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Agile Java Development
With Spring, Hibernate and Eclipse
Anil Hemrajani
[email protected]
© Visual Patterns, Inc.
About This Presentation
• Not a tutorial on any one technology!

Overview of each technology (use website, books, etc. for details)

Downloadable code (working application)

Latest buzz in the US, Europe, etc.
• End-to-end system!

Requirements

Architecture/design

Java development and debugging

Deployment

Logging/monitoring

Advanced considerations
• Content/format (text, graphs, code, comics)
© Visual Patterns, Inc.
2
Material In This Presentation Taken Directly From My Book
Agile Java Development
With Spring, Hibernate and Eclipse
Forewords by Scott W. Ambler and Rod Johnson
available on amazon.com
1. Introduction to Agile Java Development
2. The Sample Application: An Online Timesheet System
3. XP and AMDD-Based Architecture and Design Modeling
4. Environment Setup: JDK, Ant, and JUnit
5. Using Hibernate For Persistent Objects
6. Overview of the Spring Framework
7. The Spring Web MVC Framework
8. The Eclipse Phenomenon
9. Logging, Debugging, Monitoring and Profiling
10. Beyond the Basics
11. What Next?
12. Parting Thoughts
Appendices (with lots of goodies)
© Visual Patterns, Inc.
3
My Background (details at VisualPatterns.com)
• 20 years of experience in the IT

Working with Java Technology since late 1995 as a developer, entrepreneur, author,
and trainer.

Helped several Fortune 100 companies (some smaller organizations)

Published a book and 30 articles

Presented at conferences and seminars around the world

Awards:
 "Outstanding Contribution to the Growth of the Java Community"
 "Best Java Client" for BackOnline (a Java-based online backup product)
 nominated for a Computerworld-Smithsonian award by Scott McNealy
• Founder of:


Isavix Corporation – successful IT solutions company (now Inscope Solutions)
DeveloperHub.com (formerly isavix.net) - award-winning online developer community
(grew to over 100,000 registered members)
• At present – VisualPatterns.com and AgileDraw.org
© Visual Patterns, Inc.
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Practical Stuff, Not Fluff!
• Recently completed project for U.S. Fortune 50 company
• Application

Financial application process billions of $ every week

Clustered application (99.9% uptime required)

Used most the technologies covered in presentation
(spring, hibernate, eclipse, ant, JUnit…)
© Visual Patterns, Inc.
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Agenda
1.
2.
3.
4.
Introduction to Agile Java Development
Agile Processes
Agile Modeling
Agile Development

Environment Setup: Directory Structure, JDK, Ant and JUnit

Using Hibernate For Persistent Objects

(Short Break)

The Spring Framework

The Eclipse Phenomenon!

Logging, Debugging, Monitoring, and Profiling
5. Beyond The Basics
© Visual Patterns, Inc.
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Introduction to Agile Java Development
Assume simplicity.
Travel light.
- Agile Modeling principles: agilemodeling.com
© Visual Patterns, Inc.
What Is Agile Java Development? It Could Include…
1. Agile Software Lifecycle Processes (e.g. Scrum, XP, TDD)
2. Agile Architecture/Design Modeling

Incremental (just-in-time) design

“Good enough” diagrams

Agile Model Driven Development (AMDD)
3. Agile Java Design/Development

Simple design and coding!

Test-driven development (TDD)

Efficient frameworks and tools (Ant, JUnit, Hibernate, Spring, Eclipse…)

Plain Old Java Objects (POJOs), whenever possible
© Visual Patterns, Inc.
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Sample (Time Sheet) Application Used In This Presentation
Web
HTTP
Browser
Controller
Spring
DispatcherServlet
View
JSP/HTML
Model
Business
JDBC
objects,
Hibernate beans
RDBMS
(Oracle)
Spring
Scheduler
Objects managed by Spring IoC Container
BEA WebLogic Server
Downloadable code: visualpatterns.com/resources.jsp
© Visual Patterns, Inc.
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Agile Processes
Requirements change.
Design evolves.
Documents are seldom current.
© Visual Patterns, Inc.
Some Stats by The Standish Group (standishgroup.com)
© Visual Patterns, Inc.
The Solution
CHAOS Ten – Success Factors
source: standishgroup.com
In 2001, seventeen methodologists came together to
unify their methodologies under one umbrella; they
jointly defined the term, Agile!
Read story at: martinfowler.com/articles/agileStory.html
© Visual Patterns, Inc.
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AgileManifesto.org
© Visual Patterns, Inc.
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What Does “Agile” Exactly Mean?
The Term Agile incorporates a wide range of methods, for example:
• AM - Agile Modeling
•
•
•
•
•
•
ASD - Adaptive Software Development
AUP - Agile Unified Process
Crystal
FDD - Feature Driven Development
DSDM - Dynamic Systems Development Method
Lean Software Development
• Scrum
• Xbreed
• XP - eXtreme Programming
© Visual Patterns, Inc.
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Agility - All About Smaller Chunks (Shorter/Frequent Cycles)
Release 2
Release 1
Iteration
0
software
Iteration
1
software
...
software
Iteration
n
software
Iteration
0
Iteration
1
software
...
Iteration
n
software
Incrementally Build Software - Highest Priority Features First!
© Visual Patterns, Inc.
...
Agile Method: Scrum
•
•
•
•
Simple process for product/project management
Product Backlog - List of known features/changes for product
Sprint - 1-month iterations (develop highest priority items)
Meetings

