More than 5 billion people spend an average of 2 hours a day using their mobile phones to bank, shop, reserve hotel rooms, socialize, and more. This challenges companies to migrate their traditional Java EE applications in order to address the demands of mobile and tablet users.
In this session, you’ll learn about some of the approaches to migrate a traditional Java EE application to mobile using specifications like RESTful, Context and Dependency Injection (CDI), Enterprise Java Beans (EJB3), and messaging from the Java Platform, Enterprise Edition (Java EE) 6 for server-side services. You’ll also hear about various choices of client-side technologies, which depend on key differentiators between mobile native, mobile web, and mobile hybrid applications.
Lessons Learned from Real-World Deployments of Java EE 7 at JavaOne 2014
Migrating traditional Java EE Applications to mobile
1. Migrating traditional Java EE
applications to mobile
Serge Pagop
Sr. Channel MW Solution Architect, Red Hat
spagop@redhat.com
Burr Sutter
Product Management Director, Red Hat
bsutter@redhat.com
2014-04-16
2. 2
Agenda
•Migration motivations
•Traditional Java (2) EE technologies usage
•Migration approaches
•Migration of layers
•Modernize to Java EE 6 technologies – Plan for mobile
•REST fits well with the mobile strategy
•Which Mobile application model to choose?
•Mobile Gateway architecture – Mobile + JBoss EAP Runtime
•Demo and Q&A
3. 3
Motivations
•Innovation, integration, cost reduction, modernization
•Market Demand, Time to market, Go-To Market strategy
•Complexity, performance, stability, security
•Vendor lock-in, lack of functionalities, standards compliance
•Multi-tenancy, Ready for the Cloud
•Penetrate New Market Segment
•Increase developer productivity
6. 6
Traditional Java (2) EE technologies usage
Current situation
•Persistence layer
•Standards are JDBC, CMP, BMP, JPA, JDO
•Non-Standards are Hibernate, iBatis, ...
•Business layer
•Standards are Enterprise JavaBeans 2.x / 3.0
•Non-Standards are Spring Framework, JBoss Seam, Google Guice, ...
•Communication layer
•Standards are JAX-WS, JAX-RPC, RMI
•Non-Standards are legacy Web Service Frameworks
7. 7
Traditional Java (2) EE technologies usage – Cont.
Current situation
•Presentation layer
•Standards are JSP+Servlets, JSF 1.2/2.0
•Non-Standards are: Struts, Tapestry, GWT, Wicket, ...
9. 9
Migration assessment
•Looks at all facets of applications and infrastructure
•Helps to understand the risks, savings, and anticipated costs
•Enables stakeholders to scope the engineering time and effort
required to migrate applications
● Free open source tool for Java EE migration assessment
● Analyzes code and generates report with known issues
● Provides an estimate of effort required to make changes
● Offers suggestions for replacement code
● Highlights vendor specific implementations
10,000 Foot View Report
http://www.jboss.org/migration
10. 10
Complete migration – Big Bang style
•Unique new development
•Migration of the entire application in a new system
•High Complexity because of new development
11. 11
Layer-oriented migration
•Based on layer oriented approach: each layer needs a specific
handling
•Complexity is defined through
•Multiple migration with associated test and acceptance processes
•Migration of a layer affects overlying layers
12. 12
Module-oriented migration
•Defined as Migration On Demand
•Migration of technical modules will be taken in consideration
•Complexity is defined through
•A mix of technologies of new and old ones
•Delimitation of technical modules
13. 13
Persistence layer migration
Current-Situation Future-Situation
SQL/JDBC Data Access JPA 2.0 Challenges
● SQL Queries
● DAO / Repository Pattern
● Providing Value Objects
● Domain model introduction with relationship
● Detached entity objects handling
● Adaption of entity objects with unique identity
EJB 2.x Data Access JPA 2.0 Challenges
● CMP 2.x - Entity classes and XML descriptors
