Like the title suggests is there a way to get the invocationCount and threadpool functionality of testng on junit ?
If not can someone suggest a way to get around this ?
Google-ing didn't work and the docs also didn't help, any help is much appreciated.
There is support in junit for what you need. You can collect those statistics in class level or field level variables declared in the class under test. A very crude implementation would look like this:
static AtomicInteger counter = new AtomicInteger();
static Set<String> threadIds = Collections.newSetFromMap(new ConcurrentHashMap<String, String>());
public void foo() {
counter.incrementAndGet();
threadIds.add(Thread.currentThread().getId());
//do something useful
}
Using this approach you end up modifying the code thats under test. Of cource, there are other possible solutions (like using proxies) to avoid this.
Related
I have two questions about using the Comet feature with Glassfish. I'm
pretty new at this, so if there's an easy answer or some documentation
I should read please let me know! Thanks.
I'm building a system that has multiple microcontrollers sending data
to a central DB. Users view the data via their browsers ... in formats
(metric vs. English, say) of their own choosing. The display needs to
be updated without user action. It looks like Glassfish + Comet should
be perfect. And so I started with Oracle's "hidden_Comet" example, and
that works great.
So question #1 is this: how can one get session-specific information
into the "onEvent" method?
As context, here's the code; it’s straight from the Oracle example:
private class CounterHandler implements CometHandler<HttpServletResponse> {
private HttpServletResponse response;
public void onEvent(CometEvent event) throws IOException
{
if (CometEvent.NOTIFY == event.getType())
{
PrintWriter writer = response.getWriter();
writer.write("<script type='text/javascript'>");
[... etc. Here is where I need to pass some session-specific
info to the JavaScript]
event.getCometContext().resumeCometHandler(this);
}
}
It would seem that session attributes would be perfect, but it looks
like you can't get the 'session' variable from the "HttpServletResponse".
I thought about using cookies, but they seem to be accessible only with
HttpServletRequest, not "...Response", and, as above, only ‘response’
is available in the “onEvent” method.
So question #1 is: how do you do this?
Question #2 is: is this just the wrong way to attack this problem and is
there a better way?
I'm not sure I understand the data structures and control flow of Comet very well yet, but it seems that this works:
Add a constructor to "class CounterHandler" and pass in the 'session' variable from 'doGet()' where "new CounterHandler" is called. Specifically, change:
CometHandler handler = new CometHandler();
to
HttpSession session = request.getSession();
CometHandler handler = new CometHandler(session);
Have the constructor save the session variable in a class instance variable. And then the "onEvent()" method has access to session attributes. And Bob's your uncle.
(It seems straightforward enough ... well, now.)
I appreciate Robotlegs very much, but recently a GC problem came to me. I failed to dispose context object by just set the reference null.With the help of FB profile tool, I find that context object appears to be a "GC Root".
To figure it out, I wirte a simple class, which creates a context obj and leave it unreachable.Here is the detail of this class:
public class MemoryLeak extends Sprite{
public function MemoryLeak()
{
makeAndDrop();
}
public function makeAndDrop():void{
var _context = new Context(this);
_context = null;
}
}
When I ran this class, I hoped it be disposed by GC, but it didn't work(most times, not everytime). And the profile tool show me this instance is a GCRoot. I read some articles about GC, but few of them mention GCRoot itself. Could anybody tell me why and thank you so much!
PS: I tried to call System.gc() twice after makeAndDrop() but it didn't work. In fact, I'm more interested in the "is GCRoot" issue(implied by the fb profile), it may help more if you tell me about it.
I think the Context will probably listen to this so that it can perform dependency injection on any added children or create mediators for them. One would hope that the listener would not be attached until you talk to the mediatorMap or the viewMap, but I think it is likely that the RL authors would not consider a use case where you'd want a Context on a View for a time period shorter than the View's actual lifespan.
This is what I found from my initial attempts to use JMockIt. I must admit that I found the JMockIt documentation very terse for what it provides and hence I might have missed something. Nonetheless, this is what I understood:
Mockito: List a = mock(ArrayList.class) does not stub out all methods
of List.class by default. a.add("foo") is going to do the usual thing
of adding the element to the list.
JMockIt: #Mocked ArrayList<String> a;
It stubs out all the methods of a by default. So, now a.add("foo")
is not going to work.
This seems like a very big limitation to me in JMockIt.
How do I express the fact that I only want you to give me statistics
of add() method and not replace the function implementation itself
What if I just want JMockIt to count the number of times method add()
was called, but leave the implementation of add() as is?
