Craig Walls - Effective Spring

7/30/2019 Craig Walls - Effective Spring

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Craig Walls

[email protected]

Twitter: @habuma

http://github.com/habuma

Effective Spring
http://github.com/habumahttp://github.com/habumahttp://github.com/habuma


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Email: [email protected] Twitter: @habuma Blog: http://www.springinaction.com Sample Code: http://github.com/habuma

Who am I?

Java and Spring Fanatic

Senior Engineer with SpringSource

Spring Social Project Lead

Author

Mayor of Post Office,Jal NM on Foursquare
http://github.com/habuma/sampleshttp://github.com/habuma/sampleshttp://github.com/habuma/samples


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Recommendations != Best Practices

The code is more what youd call guidelines than actual rules.- Captain Hector Barbossa, Pirates of the Caribbean: The Curse of the Black Pearl


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Consider merging web application contexts


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A Tale of Two Contexts

DispatcherServlet creates an application context

So does ContextLoaderListener

DispatcherServlet can see ContextLoaderListeners beans

ContextLoaderListener cannot see DispatcherServlets beans

Confusing, unnecessary, and complicates some things (security)


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Solution: Put all beans in one context

Configure DispatcherServlet to load an empty context

Configure ContextLoaderListener to load all beans


7/62Email: [email protected] Twitter: @habuma Blog: http://www.springinaction.com Sample Code: http://github.com/habuma

Empty DispatcherServlet Context

DispatcherServlet loads an empty application context
http://github.com/habuma/sampleshttp://web.servlet.dispatcherservlet/http://web.servlet.dispatcherservlet/http://github.com/habuma/sampleshttp://github.com/habuma/samples



Simple ContextLoaderListener Config


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Consider using Springs Java-based configurationover XML configuration



The Curse of the Angle-Bracket

Not type-safe




Not refactor-friendly




XML namespace URIs impossible to remember




Verbose



More Trouble with XML Config

Not easy to do smart configuration

Not easy to test configuration



Springs Java Configuration

Type-safe




As refactorable as any Java code




@Configuration is easy to remember(@Component also works)




Still verbose?




Smart Configuration


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Smart Configuration

B h b XML ?


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But what about XML namespaces?

@E bl A


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@Enable Annotations

(Spring 3.1.0 and up)

Oh h


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Oh yeah...component-scanning

...becomes...


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Favor component-scanning and autowiring overexplicit configuration

C S i


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Component Scanning

or

Scans package(s) for @Component classes

Automatically creates beans in Spring

A i i


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Auto-wiring

Component-scanning also includes auto-wiring (by type)

JSR-330 @Inject also supported

V b i i MVC C fi i


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Verbosity in MVC Configuration

A i S i MVC C ll


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Annotating Spring MVC Controllers

@Controller is a specialized @Component(and is picked up by component-scanning)

C i C ll


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Component-scanning Controllers

or


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Consider using Spring 3.1 profiles to handleenvironment-specific details

Diff t B f Diff t E


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Different Beans for Different Envs

Diff t B f Diff t E


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Different Beans for Different Envs

S l ti ?


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Solution?

Pick a different set of Spring configs atbuild-time, of course!

B tt S l ti


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Better Solution

B tt S l ti


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Better Solution

Acti atin Profiles


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Activating Profiles

spring.profiles.active and spring.profiles.default

In web.xml

...or as a system environment variable, JVM systemproperty, or an entry in JNDI


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Consider using Spring Data JPA to createrepositories instead of writing them yourself

Ever Written This?


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Ever Written This?

Ever Written This?


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Ever Written This?

Stop Writing Boilerplate Repositories!


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Stop Writing Boilerplate Repositories!

Let Spring Data JPA Handle It


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Step 1: Add Spring Data JPA to your project

Maven

Gradle



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Step 2: Add Spring Data JPA to your Spring config

http://github.com/habuma/sampleshttp://www.springframework.org/schema/data/jpahttp://www.springframework.org/schema/data/jpahttp://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beanshttp://github.com/habuma/sampleshttp://github.com/habuma/samples


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Step 3: Write your repository interface



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Step 4: There is no step 4

No really...thats all there is to it

Just inject and use...

By the way


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By the way...

Spring Data also does NoSQL(Neo4j, MongoDB, CouchDB, etc, etc)

More on that in a different session

Back to Step 3


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Back to Step 3


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Consider using SpringJUnit4TestRunner tointegration-test your beans

Testing With and Without Spring


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Testing With and Without Spring

Two kinds of testing...

Unit-testing (Spring-supported, not Spring-involved)

Integration-testing (Spring-supported, Spring-involved)

How Not to Write Spring Tests


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How Not to Write Spring Tests

HowYou Should Write Spring Tests


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How You Should Write Spring Tests

HowYou Should Write Spring Tests


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How You Should Write Spring Tests


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Consider using Spring Test MVC to testcontrollers

Testing @Controllers as POJOs


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Only tests whats inside the handler method

Testing @Controllers as Controllers


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Testing @Controllers as Controllers

Tests Spring MVC stuffandmethod internals

Spring Test MVC
http://github.com/habuma/sampleshttp://github.com/habuma/sampleshttp://github.com/habuma/sampleshttp://repo.springsource.org/milestone


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Spring Test MVC

https://github.com/SpringSource/spring-test-mvc

Maven

Gradle

In Springs milestone repositoryhttp://repo.springsource.org/milestone
http://github.com/habuma/sampleshttp://repo.springsource.org/milestonehttp://repo.springsource.org/milestonehttp://repo.springsource.org/milestonehttp://repo.springsource.org/milestonehttp://repo.springsource.org/milestonehttp://repo.springsource.org/milestonehttps://github.com/SpringSource/spring-test-mvchttps://github.com/SpringSource/spring-test-mvchttp://github.com/habuma/sampleshttp://github.com/habuma/samples


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Consider using Spring Test MVC to test RESTclient code

Heres the problem


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Here s the problem...

How can I test this...

...without hitting the real Facebook Graph API?

Solution: Mock the Server
http://github.com/habuma/sampleshttps://graph.facebook.com/coca-colahttps://graph.facebook.com/coca-colahttp://github.com/habuma/sampleshttp://github.com/habuma/samples


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Solution: Mock the Server
http://github.com/habuma/sampleshttp://graph.facebook.com/coca-colahttp://graph.facebook.com/coca-colahttp://github.com/habuma/sampleshttp://github.com/habuma/samples


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Q & A

Documents

Craig Walls - Effective Spring