The three goals to achieve the Java persistence mastering

Table of Contents

• 1 Business
  • DDD
  • Understanding and converting to the code
• 2 Isolation
  • Abstraction
  • Layers, Layers, Layers
  • When Layer can become an enemy
• 3 Performance
  • Take advantage of the database
  • Models
  • Challenges (Leak of knowledge)
• Conclusion

1 Business

• The reason that we’re coding is the goal.

Software Engineer Definition by Modern Software Engineering’s book:

Software Engineering is the application of an empirical, scientific approach to finding efficient, economic solutions to practical problems in software.

• Rich vs Anemic model

DDD

• Bringing the code close to the business.

• There are tactical and strategic perspectives

• Strategic: it’s a business language: Bounded Context, ubiquitous language, context Maps.

• Tactical: implementation, classes, and modules.

Patterns

• Entities: Anything with continuity through a life cycle and distinctions independent of attributes essential to the application’s user.

• Aggregator: A DDD aggregate is a cluster of domain objects that can be treated as a single unit.

• Value Object: Value Object is an object that represents a concept from your problem Domain.

• Services: is used to perform domain operations and business rules

• Repository: is used to access data from persistent stores.

Books

• Learning Domain-Driven Design: Aligning Software Architecture and Business Strategy

• Domain Driven Design Quickly

Understanding and converting to the code

There are several, such as story Storming, Story Mapping, and UML. My favorite one is Domain storytelling.

• Domain Storytelling: A Collaborative, Visual, and Agile Way to Build Domain-Driven Software

The tool: Egon.io

2 Isolation

• We are keeping the business safe from technology.

• Hexagonal architecture

• Ports and Adaptors

• Clean Architecture

Abstraction

Just enough software Architecture: A risk-driven Approach:

To be successful at combating the scale and complexity of software in the next decade, developers will need improved weapons…​ in three categories: partitioning, knowledge, and abstraction.

Abstraction can effectively combat complexity and scale because it shrinks problems, and smaller problems are easier to reason about it.

Layers, Layers, Layers

• Unstructured Code Monolith

• Modular Monolith

• Layered Architecture

  • Mapper

  • DAO

  • Repository

When Layer can become an enemy

More code:

• More Work

• More code to maintain

• More bugs

• We’re terrible at seeing the future; go to evolutionary architecture instead.

  • Unknown unknowns

3 Performance

• Object-relational impedance mismatch

  • Polymorphism, types, conversion, mapper

  • 90% is on that conversion

Take advantage of the database

Hibernate and JPA were designed to work well in combination with handwritten SQL. ORM, 20 years later by Gavin King

• NoSQL

  • Key-value

  • Wide-column

  • Document

  • Graph

  • Time Series

  • Even more

• SQL

• NewSQL

• CAP

  • PACELC

Models

NoSQL Distilled: A Brief Guide to the Emerging World of Polyglot Persistence

Challenges (Leak of knowledge)

• Maturity Models

• Design Patterns

  • Migrations

• CDC

Conclusion

Understand the three rules and focus on simplicity.

• A Philosophy of Software Design