I'm currently reading code from another guy. I saw that he doesn't make any explicit request to update DB but it does update the entity. Please check below pseudo code:
#Transactional(propagation = Propagation.REQUIRED, readOnly = false)
public void updateFoo(long fooId) {
// Get foo instance from DB, foo has status = 0
Foo foo = fooDAO.getFoo(fooId);
foo.setStatus(1);
// There is no call to DAO layer from here
}
I checked from My SQL, foo is updated without any session.save(foo) or session.update(foo)
Normally, I would call some thing like this in FooDAO layer
sessionFactory.getCurrentSession().update(foo);
How's that possible? I suspect that the Transaction auto commit POJO Object. Please let me know how? And why would anyone do that, is this make code harder to read?
Related
I have the next JUnit test, and it works fine, but finally in the verify it throws expectation failure. I think it is because the mocked PsPort is different of the PsPort that I send to the DataReader.
Is there any other way to test it?
#Test
public void testguardarMensaje() throws IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException, InstantiationException{
String datoTest = "1=123456";
Constructor<PsPort> constructor = PsPort.class.getDeclaredConstructor(new Class[] {String.class});
constructor.setAccessible(true);
PsPort port = constructor.newInstance("middleware.conf");
PsPort drMock;
int hash1 = datoTest.hashCode();
String hashString1 = String.valueOf(hash1);
String combinedIdDataHashString1 = datoTest +"="+ hashString1;
drMock = strictMock(PsPort.class);
byte[] datoByte = port.encriptarDesencriptarMensaje(combinedIdDataHashString1.getBytes(), Cipher.ENCRYPT_MODE);
drMock.guardarDato(datoByte);
replayAll();
int hash = datoTest.hashCode();
String hashString = String.valueOf(hash);
String combinedIdDataHashString = datoTest +"="+ hashString;
byte[] datoByte2 = port.encriptarDesencriptarMensaje(combinedIdDataHashString.getBytes(), Cipher.ENCRYPT_MODE);
DatagramPacket paquete = new DatagramPacket(datoByte2,datoByte2.length);
paquete.getData();
DataReader dr = new DataReader(port, null, 100, "=", "C:/Users/Asier/Desktop/logs/");
dr.guardarMensaje(paquete, port);
verifyAll();
}
It is really confusing that you have two port objects. What is the sense of creating a mocked drPort; when you are then giving a "real" port object to your class under test?
You see: you either create a mock and pass that down to your code under test (and then you have to setup the mock for the expected behavior; which you can afterwards verify); or you only provide "real" objects to your code under test, but then you would normally do some kind of asserts on the results of calls to "code under test".
So, in that sense, it doesn't really matter that there is at least one problem in your code:
drMock.guardarDato(datoByte);
replayAll();
There should be a call to EasyMock.expectLastCall() after the method invocation on drMock; but as said: as the mocked object isn't really used, that doesn't matter, on the one hand. Because, if you added that statement, your test would always fail; since your un-used mock would never see the calls that you specified it to see.
In order to give you some guidance; this is how you do such kind of testing in general:
SomeClassYouNeed mockedThingy = createStrict/Nice(SomeClassYouNeed.class);
expect(mockedThingy.foo()).andReturn("whatever");
mockedThingy.bar();
expectLastCall();
replay (mockedThingy);
ClassUnderTest underTest = new ClassUnderTest(mockedThingy);
underTest.doSomething();
verify(mockedThingy)
Meaning: any "object" that
a) your "class under test" needs to do its work
b) you want/have to "control" in a certain way
needs to be mocked; including a "specification" of all expected method calls.
Then you provide the mocked things to your code under test; execute the method you want to test ... to finally verify that the mock saw the behavior that you specified for it.
In short, what I am trying solve is how to recover from certain database errors in a Grails application using Hibernate and continue on with the transaction skipping over the failed row updates that are part of a batch of changes.
The application uses Grails 2.3.11 but I have also tried with version 1.3.8 with similar failed results.
Basically there is a Grails service class that iterates over a list of imported records and attempts to update associated master records appropriately. In certain situations exceptions might occur during the domain.save(flush:true) call e.g. org.hibernate.exception.DataException thrown due to issues like (Data truncation: Data too long for column ...).
