How to install Eclipse on Mac OS X By Chaitanya Singh Filed Under: Java Tutorials In this tutorial, we will learn how to install eclipse IDE on Mac OS X. Eclipse IDE (Integrated development environment) is written in Java and mostly used for developing Java applications.
![]()
Buy this course (€29.50.).Overview.Transcripts.Exercise Files.View Offline.Course detailsUnit testing is a critical part of any software development process. JUnit is an open-source testing tool specialized for Java, and it should be part of every Java developer's toolbox. Join Peggy Fisher as she explores Java testing with JUnit.
Learn how to integrate JUnit with popular tools and IDEs (Eclipse, NetBeans, IntelliJ, and Maven), and conduct a variety of tests, including exception handling and parameterized tests.Instructor.Peggy Fisher is a programmer and content manager at LinkedIn Learning.Peggy's main focus is application programming in Java, Arduino, and C. She has also worked on courses in COBOL and discrete,athematics. Previously she was a faculty member at Penn State University's College of Information Sciences and Technology. She started out as a programmer working for a large insurance company, but after 18 years she left her job as a director of information technology to pursue her true passion teaching. She earned a master's degree in math education, and went on to teach high school math and computer science in Pennsylvania. In 2012, Peggy accepted a position as an instructional designer at Penn State, and shortly thereafter began teaching Intro to Application Programming with Java.
She is a strong supporter of women in STEM. As one of the few female programming teachers, she serves as a mentor to incoming female freshmen who are considering a career in programming. She was also the K–12 outreach coordinator for the college, where she scheduled, ran, and taught summer camps for middle school and high school students. In a PBS NewsHour interview, she expressed that all students should take at least one programming class either in high school or college. Peggy enjoys constantly learning and finding new and exciting ways to bring technology to life in and outside of the classroom, such as using Arduino microcontrollers or Lego Mindstorms, to help make learning hands-on and fun.See more about the instructorSee moreSee less about the instructorSee lessSkills covered in this course. “- Voiceover Let's review how to download and install JUnit.
To obtain the most recent version of JUnit, you can download and install it from this website at junit.org/junit4/ As you can see, at the time of this series they are working on JUnit 5. So check for the latest version before downloading.
![]()
Here it says 'Work on JUnit 5 - Milestone 1 has started.' From this page we can download the most recent version of the JUnit JAR file. Let's click on 'Download and Install' under the 'Welcome.' As you can see, under the 'Plain-old JAR,' where JAR stands for Java Archive, we can download the following JARs and put them into our test classpath. There are two files here: junit.jar and hamcrest-core.jar The Hamcrest file is used in the example provided by this JUnit website, but if you're not going to use any of its classes and methods, you don't need to download it. The Hamcrest framework extends the capabilities of JUnit testing to include what they call Matchers. In other words, you now have a type of assert statement that says 'assert that something equals something else,' which is a little different from the assert in JUnit.
For this tutorial I'm concentrating on JUnit, but the Hamcrest extension is worth taking some time to review and becoming familiar with its adding capabilities. You can get more information here at hamcrest.org/JavaHamcrest/ For now, I'm gonna download these two files.
I'll click on junit.jar and I'll download the most recent version 4.12. On the right hand side under download I'm going to download the JAR file. I have a message. It says 'This type of file can harm your computer.' I'm going to say 'Keep'. And now I'll go back and download the Hamcrest-coreJAR file as well.
I'm gonna do the same thing and get the most recent version of the JAR file. I have the same message.
I'll click 'Keep'. Now both files are downloaded. Next, I'm gonna move them from my download folder to a new folder I'll create called 'Junit-example'.
Let's do that now. I'm gonna use 'File Explore' to create my new folder and move these files. So on 'File Explorer' I'm gonna go to my 'C' drive. Users/Producer I'm gonna right click and create a new folder. The new folder's called 'JUnit-example'.
Now, I'll go to my downloads and I'm gonna highlight both files right click and copy. I'm gonna go back over to my 'JUnit-example' folder and I'm gonna right click and paste. That way I can go ahead and create a program in this folder to show you how to use the 'JUnit' framework. Once these files are downloaded you do need to make sure you take time to update your class path to point to the 'JUnit-4.12.JAR' location. Now I'd like to go back to the download page. If I scroll down you'll see there's also information about how to use 'JUnit' with 'Mavin'.
If you're using 'Mavin' for your projects you can add the dependency for 'JUnit' by simply including the group ID 'JUnit' the artifact ID 'JUnit' and in this case, my version is 4.12. That needs to match the version that you downloaded. And the scope of this dependency should say 'test'. At this point, that's all I need to do to be able to use 'JUnit'.
