I'm using JSF 2.0 and EJB 3.1 in the Glassfish v3 app server. And I'm facing actually the follwing problem:
In a MenagedBean with RequestScope I want to access a session object (an EJB with #Stateful) which should store some session relevant information as the seleced category, the seleced page (with a datatable paginator for each category), etc. - nothing special I think.
The first time a category is selected, the datatable is created and displayed. Allright so far.
Now, if an item (row) is clicked (to show the item's details) or if the next page should be displayed, the session (the stateful EJB) is recreated and again the default values are used to display and render the page.
The code looks like:
#ManagedBean
#RequestScoped
public class TableViewBean {
#EJB
SessionBean session;
public DataModel getTable() {
return session.getDataModel();
}
public SessionBean getSession(){
return session;
}
public void next() {
session.getPaginator().nextPage();
session.resetList();
}
public void previous() {
session.getPaginator().previousPage();
session.resetList();
}
// some other code
}
and the session EJB:
#Stateful
public class SessionBean {
private String selectedType = "Entity";
private DataModel dataModel;
private int rowsPerPage = 5;
private Paginator paginator;
public void setSelectedType(String type){
if(!type.equalsIgnoreCase(selectedType)){
selectedType = type;
updateService();
}
resetList();
}
public void resetList() {
dataModel = null;
}
public void resetPagination() {
paginator = null;
}
public int getRowsPerPage() {
return rowsPerPage;
}
public void setRowsPerPage(int rowsPerPage) {
this.rowsPerPage = rowsPerPage;
resetList();
resetPagination();
}
public Paginator getPaginator() {
if (paginator == null) {
paginator = new Paginator(rowsPerPage) {
#Override
public int getItemsCount() {
return selectedService.getCount();
}
#Override
public DataModel createPageDataModel() {
DataModel model = null;
if(selectedService != null){
model = new ListDataModel(....);
}
return model;
}
};
}
return paginator;
}
public DataModel getDataModel() {
if(dataModel == null){
dataModel = getPaginator().createPageDataModel();
}
return dataModel;
}
}
If I change the Scope of the ManagedBean to SessionScope everything works fine, but I don't like this, because of use of memory concerns.
What's wrong with my code...please help me.
Greetz, Gerry
Your RequestScoped ManagedBean is re-instantiated for each request (that's what RequestScoped means after all). Therefore, with each instantiation it gets injected with a new SFSB instance.
Related
I am attempting to read data from an Android Room database in a background Service. There are no exceptions but no data is returned.
I wrote a function to select all rows from a table in the DAO. Calling that function from a background service succeeds, but it returns no data.
My "Contact" class holds contact information (names, phone numbers, emails) and defines the database schema. The database holds rows of contacts, with names, phone numbers, an emails as columns.
The function that returns the LiveData in the DAO is:
#Query("SELECT * FROM contacts_table")
LiveData<List<Contact>> getAll();
where "contacts_table" is the database table holding contact information.
I called getAll as follows:
AppDatabase db = AppDatabase.getDatabase(messageSenderContext.getApplicationContext());
mContactDAO = db.contactDAO();
mAllContacts = mContactDAO.getAll();
where mContactDao is a ContactDAO (The Database Access Object for my Contact class), and mAllContacts is a LiveData>. These are private fields of the class calling getAll().
db.contactDAO() returns an object, as does mContactDAO.getAll(). But attempting to unpack the List from mAllContacts using mAllContacts.getValue() returns null.
This turned out to be a misuse of LiveData. That requires an Observer to actually get the data.
