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

Using the Metamodel API to Model Entity Classes

Using Metamodel Classes

Using the Criteria API and Metamodel API to Create Basic Typesafe Queries

Creating a Criteria Query

Query Roots

Querying Relationships Using Joins

Path Navigation in Criteria Queries

Restricting Criteria Query Results

The Expression Interface Methods

Expression Methods in the CriteriaBuilder Interface

Managing Criteria Query Results

Ordering Results

Grouping Results

Executing Queries

Single-Valued Query Results

Collection-Valued Query Results

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



Overview of the Criteria and Metamodel APIs

Similar to JPQL, the Criteria API is based on the abstract schema of persistent entities, their relationships, and embedded objects. The Criteria API operates on this abstract schema to allow developers to find, modify, and delete persistent entities by invoking Java Persistence API entity operations. The Metamodel API works in concert with the Criteria API to model persistent entity classes for Criteria queries.

The Criteria API and JPQL are closely related and are designed to allow similar operations in their queries. Developers familiar with JPQL syntax will find equivalent object-level operations in the Criteria API.

The following simple Criteria query returns all instances of the Pet entity in the data source:

EntityManager em = ...;
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Pet> cq = cb.createQuery(Pet.class);
Root<Pet> pet = cq.from(Pet.class);;
TypedQuery<Pet> q = em.createQuery(cq);
List<Pet> allPets = q.getResultList();

The equivalent JPQL query is:

FROM Pet p

This query demonstrates the basic steps to create a Criteria query:

  1. Use an EntityManager instance to create a CriteriaBuilder object.

  2. Create a query object by creating an instance of the CriteriaQuery interface. This query object’s attributes will be modified with the details of the query.

  3. Set the query root by calling the from method on the CriteriaQuery object.

  4. Specify what the type of the query result will be by calling the select method of the CriteriaQuery object.

  5. Prepare the query for execution by creating a TypedQuery<T> instance, specifying the type of the query result.

  6. Execute the query by calling the getResultList method on the TypedQuery<T> object. Because this query returns a collection of entities, the result is stored in a List.

The tasks associated with each step are discussed in detail in this chapter.

To create a CriteriaBuilder instance, call the getCriteriaBuilder method on the EntityManager instance:

CriteriaBuilder cb = em.getCriteriaBuilder();

The query object is created by using the CriteriaBuilder instance:

CriteriaQuery<Pet> cq = cb.createQuery(Pet.class);

The query will return instances of the Pet entity, so the type of the query is specified when the CriteriaQuery object is created to create a typesafe query.

The FROM clause of the query is set, and the root of the query specified, by calling the from method of the query object:

Root<Pet> pet = cq.from(Pet.class);

The SELECT clause of the query is set by calling the select method of the query object and passing in the query root:;

The query object is now used to create a TypedQuery<T> object that can be executed against the data source. The modifications to the query object are captured to create a ready-to-execute query:

TypedQuery<Pet> q = em.createQuery(cq);

This typed query object is executed by calling its getResultList method, because this query will return multiple entity instances. The results are stored in a List<Pet> collection-valued object.

List<Pet> allPets = q.getResultList();