Welcome!

Java IoT Authors: Liz McMillan, Pat Romanski, Yeshim Deniz, Zakia Bouachraoui, Elizabeth White

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
Nicolas Fierro is CEO of MIMIR Blockchain Solutions. He is a programmer, technologist, and operations dev who has worked with Ethereum and blockchain since 2014. His knowledge in blockchain dates to when he performed dev ops services to the Ethereum Foundation as one the privileged few developers to work with the original core team in Switzerland.
René Bostic is the Technical VP of the IBM Cloud Unit in North America. Enjoying her career with IBM during the modern millennial technological era, she is an expert in cloud computing, DevOps and emerging cloud technologies such as Blockchain. Her strengths and core competencies include a proven record of accomplishments in consensus building at all levels to assess, plan, and implement enterprise and cloud computing solutions. René is a member of the Society of Women Engineers (SWE) and a m...
Early Bird Registration Discount Expires on August 31, 2018 Conference Registration Link ▸ HERE. Pick from all 200 sessions in all 10 tracks, plus 22 Keynotes & General Sessions! Lunch is served two days. EXPIRES AUGUST 31, 2018. Ticket prices: ($1,295-Aug 31) ($1,495-Oct 31) ($1,995-Nov 12) ($2,500-Walk-in)
Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settlement products to hedge funds and investment banks. After, he co-founded a revenue cycle management company where he learned about Bitcoin and eventually Ethereal. Andrew's role at ConsenSys Enterprise is a mul...
Digital Transformation and Disruption, Amazon Style - What You Can Learn. Chris Kocher is a co-founder of Grey Heron, a management and strategic marketing consulting firm. He has 25+ years in both strategic and hands-on operating experience helping executives and investors build revenues and shareholder value. He has consulted with over 130 companies on innovating with new business models, product strategies and monetization. Chris has held management positions at HP and Symantec in addition to ...
The challenges of aggregating data from consumer-oriented devices, such as wearable technologies and smart thermostats, are fairly well-understood. However, there are a new set of challenges for IoT devices that generate megabytes or gigabytes of data per second. Certainly, the infrastructure will have to change, as those volumes of data will likely overwhelm the available bandwidth for aggregating the data into a central repository. Ochandarena discusses a whole new way to think about your next...
CloudEXPO | DevOpsSUMMIT | DXWorldEXPO are the world's most influential, independent events where Cloud Computing was coined and where technology buyers and vendors meet to experience and discuss the big picture of Digital Transformation and all of the strategies, tactics, and tools they need to realize their goals. Sponsors of DXWorldEXPO | CloudEXPO benefit from unmatched branding, profile building and lead generation opportunities.
Dynatrace is an application performance management software company with products for the information technology departments and digital business owners of medium and large businesses. Building the Future of Monitoring with Artificial Intelligence. Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more busine...
All in Mobile is a place where we continually maximize their impact by fostering understanding, empathy, insights, creativity and joy. They believe that a truly useful and desirable mobile app doesn't need the brightest idea or the most advanced technology. A great product begins with understanding people. It's easy to think that customers will love your app, but can you justify it? They make sure your final app is something that users truly want and need. The only way to do this is by ...
DXWorldEXPO LLC announced today that Big Data Federation to Exhibit at the 22nd International CloudEXPO, colocated with DevOpsSUMMIT and DXWorldEXPO, November 12-13, 2018 in New York City. Big Data Federation, Inc. develops and applies artificial intelligence to predict financial and economic events that matter. The company uncovers patterns and precise drivers of performance and outcomes with the aid of machine-learning algorithms, big data, and fundamental analysis. Their products are deployed...