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

What Is a Servlet?

Servlet Lifecycle

Handling Servlet Lifecycle Events

Defining the Listener Class

Handling Servlet Errors

Creating and Initializing a Servlet

Writing Service Methods

Getting Information from Requests

Constructing Responses

Filtering Requests and Responses

Programming Filters

Programming Customized Requests and Responses

Specifying Filter Mappings

To Specify Filter Mappings Using NetBeans IDE

Invoking Other Web Resources

Including Other Resources in the Response

Transferring Control to Another Web Component

Accessing the Web Context

Maintaining Client State

Accessing a Session

Associating Objects with a Session

Session Management

To Set the Timeout Period Using NetBeans IDE

Session Tracking

Finalizing a Servlet

Tracking Service Requests

Notifying Methods to Shut Down

Creating Polite Long-Running Methods

The mood Example Application

Components of the mood Example Application

Running the mood Example

To Run the mood Example Using NetBeans IDE

To Run the mood Example Using Ant

Further Information about 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

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



Sharing Information

Web components, like most objects, usually work with other objects to accomplish their tasks. Web components can do so by

  • Using private helper objects (for example, JavaBeans components).

  • Sharing objects that are attributes of a public scope.

  • Using a database.

  • Invoking other web resources. The Java Servlet technology mechanisms that allow a web component to invoke other web resources are described in Invoking Other Web Resources.

Using Scope Objects

Collaborating web components share information by means of objects that are maintained as attributes of four scope objects. You access these attributes by using the getAttribute and setAttribute methods of the class representing the scope. Table 15-2 lists the scope objects.

Table 15-2 Scope Objects

Scope Object


Accessible from

Web context


Web components within a web context. See Accessing the Web Context.



Web components handling a request that belongs to the session. See Maintaining Client State.


Subtype of javax.servlet.ServletRequest

Web components handling the request.



The JSP page that creates the object.

Controlling Concurrent Access to Shared Resources

In a multithreaded server, shared resources can be accessed concurrently. In addition to scope object attributes, shared resources include in-memory data, such as instance or class variables, and external objects, such as files, database connections, and network connections.

Concurrent access can arise in several situations:

  • Multiple web components accessing objects stored in the web context.

  • Multiple web components accessing objects stored in a session.

  • Multiple threads within a web component accessing instance variables. A web container will typically create a thread to handle each request. To ensure that a servlet instance handles only one request at a time, a servlet can implement the SingleThreadModel interface. If a servlet implements this interface, no two threads will execute concurrently in the servlet’s service method. A web container can implement this guarantee by synchronizing access to a single instance of the servlet or by maintaining a pool of web component instances and dispatching each new request to a free instance. This interface does not prevent synchronization problems that result from web components’ accessing shared resources, such as static class variables or external objects.

When resources can be accessed concurrently, they can be used in an inconsistent fashion. You prevent this by controlling the access using the synchronization techniques described in the Threads lesson at in The Java Tutorial, Fourth Edition, by Sharon Zakhour et al. (Addison-Wesley, 2006).