'JUnit' can be used as part of an 'IDE', an integrated development environment, or from the command line. If you run from the command line that's one of the reasons we needed to download the two 'JAR' files.Practice while you learn with exercise filesDownload the files the instructor uses to teach the course. Follow along and learn by watching, listening and practicing.
About this frequently asked questions listThe current version of this FAQ is maintainedby.Most of the wisdom contained in this FAQ comes from thecollective insights and hard-won experiences of the many goodfolks who participate on the JUnit mailing list and the JUnitcommunity at large.If you see your genius represented anywhere in this FAQ withoutdue credit to you, please send me an email and I'll make thingsright.Your contributions to this FAQ are greatly appreciated! TheJUnit community thanks you in advance.To contribute to this FAQ, simply write a JUnit-related questionand answer, then send the unformatted textto.Corrections to this FAQ are always appreciated, as well.No reasonable contribution will be denied. Your name willalways appear along with any contribution you make.The master copy of this FAQ is availableat.The JUnit distribution also includes this FAQ inthedocdirectory.
OverviewJUnit is a simple, open source framework to write and runrepeatable tests. It is an instance of the xUnit architecturefor unit testing frameworks. JUnit features include:. Assertions for testing expected results.
Test fixtures for sharing common test data. Test runners for running testsJUnit was originally written by Erich Gamma and Kent Beck.The official JUnit home page is.There are 3 mailing lists dedicated to everything JUnit:. (Search it for answers to frequently askedquestions not included here.).The following documents are included in the JUnit distributionin the doc directory:.JUnit is, releasedunder the and hostedon.Best Java Performance Monitoring/Testing Tool.Best Java Performance Monitoring/Testing Tool. Java org.junit.runner.JUnitCore org.junit.tests.AllTestsAll the tests should pass with an 'OK' message.If the tests don't pass, verifythat junit.jar is in the CLASSPATH.Finally, the documentation.Delete the directory structure where you unzipped the JUnitdistribution.Remove junit.jar from the CLASSPATH.JUnit does not modify the registry so simply removing all thefiles will fully uninstall it.Questions that are not answered inthe orin the should be postedtothe or the.Please stick to technical issues on the discussion forum andmailing lists. Keep in mind that these are public, sodo not include any confidential information in yourquestions!You should alsoread by Eric Raymond beforeparticipating in the discussion forum and mailing lists.NOTE:Please do NOT submit bugs, patches, or featurerequests to the discussion forum or mailing lists.Refer instead to.JUnit celebrates programmers testing their own software.
In thisspirit, bugs, patches, and feature requests that include JUnittests have a better chance of being addressed than thosewithout.JUnit is hostedon.Please use the tools provided by GitHub for yoursubmissions.Time: 0OK (1 tests)(Submitted by: Jeff Nielsen)A test fixture is useful if you have two or more tests for acommon set of objects. Using a test fixture avoids duplicatingthe code necessary to initialize (and cleanup) the commonobjects.Tests can use the objects (variables) in a test fixture, witheach test invoking different methods on objects in the fixtureand asserting different expected results. Each test runs in itsown test fixture to isolate tests from the changes made by othertests. That is, tests don't share the state of objects inthe test fixture. Because the tests are isolated, they canbe run in any order.To create a test fixture, declare instance variables for thecommon objects.
Initialize these objects in a publicvoid method annotated with @Before. TheJUnit framework automatically invokes any @Beforemethods before each test is run.The following example shows a test fixture with a commonCollection object. SetUptestEmptyCollectionsetUptestOneItemCollectionThe ordering of test-method invocations is not guaranteed, sotestOneItemCollection might be executed beforetestEmptyCollection. But it doesn't matter,because each method gets its own instance of thecollection.Although JUnit provides a new instance of the fixture objectsfor each test method, if you allocate any externalresources in a @Before method, you should releasethem after the test runs by annotating a method with@After.
The JUnit framework automatically invokesany @After methods after each test is run. CreateOutputFiletestSomethingWithFiledeleteOutputFile(Submitted by: Dave Astels)Often if a method doesn't return a value, it will have some sideeffect. Actually, if it doesn't return a value AND doesn't havea side effect, it isn't doing anything.There may be a way to verify that the side effect actuallyoccurred as expected. For example, considerthe add method in the Collection classes. Thereare ways of verifying that the side effect happened (i.e. Theobject was added).
You can check the size and assert that it iswhat is expected. SrccomxyzSomeClass.javatestcomxyzSomeClassTest.javaThese approaches allow the tests to access to all the public andpackage visible methods of the classes under test.Some developers have argued in favor of putting the tests in asub-package of the classes under test (e.g. Theauthor of this FAQ sees no clear advantage to adopting thisapproach and believes that said developers also put their curlybraces on the wrong line.:-)The desire to do this is usually a symptom of excessive couplingin your design.