At this point I have tried:
Disabling transactions
Using domainObj.withTransaction() for each individual record
Trying various #Transactional annotations
Calling domain.clearErrors() and domain.discard() after catching the exception
Tried using a nested service with Transactional annotation with noRollbackFor as shown below
A number of other approaches but nothing I've tried has worked
Example code:
#Transactional
class UpdateService {
public updateBatch(Integer batchId) {
...
list.each { record ->
record.value = 123
try {
nestedService.saveDomain()
} catch (e) {
record.clearErrors()
record.discard()
}
}
batch.status = "POSTED"
batch.save()
}
}
#Transactional
class NestedService {
#Transactional(propagation = Propagation.REQUIRED, noRollbackFor = RuntimeException.class)
public void saveDomain(domainObj) throws RuntimeException {
if (domainObj.validate() && domainObj.save(flush:true) {
log.info "domain $domain was saved"
}
}
}
Once an error occurs I can't seem to clear out the hibernate session. On each subsequent record being updated I receive the error:
org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction
where it indicates the original failed domain id.
Revision:
Vahid, Thanks for the suggestions. I have tried that. I realized one issue is that I am passing objects across transactional boundaries. So I experimented with the NestedService class do something along the lines of:
#Transactional(propagation = Propagation.REQUIRE_NEW)
public void saveDomain(domainObj) {
def newObj = new Domain.get(domainObj.id)
newObj.properties = domainObj.properties
if (newObj.validate() && newObj.save(force:true) ) { ... }
I expected that to work but the original domainObj still fails even though I'm not calling the save on it. Very strange...
A simple approach would be to loop and then use validate(). If it does fail, then just store the id of the failed entity and proceed.
if(!domainObject.validate()){
// store Id for trying it again later ?
}else{
// Save
}
Castle Windsor passes the registered concrete type to Controller's constructors. A typical implementation (no pun intended) is:
private readonly IDepartmentRepository _deptsRepository;
public DepartmentsController(IDepartmentRepository deptsRepository)
{
if (deptsRepository == null)
{
throw new ArgumentNullException("deptsRepository");
}
_deptsRepository = deptsRepository;
}
I need to pass the ctor a second parameter, if possible, so that I can pass that val on to the Repository constructor (I know: tramp data alert, but I don't know if there's a straightforward way around it:
public DepartmentsController(IDepartmentRepository deptsRepository, int DBInstance)
{
if (deptsRepository == null)
{
throw new ArgumentNullException("deptsRepository");
}
_deptsRepository = deptsRepository(DBInstance);
}
REPOSITORY
public DepartmentRepository(int dbInst)
{
string connStr = string.Format("Phoo{0}Bar", dbInst);
using (var conn = new OleDbConnection(connStr))
{
using (var cmd = conn.CreateCommand())
{
. . .
Is it possible to tweak what Castle Windsor sends to the Controller constructor this way? If so, how?
AND/BUT: For this to be of any value (to me, anyway), I need to be able to get the int val (that will be passed to the Controller) from the URL the client sends. IOW, if the client asks the server for data via:
http://locohost:4242/Platypus/GetAll/1
I need to pass a "1" as the second argument to PlatypusController.
If the user asks the server for data via:
http://locohost:4242/Platypus/GetAll/42
I need to pass a "42" as the second argument to PlatypusController.
etc.
This is what I did to solve my Controller/Repository data context Dilemma:
0) Added a database context argument to the Controller's routing attribute. IOW, this:
[Route("api/HHSUsers/GetAll")]
...got changed to this:
[Route("api/HHSUsers/GetAll/{dbContext=03}")]
1) Passed that database context arg to the Repository. To wit, this:
return _hhsusersrepository.GetAll();
...got changed to this:
return _hhsusersrepository.GetAll(dbContext);
...so that the Controller method is now:
[Route("api/HHSUsers/GetAll/{dbContext=03}")]
public IEnumerable<HHSUsers> GetAllHHSUsersRecords(int dbContext)
{
return _hhsusersrepository.GetAll(dbContext);
}
2) Changed the corresponding method in the Repository interface from:
IEnumerable<HHSUsers> GetAll();
...to this:
IEnumerable<HHSUsers> GetAll(string dbContext);
3) Changed the Repository method from this:
public HHSUsersRepository()
{
// All the data is loaded here in the ctor
}
public IEnumerable<HHSUsers> GetAll()
{
return hhsusers;
}
....to this:
public IEnumerable<HHSUsers> GetAll(string dbContext)
{
LoadHHSUsers(dbContext);
return hhsusers;
}
private void LoadHHSUsers(int dbContext)
{
string connStr = string.Format("Foo{0}Bar", dbContext);
// The same as previously from this point on, except that this:
// using (var conn = new OleDbConnection(#"Foo Bar Phoo Bar etc"...
