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Migrating from Spring 3 to Spring 4By Phillip Verheyden

@phillipuniverse

About Me

• Phillip Verheyden • @phillipuniverse

(GitHub, Twitter, et al.) • I code @broadleaf

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Do you use Spring? Is eCommerce your business?

Want to ride with us on the future-train of Java eCommerce? !

Then use Broadleaf! https://github.com/BroadleafCommerce http://demo.broadleafcommerce.com http://www.broadleafcommerce.com

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This Talk

• Upgrades in general • Spring 4 specifically

• Dependencies • Taking advantage of new (-ish) features

• Java configuration • Web Sockets

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Why should you invest in a upgrade/migration?

• Talent acquisition/retention • “Nobody ever got fired for choosing…”

• Stagnation/debt • Code you no longer have to support • Supported versions

• Who is still on Java 6? (IBM?) • New features

• Programming == fun (?) • Feature enablement++ (see Web Sockets, Lambdas)

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A balancing act

Spring 4

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How we did it

• First pass - initial update for compilation • Pass++

• Java-based configuration, resource handling

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Before you update

• Regression tests • Unit Tests • Integration tests • Functional tests

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What does the upgrade path look like?

• Migration guide on GitHub • Skip 4.0.6.RELEASE, go directly to 4.1.0.RELEASE • TL;DR - it’s not that bad

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Dependent Libraries

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Spring 4 recommended minimum versions

• In general, versions released in 2010 and later • Full list • Spring IO Platform • JPA 2.0 • Jackson 2 - no Jackson 1 support in Spring 4.1 • Hibernate 3.6 - Hibernate 4 recommended • Servlet 3.0 - Servlet 2.5 still deployable with excluded features

• Required for Spring MVC tests • Spring Security 3.2 • Thymeleaf - specific Spring 4 package

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Spring 4 recommended minimum versions

• Servers • Tomcat 6.0.33 / 7.0.20 • Jetty 7.5 • JBOSS AS 6.1 • GlassFish 3.1 (with a workaround) • Oracle WebLogic 10.3.4 (with JPA 2.0) • IBM WebSphere 7.0.0.9 (with JPA 2.0)

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Jackson

• Jackson 1.x to 2.x • Maintainer change from Codehaus to FasterXML

• Java package change from org.codehaus.jackson to com.fasterxml.jackson.core

• Want to use JAXRS? • Add jackson-jaxrs-json-provider

• Want to use JAXB annotations with Jackson serialization? Add jackson-module-jaxb-annotations

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Transitively includes jackson-annotations

and jackson-core

Jackson• JAXRS !!!!!!!

• JAXB annotations, Jackson serialization

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XSD Updates

• If you are utilizing the Spring XML namespaces, you should update these to target the -4.1.xsd • Or use the version-less version

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What should you be using right now?

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What can you immediately use in Spring 4?

• Lots of topics already covered (Java 8, sockets, resource handling)

• Java config (now is a great time to start using it) • Spring Security 3.2

• Auto CSRF protection • Better Java config

• @RestController• Ordered list bean injection • Generic injection (e.g. @Autowired Repository<Order>) • Spring MVC test framework

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$('');

Demo

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Demo Components

• Java configuration (Servlet + Spring) • Add web socket support

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What have we learned?

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What did we learn

• Upgrading == good • You don’t need to do a huge re-platform (good backwards

compatibility) • Tiered feature upgrade might be the best option • Java config - now with more standard Java extension patterns • Simple real-world web socket support is sick!

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