If two or more tests must share the same testfixture state, then the tests may be trying to tell you that theclasses under test have some undesirable dependencies.Refactoring the design to further decouple the classes undertest and eliminate code duplication is usually a betterinvestment than setting up a shared test fixture.But if you must.You can add a @BeforeClass annotation to a methodto be run before all the tests in a class, anda @AfterClass annotation to a method to be runafter all the tests in a class. Here's an example. Export CLASSPATH=$JUNITHOME/junit.jar:/myproject/classes:/myproject/lib/something.jar(Submitted by: J.B. Rainsberger and Jason Rogers)Most likely your CLASSPATH doesn't include the JUnitinstallation directory.Refer to for more guidance.Also consider runningto print the absolute location of the JUnit class files requiredto run and test JUnit and its samples.If the CLASSPATH seems mysterious, read!(Submitted by: Eric Armstrong).Invoke the runner:java org.junit.runner.JUnitCore (Submitted by: Eric Armstrong).Define any necessary Ant properties. DparameterName=parameterValueIf the number of parameters on the command line gets unwieldy,pass in the location of a property file that defines a set ofparameters. Alternatively, thecontains the XMLPropertyManagerand PropertyManager classes that allow you to define aproperty file (or XML file) containing test parameters.(Submitted by: Scott Stirling)The workaround as of JUnit 3.7 is toadd org.w3c.dom.
and org.xml.sax. toyour excluded.properties.It's just a matter of time before this fix becomes incorporatedinto the released version ofJUnit's excluded.properties, since JAXP is astandard part of JDK 1.4. It will be just likeexcluding org.omg. By the way, if you downloadthe JUnit source from its Sourceforge CVS, you will find thatthese patterns have already been added to the defaultexcluded.properties and so has a pattern for JINI. In fact, hereis the current version in CVS, which demonstrates how to addexclusions to the list too. ## The list of excluded package paths for the TestCaseClassLoader#excluded.0=sun.excluded.1=com.sun.excluded.2=org.omg.excluded.3=javax.excluded.4=sunw.excluded.5=java.excluded.6=org.w3c.dom.excluded.7=org.xml.sax.excluded.8=net.jini.This is the most common case where thedefault excluded.properties list needsmodification.
The cause of the LinkageError isrelated to using JAXP in your test cases. By JAXP I mean thewhole set of javax.xml. classes and thesupporting org.w3c.dom.and org.xml.sax. classes.As stated above, the JUnit GUI TestRunners' classloader relieson the excluded.properties for classes it shoulddelegate to the system classloader. JAXP is an unusual casebecause it is a standard Java extension library dependent onclasses whose package names ( org.w3c.dom.and org.xml.sax.) do not begin with a standardJava or Sun prefix.
This is similar to the relationshipbetween javax.rmi. and the org.omg.classes, which have been excluded by default inJUnit'ss excluded.properties for a while.What can happen, and frequently does when using the JUnit Swingor AWT UI with test cases that reference, use or depend on JAXPclasses, such as Log4J, Apache SOAP, Axis, Cocoon, etc., is thatthe JUnit class loader (properly)delegates javax.xml. classes it 'sees'to the system loader. But then the system loader, in the processof initializing and loading that JAXP class, links and loads upa bunch of org.w3c.dom/ org.xml.saxclasses. When it does so, the JUnit custom classloader is notinvolved at all because the system classloader never delegates'down' or checks with custom classloaders to see if aclass is already loaded.
At any point after this, if the JUnitloader is asked to loadan org.w3c.dom/ org.xml.sax class thatit's never seen before, it will try to load it because theclass' name doesn't match any of the patterns in the defaultexclude list. That's when a LinkageErroroccurs. This is really a flaw in the JUnit classloader design,but there is the workaround given above.Java 2 JVMs keep classes (remember, classes and objects, thoughrelated, are different entities to the JVM - I'm talkingabout classes here, not object instances) in namespaces,identifying them by their fully qualified classname plus theinstance of their defining (not initiating) loader. The JVM willattempt to assign all unloaded classes referenced by an alreadydefined and loaded class to that class's defining loader.
TheJVM's classresolver routine (implemented as a C function in theJVM source code) keeps track of all these class loading eventsand 'sees' if another classloader (such as the JUnitcustom loader) attempts to define a class that has already beendefined by the system loader. According to the rules of Java 2loader constraints, in case a class has already been defined bythe system loader, any attempts to load a class should first bedelegated to the system loader. A 'proper' way forJUnit to handle this feature would be to load classes from arepository other than the CLASSPATH that the system classloaderknows nothing about. And then the JUnit custom classloader couldfollow the standard Java 2 delegation model, which is to alwaysdelegate class loading to the system loader, and only attempt toload if that fails. Since they both load from the CLASSPATH inthe current model, if the JUnit loader delegated like it'ssupposed to, it would never get to load any classes since thesystem loader would always find them.You could try to hack around this in the JUnit source bycatching the LinkageError inTestCaseClassLoader's loadClass method and thenmaking a recovery call to findSystemClass -thereby delegating to the system loader after the violation hasbeen caught.
