OK, so before we start let me state that I have been googling and searching for an answer to my question for quite a while now and haven't been able to find a suitable one (the keywords are tricky since I keep getting unrelated posts and sites as results).
Now, moving on I have a Java class that contains a my main method and a number of other functions. I want to test these functions using JUnit but I can't instantiate a class that has main in it, if I simply try to call the function I get an error saying the function is outside the namespace even though both files are in the same package, and I get an error trying to import the file.
Is there anyway to test these functions using JUnit?
P.S. Yes I know that you can put them in a new class, but I don't think it is overkill to create a new class just for testing or to put in 2 functions that are for parsing user input, and there is still the issue of testing the main function itself (and it is not uncommon to write a main method just for testing).
So this is what happened. Since I don't use Java very often I ended up creating private data members in the class but treated them as I would globals in a C++ program. In consequence I initialized them in main and didn't think of making a constructor and hence the problem with instantiating the class. When that didn't work I tried the . form but since the methods referenced the private data members I would get an error without instantiating the class. Thanks to the guys that noticed the constructor thing.
You absolutely can create an instance of a class which contains a main method, so long as it has an accessible constructor of course.
Likewise you absolutely can call a static method directly, using MyClassName.myMethodName.
Having a main method in a class makes absolutely no difference to it in terms of the Java language itself - so you can test it just as you would any other class.
Very strange. I just wrote SomeClass with main inside and it's perfectly testable by SomeClassTest class.
Just a thought, did you declare constructors as private in the class with main method? It will help a lot if you can post some code snippet and exact error message you're getting.
Related
I have a Java program that uses 4 classes that are instantiated, plus a class for main. When I added the last class I noticed this strange thing, where my saved changes in this class were not present in the program after compilation. I noticed that I had to save main class as well, even though I did not make any changes to it.
I only use the main class file name in compilation.
I am not too experienced with java, but I'm pretty sure this has not been the case before.
Any ideas?
Found a solution to this. This one problematic class was only one that was not instantiated in the main, but in the other class. I created a dummy object from this class in my main and now everything works as intended.
Ok selenium gurus a bit of an open question here. I am looking for some guidance on the best way to organize my tests that use object oriented principles.
At the moment I am creating a testrunner main class from which I create an object of a general test class. I am then extending this class for more granular tests.
An example.
I need to open the browser, enter the url, log in as a user.
From there you can access perhaps 40 different links each containing their own pieces of functionality. E.g. A profile link which leads to a profiule screen where you can enter introduction text, upload a picture, change a picture etc...
Another example would be a notification screen where you can navigate to view and mark as read etc...notifications you have received.
I can write the code to test this by for example by creating a ton of methods in that 1 class and then calling these from the main testrunner class. There has to be a better organized way where I can have a separate class for functionality but wont I then have to create a new object for each test?
Sorry about the confused post I'm trying to learn Java thoroughly and selenium also.
EDITED
I have copied the process of creating a page object hybrid model that is documented in the YouTube video:
https://www.youtube.com/watch?v=gxwh8D_tx-0
I created a Pages package which contains all of the Page specific class such such ProfilePage, NotificationPage etc...
I have a second package which contains the tests and a testbase class which generates the driver object, opens the browser.
I want to get to the stage where in my tests class I can have a specific class for a test for example:
class test_that_user_can_upload_profile_picture
When I create such a class I have methods inside the class such as: test_that_navigation_to _profile_page_successful()
test_to_upload_valid_picture()
Should such navigation methods be inside this class?
Also I find that in order to access my methods from a package I need to mark my methods as static. Is this ok? I noticed on the youtube video the instructors methods were not static. Looking at the setup I dont quite understand why I cant access the methods unless I mark them as static. The error i get is
"Cannot make a static reference to a non-static method"
Here is my setup:
Also Im finding that in my ProfilePageNavigation class I have a bunch of methods that run in a specific order based alphabetical order.
Is it simply the case I should just have 1 method in each test class and just call the page classes methods(or any other pertinent class) to execute this test? If it is just 1 method inside each test class then wouldnt I have too many test classes each with a name like (for example) upload_valid_profile_picture with a method using the same name? and then another class with upload_invalid_profile_picture with it's method. I dont want to go down that path - how do I resolve that?