I a unable to express this in JMockIt. However, it seems I can do this
in Mockito using spy()
I really want to be proven wrong here. JMockit claims that it can do everything that
other mocking frameworks do plus a lot more. Does not seem like the case here
#Test
public void shouldPersistRecalculatedArticle()
{
Article articleOne = new Article();
Article articleTwo = new Article();
when(mockCalculator.countNumberOfRelatedArticles(articleOne)).thenReturn(1);
when(mockCalculator.countNumberOfRelatedArticles(articleTwo)).thenReturn(12);
when(mockDatabase.getArticlesFor("Guardian")).thenReturn(asList(articleOne, articleTwo));
articleManager.updateRelatedArticlesCounters("Guardian");
InOrder inOrder = inOrder(mockDatabase, mockCalculator);
inOrder.verify(mockCalculator).countNumberOfRelatedArticles(isA(Article.class));
inOrder.verify(mockDatabase, times(2)).save((Article) notNull());
}
#Test
public void shouldPersistRecalculatedArticle()
{
final Article articleOne = new Article();
final Article articleTwo = new Article();
new Expectations() {{
mockCalculator.countNumberOfRelatedArticles(articleOne); result = 1;
mockCalculator.countNumberOfRelatedArticles(articleTwo); result = 12;
mockDatabase.getArticlesFor("Guardian"); result = asList(articleOne, articleTwo);
}};
articleManager.updateRelatedArticlesCounters("Guardian");
new VerificationsInOrder(2) {{
mockCalculator.countNumberOfRelatedArticles(withInstanceOf(Article.class));
mockDatabase.save((Article) withNotNull());
}};
}
A statement like this
inOrder.verify(mockDatabase, times(2)).save((Article) notNull());
in Mockito, does not have an equivalent in JMockIt as you can see from the example above
new NonStrictExpectations(Foo.class, Bar.class, zooObj)
{
{
// don't call zooObj.method1() here
// Otherwise it will get stubbed out
}
};
new Verifications()
{
{
zooObj.method1(); times = N;
}
};
In fact, all mocking APIs mock or stub out every method in the mocked type, by default. I think you confused mock(type) ("full" mocking) with spy(obj) (partial mocking).
JMockit does all that, with a simple API in every case. It's all described, with examples, in the JMockit Tutorial.
For proof, you can see the sample test suites (there are many more that have been removed from newer releases of the toolkit, but can still be found in the old zip files), or the many JMockit integration tests (over one thousand currently).
The equivalent to Mockito's spy is "dynamic partial mocking" in JMockit. Simply pass the instances you want to partially mock as arguments to the Expectations constructor. If no expectations are recorded, the real code will be executed when the code under test is exercised. BTW, Mockito has a serious problem here (which JMockit doesn't), because it always executes the real code, even when it's called inside when(...) or verify(...); because of this, people have to use doReturn(...).when(...) to avoid surprises on spied objects.
Regarding verification of invocations, the JMockit Verifications API is considerably more capable than any other. For example:
new VerificationsInOrder() {{
// preceding invocations, if any
mockDatabase.save((Article) withNotNull()); times = 2;
// later invocations, if any
}};
Mockito's a much older library than JMockIT, so you could expect that it would have many more features. Have a read through the release list if you want to see some of the less well documented functionality. JMockIT authors have produced a matrix of features in which they missed out every single thing that other frameworks do that they don't, and got several wrong (for instance, Mockito can do strict mocks and ordering).
Mockito was also written to enable unit-level BDD. That generally means that if your tests provide a good example of how to use the code, and if your code is lovely and decoupled and well-designed, then you won't need all the shenanigans that JMockIT provides. One of the hardest things to do in Open Source is say "no" to the many requests that don't help in the long run.
Compare the examples on the front pages of Mockito and JMockIT to see the real difference. It's not about what you test, it's about how well your tests document and describe the behavior of the class.
Declaration of Interest: Szczepan and I were on the same project when he wrote the first draft of Mockito, after seeing some of us roll out our own stub classes rather than use the existing mocking frameworks of the time. So I feel like he wrote it all for me, and am thoroughly biased. Thank you Szczepan.
I've got a bit of a problem. I'm working in the Castle Windsor IOC Container. Now what i wanted to do is just mess about with some AOP principles and what i specifically want to do is based on a method name perform some logging. I have been looking at Interceptors and at the moment i am using the IInterceptor interface implemented as a class to perform this logging using aspects. The issue is if i want to perform the logging on a specific method then it gets messy as i need to put in some logic into my implemented aspect to check the method name etc...
I have read that you can do all of this using Dynamic Proxies and the IInterceptorSelector interface and the IProxyGenerationHook interface. I have seen a few examples of this done on the net but i am quite confused how this all fits into the Windsor container. I mean i am using the windsor container which in my code is actually a ref to the IWindsorContainer interface to create all my objects. All my configuration is done in code rather than XML.
