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CreationalInstantiationLess than 1 minute


Stores the objects of a single class and provide a global point of access to them.
Similar to Multiton pattern, only difference is that in a registry there is no restriction on the number of objects.


In Plain Words

Registry is a well-known object that other objects can use to find common objects and services.

Programmatic Example
Below is a Customer Class

public class Customer {

  private final String id;
  private final String name;

  public Customer(String id, String name) { = id; = name;

  public String getId() {
    return id;

  public String getName() {
    return name;


This registry of the Customer objects is CustomerRegistry

public final class CustomerRegistry {

  private static final CustomerRegistry instance = new CustomerRegistry();

  public static CustomerRegistry getInstance() {
    return instance;

  private final Map<String, Customer> customerMap;

  private CustomerRegistry() {
    customerMap = new ConcurrentHashMap<>();

  public Customer addCustomer(Customer customer) {
    return customerMap.put(customer.getId(), customer);

  public Customer getCustomer(String id) {
    return customerMap.get(id);


Class diagram



Use Registry pattern when

  • client wants reference of some object, so client can lookup for that object in the object's registry.


Large number of bulky objects added to registry would result in a lot of memory consumption as objects in the registry are not garbage collected.