1 String Processing Techniques

27

1.1 ABAP Character Types

27

1.2 Designing a Custom String Library

29

1.2.1 Developing the API

29

1.2.2 Encapsulating Basic String Processing Statements

33

1.3 Improving Productivity with Regular Expressions

36

1.3.1 Understanding Regular Expressions

36

1.3.2 Regular Expression Syntax

37

1.3.3 Using Regular Expressions in ABAP

46

1.3.4 Integrating Regular Expression Support into the String Library

53

1.4 Summary

56

2 Working with Numbers, Dates, and Bytes

57

2.1 Numeric Operations

57

2.1.1 ABAP Math Functions

58

2.1.2 Generating Random Numbers

60

2.2 Date and Time Processing

64

2.2.1 Understanding ABAP Date and Time Types

64

2.2.2 Date and Time Calculations

65

2.2.3 Working with Timestamps

66

2.2.4 Calendar Operations

70

2.3 Bits and Bytes

73

2.3.1 Introduction to the Hexadecimal Type in ABAP

73

2.3.2 Reading and Writing Individual Bits

75

2.3.3 Bitwise Logical Operators

76

2.4 Summary

79

3 Dynamic and Reflective Programming

81

3.1 Working with Field Symbols

81

3.1.1 What Is a Field Symbol

82

3.1.2 Field Symbol Declarations

83

3.1.3 Assigning Data Objects to Field Symbols

85

3.1.4 Casting Data Objects During the Assignment Process

89

3.2 Reference Data Objects

91

3.2.1 Declaring Data Reference Variables

91

3.2.2 Assigning References to Data Objects

93

3.2.3 Dynamic Data Object Creation

94

3.2.4 Performing Assignments Using Data Reference Variables

96

3.2.5 De-Referencing Data References

96

3.3 Introspection with ABAP Run Time Type Services

99

3.3.1 ABAP RTTS System Classes

99

3.3.2 Working with Type Objects

100

3.3.3 Defining Custom Data Types Dynamically

102

3.3.4 Case Study: RTTS Usage in the ALV Object Model

104

3.4 Dynamic Program Generation

106

3.4.1 Creating a Subroutine Pool

106

3.4.2 Creating a Report Program

107

3.4.3 Drawbacks to Dynamic Program Generation

108

3.5 Summary

108

4 ABAP and Unicode

109

4.1 Introduction to Character Codes and Unicode

109

4.1.1 Understanding Character-Encoding Systems

110

4.1.2 Limitations of Early Character-Encoding Systems

111

4.1.3 What Is Unicode

111

4.1.4 Unicode Support in SAP Systems

113

4.2 Developing Unicode-Enabled Programs in ABAP

113

4.2.1 Overview of Unicode-Related Changes to ABAP

114

4.2.2 Thinking in Unicode

117

4.2.3 Turning on Unicode Checks

120

4.3 Working with Unicode System Classes

121

4.3.1 Converting External Data into ABAP Data Objects

121

4.3.2 Converting ABAP Data Objects into External Data Formats

124

4.3.3 Converting Between External Formats

126

4.3.4 Useful Character Utilities

129

4.4 Summary

131

5 Working with Files

135

5.1 File Processing on the Application Server

135

5.1.1 Understanding the ABAP File Interface

136

5.1.2 Case Study: Processing Files with the ABAP File Interface

141

5.2 Working with Unicode

148

5.2.1 Changes to the OPEN DATASET Statement to Support Unicode

149

5.2.2 Using Class CL_ABAP_FILE_UTILITIES

149

5.3 Logical Files and Directories

150

5.3.1 Defining Logical Directory Paths and Files in Transaction FILE

151

5.3.2 Working with the Logical File API

155

5.4 File Compression with ZIP Archives

157

5.4.1 The ABAP ZIP File API

158

5.4.2 Creating a ZIP File

159

5.4.3 Reading a ZIP File

163

5.5 File Processing on the Presentation Server

167

5.5.1 Interacting with the SAP GUI via CL_GUI_FRONTEND_SERVICES

167

5.5.2 Downloading a File

168

5.5.3 Uploading a File

171

5.6 Transmitting Files Using FTP

173

5.6.1 Introducing the SAPFTP Library

173

5.6.2 Wrapping the SAPFTP Library in an ABAP Objects Class

175

5.6.3 Uploading and Downloading Files Using FTP

176

5.6.4 Implementation Details

179

5.7 Summary

182

6 Database Programming

183

6.1 Object-Relational Mapping and Persistence