Sprint Planning Meeting – Done at beginning of each sprint
(after planning, features moved from product backlog to sprint backlog)

Daily scrum meeting (short: 15 minutes)

Sprint review meeting
© Visual Patterns, Inc.
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Extreme Programming (XP)
• Shorter and Frequent Cycles (smaller chunks!)






Release - Quarterly Cycles (set a theme)
Iteration - Weekly Cycles (e.g. aim for last day of week)
10-minute builds
Continuous integration (multiple times per day; manual or automatic)
Incremental Design and Planning (defer investment till needed)
Development in small increments using Test-First development
• Communications - Sit Together, Informative Workspace, onsite customer
• Flow - sustainable pace versus rigid phases; velocity, continuous
integration
• Others… visit extremeprogramming.org
© Visual Patterns, Inc.
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Presentation Outline
Introduction to Agile Java Development
Agile Processes
• Agile Modeling
• Agile Development

Environment Setup: Directory Structure, JDK, Ant and JUnit

Using Hibernate For Persistent Objects

The Spring Framework

The Eclipse Phenomenon!

Logging, Debugging, Monitoring, and Profiling
• Beyond The Basics
© Visual Patterns, Inc.
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Agile Modeling
“...your goal is to build a shared understanding, it isn’t to
write detailed documentation.”
- Scott W. Ambler
© Visual Patterns, Inc.
Quick Poll
Have you ever been on a
project where documentation
was kept up-to-date through
end of project?
© Visual Patterns, Inc.
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Agile Model Driven Development (AMDD)
•
•
•
Subset of Agile Modeling (agilemodeling.com)
Agile version of Model Driven Development (MDD)
Instead of extensive models, “barely good enough”
•
Initial modeling activity
1.
2.
•
Requirements modeling



•
Requirements
Architecture
Usage models
Domain models
UI models
Architecture modeling


Free-form diagrams
Change cases
© Visual Patterns, Inc.
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Project Initiation
© Visual Patterns, Inc.
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Problem Statement
Our employees currently submit their weekly
hours worked using a paper-based timesheet
system that is manually intensive and errorprone.
We require an automated solution for
submitting employee hours worked, in the form
of an electronic timesheet, approving them,
and paying for the time worked.
In addition, we would like to have automatic
notifications of timesheet status changes and a
weekly reminder to submit and approve
employee timesheets.
© Visual Patterns, Inc.
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Project Kickoff Meeting
© Visual Patterns, Inc.
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Choices Of Release (High) Level Models
Release
Level
Models
scope table,
glossary, etc.
domain model
user stories
UI prototype
& flow map
architecture
Iteration
Level
Models
acceptance
tests
CRC cards
application
flow map
UML
diagrams
database
model
Model with a purpose -- shared understanding!
© Visual Patterns, Inc.
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Sample Scope Table
Scope
Include
Functionality
Time Expression will provide the capabilit y to enter, approve, and
pay for hours worked by employees.
Defer
Time Expression will not calculate deductions from paychecks, such
as federal/state taxes and medical expenses.
Defer
Time Expression will not track vacation or sick leave.
Shared understanding: what's in and what's out
© Visual Patterns, Inc.
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Domain Model
Shared understanding: business concepts > key domain objects
© Visual Patterns, Inc.
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User Stories Or Use Cases
3
Use Case: Login
Author
Anil Hemrajani
Description
This process allows User to log into the System
XP Style User Story Card
Actors/Interfaces


FM Trader
The System
Trigger
User performs a Login action
Preconditions

N/A
Success/Basic Flow
1. T he System displays the Login panel prompting User for login details as specified in
the
2. User completes all required fields and performs a Submit action.
Failure/Alternative Flow
Invalid User ID and/or Password - The system notifies FM trader with the message “Invalid User
ID and/or Password ”. The system displays the Login panel to User with the contents of all fields
empty.
Use Case - Casual, Brief or Fully Dressed
Shared understanding: features required of software
© Visual Patterns, Inc.
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User Interface (UI) Prototype
Shared understanding: functionality, look-and-feel, etc.
© Visual Patterns, Inc.
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UI Flow Map (Storyboard)
Shared understanding: user interface navigation/flow
© Visual Patterns, Inc.
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High-Level Architecture Diagram
Web
Browser
HTTP
Controller
Model
Spring
Business objects,
DispatcherServlet
Hibernate beans
View
JSP/HTML
JDBC
RDBMS
(Oracle)
Spring
Scheduler
Objects managed by Spring IoC Container
BEA WebLogic Server
Shared understanding: technologies, scalability, security, reliability
© Visual Patterns, Inc.
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Glossary - List Of Common Business/Technical Terms
• Accounting
The accounting department/staff.
• Approved
Status of a timesheet when a Manager approves a previously
submitted timesheet.
• Employee
A person who works on an hourly basis and reports to a manager.
• Paid
Status of a timesheet when the accounting department has
issued a check.
• Etc…
Shared understanding: common terminology
© Visual Patterns, Inc.
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Choices Of Iteration Level (Detailed) Models




