CODEWITHSUNDEEP
junitnullpointerexception
Senio Vak
Senio Vak

Reputation: 87

Junit - Null Pointer Exception with @Before

I just started learning Junit and I just got Null Pointer Exception in my first test.

If I read correctly @Before annotation means it will be called before each test but looks like it doesn't or something else is wrong with this code. In this code below I get Null Pointer in myList.add() line.

import org.junit.Before;
import org.junit.jupiter.api.Test;

import java.util.ArrayList;
import java.util.List;

import static org.junit.Assert.*;

public class StudentTest {
    private List<String> myList;

    @Before
    public void init(){
        myList = new ArrayList<>();
    }
    @Test
    public void size(){
        myList.add("TEST");
        assertEquals(1, myList.size());
    }
}

Upvotes: 2

Views: 3919

Answers (1)

Gerald M&#252;cke
Gerald M&#252;cke

Reputation: 11132

The imports (jupiter) indicate you're using Junit5. In JUnit5 you have to use the @BeforeEach annotation to indicate steps that have to be execute before each test method.

The @Before annotation was used in JUnit4.

I haven't tested this, just read the documentation https://junit.org/junit5/docs/current/user-guide/

Upvotes: 5

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