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

Overview of the EL

Immediate and Deferred Evaluation Syntax

Immediate Evaluation

Deferred Evaluation

Value and Method Expressions

Value Expressions

Referencing Objects Using Value Expressions

Referring to Object Properties Using Value Expressions

Where Value Expressions Can Be Used

Method Expressions

Parameterized Method Calls

Literal Expressions


Reserved Words

Examples of EL Expressions

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

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



Defining a Tag Attribute Type

As explained in the previous section, all kinds of expressions can be used in tag attributes. Which kind of expression and how it is evaluated, whether immediately or deferred, are determined by the type attribute of the tag’s definition in the View Description Language (VDL) that defines the tag.

If you plan to create custom tags, for each tag in the VDL, you need to specify what kind of expression to accept. Table 6-1 shows the kinds of tag attributes that accept EL expressions, gives examples of expressions they accept, and provides the type definitions of the attributes that must be added to the VDL. You cannot use #{} syntax for a dynamic attribute, meaning an attribute that accepts dynamically calculated values at runtime. Similarly, you also cannot use the ${} syntax for a deferred attribute.

Table 6-1 Definitions of Tag Attributes That Accept EL Expressions

Attribute Type

Example Expression

Type Attribute Definition







Deferred value



Deferred value



Deferred method


      java.lang.String submit()

Deferred method


      double calcTotal(int, double)

In addition to the tag attribute types shown in Table 6-1, you can define an attribute to accept both dynamic and deferred expressions. In this case, the tag attribute definition contains both an rtexprvalue definition set to true and either a deferred-value or deferred-method definition.