Release
Level
Models

scope table,
glossary, etc.
domain model
user stories
UI prototype
& flow map
architecture
Iteration
Level
Models
acceptance
tests
CRC cards
application
flow map
UML
diagrams
database
model
© Visual Patterns, Inc.
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Acceptance Tests (Serve As Detailed Requirements)
• Sign In


The employee id can be up to 6 characters. The password must be between
8 and 10 characters.
Only valid users can sign in.
• Timesheet List

Only a user's personal timesheets can be accessed.
• Enter Hours

Hours must contain numeric data.

Daily hours cannot exceed 16 hours. Weekly hours cannot exceed 96 hours.

Hours must be billed to a department.

Hours can be entered as two decimal places.

Employees can only view and edit their own timesheets.
© Visual Patterns, Inc.
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Active Stakeholder Participation (With Business Representative)
© Visual Patterns, Inc.
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Exploring Classes Using CRC Cards
First, let's reflect on what we know,
domain model, UI and architecture
Second, let's explore classes on CRC cards
using both as input models
Class Name (Noun)
Responsibilities (obligations
of this class, such as business
methods, exception handling,
security methods,
attributes/variables).
Collaborators (other
classes required to
provide a complete
solution to a high -level
requirement)
Timesheet List screen
TimesheetListController
Controller (in MVC) for
displaying a list of timesheets.
TimesheetManager
TimesheetManager
free-form architecture
Fetches timesheet(s) from
database
Timesheet
Saves timesheet to database
Timesheet
Knows of period ending date
domain model
Knows of time
Knows of department code
© Visual Patterns, Inc.
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Application Flow Map (Home Grown Artifact)
• Complementary to class diagrams and CRC cards
• Can be extended using CRUD columns
Story Tag
View
Controller Class
Collaborators
Timesheet
List
timesheetlist
TimeSheetListController
TimesheetManager
Tables
Impacted
Timesheet
Enter
Hours
enterhours
EnterHoursController
TimesheetManager
Timesheet
Department
© Visual Patterns, Inc.
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UML Class and Package Diagrams
© Visual Patterns, Inc.
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Focus Is On Working Software vs. Comprehensive Documentation
Conceptual Models
problem
statement
scope
table
domain model
user stories
UI
prototypes

glossary
architecture
Physical Models
acceptance
tests
application
flow map
Implementation
Data Base
CRC cards
database
model
UML
diagrams
“…your goal is to build a
shared understanding, it
isn’t to write detailed
documentation.”
 - Scott W. Ambler
THE FINAL AND LASTING ARTIFACTS!
UI
prototype
Code
Base
& flow map
© Visual Patterns, Inc.
39
Shifting Some Upfront Design to Refactoring
© Visual Patterns, Inc.
40
Shifting Some Upfront Design To Refactoring (Continuous Design)
• Refactoring is not a new concept; the term is relatively new
• refactoring.com

“Refactoring is a disciplined technique for restructuring an existing body of
code, altering its internal structure without changing its external behavior.”
- Martin Fowler

Over 100 refactoring techniques; for example:
 Extract superclass
 Extract interface
 Move class
 Move method
© Visual Patterns, Inc.
41
Agile Draw - Elegantly Simple Modeling Technique
High-Level Architecture
UI Flow Map
Visit AgileDraw.org
Conceptual Class Diagram
© Visual Patterns, Inc.
42
Presentation Outline
Introduction to Agile Java Development
Agile Processes
Agile Modeling
• Agile Development

Environment Setup: Directory Structure, JDK, Ant and JUnit

Using Hibernate For Persistent Objects

The Spring Framework

The Eclipse Phenomenon!