In your ROOM
#Database(entities={Contact.class}, version = 1, exportSchema = false)
public abstract class AppDatabase extends RoomDatabase {
public static final String DATABASE_NAME = "AppDatabase.db";
private static volatile AppDatabase INSTANCE;
private static final int NUMBER_OF_THREADS = 4;
public static final ExecutorService EXECUTOR_SERVICE = Executors.newFixedThreadPool(NUMBER_OF_THREADS);
public abstract ContactDAO contactDAO();
public static AppDatabase getDatabase(final Context context) {
if (INSTANCE == null) {
synchronized (AppDatabase.class) {
if (INSTANCE == null) {
INSTANCE = Room.databaseBuilder(context.getApplicationContext(),
AppDatabase.class, DATABASE_NAME)
.build();
}
}
}
return INSTANCE;
}
}
In your DAO
#Dao
public interface ContactDAO{
#Query("SELECT * FROM contacts_table")
LiveData<List<Contact>> getAll();
}
In your repository:
public class AppRepository {
private ContactDAO mContactDAO;
//constructor
public AppRepository(Application application) {
AppDatabase db = AppDatabase.getDatabase(application);
mContactDAO= db.contactDAO();
}
public LiveData<List<Contact>> getAllContacts(){
LiveData<List<Contact>> contactsList = null;
Future<LiveData<List<Contact>>> futureList = AppDatabase.EXECUTOR_SERVICE.submit(new Callable(){
#Override
public LiveData<List<Contact>> call() {
return contactDAO.getAll();
}
});
try {
contactsList = futureList.get();
} catch (ExecutionException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
return contactsList ;
}
}
In your ViewModel
public class ContactsViewModel extends AndroidViewModel {
private AppRepository appRepository;
private LiveData<List<Contact>> contactsList;
public ContactsViewModel(#NonNull Application application) {
super(application);
appRepository = new AppRepository(application);
}
public LiveData<List<Contacts>> list() {
return appRepository.getAllContacts();
}
}
In your activity (inside of onCreated put)
ContactsViewModel contactsViewModel = new ViewModelProvider(this).get(ContactsViewModel.class);
contactsViewModel.list().observe(getViewLifecycleOwner(), new Observer<List<Contact>>() {
#Override
public void onChanged(List<Contact> contactsList) {
//the contact list will be observed and will return data if there are changes.
//use for example to feed the adapter of a recyclerview
//below an example just to view the contacts data
for(Contact conctact : contactsList){
Log.d("TestApp>>>", "Id: + contact.getId);
Log.d("TestApp>>>", "Name: + contact.getName);
}
});
I use a managed bean with a view scoped because I need it ( for a p:datatable with lazy and selection modes ), but i'd like to do some things into this managed bean at the render response phase, is there a convenient way to do that ?
I need a view scoped to save a lazyDataModel, but I noticed that the rowCount method is called several times, each time a request ( Select count ) is executed.
So I deciced to save the result of the request. But if I add a data and refresh the datatable with ajax, the row count still contain the same result because of the scope. I use a boolean to know if the rowcount method has been already executed and I can set this boolean to false each time I add or remove a data but if I could do that a the render response phase it would be more convenient for me.
#ManagedBean
#ViewScoped
public class ListBean {
protected MyLazyDataModel myLazyDataModel = new MyLazyDataModel();
public MyLazyDataModel getMyLazyDataModel() {
return myLazyDataModel;
}
public void reloadList() {
this.reloadList = true;
}
protected class MyLazyDataModel extends LazyDataModel{
private int rowCount ;
#Override
public List load(int first, int pageSize, String sortField,
SortOrder sortOrder, Map<String, Object> filters) {
...
}
#Override
public Object getRowKey(Type object) {
...
}
#Override
public Type getRowData(String rowKey) {
...
}
#Override
public int getRowCount() {
if( reloadList ) {
this.rowCount = getDao().getRowCount().intValue();
reloadList = false;
}
return rowCount;
}
}
}
Thanks.
Im new using this front end framework application...
I recently started to work with smartgwt and i'm bulding a new application with a Spring MVC integration.
I'm using a ListGrid with a RestDataSource (Consume the Rest service with mvc:annotation-driven for plain JSON)
I can see that the servaice gets consuming properly perhaps my grid is never shown with the data in it.
Can someone help me here ?