183

6.1.1 Positioning of Object-Relational Mapping Tools

184

6.1.2 Persistence Service Overview

184

6.1.3 Mapping Concepts

187

6.2 Developing Persistent Classes

189

6.2.1 Creating Persistent Classes in the Class Builder

190

6.2.2 Defining Mappings Using the Mapping Assistant Tool

192

6.3 Working with Persistent Objects

198

6.3.1 Understanding the Class Agent API

199

6.3.2 Performing Typical CRUD Operations

199

6.3.3 Querying Persistent Objects with the Query Service

204

6.4 Modeling Complex Relationships

206

6.4.1 Defining Custom Attributes

207

6.4.2 Filling in the Gaps

209

6.5 Storing Text with Text Objects

214

6.5.1 Defining Text Objects

214

6.5.2 Using the Text Object API

218

6.5.3 Alternatives to Working with Text Objects

222

6.6 Connecting to External Databases

223

6.6.1 Configuring a Database Connection

223

6.6.2 Accessing the External Database

225

6.6.3 Further Reading

230

6.7 Summary

231

7 Transactional Programming

233

7.1 Introduction to the ACID Transaction Model

233

7.2 Transaction Processing with SAP LUWs

235

7.2.1 Introduction to SAP Logical Units of Work

235

7.2.2 Bundling Database Changes in Update Function Modules

239

7.2.3 Bundling Database Changes in Subroutines

242

7.2.4 Performing Local Updates

244

7.2.5 Dealing with Exceptions in the Update Task

245

7.3 Working with the Transaction Service

248

7.3.1 Transaction Service Overview

248

7.3.2 Understanding Transaction Modes

249

7.3.3 Processing Transactions in Object-Oriented Mode

253

7.3.4 Performing Consistency Checks with Check Agents

259

7.4 Implementing Locking with the Enqueue Service

262

7.4.1 Introduction to the SAP Lock Concept

262

7.4.2 Defining Lock Objects

263

7.4.3 Programming with Locks

265

7.4.4 Integration with the SAP Update System

267

7.4.5 Lock Administration

267

7.5 Tracking Changes with Change Documents

268

7.5.1 What Are Change Documents?

269

7.5.2 Creating Change Document Objects

269

7.5.3 Configuring Change-Relevant Fields

273

7.5.4 Programming with Change Documents

274

7.6 Summary

279

8 XML Processing in ABAP

283

8.1 Introduction to XML

283

8.1.1 What Is XML?

284

8.1.2 XML Syntax

285

8.1.3 Defining XML Documents Using XML Schema

289

8.2 Parsing XML with the iXML Library

291

8.2.1 Introducing the iXML Library API

291

8.2.2 Working with DOM

292

8.2.3 Case Study: Developing XML Mapping Programs in ABAP

297

8.2.4 Next Steps

304

8.3 Transforming XML Using XSLT

304

8.3.1 What Is XSLT?

305

8.3.2 Anatomy of an XSLT Stylesheet

305

8.3.3 Integrating XSLT with ABAP

308

8.3.4 Creating XSLT Stylesheets

308

8.3.5 Processing XSLT Programs in ABAP

310

8.3.6 Case Study: Transforming Business Partners with XSLT

311

8.3.7 Serialization of ABAP Data Objects Using asXML

314

8.4 Simple Transformation

317

8.4.1 What Is Simple Transformation?

318

8.4.2 Anatomy of a Simple Transformation Program

318

8.4.3 Learning Simple Transformation Syntax

319

8.4.4 Creating Simple Transformation Programs

324

8.4.5 Case Study: Transforming Business Partners with ST

325

8.5 Summary

327

9 Web Programming with the ICF

329

9.1 HTTP Overview

329

9.1.1 Working with the Uniform Interface

330

9.1.2 Addressability and URLs

332

9.1.3 Understanding the HTTP Message Format

333

9.2 Introduction to the ICF

335

9.3 Developing an HTTP Client Program

336

9.3.1 Defining the Service Call

337

9.3.2 Working with the ICF Client API

338

9.3.3 Putting It All Together

340

9.4 Implementing ICF Handler Modules

346

9.4.1 Working with the ICF Server-Side API

347

9.4.2 Creating an ICF Service Node

348

9.4.3 Developing an ICF Handler Class

354

9.4.4 Testing the ICF Service Node

358

9.5 Summary

360

10 Web Services

361

10.1 Web Service Overview