Firstly does anyone know of a way to perform method specific AOP in the windsor container besides the way i am currently doing it.
Secondly how do i use the Dynamic Proxy in the windsor container ?
Below i have added the code where i am creating my proxy and registering my class with
the interceptors
ProxyGenerator _generator = new ProxyGenerator(new PersistentProxyBuilder());
IInterceptorSelector _selector = new CheckLoggingSelector();
var loggingAspect = new LoggingAspect();
var options = new ProxyGenerationOptions(new LoggingProxyGenerationHook())
{ Selector = _selector };
var proxy = _generator.CreateClassProxy(typeof(TestClass), options, loggingAspect);
TestClass testProxy = proxy as TestClass;
windsorContainer.Register(
Component.For<LoggingAspect>(),
Component.For<CheckLoggingAspect>(),
Component.For<ExceptionCatchAspect>(),
Component.For<ITestClass>()
.ImplementedBy<TestClass>()
.Named("ATestClass")
.Parameters(Parameter.ForKey("Name").Eq("Testing"))
.Proxy.MixIns(testProxy));
The Test Class is below:
public class TestClass : ITestClass
{
public TestClass()
{
}
public string Name
{
get;
set;
}
public void Checkin()
{
Name = "Checked In";
}
}
as for the interceptors they are very simple and just enter a method if the name starts with Check.
Now when i resolve my TestClass from the container i get an error.
{"This is a DynamicProxy2 error: Mixin type TestClassProxy implements IProxyTargetAccessor which is a DynamicProxy infrastructure interface and you should never implement it yourself. Are you trying to mix in an existing proxy?"}
I know i'm using the proxy in the wrong way but as i haven't seen any concrete example in how to use a proxy with the windsor container it's kind of confusing.
I mean if i want to use the LoggingProxyGenerationHook which just tell the interceptors to first for methods that start with the word "check" then is this the correct way to do it or am i completely on the wrong path. I just went down the proxy way as it seems very powerfull and i would like to understand how to use these proxies for future programming efforts.
By using .Interceptors() you already are using Dynamic Proxy. When component has specified interceptors Windsor will create proxy for it, and use these interceptors for it. You can also use method .SelectedWith and .Proxy property to set other options you already know from DynamicProxy.
I just added a website about Windsor AOP to documentation wiki. There's not much there yet, but I (and Mauricio ;) ) will put there all the information you need. Take a look, and let us know if everything is clear, and if something is missing.
Method chaining is the only way I know to build fluent interfaces.
Here's an example in C#:
John john = new JohnBuilder()
.AddSmartCode("c#")
.WithfluentInterface("Please")
.ButHow("Dunno");
Assert.IsNotNull(john);
[Test]
public void Should_Assign_Due_Date_With_7DayTermsVia_Invoice_Builder()
{
DateTime now = DateTime.Now;
IInvoice invoice = new InvoiceBuilder()
.IssuedOn(now)
.WithInvoiceNumber(40)
.WithPaymentTerms(PaymentTerms.SevenDays)
.Generate();
Assert.IsTrue(invoice.DateDue == now.AddDays(7));
}
So how do others create fluent interfaces. How do you create it? What language/platform/technology is needed?
The core idea behind building a fluent interface is one of readability - someone reading the code should be able to understand what is being achieved without having to dig into the implementation to clarify details.
In modern OO languages such as C#, VB.NET and Java, method chaining is one way that this is achieved, but it's not the only technique - two others are factory classes and named parameters.
Note also that these techniques are not mutually exclusive - the goal is to maximize readabilty of the code, not purity of approach.
Method Chaining
The key insight behind method chaining is to never have a method that returns void, but to always return some object, or more often, some interface, that allows for further calls to be made.
You don't need to necessarily return the same object on which the method was called - that is, you don't always need to "return this;".
One useful design technique is to create an inner class - I always suffix these with "Expression" - that exposes the fluent API, allowing for configuration of another class.
This has two advantages - it keeps the fluent API in one place, isolated from the main functionality of the class, and (because it's an inner class) it can tinker with the innards of the main class in ways that other classes cannot.
You may want to use a series of interfaces, to control which methods are available to the developer at a given point in time.
Factory Classes
Sometimes you want to build up a series of related objects - examples include the NHibernate Criteria API, Rhino.Mocks expectation constraints and NUnit 2.4's new syntax.
In both of these cases, you have the actual objects you are storing, but to make them easier to create there are factory classes providing static methods to manufacture the instances you require.
For example, in NUnit 2.4 you can write:
Assert.That( result, Is.EqualTo(4));
The "Is" class is a static class full of factory methods that create constraints for evaluation by NUnit.
