Embed Size (px)
DESCRIPTION
Spring Talk. Dependency Injection and IoC – Rohit Spring Core Introduction – Rohit Spring Database Connectivity– Lalit Bhatt Introduction to Spring Roo – Rohit. Speaker Introduction. Speaker Introduction. Inversion of Control and Dependency Injection. Example Scenario. Use case. - PowerPoint PPT Presentation
Citation preview
Spring Talk
• Dependency Injection and IoC – Rohit• Spring Core Introduction – Rohit• Spring Database Connectivity– Lalit Bhatt• Introduction to Spring Roo – Rohit
Speaker Introduction
Speaker Introduction
Inversion of Control and Dependency Injection
Example Scenario
Use case
ExpressionEvaluator(3*4)+sin(cos(30))
Input12.15364048
Output
Use case
ExpressionEvaluator(3*4)+sin(cos(30))
Input12.15364048
Output
………………………….………………………….
………………………….………………………….
………………………….………………………….
………………………….………………………….
………………………….………………………….
………………………….………………………….
………………………….………………………….
………………………….………………………….
10000 input files 10000 output files
Use case
Problem Statement -Create a Test framework to test Expression Evaluator with 10,000 expressions
What’s wrong with this code?
<R> execute(<D>)
ITestCase
execute()
ITestExecutioner
<D> getInput(index);Int getCount();
IInputAdapter
<R> getExpected(index);Int getCount();
IExpectedDataAdapter
Init();collect();publish()
IPublisher<R>
log();
ILogger<L>
<R> execute(<D>)
ITestCase
execute()
ITestExecutioner
<D> getInput(index);Int getCount();
IInputAdapter
<R> getExpected(index);Int getCount();
IExpectedDataAdapter
Init();collect();publish()
IPublisher<R>
log();
ILogger<L>
If we say new for each arrow, we are
coupling components!
<R> execute(<D>)
ITestCase
void setLogger(..)void setTestCase(..)void setInputAdapter(..)void setOutputAdapter(..)void setResultPublisher(…)void execute()
TestExecutioner
<D> getInput(index);Int getCount();
IInputAdapter
<R> getExpected(index);Int getCount();
IExpectedDataAdapter
Init();collect();publish()
IPublisher<R>
log();
ILogger<L>
Lets see this in Code
Spring Core
More Theory of Spring Core
• Constructor Dependency Injection• Setter Dependency Injection• Auto Wiring• Bean Scope• Lazy Init• Initiating Spring Framework
Constructor Injection
<!-- IInputAdapter, IExpectedDataAdapter Implementation --><bean id="testDataAdapter" class="com.design.di.production.TestDataAdapter"> <constructor-arg type="java.lang.String" value="testdata.csv"/></bean>
Setter Injection
<!-- Executioner Implementation --><bean id="executioner" class="com.design.di.production.ActualExecutioner"> <property name="resultPublisher"> <ref bean="csvPublisher"/> </property> ….</bean>
Auto Wiring
Requirement - All my beans require a logger.
Q – Do I explicitly put logger ref in all beans?
A – No, Use Auto Wiring
Autowire TypesType Meaning
No No Auto wiring
ByName Bean name attribute name matched
ByType Maps property to Single object of type matched, if multiple objects found fatal error
Constructor Same as ByType but for constructor arguments
Autodetect Either ByType or Constructor through introspection of bean class
Auto Wiring
<bean id="csvPublisher" class="com.design.di.production.CSVPublisher" autowire=“autodetect”> <property name="filePrefix" value="result"> </property> <property name="logger"> <ref bean="consoleLogger"/> </property> </bean>
Bean ScopeType Meaning
Singleton As name suggests Singleton instance, good for stateless bean
Prototype A new bean for each ref or getBean(), good for stateful beans
request Application for Spring Web apps, Request Scope
session Application for Spring Web apps, Session Scope
globalesession Application for Spring Web apps, Session Scope, Valid for Port let Applications
Bean Scope
<!-- Logger Implementation --><bean id="consoleLogger" class="com.design.di.production.ConsoleLogger” scope=“prototype”> <property name="level"> <value type="com.design.di.ILogger$Level"> Info </value> </property> </bean>
Lazy Init
Lazy Init
<!- - Created at first access - -><bean id="lazy" class="com.foo.ExpensiveToCreateBean” lazy-init="true"/>
<!- - Created an at startup - -><bean name="not.lazy" class="com.foo.AnotherBean"/>
Initiating Spring Framework
Conclusion
Why use Spring1. Modular Application Development –
Maximum reuse2. Configuration based Application
Development3. TDD possible using mock objects4. Integration testing by stubbing out
production modules
Introduction to Spring Roo
Scope of this talk
• Understanding Rapid App Development• Demo Spring Roo• Excite you guys to take a session on Roo
Rapid Application Development
Configuration Burden
Commands for Convention
No Lock In
Extensible
Generated Code Adapts to new inputs
Code Demo Time
Typical Application Flow
Define Entities
CRUD DAOs
Web Controller
DAO Unit Test cases
Controller Test Cases
Security
Application Logic
Deploy
Integration Tests
Roo Commands$>roo.sh$roo> project --topLevelPackage com.test.roo$roo> persistence setup --provider HIBERNATE --database HYPERSONIC_IN_MEMORY$roo> entity --class ~.model.Employee –testAutomatically$roo> field string --fieldName firstName --notNull$roo> field string --fieldName lastName –notNull$roo> controller all --package ~.web$roo> json all$roo> exit$>mvn package tomcat:run
http://localhost:8080/roo
