SOA with Java Realizing Service Orientation with Java Technologies

--Antonio Bruno, Enterprise Architecture and Strategy, digitalStrom

“A great self-contained book on SOA using flexible Java implementations....”

--Roger Stoffers, Hewlett Packard

“Provides clarity on abstract concepts and is filled with concrete examples of implementing SOA principles in Java environments.”

--Sanjay Singh, Certified SOA Architect

“...provides a holistic, comprehensive view on leveraging SOA principles and architecture for building and deploying performant Java services.”

--Suzanne D’Souza, KBACE Technologies

“Thomas Erl’s series of books on services technology have shaped, influenced, and strengthened a whole community of enterprise and solution architects’ thinking and solution development, and the much awaited SOA with Java book is an excellent addition to the series. It is a must-read.”

--Lalatendu Rath, Wipro Technologies

The Definitive Guide to Building Service-Oriented Solutions with Lightweight and Mainstream Java Technologies

Java has evolved into an exceptional platform for building Web-based enterprise services. In SOA with Java, Thomas Erl and several world-class experts guide you in mastering the principles, best practices, and Java technologies you need to design and deliver high-value services and service-oriented solutions.

You’ll learn how to implement SOA with lightweight frameworks, mainstream Java services technologies, and contemporary specifications and standards. To demonstrate real-world examples, the authors present multiple case study scenarios. They further demystify complex concepts with a plain-English writing style. This book will be valuable to all developers, analysts, architects, and other IT professionals who want to design and implement Web-based service-oriented architectures and enterprise solutions with Java technologies.

Topic Areas

• Applying modern service-orientation principles to modern Java technology platforms
• Leveraging Java infrastructure extensions relevant to service-oriented solutions
• Exploring key concepts associated with SOA and service-orientation within the context of Java
• Reviewing relevant Java platforms, technologies, and APIs
• Understanding the standards and conventions that REST and SOAP services are built upon in relation to Java implementations
• Building Java Web-based services with JAX-WS and JAX-RS
• Applying the eight key principles of service-orientation design using Java tools and technologies
• Creating Java utility services: architectural, design, and implementation issues
• Constructing effective entity services: service contracts, messages, data access, and processing
• Constructing task services, including detailed guidance on service composition
• Using ESBs to support infrastructure requirements in complex services ecosystems

Addressing a critical need within the IT industry, it shows how to implement SOA solutions with lightweight Java frameworks such as Spring, Mule, and ServiceMix, as well as mainstream Java services technologies. Leading services author Thomas Erl and a team of experts also illuminate today's most important Java services specifications, including Service Data Objects (SDO) and Service Component Architecture (SCA).

To demonstrate options and alternatives for solving real-world design problems, the authors present multiple case studies drawn from their unsurpassed experience. They also demystify complex concepts and techniques with hundreds of easy-to-understand figures. Coverage includes:

• Introduction to service-oriented Java: Fundamental SOA concepts, basic Java distributed technologies, and Java service technologies
• Building Services with Java: service-orientation principles with Java Web Services; utility, entity, and task services; and service composition
• Building SOA Solutions with Java: orchestrated services, ESBs, and complex composition

Andre Tost works as a Senior Technical Staff Member and Software Architect in IBM’s Software Group. He is currently helping to develop and evolve the new PureApplication System cloud platform. Previously, Andre spent 10 years as an SOA consultant for IBM, leading large SOA transformation projects with clients worldwide. His specific focus was on SOA governance and middleware integration using enterprise service bus technology. Andre has co-authored several technical books and has published many articles on SOA and related topics. He is also a frequent conference speaker. Originally from Germany, he now works and lives in Rochester, Minnesota. He likes to watch, coach and play soccer whenever his busy schedule allows. Andre has a degree in Electrical Engineering from Berufsakademie Stuttgart, Germany.

