ADF Worst Practices (UKOUG Tech2013)
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The document outlines best and worst practices for developing ADF applications, focusing on challenges faced by various roles including developers and graphic designers. Key issues highlighted include adherence to coding guidelines, proper use of memory scopes, and effective debugging techniques. It emphasizes the importance of collaboration among team members to maintain quality and performance in ADF projects.
ADF Worst Practices (UKOUG Tech2013)
- 1. S Worst Practices for Developing an ADF Application UKOUG ADF EMG Version 12.1.2.3.4.0.0b Build WORST_PRACTICES_12.1.2.3.4.0.0b_UKOUG_2013 ADF EMG
- 2. S About us Paco van der Linden AMIS www.adfplus.com @pavadeli Wilfred van der Deijl The Future Group www.redheap.com @wilfreddeijl
- 3. S About us Steven Davelaar Oracle ateam-oracle.com @stevendavelaar Wilfred van der Deijl The Future Group www.redheap.com @wilfreddeijl
- 4. S Ideal project ● 1 developer That’s you of course!
- 5. S Threats to a healthy ADF project ● Customer / Business / Functional designer ● Architect ● Project manager
- 6. S Threats to a healthy ADF project ● Customer / Business / Functional designer ● Architect ● Project manager ● Other developers ● Graphic designer
- 7. S Other Developers… Are not a member of ADF EMG
- 8. S Other Developers… Do not use ADF EMG Taskflow Tester
- 9. S ADF EMG Taskflow Tester - Wiki
- 10. S ADF EMG Taskflow Tester
- 11. S Other Developers… Don’t add ADF Source code library ● How to get ADF Source ○ ○ ○ ○ ○ ○ Go to support.oracle.com Log Service Request for JDeveloper/ADF “ADF Source Code Request” as problem type Sign agreement and upload to SR Get access to ZIP, typically within one day New versions don’t need new agreement ● Allows debugging of ADF framework
- 12. S Other Developers… Don’t add ADF Source code library
- 13. S Other Developers… Don’t adhere to ADF Code Guidelines
- 14. S ADF Code Guidelines ● 38 pages of excellent content by ADF guru’s ● Topics include: ○ ○ ○ ○ ○ ○ ○ ○ General Code Guidelines ADF Business Components ADF Faces ADF TaskFlows ADF Binding Layer Security High Availability … and more
- 15. S Other developers ● Don’t adhere to your project specific coding guidelines ● Other developers need your help ○ Reserve time to review each other’s version control commits ○ You might learn from their code as well!! ● Reserve time to perform QA checks ○ Against ADF coding guidelines and project specific guidelines ○ ...or automate this ■ come back tomorrow 10:15 - Exchange 6 “Quality Assurance with JDev Auditing Framework”
- 16. W Threats to a healthy ADF project ● Customer / Business / Functional designer ● Architect ● Project manager ● Other developers ● Graphic designer
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- 23. W Graphic designer - Pitfalls ● Website ≠ Application ● “HTML is for semantics, CSS is for layout…” ○ ADF Fragment ≠ HTML, ADF skin ≠ CSS ○ ADF Skin → primarily colours, ADF Fragment → the rest ● Bad practice: CSS for layout management
- 24. W ADF Skinning Tips ● Use stand-alone Skin Editor ● Use ADF component selectors ○ don’t look at the generated HTML ○ use ADF Faces Skin Selectors Tag Reference ● Choice ○ UI Designer to learn ADF skinning (preferred choice) ○ ADF developer to learn CSS
- 25. W How to Write Code
- 26. W Logging ● Bad practice: System.err.println() ● Best practice: ADFLogger ○ ○ ○ ○ Configure at Runtime without restart Analyze Log for Performance Time your own code Better insight into ADF Framework internals
- 27. W ADFLogger - Runtime Configuration
- 28. W ADFLogger - Runtime Configuration
- 29. W ADFLogger - Log Analyzer ...or open log file from other (production) server
- 30. W Time custom code with ADFLogger::begin and ADFLogger::end bit.ly/adflogger
- 31. S Understanding ADF Layers ● Bad: code ADF applications like open source frameworks ● What do we mean by that? ○ All application state is kept in ViewController: ○ Lots of data queried from ADF BC and stored in JSF managed beans or entries in JSF memory scope maps ○ State passed back to ADF BC on subsequent requests: AM methods with lots of arguments ● Good: leverage ADF BC Active Data Model ○ Easy access to previously entered data ○ Row Currency management
- 32. S Understanding ADF Layers ● Signs of ViewController doing ADF BC work ○ import oracle.jbo… ○ Iterating RowSets ○ Storing lots of data in memory scopes or managed beans. Should only contain true UI state ○ Calling ApplicationModule methods with lots of arguments even when using binding layer ● Project Audits often show 50-80% of ViewController code is unnecessary ○ Either completely redundant ○ ...or should be moved to ADF BC layer
- 33. S ADF Faces a.k.a. the ViewController project