// becomes:
// using (var conn = new OleDbConnection(connStr))
4) Tack the dbcontext val to the end of the URL when calling the method, so that it is this:
http://localhost:28642/api/HHSUsers/GetAll/42
...instead of this:
http://localhost:28642/api/HHSUsers/GetAll
If the data context to use is "03" I can omit the dbcontext arg from the URL, as 03 is the default value I set when I appended "=03" to the Controller's "dbContext" routing attribute arg.
I know some fancy-pants propeller-heads will find fault with this for some reason (for one reason because of the tramp data going here and there and everywhere like a hobo on steroids), but my response is the same as that of an athlete who is getting trash-talked by an opposing player and yet whose team is winning: just point at the scoreboard. IOW, this works for me, so that's pretty much all I care about. Style points are for runway models and, again, fancy-pants propeller-heads (AKA Star-Bellied Sneeches (as opposed to us plain
cats with the unstarred bellies)); see "The perfect is the enemy of the good."
This simple way has that self-same benefit -- of being (relatively) simple to grok and, thus, modify/refactor as necessary. Inelegant? Sure, but so was Joe Kapp.
I post this question and I got some explanations but I couldn't solve the problem. Now since event I have a better understanding I'm going to post this again in a new angle.
I have following lines in my node.
SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
/*
* Associate the schema factory with the resource resolver, which is
* responsible for resolving the imported XSD's
*/
factory.setResourceResolver(new ResourceResolver());
Source schemaFile = new StreamSource(getClass().getClassLoader().getResourceAsStream(schemaName));
Schema schema = factory.newSchema(schemaFile);
Validator validator = schema.newValidator();
validator.validate(new DOMSource(document));
I think I have two options. Either to mock
Source schemaFile = new StreamSource(getClass().getClassLoader().getResourceAsStream(schemaName));
or
Schema schema = factory.newSchema(schemaFile);
I have been pulling my hair for two day to do the first one. I tried as follows
expectNew(StreamSource.class, InputStream.class).andReturn(mockSource);
and
expectNew(StreamSource.class, anyObject(InputStream.class)).andReturn(mockSource);
But didn't work.
Now I'm trying to mock the second line
Schema schema = factory.newSchema(schemaFile);
This one also not quite clear to me. Do I need to mock a factory like
SchemaFactory mockFactory = EasyMock.createMock(SchemaFactory.class);
or since factory is created using newInstance static method call is it a different way?
Appreciate any help on this problem.
Adding later
I got some lead with the situation. I have expectNew as follows.
expectNew(StreamSource.class, InputStream.class).andReturn(mockStreamSource);
When I run powermocks throws a error saying.
java.lang.AssertionError:
Unexpected constructor call javax.xml.transform.stream.StreamSource(null):
javax.xml.transform.stream.StreamSource(class java.io.InputStream): expected: 1, actual: 0
The reason is as I think getClass().getClassLoader().getResourceStream("..") return null anyway. So powermock didn't find it euqal to the initialization I describe by expectNew. How to say expect a null inputstream as parameter. I tried using just null. didn't work.
expectNew(StreamSource.class, null).andReturn(mockStreamSource);
If you're using easymock:
Extract the creation of the factory to a protected method.
protected SchemaFactory createSchemaFactory(){
return SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
}
In your test, instead of test the SUT itself create a partially mocked version of your SUT, mocking only the new method where the static invocation is done, and test it. Partial mocks using easymock.
I have implemented a DAL using Rob Conery's spin on the repository pattern (from the MVC Storefront project) where I map database objects to domain objects using Linq and use Linq to SQL to actually get the data.
This is all working wonderfully giving me the full control over the shape of my domain objects that I want, but I have hit a problem with concurrency that I thought I'd ask about here. I have concurrency working but the solution feels like it might be wrong (just one of those gitchy feelings).
The basic pattern is:
private MyDataContext _datacontext
private Table _tasks;
public Repository(MyDataContext datacontext)
{
_dataContext = datacontext;
}
public void GetTasks()
{
_tasks = from t in _dataContext.Tasks;
return from t in _tasks
select new Domain.Task
{
Name = t.Name,
Id = t.TaskId,
Description = t.Description
};
}
public void SaveTask(Domain.Task task)
{
Task dbTask = null;
// Logic for new tasks omitted...
dbTask = (from t in _tasks
where t.TaskId == task.Id
select t).SingleOrDefault();
dbTask.Description = task.Description,
dbTask.Name = task.Name,
_dataContext.SubmitChanges();
}
So with that implementation I've lost concurrency tracking because of the mapping to the domain task. I get it back by storing the private Table which is my datacontext list of tasks at the time of getting the original task.