Satadru Roy is a Consultant Architect who has designed and built large-scale, distributed systems using Java-based technologies for the last two decades. In that time he has worked as a product engineer and services consultant at Java infrastructure software vendors such as BEA Systems, Sun Microsystems, and Oracle Inc. He currently helps customers build mobile and cloud-hosted applications where he alternates between wearing architect and development manager hats, while his main areas of focus are API design and lightweight integration using agile development methodologies. Satadru is also immersing himself in the growing eco-system of the Scala platform and believes they will play increasingly important roles in future cloud and Big Data applications. He holds a Masters degree in Engineering from Indian Institure of Science.

Philip Thomas is an IT Architect in IBM’s Software Group. During his time in the technology sector, he has worked across industries and geographies with a range of organizations as a consultant on technology strategy and on the architecture, design, and implementation of a broad variety of solutions. His expertise spans a number of areas including Java/JEE, SOA, transaction processing systems, messaging/integration middleware, business process management, information management systems, and business analytics. He currently specializes in Big Data and analytics, based out of the UK. Prior to joining IBM in 2000, Phil trained as a physicist and holds a Ph.D. in experimental high-temperature superconductivity awarded by the University of Birmingham.

CHAPTER 1: Introduction     1

1.1 About This Book     2

Objectives of This Book     2

Who This Book Is For     2

What This Book Does Not Cover     3

1.2 Prerequisite Reading     3

How This Book Is Organized     4

1.3 How Principles and Patterns Are Used in This Book     7

1.4 Symbols and Figures     7

1.5 Additional Information     7

Updates, Errata, and Resources (www.servicetechbooks.com)      8

Referenced Specifications (www.servicetechspecs.com)      8

The Service Technology Magazine (www.servicetechmag.com)      8

Service-Orientation (www.serviceorientation.com)      8

What Is REST? (www.whatisrest.com)      8

What Is Cloud? (www.whatiscloud.com)      8

SOA and Cloud Computing Design Patterns (www.soapatterns.org, www.cloudpatterns.org)      8

SOA Certified (SOACP) Professional (www.soaschool.com)      9

Cloud Certified Professional (CCP) (www.cloudschool.com)      9

Big Data Science Certified Professional (BDSCP) (www.bigdatascienceschool.com)      9