Logging, Debugging, Monitoring, and Profiling
• Beyond The Basics
© Visual Patterns, Inc.
43
Agile Java Development:
Environment Setup (Directory Structure, JDK, Ant, and JUnit)
© Visual Patterns, Inc.
Quick Poll
How many of you are using
Ant, JUnit, Maven, Cruise
Control, etc?
© Visual Patterns, Inc.
45
Personal Opinion:
Early Environment
Setup Is Essential



Involves more than people expect/plan
Cycle 0
• Get minimal environment setup (scripts,
directory, version control, etc.)
• Get end-to-end demo working
Helps team
© Visual Patterns, Inc.
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Directory Structure, Naming Conventions, Version Control, etc.
controller/TimesheetListController.java
model/Timesheet.java
➔model/TimesheetManager.java
➔test/TimesheetListControllerTest.java
➔test/TimesheetManagerTest.java
➔view/timesheetlist.jsp
➔
➔
© Visual Patterns, Inc.
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Ant (ant.apache.org)
• Ant task types

Compile tasks (that is, javac)

Deployment tasks


File tasks such as copy, delete,
move, and others.
Property tasks for setting internal
variables

Audit/coverage tasks

Database tasks

Documentation tasks

Execution tasks

Mail tasks

Preprocess tasks

Property tasks

Remote tasks

Miscellaneous tasks (e.g. echo)
<ftp server="mirrors.kernel.org"
action="get"
remotedir="/gnu/chess"
userid="anonymous"
password="[email protected]"
verbose="yes"
binary="yes">
<fileset file="README.gnuchess"/>
</ftp>
<mail tolist="[email protected]"
subject="Hello!"
from="[email protected]"
mailhost="myhost.com"
user="myuserid"
password="mypassword"/>
© Visual Patterns, Inc.
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JUnit (junit.org)
• Originally written by

Erich Gamma (Gang of Four, Design Patterns)

Kent Beck (author of Extreme Programming and Test Driven Development)
• Simple framework – various assert methods







assertEquals
assertFalse
assertNotNull
assertNotSame
assertNull
assertSame
assertTrue
public class SimpleTest extends junit.framework.TestCase
{
int value1 = 2, value2 = 3, expectedResult = 5;
public static void main(String args[])
{
junit.textui.TestRunner.run(suite());
}
public static Test suite()
{
return new TestSuite(SimpleTest.class);
}
}
public void testAddSuccess()
{
assertTrue(value1 + value2 == expectedResult);
}
© Visual Patterns, Inc.
49
JUnit GUI Based Testing
Console Runner
Eclipse Plug-in
© Visual Patterns, Inc.
50
Agile Method: Test Driven Development (TDD) w/ JUnit
•
•
•
•
A term coined by Kent Beck
Also, a XP practice (test-first)
“Red - Green - Refactor”
Write Test First
Code, Compile, Test
Write unit test code
Write some actual code
More unit test code
More actual code
More unit test code
More actual code
Several benefits to this approach:

Minimal code written to satisfy requirements (nothing more, nothing less!)

If code passes the unit tests, it is done!

Can help design classes better (from a client/interface perspective)

Refactor with confidence
© Visual Patterns, Inc.
51
Presentation Outline
Introduction to Agile Java Development
Agile Processes
Agile Modeling
• Agile Development
Environment Setup: Directory Structure, JDK, Ant and JUnit

Using Hibernate For Persistent Objects

The Spring Framework

The Eclipse Phenomenon!

Logging, Debugging, Monitoring, and Profiling
• Beyond The Basics
© Visual Patterns, Inc.
52
Agile Java Development:
Using Hibernate For Persistent Objects
© Visual Patterns, Inc.
Quick Poll
What persistence solution
does your project use (e.g.
JDBC, ORM, entity bean)?
© Visual Patterns, Inc.
54
Where Hibernate Fits Into Our Architecture
© Visual Patterns, Inc.
55
An Overview of Object-Relational Mapping (ORM)
• ORM - Java object to database table/record mapping

Java = objects

database = relational
• Relationships

unidirectional and bidirectional

relations in a relational database are bidirectional by definition
• Cardinality (OO term is multiciplicity)

One-to-one

one-to-many

many-to-one

and many-to-many
• Object Identity
• Cascade
• Others…
© Visual Patterns, Inc.
56
Hibernate Basics
• Dialect
(DB2, Microsoft SQL Server, MySQL, Oracle, PostgreSQL, SAP DB,
Sybase, TimesTen…)
• SessionFactory, Session, and Transaction
• Work with Database Records (as Java Objects)
• Object States - persistent, detached, and transient
• Data Types – more than you'll likely need!
• Hibernate Query Language (HQL) – powerful SQL-like language
© Visual Patterns, Inc.
57
From Domain Model To A (Denormalized) Physical Data Model
© Visual Patterns, Inc.
58
Working With Hibernate - Simple Example Using Department
1. hibernate.cfg.xml – Hibernate configuration file (DB
configuration)
<mapping resource="Department.hbm.xml" />
2. Department.hbm.xml – Mapping file for our Department table
<class name="com.visualpatterns.timex.model.Department"
table="Department">
<id name="departmentCode" column="departmentCode">
<property name="name" column="name"/>
3. Department.java – Bean file with two variables:
String departmentCode;
String name;
4. HibernateTest.java – Simple test program (on next slide)
© Visual Patterns, Inc.
59
HibernateTest.java
SessionFactory sessionFactory = new Configuration().configure()
.buildSessionFactory();
Session session = sessionFactory.getCurrentSession();
Transaction tx = session.beginTransaction();
Department department = (Department)
session.get(Department.class, "IT");
System.out.println("Name for IT = " + department.getName());
...
List departmentList = session.createQuery("from Department").list();
for (int i = 0; i < departmentList.size(); i++)
{
department = (Department) departmentList.get(i);
System.out.println("Row " + (i + 1) + "> " +
department.getName()
+ " (" + department.getDepartmentCode() + ")");
}
...
sessionFactory.close();
© Visual Patterns, Inc.
60
Other Hibernate Features
• Saving (save, merge, saveOrUpdate)
session.saveOrUpdate(timesheet)
• Deleting records

session.delete(Object), or

session.createQuery("DELETE from Timesheet")
• Queries using Criteria interface (more OO and typesafe)


