Table of Contents

Part 1  Enterprise JavaBeans   1

1  Introduction to J2EE   3

1.1 The J2EE architecture 4

Bird's-eye view of the J2EE architecture 4

Characteristics of the J2EE architecture 5

J2EE platform containers 7

1.2 J2EE application system 8

Using J2EE technologies for application development 9

J2EE platform support for applications 10

1.3 The J2EE implementation 12

J2EE implementation roles 12

The J2EE reference implementation 14

1.4 The J2EE and EJB versions 14

1.5 Summary 14

2  Overview of Enterprise JavaBeans   16

2.1 Understanding the EJB architecture 17

EJB architecture: The big picture 18

Defining container requirements 20

2.2 Understanding the EJB components 21

Characteristics of enterprise beans 22

JavaBeans and Enterprise JavaBeans 23

2.3 Benefits of EJB technology 24

Reduced time to market 24

Cost effectiveness 24

Reliability and robustness 25

2.4 Three flavors of enterprise beans 25

Beans that handle synchronous communication: Entity beans and session beans 26

Beans that handle asynchronous communication: Message-driven beans 27

2.5 Specifying EJB roles and responsibilities 28

Enterprise bean provider 28

Application assembler 29

Bean deployer 29

EJB server provider and container provider 30

System administrator 31

Overlap of roles 31

2.6 Programming the beans 32

Coding the bean class 32

Coding the bean interfaces 33

Writing the deployment descriptor 36

Programming restrictions 37

2.7 The EJB environment 39

The bean's home in the environment: JNDI 39

Deployment descriptor elements for the environment 40

Required APIs and services 45

2.8 Packaging the beans into a JAR file 46

2.9 Lab exercise 46

2.10 Summary 47

Part 2  Session beans   55

3  Client view of a session bean    57

3.1 Session beans in EJB land 58

3.2 Session bean remote home interface 59

Required methods in the remote home interface 59

The create and remove methods in the home interface 62

3.3 Session bean remote component interface 65

Methods in the remote component interface 65

Methods from the EJBObject interface 67

Getting and using the remote component interface 69

3.4 Local interfaces 69

Local interfaces and their methods 70

Writing local interfaces 72

3.5 Using the client view 73

Locating the home interface 73

Accessing a session bean concurrently 75

3.6 Summary 76

4  Birth of a session bean   81

4.1 Introducing session beans 82

4.2 Implementing a session bean 84

Implementing the methods from the client view 84

Implementing methods from the SessionBean interface 86

Putting it all together in code 88

4.3 Constructing and creating a session bean 90

Creating a session bean instance 90

The stateful session bean creation process 91

The ejbCreate methods 92

4.4 Using the SessionContext interface 93

4.5 Operations permitted during bean creation 96

Operations allowed during bean construction 96

Operations permitted during bean creation 98

4.6 Responsibilities of the container 99

4.7 Summary 99

5  Lifecycle of a session bean   105

5.1 The stateful session bean lifecycle: An overview 106

The does not exist state 106

The method ready state 108

The passive state 108

5.2 The stateless session bean lifecycle: To be or not to be 109

5.3 Into and out of a nap: Passivation and activation 111

Implementing ejbPassivate() and ejbActivate() 111

Permitted operations and access 112

5.4 Removing a session bean instance 114

5.5 Where the bean rocks: The business methods 116

Implementation of business methods 116

Operations from the business methods 117

5.6 Summary 118

Part 3  Entity beans   123

6  Client view of an entity bean   125

6.1 Introducing entity beans 126

The core functionality of an entity bean 127

Entity, entity bean, and entity bean instance 129

Characteristics of an entity bean 131

6.2 Entity bean remote home interface 131

Required methods in the remote home interface 132

Additional methods in the home interface 134

6.3 Entity bean remote component interface 138

Methods in the remote component interface 138

Getting and using the remote component interface 140

6.4 Local interfaces 141

6.5 Using the client view 142

Locating the home interface 143

Accessing an entity bean 144

Accessing an entity bean concurrently 145

6.6 Summary 146

7  Birth of an entity bean   151

7.1 Here comes entity bean persistence 152

Synchronizing entity and entity bean 153

CMP and BMP entity beans 154

7.2 Implementing a CMP entity bean 155

Implementing methods from the interfaces 155

Methods for virtual persistent fields 159

Putting it all together in code 160

7.3 Constructing an entity bean 163

Constructing a bean instance 163

Using the EntityContext interface 164

Operations allowed during bean construction 166

