Document Information


Part I Introduction

1.  Overview

2.  Using the Tutorial Examples

Part II The Web Tier

3.  Getting Started with Web Applications

4.  JavaServer Faces Technology

5.  Introduction to Facelets

6.  Expression Language

7.  Using JavaServer Faces Technology in Web Pages

8.  Using Converters, Listeners, and Validators

9.  Developing with JavaServer Faces Technology

10.  JavaServer Faces Technology: Advanced Concepts

11.  Using Ajax with JavaServer Faces Technology

12.  Composite Components: Advanced Topics and Example

13.  Creating Custom UI Components and Other Custom Objects

14.  Configuring JavaServer Faces Applications

15.  Java Servlet Technology

16.  Uploading Files with Java Servlet Technology

17.  Internationalizing and Localizing Web Applications

Part III Web Services

18.  Introduction to Web Services

19.  Building Web Services with JAX-WS

20.  Building RESTful Web Services with JAX-RS

21.  JAX-RS: Advanced Topics and Example

Part IV Enterprise Beans

22.  Enterprise Beans

23.  Getting Started with Enterprise Beans

24.  Running the Enterprise Bean Examples

25.  A Message-Driven Bean Example

26.  Using the Embedded Enterprise Bean Container

27.  Using Asynchronous Method Invocation in Session Beans

Part V Contexts and Dependency Injection for the Java EE Platform

28.  Introduction to Contexts and Dependency Injection for the Java EE Platform

29.  Running the Basic Contexts and Dependency Injection Examples

30.  Contexts and Dependency Injection for the Java EE Platform: Advanced Topics

31.  Running the Advanced Contexts and Dependency Injection Examples

Part VI Persistence

32.  Introduction to the Java Persistence API

33.  Running the Persistence Examples

34.  The Java Persistence Query Language

35.  Using the Criteria API to Create Queries

36.  Creating and Using String-Based Criteria Queries

37.  Controlling Concurrent Access to Entity Data with Locking

38.  Using a Second-Level Cache with Java Persistence API Applications

Part VII Security

39.  Introduction to Security in the Java EE Platform

40.  Getting Started Securing Web Applications

41.  Getting Started Securing Enterprise Applications

42.  Java EE Security: Advanced Topics

Part VIII Java EE Supporting Technologies

43.  Introduction to Java EE Supporting Technologies

44.  Transactions

45.  Resources and Resource Adapters

Resources and JNDI Naming

Resource Injection

Field-Based Injection

Method-Based Injection

Class-Based Injection

Resource Adapters and Contracts

Management Contracts

Lifecycle Management

Work Management Contract

Generic Work Context Contract

Outbound and Inbound Contracts

Metadata Annotations

Common Client Interface

Using Resource Adapters With Contexts and Dependency Injection for the Java EE Platform (CDI)

Further Information about Resources

46.  The Resource Adapter Example

47.  Java Message Service Concepts

48.  Java Message Service Examples

49.  Bean Validation: Advanced Topics

50.  Using Java EE Interceptors

Part IX Case Studies

51.  Duke's Bookstore Case Study Example

52.  Duke's Tutoring Case Study Example

53.  Duke's Forest Case Study Example



DataSource Objects and Connection Pools

To store, organize, and retrieve data, most applications use a relational database. Java EE 6 components may access relational databases through the JDBC API. For information on this API, see

In the JDBC API, databases are accessed by using DataSource objects. A DataSource has a set of properties that identify and describe the real-world data source that it represents. These properties include such information as the location of the database server, the name of the database, the network protocol to use to communicate with the server, and so on. In the GlassFish Server, a data source is called a JDBC resource.

Applications access a data source by using a connection, and a DataSource object can be thought of as a factory for connections to the particular data source that the DataSource instance represents. In a basic DataSource implementation, a call to the getConnection method returns a connection object that is a physical connection to the data source.

A DataSource object may be registered with a JNDI naming service. If so, an application can use the JNDI API to access that DataSource object, which can then be used to connect to the data source it represents.

DataSource objects that implement connection pooling also produce a connection to the particular data source that the DataSource class represents. The connection object that the getConnection method returns is a handle to a PooledConnection object rather than being a physical connection. An application uses the connection object in the same way that it uses a connection. Connection pooling has no effect on application code except that a pooled connection, like all connections, should always be explicitly closed. When an application closes a connection that is pooled, the connection is returned to a pool of reusable connections. The next time getConnection is called, a handle to one of these pooled connections will be returned if one is available. Because connection pooling avoids creating a new physical connection every time one is requested, applications can run significantly faster.

A JDBC connection pool is a group of reusable connections for a particular database. Because creating each new physical connection is time consuming, the server maintains a pool of available connections to increase performance. When it requests a connection, an application obtains one from the pool. When an application closes a connection, the connection is returned to the pool.

Applications that use the Persistence API specify the DataSource object they are using in the jta-data-source element of the persistence.xml file:


This is typically the only reference to a JDBC object for a persistence unit. The application code does not refer to any JDBC objects.