List timesheetList =
session.createCriteria(Timesheet.class)
.add(Restrictions.eq("employeeId", employeeId))
.list();
Related classes: Restrictions, Order, Junction, Distinct, and others
• Locking Objects (Concurrency Control)
• Lots More Hibernate (associtions, annotations, filters, interceptors,
scrollable iterations, native SQL, transaction management, etc.)
© Visual Patterns, Inc.
61
Presentation Outline
Introduction to Agile Java Development
Agile Processes
Agile Modeling
• Agile Development
Environment Setup: Directory Structure, JDK, Ant and JUnit
Using Hibernate For Persistent Objects

The Spring Framework

The Eclipse Phenomenon!

Logging, Debugging, Monitoring, and Profiling
• Beyond The Basics
© Visual Patterns, Inc.
62
Agile Java Development:
The Spring Framework
© Visual Patterns, Inc.
Spring Modules
© Visual Patterns, Inc.
64
Spring Java Packaging (org.springframework.)
© Visual Patterns, Inc.
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Quick Poll
Are you familiar with
Inversion of Control (IoC)?
© Visual Patterns, Inc.
IoC Container And Dependency Injection Pattern
Using IoC
Normal Way
public class A
{
B myB = new B();
C myC = new C();
}
Class C
Class B
IOC
Container
Class A
public class A
{
B myB;
C myC;
public setB(B myB)
public setC(C myC)
• Dependency Injection Styles

Two Supported By Spring:
 Setter/getter based
 Constructor based

Fowler suggests a 3rd, interface injection,
http://www.martinfowler.com/articles/injection.html
• Spring IoC Concepts: Beans, BeanFactory, ApplicationContext…
© Visual Patterns, Inc.
67
Benefits of Using Spring
• Light weight Inversion of Control (IoC) container
• Excellent support for POJOs (e.g. declarative transaction
management)
• Modular – not an all-or-nothing approach
• Testing – dependency injection and POJOs makes for easier
testing
• Many others

No Singletons

Builds on top of existing technologies (e.g. JEE, Hibernate)

Robust MVC web framework

Consistent database exception hierarchy (e.g. wrap SQLException)
© Visual Patterns, Inc.
68
Where Spring Framework Fits Into Our Architecture
Optional
Hibernate
integration
© Visual Patterns, Inc.
69
Quick Poll
Which web framework do you
use?
© Visual Patterns, Inc.
70
Spring Web MVC
• Easier testing – mock classes, dependency injection
• Bind directly to business objects
• Clear separation of roles – validators, adaptable controllers, command
(form) object, etc.
• Simple but powerful tag libraries
• Support for various view technologies and web frameworks (e.g. Struts,
webwork, tapestry, JSF)
© Visual Patterns, Inc.
71
Spring MVC Java Concepts
1. Controller
2. ModelAndView
3. Command (Form
Backing) Object
4. Validator
5. Spring Tag
Library
(spring:bind)
© Visual Patterns, Inc.
72
Spring MVC Configuration
<servlet>
<servlet-name>timex</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>timex</servlet-name>
<url-pattern>*.htm</url-pattern>
</servlet-mapping>
web.xml
timex-servlet.xml
<bean id="urlMapAuthenticate”
class=
"org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<prop key="/enterhours.htm">enterHoursController</prop>
...
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver"
>
<property name="viewClass">
<value>org.springframework.web.servlet.view.JstlView</value>
</property>
<property name="prefix">
<value>/WEB-INF/jsp/</value>
</property>
<property name="suffix">
<value>.jsp</value>
</property>
</bean>
73
© Visual Patterns, Inc.
Sample End-To-End Flow Using Spring and Hibernate
© Visual Patterns, Inc.
74
Timesheet List: A No-Form Controller Example
public class TimesheetListController
implements Controller
{
...
public ModelAndView handleRequest(
HttpServletRequest request,
HttpServletResponse response)
mockHttpServletRequest =
new MockHttpServletRequest("GET",
"/timesheetlist.htm");
ModelAndView modelAndView =
timesheetListController.handleRequest(
mockHttpServletRequest, null);
assertNotNull(modelAndView);
assertNotNull(modelAndView.getModel());
© Visual Patterns, Inc.
75
Enter Hours: A Form Screen
1. EnterHoursController.java
2. EnterHoursValidator.java
3. enterhours.jsp
public class EnterHoursController extends SimpleFormController
© Visual Patterns, Inc.
76
View/JSP Code – Spring and JSTL Tag Libraries
<spring:bind path="command.employeeId">
<input name='<c:out value="${status.expression}"/>'
value='<c:out value="${status.value}"/>'
type="text" size="6" maxlength="6">
</spring:bind>
Special (Spring) variable named status
• status.value
• status.expression
• status.error
• status.errorMessage
• status.errorMessages
• status.displayValue
© Visual Patterns, Inc.
77
Sign In (Authentication) - Spring HandlerInterceptor
public class HttpRequestInterceptor extends HandlerInterceptorAdapter
{
public boolean preHandle(HttpServletRequest request,
HttpServletResponse response,
Object handler)
{
if (!signedIn)
{
response.sendRedirect(this.signInPage);
return false;
}
© Visual Patterns, Inc.
78
Other Spring Web Stuff
• View with no controllers (e.g. only JSP files)
<bean id="urlFilenameController"
class="org.springframework.web.servlet.mvc.UrlFilenameViewController"/>
<prop key="/help.htm">urlFilenameController</prop>
• Spring 2.0 – new tag libraries