361

10.1.1 Introduction to SOAP

362

10.1.2 Describing SOAP-Based Services with WSDL

365

10.1.3 Web Service Discovery with UDDI

365

10.2 Providing Web Services

366

10.2.1 Creating Service Definitions

367

10.2.2 Configuring Runtime Settings

373

10.2.3 Testing Service Providers

376

10.3 Consuming Web Services

378

10.3.1 Creating a Service Consumer

379

10.3.2 Defining a Logical Port

383

10.3.3 Using a Service Consumer in an ABAP Program

386

10.4 Next Steps

391

10.5 Summary

391

11 Email Programming

393

11.1 Introduction to BCS

393

11.2 Sending Email Messages

394

11.2.1 Understanding the Simple Mail Transfer Protocol

395

11.2.2 Sending a Plain Text Message

396

11.2.3 Working with Attachments

403

11.2.4 Formatting Email Messages with HTML

408

11.3 Receiving Email Messages

411

11.3.1 Configuring Inbound Processing Rules

412

11.3.2 Processing Inbound Requests

413

11.3.3 Potential Use Cases of Inbound Processing Rules

414

11.4 Summary

416

12 Security Programming

419

12.1 Developing a Security Model

419

12.1.1 Authenticating Users

420

12.1.2 Checking User Authorizations

420

12.1.3 Securing the Lines of Communication

421

12.1.4 Programming for Security

422

12.2 The SAP NetWeaver AS ABAP Authorization Concept

422

12.2.1 Overview

423

12.2.2 Developing Authorization Objects

424

12.2.3 Configuring Authorizations

430

12.2.4 Performing Authorization Checks in ABAP

433

12.2.5 Authorization Concept Review

434

12.3 Encrypting Data with ABAP

435

12.4 Performing Virus Scans

437

12.5 Protecting Web Content with CAPTCHA

438

12.5.1 What Is CAPTCHA

439

12.5.2 Developing a CAPTCHA Component with Adobe Flex

439

12.5.3 Integrating the CAPTCHA Component with BSPs

440

12.5.4 Integrating the CAPTCHA Component with Web Dynpro

443

12.6 Summary

444

13 Logging and Tracing

445

13.1 Introducing the Business Application Log

446

13.1.1 Configuring Log Objects

446

13.1.2 Displaying Logs

448

13.1.3 Organization of the BAL API

450

13.2 Developing a Custom Logging Framework

450

13.2.1 Organization of the Class-Based API

451

13.2.2 Configuring Log Severities

452

13.3 Case Study: Tracing an Application Program

453

13.3.1 Integrating the Logging Framework into an ABAP Program

453

13.3.2 Viewing Log Instances in Transaction SLG1

456

13.4 Summary

458

14 Interacting with the Operating System

459

14.1 Programming with External Commands

459

14.1.1 Maintaining External Commands

460

14.1.2 Restricting Access to External Commands

462

14.1.3 Testing External Commands

463

14.1.4 Executing External Commands in an ABAP Program

465

14.2 Case Study: Executing a Custom Perl Script

467

14.2.1 Defining the Command to Run the Perl Interpreter

468

14.2.2 Executing Perl Scripts

469

14.3 Summary

474

15 Interprocess Communication

475

15.1 SAP NetWeaver AS ABAP Memory Organization

476

15.2 Data Clusters

477

15.2.1 Working with Data Clusters

478

15.2.2 Storage Media Types

478

15.2.3 Sharing Data Objects Using ABAP Memory

479

15.2.4 Sharing Data Objects Using the Shared Memory Buffer

482

15.3 Working with Shared Memory Objects

486

15.3.1 Architectural Overview

486

15.3.2 Defining Shared Memory Areas

489

15.3.3 Accessing Shared Objects

495

15.3.4 Locking Concepts

506

15.3.5 Area Instance Versioning

507

15.3.6 Monitoring Techniques

509

15.4 Summary

510

16 Parallel and Distributed Processing with RFCs

511

16.1 RFC Overview

512

16.1.1 Understanding the Different Variants of RFC

512

16.1.2 Developing RFC-Enabled Function Modules

513

16.2 Parallel Processing with aRFC

515

16.2.1 Syntax Overview

515

16.2.2 Configuring an RFC Server Group

518

16.2.3 Defining Parallel Algorithms

520

16.2.4 Case Study: Processing Messages in Parallel

522

16.3 Summary

529