78 lines
2.2 KiB
Java

package com.baeldung.map;
import static org.assertj.core.api.Assertions.assertThat;
import java.util.HashMap;
import java.util.Map;
import org.junit.Test;
import com.google.common.collect.ImmutableMap;
public class CopyHashMapUnitTest {
@Test
public void givenHashMap_whenShallowCopy_thenCopyisNotSameAsOriginal() {
HashMap<String, Employee> map = new HashMap<>();
Employee emp1 = new Employee("John");
Employee emp2 = new Employee("Norman");
map.put("emp1",emp1);
map.put("emp2",emp2);
HashMap<String, Employee> shallowCopy = CopyHashMap.shallowCopy(map);
assertThat(shallowCopy).isNotSameAs(map);
}
@Test
public void givenHashMap_whenShallowCopyModifyingOriginalObject_thenCopyShouldChange() {
HashMap<String, Employee> map = new HashMap<>();
Employee emp1 = new Employee("John");
Employee emp2 = new Employee("Norman");
map.put("emp1",emp1);
map.put("emp2",emp2);
HashMap<String, Employee> shallowCopy = CopyHashMap.shallowCopy(map);
emp1.setName("Johny");
assertThat(shallowCopy.get("emp1")).isEqualTo(map.get("emp1"));
}
@Test
public void givenHashMap_whenDeepCopyModifyingOriginalObject_thenCopyShouldNotChange() {
HashMap<String, Employee> map = new HashMap<>();
Employee emp1 = new Employee("John");
Employee emp2 = new Employee("Norman");
map.put("emp1",emp1);
map.put("emp2",emp2);
HashMap<String, Employee> deepCopy = CopyHashMap.deepCopy(map);
emp1.setName("Johny");
assertThat(deepCopy.get("emp1")).isNotEqualTo(map.get("emp1"));
}
@Test
public void givenImmutableMap_whenCopyUsingGuava_thenCopyShouldNotChange() {
Employee emp1 = new Employee("John");
Employee emp2 = new Employee("Norman");
Map<String, Employee> map = ImmutableMap.<String, Employee> builder()
.put("emp1",emp1)
.put("emp2",emp2)
.build();
Map<String, Employee> shallowCopy = ImmutableMap.copyOf(map);
assertThat(shallowCopy).isSameAs(map);
}
}