form:form - org.springframework.web.servlet.tags.form.FormTag

form:input- org.springframework.web.servlet.tags.form.InputTag

form:password - org.springframework.web.servlet.tags.form.PasswordInputTag

form:hidden - org.springframework.web.servlet.tags.form.HiddenInputTag

form:select - org.springframework.web.servlet.tags.form.SelectTag

form:option - org.springframework.web.servlet.tags.form.OptionTag

form:radiobutton - org.springframework.web.servlet.tags.form.RadioButtonTag

Others…
• Other

Web Flow – gaining a lot of momentum! Wizard-like features.

Portlet API – based on JSR-168 Portlet Specification (jcp.org).
© Visual Patterns, Inc.
79
Spring ORM Module: Support for Hibernate
• Management of sessionfactory and session (no close calls)
• Declarative transaction management in light-weight containers
• Easier testing (pluggable Sessionfactory via XML file)
• Less lines of code – focus on business logic!
© Visual Patterns, Inc.
80
Spring ORM Module: Support for Hibernate (cont’d)
Session session =
HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
try
{
session.saveOrUpdate(timesheet);
session.getTransaction().commit();
}
catch (HibernateException e)
{
session.getTransaction().rollback();
throw e;
}
getHibernateTemplate().saveOrUpdate(timesheet);
File
DepartmentManager.java
EmployeeManager.java
T imesheetManager.java
TOTAL
Programmatic
39
66
166
271
Declarative
22
36
87
145
Less lines of code
© Visual Patterns, Inc.
81
More Spring…
• Scheduling Jobs (with Quartz or JDK timers)
<bean id="reminderEmailJobDetail" class=
"org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
<property name="targetObject" ref="reminderEmail" />
<property name="targetMethod" value="sendMail" />
</bean>
<bean id="reminderEmailJobTrigger"
class="org.springframework.scheduling.quartz.CronTriggerBean">
<property name="jobDetail" ref="reminderEmailJobDetail" />
<property name="cronExpression" value="0 0 14 ? * 6" />
</bean>
• Spring email support
• Much more

JEE support

Sub-projects (Acegi, BeanDoc, Spring IDE, etc.)
© Visual Patterns, Inc.
82
Presentation Outline
Introduction to Agile Java Development
Agile Processes
Agile Modeling
• Agile Development
Environment Setup: Directory Structure, JDK, Ant and JUnit
Using Hibernate For Persistent Objects
The Spring Framework

The Eclipse Phenomenon!

Logging, Debugging, Monitoring, and Profiling
• Beyond The Basics
© Visual Patterns, Inc.
83
Agile Java Development:
The Eclipse Phenomenon!
© Visual Patterns, Inc.
Quick Poll
Which IDE do you use?
© Visual Patterns, Inc.
85
The Eclipse Foundation, Platform and Projects
• Foundation


Originally developed by Object Technology International (OTI), purchased
by IBM ($40 million) and donated it to open source!
Recruited various corporations; from eclipse.org: Industry leaders Borland, IBM,
MERANT, QNX Software Systems, Rational Software, Red Hat, SuSE, TogetherSoft and
Webgain formed the initial eclipse.org Board of Stewards in November 2001. By the
end of 2003, this initial consortium had grown to over 80 members.