Here's my ListGrid class
public class ListGrid extends com.smartgwt.client.widgets.grid.ListGrid {
private final SpringJSONDataSource springJSONDataSource;
public ListGrid(List<DataSourceField> fields) {
this(new PatientDataSource(fields));
}
public ListGrid(SpringJSONDataSource springJSONDataSource) {
this.springJSONDataSource = springJSONDataSource;
init();
}
private void init() {
setAutoFetchData(true);
setAlternateRecordStyles(true);
setEmptyCellValue("???");
setDataPageSize(50);
setDataSource(springJSONDataSource);
}
}
Now there's the DataSource implmentation
public abstract class SpringJSONDataSource extends RestDataSource {
protected final HTTPMethod httpMethod;
public SpringJSONDataSource(List<DataSourceField> fields) {
this(fields, HTTPMethod.POST);
}
public SpringJSONDataSource(List<DataSourceField> fields, HTTPMethod httpMethod) {
this.httpMethod = httpMethod;
setDataFormat(DSDataFormat.JSON);
addDataSourceFields(fields);
setOperationBindings(getFetch());
addURLs();
}
private void addURLs() {
if(getUpdateDataURL() != null)
setUpdateDataURL(getUpdateDataURL());
if(getRemoveDataURL() != null)
setRemoveDataURL(getRemoveDataURL());
if(getAddDataURL() != null)
setAddDataURL(getAddDataURL());
if(getFetchDataURL() != null)
setFetchDataURL(getFetchDataURL());
}
private void addDataSourceFields(List<DataSourceField> fields) {
for (DataSourceField dataSourceField : fields) {
addField(dataSourceField);
}
}
protected abstract OperationBinding getFetch();
protected abstract OperationBinding getRemove();
protected abstract OperationBinding getAdd();
protected abstract OperationBinding getUpdate();
public abstract String getUpdateDataURL();
public abstract String getRemoveDataURL();
public abstract String getAddDataURL();
public abstract String getFetchDataURL();
}
The class PatientDataSource that extends SpringJSONDataSource
public class PatientDataSource extends SpringJSONDataSource {
public PatientDataSource(List<DataSourceField> fields) {
super(fields);
setPrettyPrintJSON(true);
}
#Override
protected OperationBinding getFetch() {
OperationBinding fetch = new OperationBinding();
fetch.setOperationType(DSOperationType.FETCH);
fetch.setDataProtocol(DSProtocol.POSTMESSAGE);
DSRequest fetchProps = new DSRequest();
fetchProps.setHttpMethod(httpMethod.toString());
fetch.setRequestProperties(fetchProps);
return fetch;
}
#Override
public String getFetchDataURL() {
return "/spring/fetchPatients";
}
#Override
protected OperationBinding getRemove() {
return null;
}
#Override
public String getRemoveDataURL() {
return null;
}
#Override
protected OperationBinding getAdd() {
return null;
}
#Override
public String getAddDataURL() {
return null;
}
#Override
protected OperationBinding getUpdate() {
return null;
}
#Override
public String getUpdateDataURL() {
return null;
}
}
My spring controller PatientControler
#Controller
public class PatienController {
Logger logger = Logger.getLogger(PatienController.class);
#Autowired
private PatientServices patientServices;
#RequestMapping(value = "/patientTest", method = RequestMethod.GET)
#ResponseBody
public Object getTest()
{
return patientServices.getAllPatients();
}
#RequestMapping(value = "/fetchPatients", method = RequestMethod.POST)
#ResponseBody
public Object getAllPatients()
{
return patientServices.getAllPatients();
}
}
PatientServiceImpl
public class PatientServicesImpl implements PatientServices {
public List<Patient> getAllPatients() {
List<Patient> patients = new ArrayList<Patient>();
Patient patient;
for(int i = 0 ; i < 500 ; i++){
patient = new Patient();
patient.setDateOfBirth(new Date());
patient.setFirstName("Joe");
patient.setMiddleName("Moe");
patient.setLastName("Blow");
patient.setLastConsultation(new Date());
patient.setSex(Sex.M);
patients.add(patient);
}
return patients;
}
}
*Im Really stuck right now i've been looking for all type of answers .... but so far nothing worked when i tried to override the transformResponse from my RestDataSource impentation the parameter "data" as an OBJECT, returns me an array [object Object],[object Object],[object Object],[object Object],[object Object] *
The Data which is transferred from the RestDataSource has a specific format which is described in the JavaDoc of the RestDataSource
Your server must understand the request and send back a valid response.
At the moment your example doesn't seem to honour the contract.
