spring-hibernate-20120924

Course Outline

Day 1

• class design: Contact, Address ContactRepository (init, findAll, find, create, update, delete), AddressRepository (...) Setup (servlet context listener)

• servlets / jsps: view all contact names, add a contact contact: edit name, address, delete contact

• JDBC / JNDI / DataSource initialize tables in repositories, use raw sql

Day 2

• finish servlets

• intro hibernate/jpa META-INF/persistence.xml, persistence-unit-ref in web.xml javax.persistence.{ Persistence, EntityManager } @Entity, @Column, @OneToOne Rewrite ContactRepository and AddressRepository (findAll, find, create, update, delete) and refactor

Day 3

• intro spring container-managed objects, dependency injection Spring MVC: controllers, @RequestMapping Spring JPA: JpaRepository, bytecode generation

• refactor controller methods model, view, injecting request parameters, redirects

• new class design: Contact, Person, Company, Office, Address how to represent polymorphism in jpa? @OneToMany, @ManyToOne, @ManyToMany

• controllers: person: edit name, address, delete person company: edit name, view all offices, add an office, delete company

Day 4

• office front-end introduce UrlEntity helper

• horrible bugs! why doesn't delete work? ... orphan removal lazy loaded associations, open session in view filter

• discussion: Spring high level

• discussion: Transactions and AOP

• discussion: Entity versioning, optimistic locking

• data constraints nullable, length Validation (ex: @NotBlank, all employees of a manager must work for the same company)

Day 5

• REST services more Spring MVC annotations Jackson

JDBC Pain Points / ORM Requirements

Code maintenance/evolution issues:

• entity and sql can get out of sync as code evolves => objects must determine DB schema!
• one must know sql => should be able to just get objects from somewhere / persist objects
• no explicit relationship between entities (one-to-one???) => system must know relationships and constraints

Flexibility/reuse issues:

• code is tied to a specific SQL implementation (dialect)

General ugliness/boilerplate:

• very repetitive code, lots of try-finally => forget JDBC
• checked SQLExceptions everywhere => forget JDBC
• marshalling and unmarshalling is very clumsy

Performance/correctness issues:

• no joins
• no transactions
• no good way to "create table if not exists"

Reference Material

• http://static.springsource.org/spring/docs/current/spring-framework-reference/html/mvc.html
• http://docs.jboss.org/hibernate/annotations/3.5/reference/en/html_single/

Videos

• Day 1
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/1.1.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/1.2.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/1.3.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/1.4.mov
• Day 2
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/2.1.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/2.2.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/2.3.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/2.4.mov
• Day 3
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/3.1.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/3.2.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/3.3.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/3.4.mov
• Day 4
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/4.1.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/4.2.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/4.3.mov
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/4.4.mov
• Day 5
  • https://mrkn.s3.amazonaws.com/recordings/spring-hibernate-20120924/5.1.mov