Pattern Archives

Common Patterns in Distributed Systems

Sample application: https://github.com/microservices-patterns/ftgo-application http://eventuate.io/exampleapps.html Microservices Patterns: https://microservices.io/patterns/index.html Enterprise Integration Patterns: https://www.enterpriseintegrationpatterns.com/patterns/messaging/ Configuration Management Centralizing configuration and secret values: AWS Secrets Manager AWS Key Management Service Apache ZooKeeper Spring Cloud Config (Spring Cloud Vault, Spring Cloud Zookeeper) etcd – distributed reliable key-value store Service Discovery Client make request to Service Registry or Load Balancer (Router): Apache […]

Software Design Patterns

GoF: Creational Singleton Abstract Factory Factory Method Builder Prototype Object Pool GoF: Structural Facade Decorator Composite Bridge http://norows.com/structural-patterns-bridge.html Adapter Proxy http://norows.com/structural-patterns-proxy.html Flyweight http://norows.com/structural-patterns-flyweight.html GoF: Behavioral Visitor Template Method Strategy http://norows.com/behavioral-patterns-strategy.html Observer http://norows.com/behavioral-patterns-observer.html Memento http://norows.com/behavioral-patterns-memento.html Mediator http://norows.com/behavioral-patterns-mediator.html Iterator http://norows.com/behavioral-patterns-iterator.html State Interpreter http://norows.com/behavioral-patterns-interpreter.html Command http://norows.com/behavioral-patterns-command.html Chain of Responsibility […]

Object Pool – Creational patterns

Object Pool kept ready to use objects for a client Creational patterns: Singleton ¦ Builder ¦ Factory Method ¦ Abstract Factory ¦ Prototype ¦ Object Pool

Builder – Creational patterns

Builder provide a flexible design solution – how we can create a class and how we can simplified (and reduce parameters count passed to the constructor) instantiation process of the class:

public class Dog {

    private String name;
    private int age;

    public static class Builder {

        private String name;
        private int age;

        public Builder name(String name) {
            this.name = name;
            return this;
        }

        public Builder age(int age) {
            this.age = age;
            return this;
        }

        public Dog build() {
            return new Dog(this);
        }

    }

    private Dog(Builder builder) {
        name = builder.name;
        age = builder.age;
    }

}

/////////////////////////

Dog d = new Dog.Builder().name("jack").age(3).build();

public class Dog {

private String name;

private int age;

public static class Builder {

private String name;

private int age;

public Builder name(String name) {

this.name = name;

return this;

}

public Builder age(int age) {

this.age = age;

return this;

}

public Dog build() {

return new Dog(this);

}

private Dog(Builder builder) {

name = builder.name;

age = builder.age;

}

/////////////////////////

Dog d = new Dog.Builder().name("jack").age(3).build();

disadvantages: Requires creating a separate ConcreteBuilder for each different type of product. Requires the builder classes to be mutable. Data members of […]