7.4 Creating an entity bean 168

CMP entity bean creation process 168

Operations allowed during bean creation 171

7.5 Identifying entity beans 172

Constructing the primary key 173

Identifying entity beans with primary keys 174

7.6 Summary 175

8  Lifecycle of an entity bean    181

8.1 Entity bean lifecycle overview 182

The does not exist state 182

The pooled state: No strings attached 184

The ready state: I'm yours until I go back to the pool 185

8.2 Finding a bean and doing a select 186

The ejbFind methods 186

The ejbSelect methods 187

8.3 Doing business from home 188

Writing home business methods 189

Using EntityContext: Communicating with the container 189

8.4 In and out of the pool 190

Activating a bean instance 191

Passivating a bean instance 192

8.5 Where the bean rocks: The ready state 193

Implementation of business methods 193

Operations from business methods 194

Removing a bean instance 195

8.6 Summary 196

9  Entity bean relationships   202

9.1 Using beans to represent database tables 203

Beans representing related tables 203

Establishing a relationship between two entity beans 206

9.2 Container-managed relationships 207

One-to-one relationships 207

One-to-many relationships 208

Many-to-many relationships 210

9.3 Managing persistence and relationships 211

Container-managed persistent fields 212

Container-managed relationship fields 214

9.4 Programming for CMP and CMR 217

9.5 Relationships and remove protocols 221

9.6 Summary 221

10  EJB query language   227

10.1 The role of EJB QL in persistence 228

Pieces of the persistence puzzle 228

From abstract schema to database table 229

10.2 Abstract schema and query syntax 231

EJB QL syntax and definitions 231

Handling the query return types 232

10.3 Query domains and navigation 233

Navigating the path 233

Dealing with Collections in path navigation 234

10.4 Identifiers and input parameters 235

Identifiers 235

Input parameters 236

10.5 Operators and expressions 237

Operators 237

Expressions 238

10.6 Summary 239

Part 4  Message-driven beans   245

11  Message-driven beans   247

11.1 Using message-driven beans for asynchronous communication 248

Message-driven bean: A JMS message consumer 249

Client view of an MDB 250

11.2 Implementing a message-driven bean 251

Writing an MDB class 251

Requirements for an MDB class 253

11.3 The lifecycle of a message-driven bean 254

States of the lifecycle 254

Using the MessageDrivenContext interface 256

11.4 The message destination types 258

The Queue destination 258

The Topic destination 258

11.5 Summary 259

Part 5  EJB services   265

12  EJB transactions   267

12.1 Understanding transactions 268

Defining transactions 268

Distributed transactions 270

12.2 Implementing EJB transactions 270

Interfaces for transactions 271

Using bean-managed transactions demarcation 272

Using container-managed transaction demarcation 274

12.3 Transaction attributes 274

Defining transaction attributes 275

Transaction attributes in action 278

Using transaction attributes 279

Transaction attributes used by beans 281

12.4 Specifying transactions in a deployment descriptor 282

Specifying the transaction type for a bean 282

Specifying the transaction attribute for a bean method 282

12.5 Transaction synchronization 284

12.6 Summary 286

13  EJB exceptions   292

13.1 Exceptions in Java 293

The exceptions tree in Java 293

Checked exceptions and runtime exceptions 294

13.2 Exceptions in EJB 295

Standard EJB application exceptions 295

Standard EJB system exceptions 298

13.3 Bean provider's responsibilities 301

Dealing with application exceptions 301

Dealing with system exceptions 303

13.4 Container's responsibilities 304

Application exceptions 304

System exceptions 304

13.5 Summary 305

14  EJB security    310

14.1 Implementing security in EJB 311

Understanding basic security concepts 311

Security in EJB 312

14.2 Defining the security roles 313

14.3 Defining method permissions 314

Granting permission to all methods 314

Granting permission method by method 315

Distinguishing between overloaded methods 316

Distinguishing between interfaces 316

14.4 Controlling the propagating security identity 317

14.5 Disabling methods 319

14.6 Programming security 319

Limitations of declarative security 319

Implementing programmatic security 320

References to security roles 321

14.7 Responsibilities in implementing EJB security 322

Implementing EJB security 322

Deploying EJB security 323

14.8 Summary 324

A  Installing and running RI J2SDKEE 1.3   329

B  An introduction to XML   344

C  A sample deployment descriptor file   355

D  Review questions and answers   359

E  Exam Quick Prep   404

index 447