I then update the tasks from this stored Table and save what I've updated
This is working - I get change conflict exceptions raised when there are concurrency violations, just as I want.
However, it just screams to me that I've missed a trick.
Is there a better way of doing this?
I've looked at the .Attach method on the datacontext but that appears to require storing the original version in a similar way to what I'm already doing.
I also know that I could avoid all this by doing away with the domain objects and letting the Linq to SQL generated objects all the way up my stack - but I dislike that just as much as I dislike the way I'm handling concurrency.
I worked through this and found the following solution. It works in all the test cases I (and more importantly, my testers!) can think of.
I am using the .Attach() method on the datacontext, and a TimeStamp column. This works fine for the first time that you save a particular primary key back to the database but I found that the datacontext throws a System.Data.Linq.DuplicateKeyException "Cannot add an entity with a key that is already in use."
The work around for this I created was to add a dictionary that stored the item I attach the first time around and then every subsequent time I save I reuse that item.
Example code is below, I do wonder if I've missed any tricks - concurrency is pretty fundamental so the hoops I'm jumping through seem a little excessive.
Hopefully the below proves useful, or someone can point me towards a better implementation!
private Dictionary<int, Payment> _attachedPayments;
public void SavePayments(IList<Domain.Payment> payments)
{
Dictionary<Payment, Domain.Payment> savedPayments =
new Dictionary<Payment, Domain.Payment>();
// Items with a zero id are new
foreach (Domain.Payment p in payments.Where(p => p.PaymentId != 0))
{
// The list of attached payments that works around the linq datacontext
// duplicatekey exception
if (_attachedPayments.ContainsKey(p.PaymentId)) // Already attached
{
Payment dbPayment = _attachedPayments[p.PaymentId];
// Just a method that maps domain to datacontext types
MapDomainPaymentToDBPayment(p, dbPayment, false);
savedPayments.Add(dbPayment, p);
}
else // Attach this payment to the datacontext
{
Payment dbPayment = new Payment();
MapDomainPaymentToDBPayment(p, dbPayment, true);
_dataContext.Payments.Attach(dbPayment, true);
savedPayments.Add(dbPayment, p);
}
}
// There is some code snipped but this is just brand new payments
foreach (var payment in newPayments)
{
Domain.Payment payment1 = payment;
Payment newPayment = new Payment();
MapDomainPaymentToDBPayment(payment1, newPayment, false);
_dataContext.Payments.InsertOnSubmit(newPayment);
savedPayments.Add(newPayment, payment);
}
try
{
_dataContext.SubmitChanges();
// Grab the Timestamp into the domain object
foreach (Payment p in savedPayments.Keys)
{
savedPayments[p].PaymentId = p.PaymentId;
savedPayments[p].Timestamp = p.Timestamp;
_attachedPayments[savedPayments[p].PaymentId] = p;
}
}
catch (ChangeConflictException ex)
{
foreach (ObjectChangeConflict occ in _dataContext.ChangeConflicts)
{
Payment entityInConflict = (Payment) occ.Object;
// Use the datacontext refresh so that I can display the new values
_dataContext.Refresh(RefreshMode.OverwriteCurrentValues, entityInConflict);
_attachedPayments[entityInConflict.PaymentId] = entityInConflict;
}
throw;
}
}
I would look at trying to utilise the .Attach method by passing the 'original' and 'updated' objects thus achieving true optimistic concurrency checking from LINQ2SQL. This IMO would be preferred to using version or datetime stamps either in the DBML objects or your Domain objects. I'm not sure how MVC allows for this idea of persisting the 'original' data however.. i've been trying to investigate the validation scaffolding in the hope that it's storing the 'original' data.. but i suspect that it is as only as good as the most recent post (and/or failed validation). So that idea may not work.
Another crazy idea i had was this: override the GetHashCode() for all of your domain objects where the hash represents the unique set of data for that object (minus the ID of course). Then, either manually or with a helper bury that hash in a hidden field in the HTML POST form and send it back to your service layer with your updated domain object - do the concurrency checking in your service layer or data layer (by comparing the original hash with a newly extracted domain object's hash) but be aware that you need to be checking for and raising concurrency exceptions yourself. It's nice to use the DMBL functions but the idea of abstracting away the data layer is so to not depend on the particular implementation's features etc. So having full control of the optimistic concurrency checking on your domain objects in your service layer (for example) seems like a good approach to me.