To debug the traffic send to and from your server you can use the SmartClient-Console. You can open it by a browser bookmark like this:
javascript:isc.showConsole()
Of cause you need to deploy this console by adding the following module to your gwt.xml
<inherits name="com.smartclient.tools.SmartClientTools"/>
Now go to the RPC Tab and check Track-RPCs
This code works fine, However, if I run execute a storedprocedure in my unit of work class (or any update, delete, add operation), I'm still getting original the data. Actually, I have already a solution(posted below in controller) but Im sure this is not the most elegant way, I hope someone can help me refactor the code. please help. Thanks
My unit of work
public class UnitOfWork : IUnitOfWork, IDisposable
{
private readonly ObjectContext _context;
private BookRepository _books;
public UnitOfWork(ObjectContext context)
{
if (context == null)
{
throw new ArgumentNullException("Context was not supplied");
}
_context = context;
}
public IRepository<Book> Books
{
get
{
if (_books== null)
{
_books= new BookRepository (_context);
}
return _books;
}
}
public void UpdateAuthor(int id)
{
_context.ExecuteStoreCommand("sp_UpdateAuthor #param1",
new SqlParameter("param1", id));
}
public void Commit()
{
_context.SaveChanges();
}
Book Repository
public class BookRepository : Repository<Book>
{
public BookRepository (ObjectContext context)
: base(context)
{
}
public override Machine GetById(object id)
{
return _objectSet.SingleOrDefault(s => s.Id== (int)id);
}
}
Generic Repository
public abstract class Repository<T> : IRepository<T>
where T : class, IAuditEntity
{
protected IObjectSet<T> _objectSet;
public Repository(ObjectContext context)
{
_objectSet = context.CreateObjectSet<T>();
}
public abstract T GetById(object id);
public IEnumerable<T> GetAll()
{
return _objectSet;
}
public IEnumerable<T> Query(Expression<Func<T, bool>> filter)
{
return _objectSet.Where(filter);
}
public void Add(T entity)
{
_objectSet.AddObject(entity);
}
public void Remove(T entity)
{
_objectSet.DeleteObject(entity);
}
}
Controller Code
public class HomeController : Controller
{
private IUnitOfWork _unitOfWork;
#region Core Action Methods
public HomeController()
{
this._unitOfWork = new UnitOfWork(((IObjectContextAdapter)new BookContext()).ObjectContext);
}
private IEnumerable<BookViewModel> GetBookdsViewModels(int id)
{
//THE CODE WHERE ITS NOT RETURNING THE UPDATED VLAUES
//var query = _unitOfWork.Books.GetAll().Where(d => d.Id== id);
//I WANT TO CHANGE THIS CODE
ObjectContext objectContext = ((IObjectContextAdapter)new BookContext()).ObjectContext;
ObjectSet<Book> set = objectContext.CreateObjectSet<Book>();
set.MergeOption = MergeOption.OverwriteChanges;
var query = from a in set
where a.Id== id && !a.IsDeleted
select a;
return query
.Select(
c => new BookViewModel
{
Id = c.Id ,
Name = c.Name
});
}
I believe the problem is because you're executing things directly against your database, and then trying to refer back to the local copy that's stored in your repository and they're different.
public void UpdateAuthor(int id)
{
_context.ExecuteStoreCommand("sp_UpdateAuthor #param1",
new SqlParameter("param1", id));
}
When you run this query, you're making a change in your db instead of your local - why dont you do something like this:
public void UpdateAuthor(int id)
{
var book = Books.GetById(id);
/* make changes to your book object */
_unit.Save();
}
If you're wanting to make changes using store procs, you're going to have to dispose of your context, and recreate the repo's so that you're working with data from the DB instead of the local copy.
Expanding on Mark Oreta's answer, you need to ensure your Model is updated after manually executing a stored proc on your database. If you must manually call that stored proc then try this afterward:
_context.Entry<Book>(instanceOfAuthor).Reload();
Which might be:
_context.Entry<Book>(_context.Books.GetById(id)).Reload();
I have a Singleton class that uses the thread-safe Singleton pattern from Jon Skeet as seen in the TekPub video. The class represents a cached list of reference data for dropdowns in an MVC 3 UI.