In fact, to allow for rounding errors and other imprecision of floating point numbers, you can specify a precision for the test:
Assert.That( result, Is.EqualTo(4.0).Within(0.01));
(Advance apologies - my syntax may be off.)
Named Parameters
In languages that support them (including Smalltalk, and C# 4.0) named parameters provide a way to include additional "syntax" in a method call, improving readability.
Consider a hypothetical Save() method that takes a file name, and permissions to apply to the file after saving:
myDocument.Save("sampleFile.txt", FilePermissions.ReadOnly);
with named parameters, this method could look like this:
myDocument.Save(file:"SampleFile.txt", permissions:FilePermissions.ReadOnly);
or, more fluently:
myDocument.Save(toFile:"SampleFile.txt", withPermissions:FilePermissions.ReadOnly);
You can create a fluent interface in any version of .NET or any other language that is Object Oriented. All you need to do is create an object whose methods always return the object itself.
For example in C#:
public class JohnBuilder
{
public JohnBuilder AddSmartCode(string s)
{
// do something
return this;
}
public JohnBuilder WithfluentInterface(string s)
{
// do something
return this;
}
public JohnBuilder ButHow(string s)
{
// do something
return this;
}
}
Usage:
John = new JohnBuilder()
.AddSmartCode("c#")
.WithfluentInterface("Please")
.ButHow("Dunno");
AFAIK, the term fluent interface does not specify a specific technology or framework, but rather a design pattern. Wikipedia does have an extensive example of fluent interfaces in C♯.
In a simple setter method, you do not return void but this. That way, you can chain all of the statements on that object which behave like that. Here is a quick example based on your original question:
public class JohnBuilder
{
private IList<string> languages = new List<string>();
private IList<string> fluentInterfaces = new List<string>();
private string butHow = string.Empty;
public JohnBuilder AddSmartCode(string language)
{
this.languages.Add(language);
return this;
}
public JohnBuilder WithFluentInterface(string fluentInterface)
{
this.fluentInterfaces.Add(fluentInterface);
return this;
}
public JohnBuilder ButHow(string butHow)
{
this.butHow = butHow;
return this;
}
}
public static class MyProgram
{
public static void Main(string[] args)
{
JohnBuilder johnBuilder = new JohnBuilder().AddSmartCode("c#").WithFluentInterface("Please").ButHow("Dunno");
}
}
Sometime ago I had the same doubts you are having now. I've done some research and now I'm writing a series of blog posts about techinics of designing a fluent interface.
Check it out at:
Guidelines to Fluent Interface design in C# part 1
I have a section there about Chaining X Nesting that can be interesting to you.
In the following posts I will talk about it in a deeper way.
Best regards,
André Vianna
Fluent interface is achieved in object oriented programming by always returning from your methods the same interface that contains the method. Consequently you can achieve this effect in java, javascript and your other favorite object oriented languages, regardless of version.
I have found this technique easiest to accomplish through the use of interfaces:
public interface IFoo
{
IFoo SetBar(string s);
IFoo DoStuff();
IFoo SetColor(Color c);
}
In this way, any concrete class that implements the interface, gets the fluent method chaining capabilities. FWIW.. I wrote the above code in C# 1.1
You will find this technique littered throughout the jQuery API
A couple of things come to mind that are possible in .Net 3.5/C# 3.0:
If an object doesn't implement a fluent interface, you could use Extension Methods to chain your calls.
You might be able to use the object initialization to simulate fluent, but this only works at instantiation time and would only work for single argument methods (where the property is only a setter). This seems hackish to me, but the there it is.
Personally, I don't see anything wrong with using function chaining if you are implementing a builder object. If the builder object has chaining methods, it keeps the object you are creating clean. Just a thought.
This is how I've built my so called fluent interfaces or my only forary into it
Tokenizer<Bid> tkn = new Tokenizer<Bid>();
tkn.Add(Token.LambdaToken<Bid>("<YourFullName>", b => Util.CurrentUser.FullName))
.Add(Token.LambdaToken<Bid>("<WalkthroughDate>",
b => b.WalkThroughDate.ToShortDateString()))
.Add(Token.LambdaToken<Bid>("<ContactFullName>", b => b.Contact.FullName))
.Cache("Bid")
.SetPattern(#"<\w+>");
My example required .net 3.5 but that's only cause of my lambda's. As Brad pointed out you can do this in any version of .net. Although I think lambda's make for more interesting possibilities such as this.
======
Some other good examples are nHibernate's Criteria API, there is also a fluent nhibernate extension for configuring nhibernate but I've never used it
Dynamic keyword in C# 4.0 will make it possible to write dynamic style builders. Take a look at following article about JSON object construction.