What are JUnit @Before and @Test

Question

What is the use of a Junit @Before and @Test annotations in java? How can I use them with netbeans?

PLEASE provide more information, otherwise we don't know what you want to know. — guerda, Feb 10 '09 at 07:52
https://onlyfullstack.blogspot.com/2019/02/junit-tutorial.html — Saurabh Oza, Mar 12 '19 at 15:19

score 56 · Answer 1 · edited Oct 10 '16 at 07:26

56

Can you be more precise? Do you need to understand what are @Before and @Test annotation?

@Test annotation is an annotation (since JUnit 4) that indicates the attached method is an unit test. That allows you to use any method name to have a test. For example:

@Test
public void doSomeTestOnAMethod() {
  // Your test goes here.
  ...
}

The @Before annotation indicates that the attached method will be run before any test in the class. It is mainly used to setup some objects needed by your tests:

(edited to add imports) :

import static org.junit.Assert.*; // Allows you to use directly assert methods, such as assertTrue(...), assertNull(...)

import org.junit.Test; // for @Test
import org.junit.Before; // for @Before

public class MyTest {

    private AnyObject anyObject;

    @Before
    public void initObjects() {
        anyObject = new AnyObject();
    }

    @Test
    public void aTestUsingAnyObject() {
        // Here, anyObject is not null...
        assertNotNull(anyObject);
        ...
    }

}

edited Oct 10 '16 at 07:26

Ondrej Bozek

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answered Feb 10 '09 at 07:48

Romain Linsolas

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hey thanks a lot..this is what i wanted to know..What packages do i add to use the @test and @ before annotations and how do i do it in netbeans? – Feb 10 '09 at 08:03
As provided in romaintaz' answer: import org.junit.Test; // for @Test import org.junit.Before; // for @Before – guerda Feb 10 '09 at 13:09
@romaintaz - Does the '@Before' method run before each of the tests in the file or does it run once for all the tests in the file? – ziggy Feb 18 '12 at 13:26
3

@ziggy '@Before' is called before every test in the class. Use '@BeforeClass' on a static method to run the method only once, for ex. To initialize your tests context. – Romain Linsolas Feb 19 '12 at 10:07
1

Is it before *any* test or before *each* test (as guerda says)? The documentation is unclear, but I suspect guerda has the right of it. Please update your answer if you have it wrong here. – B T Sep 13 '13 at 16:45

score 22 · Answer 2 · edited Jan 08 '13 at 20:27

If I understood you correctly, you want to know, what the annotation @Before means. The annotation marks a method as to be executed before each test will be executed. There you can implement the old setup() procedure.
The @Test annotation marks the following method as a JUnit test. The testrunner will identify every method annotated with @Test and executes it. Example:
```
import org.junit.*;

public class IntroductionTests {
    @Test
    public void testSum() {
      Assert.assertEquals(8, 6 + 2);
    }
}
```
How can i use it with Netbeans? In Netbeans, a testrunner for JUnit tests is included. You can choose it in your Execute Dialog.

Hi am sorry i meant @ test annotation and how do i add the JUNIt package and use it in my netbeans project. — , Feb 10 '09 at 08:12

What are JUnit @Before and @Test

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