My view: Eclipse foundation is similar to Apache foundation for GUI tools
• Platform objectives

robust platform for highly integrated dev tools

enable view and/or editing of any content type

attract a large community of developers to develop plug-ins
• Projects
Application Development, editors, modeling, performance, testing, reporting,
and many more
© Visual Patterns, Inc.
86
Many Platforms Supported (Windows, Unix, Linux, Mac OS X…)
© Visual Patterns, Inc.
87
Personal Opinion:
The Java versus
Microsoft Thing




First exciting IDE
Huge community - Plug-ins galore (thousand+)
Ward Cunningham and Erich Gamma
Battle of IDEs has only now begun!
© Visual Patterns, Inc.
88
Eclipse Basic Concepts
1.
2.
3.
4.
5.
6.
Workspace (directory of projects)
Workbench
Perspectives
Editors and Views
Project
Wizards (hundreds)
7. Plug-ins (galore!)
sample workspace
© Visual Patterns, Inc.
89
Project/Plug-in: Java Development Tools (JDT)
•
•
•
•
•
Java views (e.g. packages, types, members)
Intelligent code fix and content assist
Compile during save (within the blink of an eye)
Powerful debugger (than works!)
Pre-configured for JUnit and Ant
• Others

Formatting options

Powerful search

Code refactoring (some based on Fowler's refactoring.com)

TODO lists

Scrapbook

Export feature (create zip files, etc.)
© Visual Patterns, Inc.
90
JDT Features
Java Browsing
JUnit
Java Compile Errors/Warnings
Ant Assist
© Visual Patterns, Inc.
91
Project/Plug-ins: Eclipse Web Tools Platform (WTP)
• Tools for developing J2EE Web applications
• Editors

Source - HTML, JavaScript, CSS, JSP, SQL, XML, DTD, XSD, and WSDL

Graphical - XSD and WSDL
• Database access and query tools and models
• Web service wizards
• J2EE - project natures, builders, models navigator
© Visual Patterns, Inc.
92
WTP Web Services Related Screens
© Visual Patterns, Inc.
Other WTP Features
Servers
JSP Assist
Database
© Visual Patterns, Inc.
94
CVS (Eclipse Team Sharing)
© Visual Patterns, Inc.
95
Hibernate and Spring Plug-Ins
Hibernate
Spring IDE
© Visual Patterns, Inc.
96
Startup Time Comparison To IntelliJ and NetBeans
IntellIJ - 1 minute, 5 seconds!
NetBeans - 42 seconds.
Eclipse with JDT, WTP, Hibernate, Eclipse... 19 seconds!
© Visual Patterns, Inc.
97
Presentation Outline
Introduction to Agile Java Development
Agile Processes
Agile Modeling
• Agile Development
Environment Setup: Directory Structure, JDK, Ant and JUnit
Using Hibernate For Persistent Objects
The Spring Framework
The Eclipse Phenomenon!

Logging, Debugging, Monitoring, and Profiling
• Beyond The Basics
© Visual Patterns, Inc.
98
Agile Java Development:
Logging, Debugging, Monitoring, and Profiling
© Visual Patterns, Inc.
Quick Poll
Do you use a GUI debugger?
Or, a logging framework?
Or, use println statements?
© Visual Patterns, Inc.
100
Logging Basics and Frameworks
• Types
1.Audit log
2.Tracing
3.Error reporting
• Pros
• No human
intervention
(automated)
• Great for
head-less
servers
• Cons
• Performance
hit
• Can clutter
code
Logging Frameworks
• Alternative to println statements
• Key benefit - Output control (destination, format, log level)
• Most popular - Apache Log4J and JDK Logging
• Jakarta Commons Logging -- bridge to frameworks
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
public class CommonsLoggingTest
{
private static Log log =
LogFactory.getLog(CommonsLoggingTest.class);
public static void main(String[] args)
{
log.fatal("This is a FATAL message.");
log.error("This is an ERROR message.");
log.warn("This is a WARN message.");
log.info("This is an INFO message.");
log.debug("This is a DEBUG message.");
}
}
© Visual Patterns, Inc.
101
Headaches of Finding and Fixing Bugs!
© Visual Patterns, Inc.
102
Debugging Java Code With Eclipse
• Debug
perspectives
and views
“consolidated debugging”
• Breakpoints
• Step through
code
• Variable
inspection
• Hotswap
• Remote
debugging
© Visual Patterns, Inc.
103
Debugging Web User Interfaces Using Mozilla Firefox
JavaScript debugger
Web Developer
Tamper Data
© Visual Patterns, Inc.
104
Java Monitoring and Profiling
• Monitoring




JSE 5.0 includes
JConsole
Memory issues
Class loading and
garbage collection
Spring MBean Exporter
<bean id="timexJmxBean” class=
"com.visualpatterns.timex.util.TimexJmxBean" />
<bean id="exporter” class=
"org.springframework.jmx.export.MBeanExporter">
<property name="beans">
<map>
<entry key="Time Expression:name=timex-stats"
value-ref="timexJmxBean" />
Management of
MBeans and JDK
logging level, etc …
• Profiling




