Enterprise Java Development using JPA, Hibernate and Springxa.yimg.com/.../name/EnterpriseJavaDevelopmentSpringHibernate.pdf · Enterprise Java Development using JPA, Hibernate and

Enterprise Java Development using

JPA, Hibernate and Spring

Srini Penchikala

Detroit JUG Developer Day Conference

November 14, 2009

2

About the Speaker

Enterprise Architect

Writer, Speaker, Editor (InfoQ)

Working with Java since 1996, JEE (2000), SOA (2006), & PowerPoint since July 2009

Current: Agile Architectures, Domain-Driven Design,

Architecture Enforcement, Model Driven Development, SOA

Future: Security Architecture, Role of DSL's in

Architecture Enforcement

3

Goals for this Presentation

“What” are the essential ingredients of JEE development recipe and “How” Spring Portfolio helps in implementing a JEE project

4

Format

Interactive

Demos

Duration: ~120 minutes

Discussion oriented tutorial

Not a hands-on workshop

Q & A

5

Before we start…

How many are currently using Spring?

Level of experience

6

Agenda (1/2) Introduction

Tutorial Sample Application

Spring Framework

Why Spring?

JEE Application Architecture

Domain-Driven Design

Dependency Injection

Aspect-oriented Programming

Annotations

7

Agenda (2/2) Application Concerns

Persistence

Transaction Management

Application Security

MVC

Validation

Web Services (REST)

Conclusions

8

Agenda Introduction


Spring Framework

Why Spring?





Annotations

9

Tutorial Application (1/5)

Loan processing application

Demonstrates how to use JPA, Hibernate and

Spring in developing enterprise Java applications

Covers JEE application concerns that developers

run into in real-world applications

10


Loan processing application

Demonstrates how to use JPA, Hibernate and

Spring in developing enterprise Java applications

JEE application concerns that developers run into in

real-world applications:


Persistence


Data Binding/ Data Validation

Web Services (REST)

11


Tools:

JDK 1.6

Maven

Eclipse

Testing:

JUnit 4.4

Mockito

Spring Test Module

12


Technologies (non-Spring):

JPA

Hibernate

JAXB

Jetty

Dozer

HSQL

JBossCache/EHCache

13


Technologies (Spring):

Spring Core (IoC)

Spring AOP

Spring JPA

Spring Security

Spring Modules

14

How to build sample application

Checkout the code from Google Project

(https://enterprise-java-

spring.googlecode.com/svn/trunk)

Install JDK, Maven and Eclipse (if needed)

Modify setBaseEnv.bat file

To compile and unit test:

mvn clean compile test

To run the web application:

mvn package jetty:run

15

Agenda (1/2) Introduction


Spring Framework

Why Spring?





Annotations

16

Spring Framework

Light-weight JEE middleware framework

Separation of concerns (business v. infrastructure)

POJO Based Design

Business domain first, infrastructure concerns

second

Agile Development and Testing

17

Spring Portfolio Projects

Spring Core

Spring AOP

Spring Security

Spring MVC/Spring WebFlow

18

Agenda Introduction


Spring Framework

Why Spring?





Annotations

Why Spring (1/3)

Test Driven Development

Unit testing in isolation

Mock objects

System integration testing support

Why Spring (2/3)

Agile Software Development (Scrum)

Iterative Design, Development, Unit Testing and

Refactoring

Modular Application Architecture

POJO Programming Model

Why Spring (3/3)


22

Agenda Introduction


Spring Framework

Why Spring?





Annotations

23

Architecture Layers

User Interface

Application

Domain

Infrastructure

24

Layered Architecture Example

25

Typical J2EE Architecture ModelController

Facade

Data Access Object

Domain Object*

Database

Application

Data Access

Persistence

Data Store

Notes:· No real Domain Layer

· Business Logic in Façade Layer (Stateless

Session Beans)

· Direct Access to Data Access Objects

(CRUD logic is infrastructure not business)