Also all my Pages class methods have to take WebDriver driver as a parameter is there any way around this - it is a lot of duplication.
If you could point me on the right track and let me know in it is ok to have the pages class methods as static it would be appreciated.
I guess I just want to know whether I am on the right track or going down the wrong route at this early stage.
#tarquin - you can find many articles on that #web, There are multiple ways to handle your code and work with it, my way is :
Create a objects repository in notepad or excel, from where you can pick/change/manage all your objects.
Create a class with all re-usable methods.
Create a class of your tests.
Thanks
Keshav
I know that I'll need a main method, but can that main method be in a different class other than the Main class?
Not all Java applications require a main method.
Java can also be used to create web applications, for instance, which don't require main methods to run.
The answer to your question depends on what exactly you mean. Do you mean a class with the name 'Main'? Then, no, there is no requirement for this at all.
The only requirement that Java has, is that the signature of the method is correct. the main method must:
be public
be main
be static
have returntype void
accept an array of Strings as (only) parameter
It's easier to add it in the public class in a file, but not mandatory. The name of the class it is in, is entirely up to you, though many will choose a name like 'Main' or 'Open', simply to more easily find it.
If you want to be able to run your application, by simple double-clicking the .jar file, you'll need to point to the class that contains the main method (to use: your application might contain a lot of main classes, used for internal testing, but only one can be used to start the actual application) in the manifest file: Manifest files
Prior to Java 7, it was possible to run a desktop application without a main method, by (ab)using an instantiation block, but this was removed as of Java 7, because this is not what the instantiation block was intended for.
It's not necessary to define yout main method in a main class. You can place your main method wherever you want, as long the syntax i correct :
public static void main (String[] args){
//...
}
You absolutely don't.
The method itself can be placed whereever you want it to be, there is no limitation.
However, I personally would recommend putting it in a class which at least contains something like "Main", because when others look at your code, and they are not using an IDE which supports jumping to the main method, people usually have an easier time finding your starting point.
However, that is just for sake of readability, and as I said, jumping to main is/should be usually a widespread supported feature
Yes, the Main method is required to run a function although a java class can be without the Main method. Though, it won't run...
I have a Java project(running in Eclipse) without main method and need to debug and see which is the caller class and the flow of the program. How do I start?
It is a simple project and does not contain any web/tomcat related data.
Thank you for your responses. I am new to StackOverflow and so pardon my writing and asking questions.
I am including packages and trying to create objects of a class, but it is not recognizing the classes. All the classes are public.
There is no way to run a Java SE application without starting with public static void main. If you want to debug the code of a library or framework you need to create a main method and call the code from there.
Take a look to JUnit. If you just want to debug your code is what you normally have to do.
Since Java requires all methods and variables to be within classes, the JVM needs a starting point that exists before any objects are initialized. Therefore, main must be static and public for the JVM to find it. Unlike C++, the main method does not return a status code, so it is of return type void rather than int.
For a college assignment I need to write a SAX parser and a filter that reads the original XML file then creates a new modified one. The assignment requires that my program need to be run by console with "java Sax inputFileDestination OutputFileDestination" and it requires that there is only one file. I means I need to implement the interfaces with in the Sax.java. I am familiar with the inner classes but I dont know how to implement this with a main method in the outer class.
Any sugestions?
Since this is an assignment, I'm not going to post any code, but explain how to do it.
I don't think you need an inner class at all to do this. Your class will have a main method, which creates a SAXParser, and registers itself (this) as a callback. You will then implement the SAX methods you desire (startElement, endElement, characters) from HandlerBase.
All your're doing is writing a SAXParser, and then tacking a main() method on it, so it will run from the command line.
Consider creating a MySAXParser class with a usage outside in another class having a main. Then place that main method inside your MySAXParser class as test code.
XML Parsers deliver a jar with a META-INF/MANIFEST.MF using the SPI (Service Provider Interface). You might think of doing the same thing as a bonus.
Other inner classes can be private static if they are independent, or just private storing an extra outer MySAXParser.this; so one error often made is forgetting static.