But this hack only works some of the time, becausenow you can have the reverse problem where the JUnit loader willload a host of org.w3c.dom/ org.xml.saxclasses, and then the system loader violates the loaderconstraints at some point when it tries to do exactly what Idescribed above with JAXP because it doesn't ever delegate toits logical child (the JUnit loader). Inevitably, if your testcases use many JAXP and related XML classes, one or the otherclassloader will end up violating the constraints whatever youdo.Make sure you have more or more method annotated with @Test.For example. DirectorySuiteBuilder builder = new DirectorySuiteBuilder;builder.setSuffix('Test');Test suite = builder.suite('/home/project/myproject/tests');Documentation and examples are at.Write your own custom suite builder.Have your test classes implement an interface and write atreewalker to load each class in a directory, inspect theclass, and add any classes that implement the interface to aTestSuite.You might only want to do this if you are veryuncomfortable with using a naming convention for testclasses. Aside from being slow for larger suites, ultimatelyit's arguable whether it's more effort to follow a namingconvention that have test classes implement an interface!An example of this approach is at. Best PracticesTests should be written before the code. Test-first programmingis practiced by only writing new code when an automated test isfailing.Good tests tell you how to best design the system for itsintended use. They effectively communicate in an executableformat how to use the software.
They also prevent tendencies toover-build the system based on speculation. When all the testspass, you know you're done!Whenever a customer test fails or a bug is reported, first writethe necessary unit test(s) to expose the bug(s), thenfix them. This makes it almost impossible for that particularbug to resurface later.Test-driven development is a lot more fun than writing testsafter the code seems to be working. Give it a try!No, just test everything that could reasonably break.Be practical and maximize your testing investment. Rememberthat investments in testing are equal investments in design.
Ifdefects aren't being reported and your design responds well tochange, then you're probably testing enough. If you're spendinga lot of time fixing defects and your design is difficult togrow, you should write more tests.If something is difficult to test, it's usually an opportunityfor a design improvement. Look to improve the design so thatit's easier to test, and by doing so a better design willusually emerge.(Submitted by: J. Rainsberger)The general philosophy is this: if it can't break on itsown, it's too simple to break.First example is the getX method. Supposethe getX method only answers the value of aninstance variable.
In that case, getX cannotbreak unless either the compiler or the interpreter is alsobroken. For that reason, don't test getX; thereis no benefit. The same is true of the setXmethod, although if your setX method does anyparameter validation or has any side effects, you likely need totest it.Next example: suppose you have written a method that doesnothing but forward parameters into a method called on anotherobject. That method is too simple to break. BecomeTimidAndTestEverythingwhile writingTheSameThingOverAndOverAgainbecomeMoreAggressivewriteFewerTestswriteTestsForMoreInterestingCasesif getBurnedByStupidDefectfeelStupidbecomeTimidAndTestEverythingendendThe loop, as you can see, never terminates.Run all your unit tests as often as possible, ideally every timethe code is changed.
![]()
Make sure all your unit tests always runat 100%. Frequent testing gives you confidence that yourchanges didn't break anything and generally lowers the stress ofprogramming in the dark.For larger systems, you may just run specific test suites thatare relevant to the code you're working on.Run all your acceptance, integration, stress, and unit tests atleast once per day (or night).If you're using Eclipse, be sure to check out David Saff's.Test-driven development generally lowers the defect density ofsoftware. But we're all fallible, so sometimes a defect willslip through. When this happens, write a failing test thatexposes the defect. When the test passes, you know the defectis fixed!Don't forget to use this as a learning opportunity.
Perhaps thedefect could have been prevented by being more aggressive abouttesting everything that could reasonably break.Inserting debug statements into code is a low-tech method fordebugging it. It usually requires that output be scannedmanually every time the program is run to ensure that the codeis doing what's expected.It generally takes less time in the long run to codifyexpectations in the form of an automated JUnit test that retainsits value over time. If it's difficult to write a test toassert expectations, the tests may be telling you that shorterand more cohesive methods would improve your design.Debuggers are commonly used to step through code and inspectthat the variables along the way contain the expected values.But stepping through a program in a debugger is a manual processthat requires tedious visual inspections. In essence, thedebugging session is nothing more than a manual check ofexpected vs. Actual results. Moreover, every time the programchanges we must manually step back through the program in thedebugger to ensure that nothing broke.It generally takes less time to codify expectations in the formof an automated JUnit test that retains its value over time. Ifit's difficult to write a test to assert expected values, thetests may be telling you that shorter and more cohesive methodswould improve your design.
![]() Comments are closed.
|
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |