實現領域驅動設計英文版

《實現領域驅動設計英文版》是2016年4月電子工業出版社出版發行的圖書，作者是Vaughn Vernon（沃恩.弗農）。

基本介紹

• 書名：實現領域驅動設計英文版
• 作者：Vaughn Vernon（沃恩.弗農） 
• ISBN：978-7-121-27274-5
• 頁數：648
• 定價：118.00元 
• 出版社：電子工業出版社
• 出版時間：2016年4月
• 開本：16

圖書簡介

領域驅動設計（DDD）是教我們如何做好軟體的，同時也是教我們如何更好地使用面向對象技術的。它為我們提供了設計軟體的全新視角，同時也給開發者留下了一大難題：如何將領域驅動設計付諸實踐？VaughnVernon的這本《實現領域驅動設計》為我們給出了全面的解答。《實現領域驅動設計英文版》分別從戰略和戰術層面詳盡地討論了如何實現DDD，其中包含了大量的優秀實踐、設計準則和對一些問題的折中性討論。《實現領域驅動設計英文版》共分為14章。DDD戰略部分講解了領域、限界上下文、上下文映射圖和架構等內容；戰術部分包括實體、值對象、領域服務、領域事件、聚合和資源庫等內容。一個虛構的案例研究貫穿全書，這對於實例講解DDD實現來說非常有用。《實現領域驅動設計英文版》在DDD的思想和實現之間建立起了一座橋樑，架構師和程式設計師均可閱讀，同時也可以作為一本DDD參考書。

內容簡介

領域驅動設計（DDD）是教我們如何做好軟體的，同時也是教我們如何更好地使用面向對象技術的。它為我們提供了設計軟體的全新視角，同時也給開發者留下了一大難題：如何將領域驅動設計付諸實踐？VaughnVernon的這本《實現領域驅動設計》為我們給出了全面的解答。《實現領域驅動設計英文版》分別從戰略和戰術層面詳盡地討論了如何實現DDD，其中包含了大量的優秀實踐、設計準則和對一些問題的折中性討論。《實現領域驅動設計英文版》共分為14章。DDD戰略部分講解了領域、限界上下文、上下文映射圖和架構等內容；戰術部分包括實體、值對象、領域服務、領域事件、聚合和資源庫等內容。一個虛構的案例研究貫穿全書，這對於實例講解DDD實現來說非常有用。《實現領域驅動設計英文版》在DDD的思想和實現之間建立起了一座橋樑，架構師和程式設計師均可閱讀，同時也可以作為一本DDD參考書。

目錄

Chapter 1 Getting Started with DDD

Can I DDD?

Why You Should Do DDD

How to Do DDD

The Business Value of Using DDD

1. The Organization Gains a Useful Model of Its Domain

2. A Refined, Precise Definition and Understanding of the Business Is Developed

3. Domain Experts Contribute to Software Design

4. A Better User Experience Is Gained

5. Clean Boundaries Are Placed around Pure Models

6. Enterprise Architecture Is Better Organized

7. Agile, Iterative, Continuous Modeling Is Used

8. New Tools, Both Strategic and Tactical, Are Employed

The Challenges of Applying DDD

Fiction, with Bucketfuls of Reality

Wrap-Up

Chapter 2 Domains, Subdomains, and Bounded Contexts

Big Picture

Subdomains and Bounded Contexts at Work

Focus on the Core Domain

Why Strategic Design Is So Incredibly Essential

Real-World Domains and Subdomains

Making Sense of Bounded Contexts

Room for More than the Model

Size of Bounded Contexts

Aligning with Technical Components

Sample Contexts

Collaboration Context.

Identity and Access Context.

Agile Project Management Context

Wrap-Up

Chapter 3 Context Maps

Why Context Maps Are So Essential

Drawing Context Maps

Projects and Organizational Relationships

Mapping the Three Contexts

Wrap-Up

Chapter 4 Architecture

Interviewing the Successful CIO

Layers

Dependency Inversion Principle

Hexagonal or Ports and Adapters

Service-Oriented

Representational State Transfer—REST

REST as an Architectural Style

Key Aspects of a RESTful HTTP Server

Key Aspects of a RESTful HTTP Client

REST and DDD

Why REST?

Command-Query Responsibility Segregation, or CQRS

Examining Areas of CQRS

Dealing with an Eventually Consistent Query Model

Event-Driven Architecture

Pipes and Filters

Long-Running Processes, aka Sagas

Event Sourcing

Data Fabric and Grid-Based Distributed Computing

Data Replication

Event-Driven Fabrics and Domain Events

Continuous Queries

Distributed Processing

Wrap-Up

Chapter 5 Entities

Why We Use Entities

Unique Identity.

User Provides Identity

Application Generates Identity

Persistence Mechanism Generates Identity

Another Bounded Context Assigns Identity

When the Timing of Identity Generation Matters

Surrogate Identity

Identity Stability.

Discovering Entities and Their Intrinsic Characteristics

Uncovering Entities and Properties

Digging for Essential Behavior

Roles and Responsibilities

Construction

Validation

Change Tracking

Wrap-Up

Chapter 6 Value Objects

Value Characteristics

Measures, Quantifies, or Describes

Immutable

Conceptual Whole

Replaceability

Value Equality.

Side-Effect-Free Behavior

Integrate with Minimalism.

Standard Types Expressed as Values

Testing Value Objects

Implementation.

Persisting Value Objects

Reject Undue Influence of Data Model Leakage.

ORM and Single Value Objects

ORM and Many Values Serialized into a Single Column

ORM and Many Values Backed by a Database Entity.

ORM and Many Values Backed by a Join Table.

ORM and Enum-as-State Objects

Wrap-Up

Chapter 7 Services

What a Domain Service Is (but First, What It Is Not)

Make Sure You Need a Service.

Modeling a Service in the Domain

Is Separated Interface a Necessity?

A Calculation Process

Transformation Services.

Using a Mini-Layer of Domain Services

Testing Services.

Wrap-Up

Chapter 8 Domain Events

The When and Why of Domain Events

Modeling Events

With Aggregate Characteristics

Identity

Publishing Events from the Domain Model

Publisher

Subscribers

Spreading the News to Remote Bounded Contexts

Messaging Infrastructure Consistency

Autonomous Services and Systems

Latency Tolerances

Event Store

Architectural Styles for Forwarding Stored Events

Publishing Notifications as RESTful Resources

Publishing Notifications through Messaging Middleware

Implementation

Publishing the NotificationLog

Publishing Message-Based Notifications

Wrap-Up

Chapter 9 Modules

Designing with Modules

Basic Module Naming Conventions

Module Naming Conventions for the Model.

Modules of the Agile Project Management Context

Modules in Other Layers

Module before Bounded Context

Wrap-Up

Chapter 10 Aggregates

Using Aggregates in the Scrum Core Domain

First Attempt: Large-Cluster Aggregate

Second Attempt: Multiple Aggregates

Rule: Model True Invariants in Consistency Boundaries

Rule: Design Small Aggregates

Don’t Trust Every Use Case

Rule: Reference Other Aggregates by Identity

Making Aggregates Work Together through Identity

References

Model Navigation

Scalability and Distribution

Rule: Use Eventual Consistency Outside the Boundary

Ask Whose Job It Is

Reasons to Break the Rules

Reason One: User Interface Convenience

Reason Two: Lack of Technical Mechanisms

Reason Three: Global Transactions

Reason Four: Query Performance

Adhering to the Rules

Gaining Insight through Discovery.

Rethinking the Design, Again

Estimating Aggregate Cost

Common Usage Scenarios

Memory Consumption

Exploring Another Alternative Design

Implementing Eventual Consistency.

Is It the Team Member’s Job?

Time for Decisions

Implementation

Create a Root Entity with Unique Identity

Favor Value Object Parts

Using Law of Demeter and Tell, Don’t Ask

Optimistic Concurrency.

Avoid Dependency Injection.

Wrap-Up

Chapter 11 Factories

Factories in the Domain Model

Factory Method on Aggregate Root

Creating CalendarEntry Instances

Creating Discussion Instances

Factory on Service

Wrap-Up

Chapter 12 Repositories

Collection-Oriented Repositories

Hibernate Implementation

Considerations for a TopLink Implementation

Persistence-Oriented Repositories

Coherence Implementation

MongoDB Implementation

Additional Behavior

Managing Transactions

A Warning

Type Hierarchies

Repository versus Data Access Object

Testing Repositories

Testing with In-Memory Implementations

Wrap-Up

Chapter 13 Integrating Bounded Contexts

Integration Basics

Distributed Systems Are Fundamentally Different

Exchanging Information across System Boundaries

Integration Using RESTful Resources

Implementing the RESTful Resource

Implementing the REST Client Using an Anticorruption Layer

Integration Using Messaging

Staying Informed about Product Owners and Team Members

Can You Handle the Responsibility?

Long-Running Processes, and Avoiding Responsibility

Process State Machines and Time-out Trackers

Designing a More Sophisticated Process

When Messaging or Your System Is Unavailable

Wrap-Up

Chapter 14 Application.

User Interface

Rendering Domain Objects

Render Data Transfer Object from Aggregate Instances

Use a Mediator to Publish Aggregate Internal State

Render Aggregate Instances from a Domain Payload Object

State Representations of Aggregate Instances

Use Case Optimal Repository Queries.

Dealing with Multiple, Disparate Clients

Rendition Adapters and Handling User Edits

Application Services

Sample Application Service

Decoupled Service Output

Composing Multiple Bounded Contexts

Infrastructure

Enterprise Component Containers

Wrap-Up

Appendix A Aggregates and Event Sourcing: A+ES

Inside an Application Service

Command Handlers

Lambda Syntax

Concurrency Control.

Structural Freedom with A+ES

Performance

Implementing an Event Store

Relational Persistence

BLOB Persistence

Focused Aggregates

Read Model Projections

Use with Aggregate Design

Events Enrichment

Supporting Tools and Patterns

Event Serializers

Event Immutability

Value Objects

Contract Generation

Unit Testing and Specifications

Event Sourcing in Functional Languages

Bibliography

Index

序言

在本書中，Vaughn Vernon以一種特有的方式向我們展示了領域驅動設計（Domain-Driven Design，DDD）的各個方面，其中包括對新概念的解釋、新的例子和原創的話題組織方式。我相信，這種新穎的方式可以幫助大家掌握DDD的各種微妙之處，特別是非常抽象的聚合和限界上下文。不同的人習慣用不同的方式來理解這些概念，而在缺少多種解釋的情況下，想要了解這些微妙的抽象概念是非常困難的。

本書包含了在過去9年中出現在各種論文和講稿中的對DDD的深層剖析，而這些是在之前的書籍中沒有的。本書將領域事件與實體和值對象一道看作是模型的基礎部件。另外，書中還討論了“大泥球”（Big Ball of Mud）架構和如何將其放置在上下文映射圖（Context Map）中。Vaughn還向我們闡述了六邊形架構（Hexagonal Architecture），這種新興的架構與分層架構相比，能夠更好地描述我們要完成的事情。

我是在將近兩年前第一次接觸到本書內容的，那時Vaughn已經開始撰寫本書有一段時間了。在第一次DDD峰會上，我們中的幾個編寫了關於DDD的若干話題，比如有關DDD的新知識，或者DDD社區所期待的一些針對性建議等。Vaughn負責寫聚合部分，這一寫便是一個有關聚合的文章系列，並且寫得非常出色，最後，這個系列成為了本書中的一個章節。

在那次峰會上，與會人員們一致認為：一套更加具有規約性的DDD模式是大有裨益的。誠實地講，對於軟體開發中的任何問題，答案都是“得看情況”。然而，這對於那些希望學到實際套用技術的人來說卻沒多大用處。人們需要更加實際的指導。經驗法則不見得一定要放之四海而皆準，但在通常情況下，它們可以工作得很好，也應該被首先嘗試。出於自身的果決性，這些經驗法則蘊含著解決問題的思想方法。Vaughn的這本《實現領域驅動設計》將各種明晰的建議很好地融合在一起，同時又給出了一些折中性的討論，從而避免了將這些建議過於簡單化。

一些額外的DDD模式，比如領域事件，已經成為了DDD的主流模式，人們也學會了如何套用這些模式，並嘗試著在新架構和新技術中採用這些模式。在我的《領域驅動設計：軟體核心複雜性應對之道》出版9年後，有太多關於DDD的新知識需要談及，Vaughn的這本書則是最全面的闡述。

Eric Evans

Domain Language, Inc.

作者簡介

Vaughn Vernon 是一個經驗豐富的軟體工程師，在軟體設計、開發和架構方面擁有超過25年的從業經驗。他提倡通過創新來簡化軟體的設計和實現。從20世紀80年代起，他便開始使用面向對象語言進行編程；在20世紀90年代早期，他便在領域建模中套用了領域驅動設計，那時他使用的是Smalltalk語言。他在很多業務領域都有從業經驗，包括航空、環境、地理、保險、醫學和電信等領域。同時，Vaughn在技術上也取得了很大的成功，包括開發可重用的框架和類庫等。他在全球範圍之內提供軟體諮詢和演講，此外，他還在許多國家教授《實現領域驅動設計》的課程。