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BAEL-2800_Copying_a_HashMap_in_Java - code cleanup

This commit is contained in:
Anshul Bansal 2019-04-05 12:53:14 +03:00
parent 8455bfc1d0
commit b17c1c720f
3 changed files with 38 additions and 49 deletions
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4
core-java-collections-2/src/main/java/com/baeldung/copyinghashmap/CopyHashMap.java
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@ -43,11 +43,11 @@ public class CopyHashMap {
return copyMap; return copyMap;
} }
public static HashMap copyMapAndConvertCmsToInches(HashMap originalMap) { public static HashMap copyMapAndDivideValuesBy2(HashMap originalMap) {
Set<Map.Entry> entries = originalMap.entrySet(); Set<Map.Entry> entries = originalMap.entrySet();
HashMap copyMap = (HashMap) entries HashMap copyMap = (HashMap) entries
.stream() .stream()
.collect(Collectors.toMap(mapEntry -> mapEntry.getKey(), mapEntry -> (int)mapEntry.getValue()/2.54)); .collect(Collectors.toMap(mapEntry -> mapEntry.getKey(), mapEntry -> (int)mapEntry.getValue()/2));
return copyMap; return copyMap;
} }

57
core-java-collections-2/src/test/java/com/baeldung/copyinghashmap/CopyHashMapUnitTest.java
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@ -15,64 +15,63 @@ public class CopyHashMapUnitTest {
@Test @Test
public void givenHashMap_whenShallowCopy_thenCopyisNotSameAsOriginal() { public void givenHashMap_whenShallowCopy_thenCopyisNotSameAsOriginal() {
HashMap<String, Employee> employeeMap = new HashMap<>(); HashMap<String, Employee> map = new HashMap<>();
Employee emp1 = new Employee("John", "Smith"); Employee emp1 = new Employee("John");
Employee emp2 = new Employee("Norman", "Lewis"); Employee emp2 = new Employee("Norman");
employeeMap.put("employee1",emp1); map.put("emp1",emp1);
employeeMap.put("employee2",emp2); map.put("emp2",emp2);
HashMap employeeMapShallowCopy = CopyHashMap.shallowCopy(employeeMap); HashMap shallowCopy = CopyHashMap.shallowCopy(map);
assertThat(employeeMapShallowCopy).isNotSameAs(employeeMap); assertThat(shallowCopy).isNotSameAs(map);
} }
@Test @Test
public void givenHashMap_whenShallowCopyModifyingOriginalObject_thenCopyShouldChange() { public void givenHashMap_whenShallowCopyModifyingOriginalObject_thenCopyShouldChange() {
HashMap<String, Employee> employeeMap = new HashMap<>(); HashMap<String, Employee> map = new HashMap<>();
Employee emp1 = new Employee("John", "Smith"); Employee emp1 = new Employee("John");
Employee emp2 = new Employee("Norman", "Lewis"); Employee emp2 = new Employee("Norman");
employeeMap.put("employee1",emp1); map.put("emp1",emp1);
employeeMap.put("employee2",emp2); map.put("emp2",emp2);
HashMap employeeMapShallowCopy = CopyHashMap.shallowCopy(employeeMap);
emp1.setFirstName("Johny"); HashMap shallowCopy = CopyHashMap.shallowCopy(map);
assertThat(employeeMapShallowCopy.get("employee1")) emp1.setName("Johny");
.isEqualTo(employeeMap.get("employee1"));
assertThat(shallowCopy.get("emp1")).isEqualTo(map.get("emp1"));
} }
@Test @Test
public void givenHashMap_whenDeepCopyModifyingOriginalObject_thenCopyShouldNotChange() { public void givenHashMap_whenDeepCopyModifyingOriginalObject_thenCopyShouldNotChange() {
HashMap<String, Employee> employeeMap = new HashMap<>(); HashMap<String, Employee> map = new HashMap<>();
Employee emp1 = new Employee("John", "Smith"); Employee emp1 = new Employee("John");
Employee emp2 = new Employee("Norman", "Lewis"); Employee emp2 = new Employee("Norman");
employeeMap.put("employee1",emp1); map.put("emp1",emp1);
employeeMap.put("employee2",emp2); map.put("emp2",emp2);
HashMap employeeMapDeepCopy = CopyHashMap.deepCopy(employeeMap); HashMap deepCopy = CopyHashMap.deepCopy(map);
emp1.setFirstName("Johny"); emp1.setName("Johny");
assertThat(employeeMapDeepCopy.get("employee1")) assertThat(deepCopy.get("emp1")).isNotEqualTo(map.get("emp1"));
.isNotEqualTo(employeeMap.get("employee1"));
} }
@Test @Test
public void givenHashMapWithValuesInCms_whenCopy_thenCopyMapShouldHaveValuesInInches() { public void givenHashMap_whenCopy_thenCopyMapShouldHaveValuesDivideBy2() {
HashMap<String, Integer> heightMap = new HashMap<>(); HashMap<String, Integer> heightMap = new HashMap<>();
heightMap.put("emp1", 160); heightMap.put("emp1", 160);
heightMap.put("emp2", 165); heightMap.put("emp2", 165);
heightMap.put("emp3", 163); heightMap.put("emp3", 163);
HashMap heightMapInInches = CopyHashMap.copyMapAndConvertCmsToInches(heightMap); HashMap heightMapCopy = CopyHashMap.copyMapAndDivideValuesBy2(heightMap);
assertThat(heightMap).isNotEqualTo(heightMapInInches); assertThat(heightMap).isNotEqualTo(heightMapCopy);
assertThat(heightMap.get("emp1")/2.54).isEqualTo(heightMapInInches.get("emp1")); assertThat(heightMap.get("emp1")/2).isEqualTo(heightMapCopy.get("emp1"));
} }
@Test @Test

26
core-java-collections-2/src/test/java/com/baeldung/copyinghashmap/Employee.java
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@ -4,33 +4,23 @@ import java.io.Serializable;
public class Employee implements Serializable{ public class Employee implements Serializable{
private String firstName; private String name;
private String lastName;
public Employee(String firstName, String lastName) { public Employee(String name) {
super(); super();
this.firstName = firstName; this.name = name;
this.lastName = lastName;
} }
public String getFirstName() { public String getName() {
return firstName; return name;
} }
public void setFirstName(String firstName) { public void setName(String name) {
this.firstName = firstName; this.name = name;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
} }
@Override @Override
public String toString() { public String toString() {
return this.firstName + " " + this.lastName; return this.name;
} }
} }