import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class ImmutableClassDemo {
public static void main(String[] args) throws CloneNotSupportedException {
Address address1 = new Address("s1", "c1");
List<String> phoneNumbers = new ArrayList<>();
phoneNumbers.add("123345");
phoneNumbers.add("456789");
Map<String, String> metadata = new HashMap<>();
metadata.put("hobby", "Watching Movies");
Employee e = new Employee("John", 23, address1, phoneNumbers, metadata);
// modifications
e.getAddress().setCity("c3");
e.getAddress().setStreet("s3");
e.getPhoneNumbers().add("1234");
e.getMetadata().put("skill", "Java");
e.getMetadata().put("designation", "HR");
System.out.println(e.getEmpName());
System.out.println(e.getAge());
System.out.println(e.getAddress());
System.out.println(e.getPhoneNumbers());
System.out.println(e.getMetadata());
}
}
//Immutable Classes in Java
final class Employee {
private final String empName;
private final int age;
private final Address address;
private final List<String> phoneNumbers;
private final Map<String, String> metadata;
public Employee(String name, int age, Address address, List<String> phoneNumbers, Map<String, String> metadata) {
super();
this.empName = name;
this.age = age;
this.address = address;
this.phoneNumbers = phoneNumbers;
this.metadata = metadata;
}
public String getEmpName() {
return empName;
}
public int getAge() {
return age;
}
// clone the address object
public Address getAddress() throws CloneNotSupportedException {
return (Address) address.clone();
}
// deep copy the list of phone numbers
public List<String> get phone numbers() {
return new ArrayList<>(phoneNumbers);
}
// deep copy the map of metadata
public Map<String, String> getMetadata() {
return new HashMap<>(metadata);
}
}
final class Address implements Cloneable {
private String street;
private String city;
public Address(String street, String city) {
this.street = street;
this.city = city;
}
public String getStreet() {
return street;
}
public void setStreet(String street) {
this.street = street;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public Object clone() throws CloneNotSupportedException {
return super.clone();
}
@Override
public String toString() {
return "{Street: " + street + ", City: " + city + "}";
}
}
