|By David Bismut, Krishnakumar Pooloth, Swaminathan Natarajan||
|July 31, 2005 07:00 PM EDT||
Property files are frequently used in systems built using Java whether it's a thick Java client, a servlet, or a business component. Java specifies the format for a property file and provides the Properties class to read from and write to these files. However, Java is silent on the aspects related to validations of a value entered in a property file, providing room for errors to creep into an application system. How many times have you started to debug a failure in an application only to realize that it's because of an incorrect value in a property file?
The Properties Editor Framework detailed in this article was developed to solve the problem of managing application properties. It provides a convenient way to define a data type for each property and have a companion component in Swing to edit the property value. The framework can be used as a standalone tool or as part of a user interface.
One of the framework's design criteria was that it should work out of a property file, i.e., no other files or databases should be required for managing the property file. This is achieved by using certain meta-attributes to describe the characteristics of each property in the properties file. These meta-attributes are embedded along with each property in the property file as comments (Any line, in a property file, starting with '#' is considered a comment in Java).
In this article, we'll describe the framework's use, the concept of meta-attributes, and the default set of the attributes supported by the framework. And then, we'll explain the framework's design and how to extend it to support a new property data type.
Using the Property Editor Framework
The first step in using the Property Editor Framework is to decide on the Parameter type of each property in the properties file. Currently the framework supports the types listed in Table 1.
The next step is to modify the properties file and add the necessary meta-attributes for each property. Listing 1 shows a sample properties file with meta-attributes.
The final step is to set up the environment for the Property Editor Framework and invoke the Property Editor Dialog to start updating the property values. Figure 1 shows the properties as rendered in the Property editor Dialog.
The basic meta-attributes speci-fied by the framework for each property are Parameter Type, Editable, and Documentation. The Parameter Type represents the type of a property. It's used to render a suitable component for editing the property value. The table below lists the components rendered for the each of the possible values of PARAMETER TYPE.
The meta-attribute EDITABLE indicates whether the user can edit the value of a property. In the Property Editor Dialog, only properties that have a true value for EDITABLE meta-attribute are displayed. This lets the application developer make certain attributes in a property file not editable through the dialog.
The DOCUMENTATION meta-attribute specifies the text (which can be specified using HTML) that provides assistance to the end user while editing any particular property. In Figure 1, this documentation is displayed below the JTable con-taining the editable properties. As HTML tags are accepted, the <A> anchor tag can be used to provide a link to more comprehensive documentation.
Apart from the basic meta-attributes, there are two special meta-attributes. First one, GROUP NAME, is used to group related properties together. In the Property Editor Dialog, each property group is displayed in a separate tab. This could be used to group your attributes into, say, 'Basic' and 'Advanced.' Note that this parameter shouldn't be specified for each property separately. Once a GROUP NAME tag appears, all the parameters till the next GROUP NAME tag are grouped together. Another special meta-attribute is ALLOWED VALUES, which is used in conjunction with the SYMBOL parameter type. This lets you specify the list of valid choices for a SYMBOL property. These values should be separated by commas.
Now that we have a good idea about meta-attributes, let's walk through the steps in adding them to the Property File. Consider the following set of Properties.
Step 1: Decide the Grouping of the Properties
In the example the properties can be split into two groups based on their purpose, Logging and Database connection. Let's call these groups Logging and Database.
#GROUPNAME = Database
# GROUPNAME = Logging
Step 2: Decide on the Type for Each Property
In the example above, the types to be assigned to each property are shown in Table 3.
Step 3: Add Meta-Attributes to Each Property
The complete listing of this sample is available for download along with the source (see Listing 2).
Design of the Property Editor Framework
In this section, we will detail the design of the Properties Editor Framework. To reduce complexity, we'll break the discussion into: Creating the model of the Properties Editor component, creating the UI of the Properties Editor component, and the framework's persistence mechanism for the properties file.
Creating the Model
The classes involved in reading the properties file into memory and creating the data model are depicted in Figure 2.
The EditorFile class, which ex-tends the File class, is used as a thin wrapper for the Properties file. The EditorFile class provides the facility to add an Observer, which will be notified when changes are made to the property values.
