Welcome!

Java IoT Authors: Pat Romanski, Elizabeth White, Liz McMillan, Yeshim Deniz, Mehdi Daoudi

Related Topics: Java IoT, Recurring Revenue

Java IoT: Blog Feed Post

Retrieving Managed Beans Programmatically

There’s essentially three avenues to solving this problem

From time to time in JSF and ADF Faces RC applications there’s the need from one managed bean to retrieve another, typically from a lesser scoped bean to a greater, such as a requestScope bean retrieving a sessionScope bean to access its methods. There’s essentially three avenues to solving this problem:

1) The following JSF 1.1 createValueBinding method that retrieves the bean using EL:

FacesContext ctx = FacesContext.getCurrentInstance();
Application app = ctx.getApplication();
ValueBinding bind = app.createValueBinding("#{beanName}");
Bean bean = (Bean) bind.getValue(ctx);

Note parts of this code were deprecated since JSF 1.1

2) A JSF 2.0 compliant way using evaluateExpressionGet also evaluating EL to retrieve a bean:

FacesContext context = FacesContext.getCurrentInstance();
Bean bean = (Bean) context.getApplication().evaluateExpressionGet(context, "#{beanName}", Bean.class);

(Thanks to BalusC on StackOverFlow for the technique).

3) Or a direct programmatic method that doesn’t use EL:

ExternalContext exctxt = FacesContext.getCurrentInstance().getExternalContext();

AppBean appBean = (AppBean) exctxt.getApplicationMap().get("appBeanName");
SessionBean sessionBean = (SessionBean) exctxt.getSessionMap().get("sessionBeanName");
RequestBean sessionBean = (RequestBean) exctxt.getRequestMap().get("requestBeanName");

AdfFacesContext adfctxt = AdfFacesContext.getCurrentInstance();

ViewBean viewBean = (ViewBean)adfctxt.getViewScope().get("viewBeanName");
PageFlowBean pageFlowBean = (PageFlowBean)adfctxt.getPageFlowScope().get("pageFlowBeanName");

With these three approaches in mind it’s interesting to gather some statistics on how long it takes each method to retrieve each type of bean. The following chart shows 5 consecutive runs of each method, per bean type, where each method is repeated in a loop 10000 times (so we can see the statistical differences).

(Note each run included an initialization section that wasn’t recorded in the statistics, designed to prime the beans and the access methods such that startup times didn’t impact the results).

The numbers represent nanoseconds but their individual values mean little. However the ratios between each method is of more interest and the following conclusions can be made:

a) The older createValueBinding method is slower than the evaluateExpressionGet method, at least initially but this trends to insignificant over subsequent runs.
b) The direct method is faster than the other methods in all cases.
c) Particular gains are to be made in using the direct method to access application, session and request scoped beans. Less so but still positive gains for view and pageFlow scoped beans.

Sample App
The sample app can be downloaded from here.

Platform
MacBookPro 2.3GHz Core i7, 8GB RAM, Mac OS X 10.6.8
JDev 11.1.2 JDK 64bit 1.6.0_26

Thanks
My thanks must go to Simon Lessard who inspired this post sometime back.

Read the original blog entry...

More Stories By Chris Muir

Chris Muir, an Oracle ACE Director, senior developer and trainer, and frequent blogger at http://one-size-doesnt-fit-all.blogspot.com, has been hacking away as an Oracle consultant with Australia's SAGE Computing Services for too many years. Taking a pragmatic approach to all things Oracle, Chris has more recently earned battle scars with JDeveloper, Apex, OID and web services, and has some very old war-wounds from a dark and dim past with Forms, Reports and even Designer 100% generation. He is a frequent presenter and contributor to the local Australian Oracle User Group scene, as well as a contributor to international user group magazines such as the IOUG and UKOUG.

IoT & Smart Cities Stories
The platform combines the strengths of Singtel's extensive, intelligent network capabilities with Microsoft's cloud expertise to create a unique solution that sets new standards for IoT applications," said Mr Diomedes Kastanis, Head of IoT at Singtel. "Our solution provides speed, transparency and flexibility, paving the way for a more pervasive use of IoT to accelerate enterprises' digitalisation efforts. AI-powered intelligent connectivity over Microsoft Azure will be the fastest connected pat...
There are many examples of disruption in consumer space – Uber disrupting the cab industry, Airbnb disrupting the hospitality industry and so on; but have you wondered who is disrupting support and operations? AISERA helps make businesses and customers successful by offering consumer-like user experience for support and operations. We have built the world’s first AI-driven IT / HR / Cloud / Customer Support and Operations solution.
Codete accelerates their clients growth through technological expertise and experience. Codite team works with organizations to meet the challenges that digitalization presents. Their clients include digital start-ups as well as established enterprises in the IT industry. To stay competitive in a highly innovative IT industry, strong R&D departments and bold spin-off initiatives is a must. Codete Data Science and Software Architects teams help corporate clients to stay up to date with the mod...
At CloudEXPO Silicon Valley, June 24-26, 2019, Digital Transformation (DX) is a major focus with expanded DevOpsSUMMIT and FinTechEXPO programs within the DXWorldEXPO agenda. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive over the long term. A total of 88% of Fortune 500 companies from a generation ago are now out of business. Only 12% still survive. Similar percentages are found throug...
Druva is the global leader in Cloud Data Protection and Management, delivering the industry's first data management-as-a-service solution that aggregates data from endpoints, servers and cloud applications and leverages the public cloud to offer a single pane of glass to enable data protection, governance and intelligence-dramatically increasing the availability and visibility of business critical information, while reducing the risk, cost and complexity of managing and protecting it. Druva's...
BMC has unmatched experience in IT management, supporting 92 of the Forbes Global 100, and earning recognition as an ITSM Gartner Magic Quadrant Leader for five years running. Our solutions offer speed, agility, and efficiency to tackle business challenges in the areas of service management, automation, operations, and the mainframe.
The Jevons Paradox suggests that when technological advances increase efficiency of a resource, it results in an overall increase in consumption. Writing on the increased use of coal as a result of technological improvements, 19th-century economist William Stanley Jevons found that these improvements led to the development of new ways to utilize coal. In his session at 19th Cloud Expo, Mark Thiele, Chief Strategy Officer for Apcera, compared the Jevons Paradox to modern-day enterprise IT, examin...
With 10 simultaneous tracks, keynotes, general sessions and targeted breakout classes, @CloudEXPO and DXWorldEXPO are two of the most important technology events of the year. Since its launch over eight years ago, @CloudEXPO and DXWorldEXPO have presented a rock star faculty as well as showcased hundreds of sponsors and exhibitors! In this blog post, we provide 7 tips on how, as part of our world-class faculty, you can deliver one of the most popular sessions at our events. But before reading...
DSR is a supplier of project management, consultancy services and IT solutions that increase effectiveness of a company's operations in the production sector. The company combines in-depth knowledge of international companies with expert knowledge utilising IT tools that support manufacturing and distribution processes. DSR ensures optimization and integration of internal processes which is necessary for companies to grow rapidly. The rapid growth is possible thanks, to specialized services an...
At CloudEXPO Silicon Valley, June 24-26, 2019, Digital Transformation (DX) is a major focus with expanded DevOpsSUMMIT and FinTechEXPO programs within the DXWorldEXPO agenda. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive over the long term. A total of 88% of Fortune 500 companies from a generation ago are now out of business. Only 12% still survive. Similar percentages are found throug...