Memory usage and
leaks
CPU utilization
Trace objects and
methods
Determine performance
bottlenecks
© Visual Patterns, Inc.
105
Presentation Outline
Introduction to Agile Java Development
Agile Processes
Agile Modeling
Agile Development
Environment Setup: Directory Structure, JDK, Ant and JUnit
Using Hibernate For Persistent Objects
The Spring Framework
The Eclipse Phenomenon!
Logging, Debugging, Monitoring, and Profiling
• Beyond The Basics
© Visual Patterns, Inc.
106
Beyond The Basics
© Visual Patterns, Inc.
Custom Tag Libraries
<timex:periodcheck
checkDate="${command.periodEndingDate}">
<input name="save" type="submit" value="Save">
</timex:periodcheck>
public class PayPeriodCheckTag extends TagSupport
{
public int doStartTag()
throws JspException
{
boolean includeText = ; // do something
if (includeText)
return TagSupport.EVAL_BODY_INCLUDE;
return TagSupport.SKIP_BODY;
}
© Visual Patterns, Inc.
108
Security, Reliability and Scalability Considerations
© Visual Patterns, Inc.
109
Application Security Considerations
• Authentication (user and application levels)
• Authorization (roles, groups, etc.)
• Encryption (wire protocol, configuration files)
User-level
authentication
& authorization
Wire protocol
(HTTP/S)
Application-level
authentication
© Visual Patterns, Inc.
110
Other Considerations
• Exception Handling
1. Checked exceptions (e.g. IOException) – required catch or throw
2. Unchecked exceptions (e.g. NullPointerException) - no catch/throw needed
3. Errors (e.g. OutOfMemoryError)
• Clustering (serialize, no static variables, simplicity…)
• Multi-threading (JDK 1.5 concurrent API)
• Rich Internet Applications (RIA)

AJaX  Google Web Toolkit (GWT) - http://code.google.com/webtoolkit/
 Direct Web Remoting (DWR) - http://getahead.ltd.uk/dwr/

Adobe Flex

Java Swing and Web Start
© Visual Patterns, Inc.
111
Cool Concept For Smaller Apps - Entire System In A WAR File!
•
•
•
•
Code (source, binary)
Relational database (e.g. HSQLDB)
Job Scheduling
More…
© Visual Patterns, Inc.
112
Wrap Up!
© Visual Patterns, Inc.
Presentation Outline
Introduction to Agile Java Development
Agile Processes
Agile Modeling
Agile Development
Environment Setup: Directory Structure, JDK, Ant and JUnit
Using Hibernate For Persistent Objects
The Spring Framework
The Eclipse Phenomenon!
Logging, Debugging, Monitoring, and Profiling
Beyond The Basics
© Visual Patterns, Inc.
Constant Learning – Be a “Generalizing Specialist”
© Visual Patterns, Inc.
115
Don’t Forget - Release Completion Celebration!
RON
STEVE
© Visual Patterns, Inc.
RAJ

SUSAN
116
Some Near Term Plans
© Visual Patterns, Inc.
Book - Released 12th May, 2006
Agile Java Development
With Spring, Hibernate and Eclipse
Forewords by Scott W. Ambler and Rod Johnson
available on amazon.com
1. Introduction to Agile Java Development
2. The Sample Application: An Online Timesheet System
3. XP and AMDD-Based Architecture and Design Modeling
4. Environment Setup: JDK, Ant, and JUnit
5. Using Hibernate For Persistent Objects
6. Overview of the Spring Framework
7. The Spring Web MVC Framework
8. The Eclipse Phenomenon
9. Logging, Debugging, Monitoring and Profiling
10. Beyond the Basics
11. What Next?
12. Parting Thoughts
Appendices (with lots of goodies)
© Visual Patterns, Inc.
118
Interesting Stuff At VisualPatterns.com - Visit Site Periodically
Planning
Coding











Comics
User stories are written.
Release planning creates the
schedule.
Make frequent small releases.
The Project Velocity is measured.
The project is divided into iterations.
Iteration planning starts each
iteration.
Move people around.
A stand-up meeting starts each day.
Fix XP when it breaks.







The customer is always available.
Code must be written to agreed
standards.
Code the unit test first.
All production code is pair programmed.
Only one pair integrates code at a time.
Integrate often.
Use collective code ownership.
Leave optimization till last.
No overtime.
Designing
Testing








Simplicity.
Choose a system metaphor.
Use CRC cards for design sessions.
Create spike solutions to reduce risk.
No functionality is added early.
Refactor whenever and wherever
possible.


All code must have unit tests.
All code must pass all unit tests before it
can be released.
When a bug is found tests are created.
Acceptance tests are run often and the
score is published.
Cheat Sheets
R&D Concepts
© Visual Patterns, Inc.
119
THE END!
•
•
•
•
•
•
•
agilemodeling.com
agiledata.org
Stay in touch!
agilemanifesto.org
extremeprogramming.org
[email protected]
hibernate.org
springframework.org
eclipse.org
• code.google.com/webtoolkit/
• getahead.ltd.uk/dwr/
• VisualPatterns.com (links, comics, code, cheat sheets…)
© Visual Patterns, Inc.
120