Notification Service     9

CHAPTER 2: Case Study Examples     11

2.1 How Case Study Examples Are Used     12

Style Characteristics     12

Relationship to Abstract Content     12

Code Samples     12

2.2 Case Study Background: NovoBank     13

Technical Infrastructure     13

Automation Solutions     13

Business Obstacles and Goals     14

Future IT Roadmap     15

1. Build Reusable Business Services     15

2. Consolidate Information     16

3. Improve Channel Experience     16

4. Build Services Infrastructure     16

2.3 Case Study Background: SmartCredit Co     16

Technical Infrastructure     17

Automation Solutions     17

Business Goals     17

Future IT Roadmap     18

PART I: FUNDAMENTALS

CHAPTER 3: Fundamental SOA Concepts     21

3.1 Basic Terminology and Concepts     22

Service-Oriented Computing     22

Service-Orientation     24

Service-Oriented Architecture (SOA)      27

SOA Manifesto     28

Services     29

Cloud Computing     29

IT Resources     30

Service Models     30

Agnostic Logic and Non-Agnostic Logic     31

Service Inventory     32

Service Portfolio     32

Service Candidate     33

Service Contract     33

Service-Related Granularity     34

Service Profiles     35

SOA Design Patterns     36

3.2 Further Reading     38

CHAPTER 4: Basic Java Distributed Technologies     39

4.1 Java Distributed Computing Basics     40

Java SE Architecture     41

Java EE Architecture     41

The Beginning of Java EE     41

Application Packaging and Deployment     44

Deployment Descriptors     44

Java EE Architectural Tiers     45

4.2 Java Distributed Technologies and APIs     46

Java SE APIs     46

RMI     46

RMI / IIOP     47

JNDI     48

JDBC     49

Java EE APIs     49

Contexts and Dependency Injection     49

JTA     50

Java EE Connector Architecture     51

EJB     51

Session EJBs     52

Persistence Entities     53

Service-Orientation Principles and the EJB Model     55

JMS     56

Message-Driven Beans     58

Security in Java EE     58

4.3 XML Standards and Java APIs     59

XML     59

XML Schema Definition     61

XSLT     63

JAXP     63

JAXB     64

4.4 Building Services with Java Components     64

Components as Services     65

Application Protocols     65

Service Contracts     68

Location     68

Operations     69

Messages     69

Further Considerations     70

Components as Services and Service-Orientation     71

Standardized Service Contract     71

Service Loose Coupling     71

Service Abstraction     72

Service Discoverability     72

4.5 Java Vendor Platforms     74

GlassFish Enterprise Server     74

IBM WebSphere Application Server     75

IBM WebSphere Application Server Community Edition     78

Oracle WebLogic Server     79

CHAPTER 5: Web-Based Service Technologies     81

5.1 SOAP-Based Web Services     82

Extensibility of Web Services Standards (WS-*)     88

WS-Addressing     89

SOAP with Attachments (SwA)      90

WS-ReliableMessaging     91

WS-Transaction     92

WS-Security     93

WS-Policy     94

Web Services Distributed Management     95

Common Web Services Middleware     95

Enterprise Service Bus (ESB)      95

Orchestration     97

Management and Monitoring     99

Registries and Repositories     99

Service Construction and Assembly     100

5.2 REST Services     101

HTTP Response Codes     102

Resources and Addresses     103

Service Request     104

Service Response     104

Service Request     104

Service Response     104

HTTP Methods     106

Resource Representations     108

The ACCEPT Header     109

CHAPTER 6: Building Web-Based Services with Java     111

6.1 JAX-WS     112

SAAJ     115

Handlers     118

Web Services Engines and Toolkits     119

JAXR     120

6.2 Java Implementations of WS-* Standards     122

Advanced Web Services Standards and Frameworks     122

Service Component Architecture     123

Spring-WS     124

6.3 JAX-RS     124

Implementing JAX-RS     125

Implementing REST Services     129

Scalability     130

Statelessness     131

Uniform Contract     131

Cacheability     131

Addressability     132

Security     132

REST Service Support     134

PART II: SERVICES

CHAPTER 7: Service-Orientation Principles with Java Web-Based Services     139

7.1 Service Reusability     140

Agnostic Functional Contexts     140

Highly Generic Service Logic     141

Generic and Extensible Service Contracts     144

Concurrent Access to Service Logic     145

7.2 Standardized Service Contract     151

Top-Down vs. Bottom-Up     151

Mapping Between Java and WSDL     152

Wrapped Document/Literal Contracts     153

Implicit and Explicit Headers     154

Explicit Headers     154

Implicit Headers     157

No Headers     159

Data Mapping with REST     159

Conversion Between JSON and POJOs     161

Binary Data in Web Services     165

Binary Data in REST Services     170

Use of Industry Standards     175

7.3 Service Loose Coupling     176

Separation of Contract and Implementation     177

Independent Functional Contexts     179

Service Consumer Coupling     180

7.4 Service Abstraction     184

Abstracting Technology Details     185

Hiding Service Details     185

Document Constraints     188

7.5 Service Composability     189

Runtime Environment Efficiency     190

Service Contract Flexibility     192

Standards-Based Runtime     193

7.6 Service Autonomy     194

Well-Defined Functional Boundary     194

Runtime Environment Control     195

High Concurrency     196

7.7 Service Statelessness     197

Orchestration Infrastructure     198

