vain.
Here is my facelet
<p:pickList value="#{customerBean.preferredCategories}" var="category"
itemLabel="#{category.description}" itemValue="#{category}" converter="#{categoryConverter}">
</p:pickList>
and here my custom converter
#FacesConverter(forClass=CategoryLevelView.class,value="categoryLevelConverter")
public class CategoryConverter implements Converter {
public String getAsString(FacesContext context, UIComponent component, Object value) {
return String.valueOf(((Category) value).getId());
}
public Object getAsObject(FacesContext arg0, UIComponent arg1, String value) {
Category category = new Category();
category.setId(Integer.parseInt(value));
return category;
}
}
Category is composed by an id (int) and a description (String)
I want both source and target Lists to display the description String, and the selected categories set as a List of Category in my bean. Both lists are correctly loaded in the bean and the DualListModel is populated in preferredCategories. The problem is the PickList is not even rendered. Nothing happens, no error displayed, the page just stops rendering when the turns arrives to PickList, and I think it's because a wrong usage of converter. Which would be a correct way to implement my this case?
Thanks.
I think
#FacesConverter(forClass=CategoryLevelView.class,value="categoryConverter")
public class CategoryConverter implements Converter {
should be
#FacesConverter(forClass=Category.class,value="categoryConverter")
public class CategoryConverter implements Converter {
Change value of forClass to Category.class.
And, you should not need to mention the value of converter attribute in <p:picklist.
This working without an ArrayIndexOutOfBounds exception.
#FacesConverter("PickListConverter")
public class PickListConverter implements Converter {
public Object getAsObject(FacesContext facesContext, UIComponent component, String submittedValue) {
PickList p = (PickList) component;
DualListModel dl = (DualListModel) p.getValue();
for (int i = 0; i < dl.getSource().size(); i++) {
if (dl.getSource().get(i).toString().contentEquals(submittedValue)) {
return dl.getSource().get(i);
}
}
for (int i = 0; i < dl.getTarget().size(); i++) {
if (dl.getTarget().get(i).toString().contentEquals(submittedValue)) {
return dl.getTarget().get(i);
}
}
return null;
}
public String getAsString(FacesContext facesContext, UIComponent component, Object value) {
PickList p = (PickList) component;
DualListModel dl = (DualListModel) p.getValue();
// return String.valueOf(dl.getSource().indexOf(value));
return value.toString();
}
}
In this line:
#FacesConverter(forClass=CategoryLevelView.class,value="categoryLevelConverter")
It looks like you're trying to set the converter id to categoryLevelConverter.
In this line of your Facelet:
converter="#{categoryConverter}"
The converter id does not match.
i made one simple converter and it works well with all values in Primefaces PickList:
#FacesConverter("PickListConverter")
public class PickListConverter implements Converter{
public Object getAsObject(FacesContext facesContext, UIComponent component, String submittedValue) {
PickList p = (PickList) component;
DualListModel dl = (DualListModel) p.getValue();
return dl.getSource().get(Integer.valueOf(submittedValue));
}
public String getAsString(FacesContext facesContext, UIComponent component, Object value) {
PickList p = (PickList) component;
DualListModel dl = (DualListModel) p.getValue();
return String.valueOf(dl.getSource().indexOf(value));
}
}
I do not know if you have solved your problem but if not, you can try this.
In the getAsObject method , what you are doing is creating a new category object and setting its id and returning it. I think what you should do here is get the category from the database with that id and then return that.

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