Cannot find symbol assertEquals

assertEquals is a static method. Since you can't use static methods without importing them explicitly in a static way, you have to use either:

import org.junit.Assert;
...
Assert.assertEquals(...)

or:

import static org.junit.Assert.assertEquals;
...
assertEquals(...)

For @Test it's a little bit different. @Test is an annotation as you can see by the @. Annotations are imported like classes.

So you should import it like:

import org.junit.Test;

Generally avoid using wildcards on imports like import org.junit.*. For reasons see Why is using a wild card with a Java import statement bad?.

JUnit 5 Jupiter

In JUnit 5 the package name has changed and the Assertions are at org.junit.jupiter.api.Assertions and Assumptions at org.junit.jupiter.api.Assumptions

So you have to add the following static import:

import static org.junit.jupiter.api.Assertions.*;

See also http://junit.org/junit5/docs/current/user-guide/#writing-tests-assertions