Session State     198

Storing State     199

7.8 Service Discoverability     204

Design-Time Discoverability     204

Runtime Discoverability     205

Service Registries     208

CHAPTER 8: Utility Services with Java     211

8.1 Inside the Java Utility Service     212

Architectural Considerations     212

Utility Service Taxonomy     220

8.2 Utility Service Design and Implementation     221

Utility Service Design     221

Utility Services and Java Editions     226

Utility Services in Java SE     226

Utility Services in Java EE     227

Utility Services and Open-Source Frameworks     229

Spring Framework     229

Transaction Management     229

Data Access Objects     230

Object-Relational Mapping     230

JMS     230

JMX     230

JCA     231

Spring MVC      231

Hibernate     231

Commons Logging and Log4J     231

Utility Services as Web-Based Services     231

Sending XML Data as a String     232

Utilizing      233

Provider-Style Web Service Logic in JAX-WS     234

Building REST Utility Services     236

Testing Considerations     238

Packaging Considerations     239

8.3 Utility Service Types     240

Omni Utility Services     240

Design Considerations     241

Service Implementation     241

Service Consumption     241

Resource Utility Services     248

Persistence/Data Access Resources     248

Messaging Resources     248

Transaction Resources     249

Design Considerations     249

Service Implementation     251

Service Consumption     251

Micro-Utility Services     253

Design Considerations     253

Service Implementation     253

Service Consumption     254

Wrapper Utility Services     257

Design Considerations     258

Service Implementation     259

Service Consumption     259

CHAPTER 9: Entity Services with Java     261

9.1 Inside the Java Entity Service     262

Architectural Considerations     263

Domain Entities vs. Message Entities     265

Data Aggregation     266

Data Access Modes     267

Change Notifications     268

9.2 Java Entity Service Design and Implementation     270

Entity Service Design     270

Designing Domain Entities and Message Entities     271

Designing Stateless Entity Services     272

Designing Business-Relevant Entity Services     273

Designing Generic Entity Services     273

Designing Aggregating Entity Services     275

Entity Service Implementation     278

Java Editions     278

Entity Services as Web-Based Services     282

Entity Web Services Using SOAP     283

REST Entity Services     291

Read-Only and Read-Write Resources     292

Resource Granularity     292

Resource Creation and Location     292

Request Message     292

Response Message     293

Resource Relationships     294

Request Message     294

Response Message     294

Request Message     295

Resource Collections     295

Request Message     295

Response Message     295

Aggregate Entities     297

Request Message     298

Response Message     298

Open-Source Frameworks     302

Testing Considerations     302

Java Packaging Considerations     303

PART III: SERVICE COMPOSITION AND INFRASTRUCTURE

CHAPTER 10: Task Services with Java     307

10.1 Inside a Task Service     308

Performance Considerations     315

10.2 Building Task Services     316

Implementation Considerations     316

Web-Based Task Services     320

Task Services with SOAP and WSDL     320

Task Services with REST     324

Testing Considerations     332

Packaging Considerations     334

CHAPTER 11: Service Composition with Java     335

11.1 Inside Service Compositions     336

Service Composition Roles     336

Compositions and MEPs     337

Synchronous and Asynchronous Invocation     338

Service Level Agreements (SLAs)      339

11.2 Java Service Composition Design and Implementation     340

Composition Logic: Coding vs. Orchestration     340

REST Service Composition Considerations     341

Composition Member Endpoints     344

Error Handling     345

Schema Type Reuse     353

Web-Based Services vs. Java Components     359

Packaging, Testing and Deploying Composed Services     362

11.3 Service and Service Composition Performance Guidelines     368

Measuring Performance     368

Testing Performance     370

Caching     371

Data Grids     371

REST Caching     372

Scaling Out Services with State     374

Handling Failures     375

Parsing and Marshaling     376

CHAPTER 12: ESB as SOA Infrastructure     379

12.1 Basic Traditional Messaging Frameworks     380

RPC vs. Messaging     381

Technology Coupling     82

Spatial Coupling     382

Temporal Coupling     382

Message Producers and Message Consumers     385

12.2 Basic Service Messaging Frameworks     389

Basic Service Message Processing without ESBs     389

Message Routing without an ESB     390

Message Transformation without an ESB     391

Basic Service Message Processing with ESBs     392

Message Routing with an ESB     392

Message Transformation with an ESB     392

12.3 Common ESB Features Relevant to SOA     397

Service Lookup and Invocation     397

Service Processing     399

Service Composition Support      401

REST API Management Support     402

PART IV: APPENDICES

APPENDIX A: Case Study Conclusion     405

A.1 NovoBank     406

A.2 SmartCredit Co.     407

APPENDIX B: Service-Orientation Principles Reference     409

APPENDIX C: SOA Design Patterns Reference     425

APPENDIX D: The Annotated SOA Manifesto     519

About the Authors     533

About the Foreword Contributor     535

About the Contributors     537

Index     539