JUnit assertNotSame Example

In this article, we will learn about the assertNotSame() static method which belongs to JUnit 5 org.junit.jupiter.api.Assertions Class. Note that in JUnit 5 all JUnit 4 assertion methods are moved to org.junit.jupiter.api.Assertions class.
The assertNotSame() method asserts that two objects do not refer to the same object. If they do refer to the same object, an AssertionError without a message is thrown. 

The assertNotSame() Method Example

import static org.junit.Assert.assertNotSame;

import java.util.HashMap;
import java.util.Map;

import org.junit.jupiter.api.Test;

public class JUnit5AssertNotSameExample {
    private String processMap(final String key) {
       final Map<String, String> map = new HashMap<>();
       map.put("key1", "value1");
       map.put("key2", "value2");
       map.put("key3", "value3");
       map.put("key4", "value4");
       map.put("key5", "value5");
       map.put("key6", "value6");
       map.put("key7", "value7");
       map.put("key8", "value8");
       return map.get(key);

    public void checkSameReferenceTest() {
      final JUnit5AssertNotSameExample example = new JUnit5AssertNotSameExample();
      assertNotSame(example.processMap("key1"), example.processMap("key2"));