· *Domain objects are really Persistence

classes with getters/setters

· Infrastructure concerns have overtaken/

overshadowed the domain concerns


Caching

HTTP

Session Management

26

The Problem

Architects/Developers are thinking only about

infrastructure

Most of the development time is still spent on writing

plumbing code instead of real business logic

We have lost real OOD/OOP

27

Domain Driven Architecture

Controller

Facade

Domain

Data Access Object

Database

Application

Domain

Data Access/

Persistence

Data Store

Notes:· All Layers support POJO based design

· Controller and Façade layers are consumers of

Domain Classes

· Business Logic only in Domain Classes

· No direct Access to DAO’s except from Domain

Classes

· Domain First, Infrastructure Second

· Infrastructure concerns are implemented via DI,

AOP, Annotations

Infrastructure

· HTTP

· Session Management

· Remoting

· Persistence

· Caching

· Transaction Management

· Security (Authentication &

Authorization

· Asynchronous Messaging

Application Architecture Layers

29

Agenda Introduction


Spring Framework

Why Spring?





Annotations

30

Domain Driven Design

What:

Domain Driven Design (DDD) is about mapping business

domain concepts into software artifacts.

Why:

To create better software by focusing on a model of the

domain rather than the technology.

31

Advantages

Promotes high cohesion and low coupling in the

application code

Easy to test domain components

Business (domain) logic is isolated from non-

domain and infrastructure code

Adding/changing services does not influence the

domain or other services

32

Domain Elements Domain objects: Instances of real entities which hold knowledge or

activity of business domain

Entities:

Objects defined by their identity, which remains same throughout life of software (Customer, Account)

Value Objects

Immutable objects that have no identity & are used to describe an attribute of another object (Product, State lookup)

(Domain) Services

Objects that have no state & only have a defined behavior that’s not part of any domain object (FundTransfer service, Loan Interest Calculation)

33

Other DDD Elements

Module (Package):

A method of organizing related concepts and tasks in

order to reduce complexity.

Domain object Lifecycle is managed by:

Aggregate

Factory

Repository

34

Design Recipe

Object Oriented Programming (OOP)

Dependency Injection (DI)

Aspect-oriented Programming (AOP)

Annotations

35

Domain Elements and OOP

Domain Element Encapsulation

Entity,Value Object,Aggregate

State and Behavior

Data Transfer Object State only

Service, Repository Behavior only

36

Agenda Introduction


Spring Framework

Why Spring?





Annotations

37

Dependency Injection (DI)

aka Inversion of Control (IoC)

Based on Hollywood Principle

Decouple and manage the dependencies of the

components in the application

DI Frameworks:

Spring

Google Guice

Pico Container

38

DI Use Cases

Service

Domain Classes

Transaction Manager

Domain

Data Access Object (DAO)

DAO class

Data Source

JPA Entity Manager

39

Domain Object DI

Domain objects not instantiated by Spring IoC

container

@Configurable annotation

40

DEMO

41

Agenda Introduction


Spring Framework

Why Spring?





Annotations

42


Allows developers to add behavior to objects in a

non-obtrusive manner through use of static and

dynamic crosscutting

Main goal is to code cross-cutting concerns in

separate modules and apply them in a declarative

way

43

AOP Use Cases

Spring Framework Built-In Aspects


Security

Custom Aspects

Profiling

Caching

Rules

Architecture Governance/Policy Enforcement

44

DEMO

45

Agenda Introduction


Spring Framework

Why Spring?





Annotations

46

Annotations

Added in Java SE 5.0 as Java Metadata facility

(JSR 175)

Provide a way to add metadata to program

elements

Defined by nearly every recent JSR standard

Also include a mechanism for adding custom

annotations to the Java code

47

Annotations For Domain Elements

Layer Domain Element Annotation

DomainEntity,

Value Object

@Entity (JPA),

@Configurable

Domain Repository @Repository

Domain Service @Service

Application Controller @Controller

All All @Component

48

Custom Annotations

Use Cases:

Caching

Validation

Implementation options:

Reflection

Annotation Processing Tool (APT)

Byte-code Instrumentation (Javassist)

Aspects/AOP (AspectJ and Spring AOP)

49

DEMO

50

Application Architecture Layers

Database

Data Access

Domain

Controller

Presentation

51

Agenda Application Concerns

Persistence



MVC

Validation

Web Services (REST)