The Parser class is a simple line parser that reads data from the EditorFile instance line-by-line and creates an in-memory model of the property file. It also defines the regular expression patterns to match the different meta-attributes supported by the framework. This class creates a new instance of Group class each time the meta-attribute '#GROUP NAME = <Group Name>' is encountered.
For each property key-value that falls under the same #GROUP NAME, an instance of one of the sub-classes of the Parameter class hierarchy is created. The exact sub-class is decided by the value of the meta-attribute #PARAMETER TYPE, which also keeps track of the value of meta-attribute EDITABLE that's used later by the view to decide whether to make it visible.
Creating the User Interface
The classes involved in rendering the user interface of the component are depicted Figure 3.
Referring to Figure 1, the visual area of the dialog is split between the Panel used to render the table of property key-value pairs and the JEditorPane showing the documentation text of different properties.
|Java Developer's Journal 07/31/05 06:42:09 PM EDT|
Enterprise Java - Properties Editor Framework
Microservices are a very exciting architectural approach that many organizations are looking to as a way to accelerate innovation. Microservices promise to allow teams to move away from monolithic "ball of mud" systems, but the reality is that, in the vast majority of organizations, different projects and technologies will continue to be developed at different speeds. How to handle the dependencies between these disparate systems with different iteration cycles? Consider the "canoncial problem" ...
Feb. 27, 2017 06:00 AM EST Reads: 6,144
SYS-CON Events announced today that delaPlex will exhibit at SYS-CON's @CloudExpo, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. delaPlex pioneered Software Development as a Service (SDaaS), which provides scalable resources to build, test, and deploy software. It’s a fast and more reliable way to develop a new product or expand your in-house team.
Feb. 27, 2017 04:30 AM EST Reads: 2,227
Data is the fuel that drives the machine learning algorithmic engines and ultimately provides the business value. In his session at 20th Cloud Expo, Ed Featherston, director/senior enterprise architect at Collaborative Consulting, will discuss the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.
Feb. 27, 2017 04:30 AM EST Reads: 4,291
910Telecom exhibited at the 19th International Cloud Expo, which took place at the Santa Clara Convention Center in Santa Clara, CA, in November 2016. Housed in the classic Denver Gas & Electric Building, 910 15th St., 910Telecom is a carrier-neutral telecom hotel located in the heart of Denver. Adjacent to CenturyLink, AT&T, and Denver Main, 910Telecom offers connectivity to all major carriers, Internet service providers, Internet backbones and exchanges.
Feb. 27, 2017 03:30 AM EST Reads: 2,181
Why do your mobile transformations need to happen today? Mobile is the strategy that enterprise transformation centers on to drive customer engagement. In his general session at @ThingsExpo, Roger Woods, Director, Mobile Product & Strategy – Adobe Marketing Cloud, covered key IoT and mobile trends that are forcing mobile transformation, key components of a solid mobile strategy and explored how brands are effectively driving mobile change throughout the enterprise.
Feb. 27, 2017 02:00 AM EST Reads: 7,547
As businesses adopt functionalities in cloud computing, it’s imperative that IT operations consistently ensure cloud systems work correctly – all of the time, and to their best capabilities. In his session at @BigDataExpo, Bernd Harzog, CEO and founder of OpsDataStore, will present an industry answer to the common question, “Are you running IT operations as efficiently and as cost effectively as you need to?” He will expound on the industry issues he frequently came up against as an analyst, and...
Feb. 27, 2017 01:00 AM EST Reads: 2,149
The explosion of new web/cloud/IoT-based applications and the data they generate are transforming our world right before our eyes. In this rush to adopt these new technologies, organizations are often ignoring fundamental questions concerning who owns the data and failing to ask for permission to conduct invasive surveillance of their customers. Organizations that are not transparent about how their systems gather data telemetry without offering shared data ownership risk product rejection, regu...