To get the list data the class calls a static method on a static class in my DAL.
Now I'm moving into testing an I want to implement an interface on my DAL class but obviously cannot because it is static and has only one static method so there's no interface to create. So I want to remove the static implementation so I can do the interface.
By doing so I can't call the method statically from the reference class and because the reference class is a singleton with a private ctor I can't inject the interface. How do I get around this? How do I get my interface into the reference class so that I can have DI and I can successfully test it with a mock?
Here is my DAL class in current form
public static class ListItemRepository {
public static List<ReferenceDTO> All() {
List<ReferenceDTO> fullList;
... /// populate list
return fullList;
}
}
This is what I want it to look like
public interface IListItemRepository {
List<ReferenceDTO> All();
}
public class ListItemRepository : IListItemRepository {
public List<ReferenceDTO> All() {
List<ReferenceDTO> fullList;
... /// populate list
return fullList;
}
}
And here is my singleton reference class, the call to the static method is in the CheckRefresh call
public sealed class ListItemReference {
private static readonly Lazy<ListItemReference> instance =
new Lazy<ListItemReference>(() => new ListItemReference(), true);
private const int RefreshInterval = 60;
private List<ReferenceDTO> cache;
private DateTime nextRefreshDate = DateTime.MinValue;
public static ListItemReference Instance {
get { return instance.Value; }
}
public List<SelectListDTO> SelectList {
get {
var lst = GetSelectList();
lst = ReferenceHelper.AddDefaultItemToList(lst);
return lst;
}
}
private ListItemReference() { }
public ReferenceDTO GetByID(int id) {
CheckRefresh();
return cache.Find(item => item.ID == id);
}
public void InvalidateCache() {
nextRefreshDate = DateTime.MinValue;
}
private List<SelectListDTO> GetSelectList() {
CheckRefresh();
var lst = new List<SelectListDTO>(cache.Count + 1);
cache.ForEach(item => lst.Add(new SelectListDTO { ID = item.ID, Name = item.Name }));
return lst;
}
private void CheckRefresh() {
if (DateTime.Now <= nextRefreshDate) return;
cache = ListItemRepository.All(); // Here is the call to the static class method
nextRefreshDate = DateTime.Now.AddSeconds(RefreshInterval);
}
}
}
You can use the singleton based on instance(not based on static), for which you can declare interface like this.
public interface IListItemRepository
{
List<ReferenceDTO> All();
}
public class ListItemRepository : IListItemRepository
{
static IListItemRepository _current = new ListItemRepository();
public static IListItemRepository Current
{
get { return _current; }
}
public static void SetCurrent(IListItemRepository listItemRepository)
{
_current = listItemRepository;
}
public List<ReferenceDTO> All()
{
.....
}
}
Now, you can mock IListItemRepository to test.
public void Test()
{
//arrange
//If Moq framework is used,
var expected = new List<ReferneceDTO>{new ReferneceDTO()};
var mock = new Mock<IListItemRepository>();
mock.Setup(x=>x.All()).Returns(expected);
ListItemRepository.SetCurrent(mock.Object);
//act
var result = ListItemRepository.Current.All();
//Assert
Assert.IsSame(expected, result);
}
Which DI framework are you using? Depending on your answer, IOC container should be able to handle single-instancing so that you don't have to implement your own singleton pattern in the caching class. In your code you would treat everything as instanced classes, but in your DI framework mappings you would be able to specify that only one instance of the cache class should ever be created.
One way to test it would be if you refactor your ListItemReference by adding extra property:
public sealed class ListItemReference {
...
public Func<List<ReferenceDTO>> References = () => ListItemRepository.All();
...
private void CheckRefresh() {
if (DateTime.Now <= nextRefreshDate) return;
cache = References();
nextRefreshDate = DateTime.Now.AddSeconds(RefreshInterval);
}
}
And then in your test you could do:
ListItemReference listReferences = new ListItemReference();
listReferences.References = () => new List<ReferenceDTO>(); //here you can return any mock data
Of course it's just temporary solution and I would recommend getting rid of statics by using IoC/DI.