● BMP 2.x - CRUD callback methods
● Domain model introduction with relationship
● Detached entity objects handling
● Adaption of entity objects with unique identity
● Data Access Objects introduction
Hibernate Data Access JPA 2.0 Challenges
● O/R Mapping via XML
● Using Hibernate APIs
● No challenges (Hibernate is JPA provider in JBoss EAP)
● May be some challenges with proprietary Hibernate
features
JDO Data Access JPA 2.0 Challenges
● Domain model approach similar to JPA (based on
annotation or configuration)
● JDO and JPA have similarities
14. 14
Business layer migration
Current-Situation Future-Situation
EJB 2.x components EJB 3.1 Challenges
● Stateless and Stateful Session Beans
● EJB 2.x Pattern and communication
● No challenges
● Eliminate J2EE Pattern
● Eliminate proprietary infrastructure code
EJB 2.x components CDI 1.0 Challenges
● Stateless and Stateful Session Beans
● EJB 2.x Pattern and communication
● No challenges
● Eliminate J2EE Pattern
● Eliminate proprietary infrastructure code
Spring – lightweight DI Framework CDI 1.0 Challenges
● Based on XML or annotation
● Strong integration support (JDBC template, Tx template,
JMS template, Mail template)
● Supports other annotations (@Resource, @Inject)
● No challenges
● May be some challenges with Spring Add-On
● Different semantics in the field of scopes
15. 15
Communication layer migration
Future-Situation – Introduction of a new communication interface
JAX-RS - Challenges
●New fresh start
●Provide distinct URI for each resource you wish to expose
●Expose REST services by injecting EJBs into JAX-RS annotated POJOs
●Use nouns in the URIs
●Use links in your responses
●Make service stateless
●Define what actions should be able to perform on each resource
●Map the actions to an appropriate HTTP verbs (@DELETE, @GET, @POST, @PUT,
@HEAD)
●Use JSON via JAXB as interchange data format
16. 16
Presentation layer migration
Standard like JSP with Servlet or
JSF 2.0/2.1 and non-standard
web frameworks like Struts,
Tapestry, GWT, … do not have a
migration path in a mobile
strategy
Client side needs a clean / fresh
start
Mobile-First strategy
creating pages, UI components
that address the constraints of
mobile, then progressively
enhances the experience to other
screen spaces, features, and
more
17. 17
Modernize to Java EE 6 technologies
Future situation to enable mobile capabilities
18. 18
REST fits well with mobile strategy
•REST is flexible and adequate for Client-Server communication
•Communication happens over HTTP using REST styles
•JSON over HTTP/HTTPs should be used for data-interchange
•Stateless, Cacheable, Lightweight, Scalable
•Using HTTP verbs (DELETE, GET, POST, PUT)
•Using Web technologies and security standards
•Fully supported in JBoss EAP (Java EE 6 compliant environment)
by a JAX-RS implementation (RESTEasy)
19. 19
REST fits well with mobile strategy
Securing endpoints - Possibilities
•JBoss EAP 6.2 – Basic Auth
•RealmUsersRoles with *-users.properties and *-roles.properties files
•Database login module - users and roles from a database system
•LDAP login module – users and roles from a LDAP server
•JBoss EAP 6.3 – PicketLink
•Identity Management (IDM)
20. Which Mobile application model to choose?
Mobile Web
<html>
<body>
<div id=”name”/>
<script src=”x.js”/>
</body>
</html>
Native Shell Native App
Native Code
Apple apple apple
Android android
Windows windows
IOS ios ios
Jave
Objectve c
<html>
<body>
<div id=”name”/>
<script src=”x.js”/>
</body>
</html>
HTML5HTML5
Device Browser Apache Cordova Objective-C / Android Java
Pros:
Instant Deployment
Reuse of Web Talents
No App Stores
Cons:
Limited Device Features
Limited Offline Capabilities
No Push
No App Stores
Pros:
Cross-Platform
Native Device Features
Push
App Stores
Cons:
HTML/JS-based UI
Non-native look & feel
App Stores
Pros:
Limitless capability
Cons:
Unique Codebases
Unique skill-sets
Addressing multiple screen dimensions
App Stores
20