Feb. 26, 2017 11:45 PM EST Reads: 2,181
Who are you? How do you introduce yourself? Do you use a name, or do you greet a friend by the last four digits of his social security number? Assuming you don’t, why are we content to associate our identity with 10 random digits assigned by our phone company? Identity is an issue that affects everyone, but as individuals we don’t spend a lot of time thinking about it. In his session at @ThingsExpo, Ben Klang, Founder & President of Mojo Lingo, discussed the impact of technology on identity. Sho...
Feb. 26, 2017 11:45 PM EST Reads: 6,266
SYS-CON Media announced today that @WebRTCSummit Blog, the largest WebRTC resource in the world, has been launched. @WebRTCSummit Blog offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. @WebRTCSummit Blog can be bookmarked ▸ Here @WebRTCSummit conference site can be bookmarked ▸ Here
Feb. 26, 2017 10:00 PM EST Reads: 13,768
SYS-CON Events announced today that CA Technologies has been named "Platinum Sponsor" of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, New York, and 21st International Cloud Expo, which will take place in November in Silicon Valley, California.
Feb. 26, 2017 09:15 PM EST Reads: 2,541
You think you know what’s in your data. But do you? Most organizations are now aware of the business intelligence represented by their data. Data science stands to take this to a level you never thought of – literally. The techniques of data science, when used with the capabilities of Big Data technologies, can make connections you had not yet imagined, helping you discover new insights and ask new questions of your data. In his session at @ThingsExpo, Sarbjit Sarkaria, data science team lead ...
Feb. 26, 2017 09:00 PM EST Reads: 9,052
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
Feb. 26, 2017 08:45 PM EST Reads: 2,090
Bert Loomis was a visionary. This general session will highlight how Bert Loomis and people like him inspire us to build great things with small inventions. In their general session at 19th Cloud Expo, Harold Hannon, Architect at IBM Bluemix, and Michael O'Neill, Strategic Business Development at Nvidia, discussed the accelerating pace of AI development and how IBM Cloud and NVIDIA are partnering to bring AI capabilities to "every day," on-demand. They also reviewed two "free infrastructure" pr...
Feb. 26, 2017 08:45 PM EST Reads: 5,246
WebRTC is about the data channel as much as about video and audio conferencing. However, basically all commercial WebRTC applications have been built with a focus on audio and video. The handling of “data” has been limited to text chat and file download – all other data sharing seems to end with screensharing. What is holding back a more intensive use of peer-to-peer data? In her session at @ThingsExpo, Dr Silvia Pfeiffer, WebRTC Applications Team Lead at National ICT Australia, looked at differ...
Feb. 26, 2017 08:30 PM EST Reads: 7,267
SYS-CON Events announced today that Hitrons Solutions will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Hitrons Solutions Inc. is distributor in the North American market for unique products and services of small and medium-size businesses, including cloud services and solutions, SEO marketing platforms, and mobile applications.
Feb. 26, 2017 08:30 PM EST Reads: 901
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place June 6-8, 2017, at the Javits Center in New York City, New York, is co-located with 20th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry p...
Feb. 26, 2017 07:45 PM EST Reads: 2,164
The Internet of Things can drive efficiency for airlines and airports. In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect with GE, and Sudip Majumder, senior director of development at Oracle, discussed the technical details of the connected airline baggage and related social media solutions. These IoT applications will enhance travelers' journey experience and drive efficiency for the airlines and the airports.
Feb. 26, 2017 06:45 PM EST Reads: 2,496
In 2014, Amazon announced a new form of compute called Lambda. We didn't know it at the time, but this represented a fundamental shift in what we expect from cloud computing. Now, all of the major cloud computing vendors want to take part in this disruptive technology. In his session at 20th Cloud Expo, John Jelinek IV, a web developer at Linux Academy, will discuss why major players like AWS, Microsoft Azure, IBM Bluemix, and Google Cloud Platform are all trying to sidestep VMs and containers...
Feb. 26, 2017 05:30 PM EST Reads: 2,343
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, whic...
Feb. 26, 2017 05:15 PM EST Reads: 2,013
SYS-CON Events announced today that CA Technologies has been named “Platinum Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business – from apparel to energy – is being rewritten by software. From ...
Feb. 26, 2017 03:45 PM EST Reads: 2,774