Conclusions

52

Application Concerns

Persistence


Application Security (AuthN & AuthZ)

Caching

53

Other Application Concerns

Monitoring (JMX, Spring JMX)

Conversational Web Applications (Web Flow)

Asynchronous Messaging (JMS, MDP)

Enterprise Integration (Spring Integration)

Batch Processing (Spring Batch)

* Not covered in this presentation

54


Persistence



MVC

Validation

Web Services (REST)

Conclusions

55

Persistence – The Spring Way

JDBC (Spring JDBC Template)

JPA w/ Hibernate, OpenJPA, EclipseLink (TopLink)

Spring JPA Utils & Data Source DI

56

DEMO

57


Persistence



MVC

Validation

Web Services (REST)

Conclusions

58

Transaction Management – The

Spring Way

Declarative transaction semantics

Similar to EJB3 transaction model and more

Spring JTA Support

Support for multiple transaction managers

JDBC

Hibernate

JTA

Transactions are managed in Service classes using

“@Transactional” annotation

59

DEMO

60


Persistence



MVC

Validation

Web Services (REST)

Conclusions

61


Spring Security Module

Declarative application security support

Fits in very well with Spring Core framework

Authentication

Authorization

URL level

Domain Object

Service Method

JDBC and LDAP Authentication Providers

JSR-250 compliant

62

Authentication

Code Example

63

Authorization

Code Example

64

DEMO

65


Persistence



MVC

Validation

Web Services (REST)

Conclusions

66

Ideal Web Application Framework

Isolation from domain layer so presentation and

domain layers can evolve independently

Simple and Easy Data binding between Domain,

Controller and Presentation layers

Support for data validation that works in all layers

w/o any additional coding

Support for AJAX functionality

Controller methods can be exposed as RESTful

Web Services w/o extra coding or configuration

67

MVC

Spring MVC

Annotation-based Controller Configuration

(@Controller)

@RequestMapping

@ModelAttribute

@RequestParam

@SessionAttributes

68

DEMO

69


Persistence



MVC

Validation

Web Services (REST)

Conclusions

70

Data Binding and Validation

Data binding using @ModelAttribute

@InitBinder

Example: FeeController

Validation:

Declaration Validation Logic

Custom Validation Error Messages

JSR 303 support

71

DEMO

72


Persistence



MVC

Validation

Web Services (REST)

Conclusions

73

Web Services Support Spring WS

Spring 3.0 REST support

Message Converters

RestTemplate

74

Project Lifecycle Diagram

75


Persistence



MVC

Validation

Web Services (REST)

Conclusions

76

Conclusions

Domain First, Infrastructure Second

Layered Architecture & Separation of Concerns

POJO’s are fun to work with again

Balance between the “right” vs. the “right now”

Java EE 6 release focuses on development &

deployment simplicity

JPA 2.0, EJB 3.1, Spring 3.0

77

References (1/2) Sample Application Project Site (https://enterprise-java-

spring.googlecode.com/svn/trunk)

Spring Framework Reference Manual (http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/)

Spring In Action 3rd Edition (http://www.manning.com/walls4/)

Domain Driven Design and Development In Practice (http://www.infoq.com/articles/ddd-in-practice)

Domain-Driven Design Website (http://www.domaindrivendesign.org/)

78

References (2/2) Domain-Driven Design by Eric Evans

Applying Domain-Driven Design and Patterns, Jimmy Nilsson

Patterns of Enterprise Application Architecture, Martin Fowler

Can DDD be Adequately Implemented Without DI and AOP (http://www.infoq.com/news/2008/02/ddd-di-aop)

Contact Information

Domain-Driven Design and Enterprise

Architecture articles on InfoQ

website: http://www.infoq.com

[email protected]

http://srinip2007.blogspot.com

@srinip

11/21/2009 Srini Penchikala79

80

Q & A

81

Thank You

Thank you for your attention

Feedback survey

Happy Holidays

Enterprise Java Development using JPA, Hibernate and Springxa.yimg.com/.../name/EnterpriseJavaDevelopmentSpringHibernate.pdf · Enterprise Java Development using JPA, Hibernate and

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