- 34. S ADF Lifecycle - Immediate property ● Bad: I run into issues, let’s try immediate=true ● Big difference: immediate on input component vs input on command component ● Almost always wrong in input components ● Make sure you understand both JSF lifecycle and ADF Optimized Lifecycle ● Steven Davelaar’s 18 Lessons ○ also available as ADF Insider Video bit.ly/jsf-lifecycle
- 35. S Know your ADF Memory Scopes ● Bad: Overuse of SessionScope & PageFlowScope ● Can have significant impact on mem usage ● Good: The smaller, the better ● Do not cache shorter living objects ○ Should be cheap to request each time when needed ○ Can have disastrous consequences, for example caching binding objects
- 38. S Memory Scopes Guidelines ● SessionScope ○ only use for user context ○ often (UTF) PageFlowScope is better ■ Two browser tabs share SessionScope but have independent UTF PageFlowScope ● RequestScope ○ often BackingBeanScope is better ○ each ADF Region or Declarative Component has own BackingBeanScope but share RequestScope ● Bad: Accessing SessionScope beans from BTF ○ BTF should be reusable and not rely on SessionScope ○ taskflow parameters are there for a reason
- 39. W tion olu “My ADF application is memoryhhungry” es a l) p al ave th We igh m (sm a of t rt
- 40. W JSF Component Binding JDeveloper Generated Code <af:inputText binding=”#{pageFlowScope.MyBean.lastName}”/>
- 41. W JSF Component Binding ● First ask yourself if it is really needed ● binding=”#{pageFlowScope.MyBean.lastName}” references UIComponent in PageFlow bean ● UIComponents should be released after each request ● But Managed Bean might require PageFlowScope for its functionality
- 42. W JSF Component Binding ComponentReference Enhancement Request logged
- 43. W “My JSF Component seems to travel around”
- 44. W Building Component Tree binding attribute No create component Not Null use component Yes call getter Null create component call setter bit.ly/compbind
- 45. W ADF Business Components a.k.a. the Model project
- 46. S ADF BC Data Model - Master Detail Beware of excessive querying Navigate row here... Requery (if populated)
- 47. S ADF BC Data Model - Master Detail Prevent excessive querying ● Use top level ViewObject instances with bind variables ● or reset detail ViewObject on master row navigation bit.ly/masterdetail
- 48. S ADF BC Data Model - Master Detail Prevent excessive querying
- 49. W “I encountered a dramatic ADF bug!!! Sometimes users lose entered data when the application is under heavy load.”
- 50. W Disable Application Module Pooling
- 51. W Don’t Simply passivate all!
- 52. W “ADF has huge performance problems!!! When under heavy load requests can take several minutes.” “Besides, what is this PS_TXN table for? It is eating up our tablespace.”
- 53. W Don’t Simply Passivate All ● Every ViewRow with transient atts is persisted ● During activation all state is applied
- 54. W Simply passivate all? No! ○ Every ViewRow with transient atts is persisted ○ During activation all state is applied
- 55. S What is passivated? ○ Set logger: oracle.jbo.server.Serializer ○ To:
- 56. W What is passivated? ○ Set logger: oracle.jbo.server.Serializer ○ To:
- 57. W “My ADF application is hacked!!! Sometimes users see data from other sessions.” “By the way, I did test the application with AM pooling off.”
- 58. W Application Module Recycling Not Losing, but Leaking state ● AM Instances Recycled for other users under load ● Not detected by disabling AM pooling!
- 60. W Default AM Pool Tuning
- 62. W Eclipse Memory Analyzer Tool bit.ly/eclipsemat
- 63. W Eclipse Memory Analyzer Tool (MAT) ● Make heap dump of running server JDK_HOME/bin/jmap -dump:file=path jvm_process_id ● ● ● ● Download and run standalone Eclipse MAT Inspect all objects in heap Query Heap Objects Predefined Reports and Tools bit.ly/eclipsemat
- 65. W Java Mission Control ● ● ● ● Any version of JRockit Hotspot (aka Sun JVM) since 1.7.0_40 Record a period of time Analyze ○ ○ ○ ○ ○ CPU performance Memory Usage Garbage Collection Thread Concurrency etcetera
- 66. W Miscellaneous
- 67. W Password management ● Bad: Credentials in clear text (eg. web.xml) ● Worse: Override with deployment plans bit.ly/secure-adf
- 69. S Load/Stress Testing ● 5 developers on a Friday afternoon: “Ready…. Set…. Go” ● Every ADF project initially has performance issues ● Consider ○ JMeter - Free open source, not optimized for ADF ○ Oracle Application Testing Suite - ADF aware ● Requires ○ Production like testing environment ○ Good knowledge of chosen test tool ○ 10 days setup (assuming test tool experience)
- 70. S Further Reading ● bit.ly/adflogger ○ ADFLogger Custom Timings ● bit.ly/secure-adf ○ FMW Credential Store ● bit.ly/eclipsemat ○ Memory Analyzer Tool ● bit.ly/miscontrol ○ Java Mission Control ● bit.ly/jsf-lifecycle ○ Steven Davelaar’s JSF Lifecycle Lessons ● bit.ly/compbind ○ JSF Component Bindings ● bit.ly/masterdetail ○ Lazy Master Detail Query