|By Jinsong Yang||
|January 14, 2009 09:59 PM EST||
Since its emergence, Web Service technology has gone a long way towards perfecting itself and finding its right application in the real world. With the maturity of the specifications, Web Service technology, with its power of interoperability, is now the major enabling technology of SOA, which is being adopted by more and more enterprises to build their application integration infrastructure.
Developing Web Services involves a variety of technologies, XML processing, SOAP, and WSDL, to name a few. Luckily, there are frameworks that target handling theses kinds of middleware functions, freeing up developers to focus on the business logic.
Nowadays, many Web Service frameworks exist for all kinds of programming languages. Some of them are open source, others are commercially available. Some examples of such frameworks are Apache Axis and Axis2, WS02 Web Services Framework (WSF), Java Web Services Development Pack (GlassFish), JBossWS, and XINS.
Being one of the Web Service frameworks for Java, Apache CXF is an open source framework developed by the Apache Software Foundation. It's a continuation and merging of two open source projects, Codehaus' XFire project and ObjectWeb's Celtix project. When this was written, the stable version was 2.0.
CXF enables the creation of Web Services using Java technologies. It supports a variety of Web Service standards including WS-I Basic Profile 1.0, WS-Addressing, WS-Policy, WS-ReliableMessaging, and WS-Security.
CXF supports transport protocols like HTTP and JMS. The messaging formats supported include SOAP, XML, RESTFul HTTP, and CORBA. Besides JAXB data binding, it also supports Aegis binding.
CXF is JAX-WS (JSR 224)-compliant and version 2.0 has passed the TCK for JAX-WS 2.0. It makes intensive use of Java 5 annotations and so requires JDK/JRE 5.0 and above.
CXF leverages the Spring application framework for bean management. Endpoints and service clients can be managed as Spring beans.
In the first section of this article, a step-by-step Web Service example using CXF is presented. Some of CXF's basic features are revealed while going through the steps of creating the example. Then we'll touch on some of the unique features of CXF, including RESTful service support and Spring integration. At the end, a brief performance test will compare CXF with JBossWS and the JAX-WS Reference Implementation (RI).
An Example: Getting Movie Show Times
In this example, we'll build a Web Service that lets a client system query for movie show times using the ZIP code entered by a user. For demonstration purposes, most of the irrelevant details are ignored.
CXF supports both code-first development and contract-first development. While code-first development is a handy feature, and most developers find it more straightforward and easier to get start with, it has a vital weakness.
There are several reasons for this. First, a key aspect in successfully developing Web Services is to determine its granularity. Considering the fact that the major application of Web Services is to implement SOA solution at a really high level (e.g., at the enterprise level), the granularity couldn't be too small. In contrast are the Java classes and methods, which tend to be very fine-grained, and are often designed at the very low level (i.e. the class level). Secondly, Web Services bare the nature of language neutral. Building a service from a specific language (like Java) and transforming it into a language-neutral form through some tools would, in some cases, bring over language-specific features, which will degrade the language-neutral nature, thus hurt the interoperability, of the service. Lastly, from a design point of view, service-oriented principles are significantly different from object-oriented paradigms. Although an individual service might be realized using OO principles and techniques, the interaction between services rarely using any of them.
Due to the aforementioned reasons, code-first development will never let you get to the spirit of service-oriented development because developing in Java code and developing in WSDL requires different mindset. Developing with Java code-first and avoiding WSDL as much as possible will guarantee that you will build mediocre software at the best. This is especially true when it comes to designing and developing a SOA solution rather than just individual services.
With that said, let's start with contract-first development for our example, the first step of which is to create the contract - the WSDL document that describes the service.
Listing 1 shows a segment of the WSDL document. In this document a service called MovieService is defined. This service has only one operation GetShowtimesForZip. The input of this operation is a message containing the ZIP code that the user entered, and the response is a list of theaters and movies along with show times.
The types are defined in a separated XML Schema document and are imported using <xsd:import> statement. The schema document isn't listed here to avoid lengthy text.
Nothing is really special about this WSDL document. Let's now generate the service interface and the service endpoint interface (SEI) from the WSDL document.
Service and Service Endpoint Interfaces
With the WSDL document ready, our next step is to generate server-side Java code from it. CXF provides a tool called wsdl2java that can be used to generate fully annotated Java code from a WSDL document. This tool operates according to the JAX-WS rules for WSDL <--> Java mapping, and its data binding mechanism conforms to JAXB (JSR 22). The tool comes with a set of optional arguments that allow control of the behavior of the tool.
The WSDL document used to generate the Java code has to have a valid portType element, but it doesn't require a binding element or a service element.
The simplest form of running the tool on the command line is listed in Listing 2.
You can specify the package of the generated code using the -p option as shown in Listing 3.
JAX-WS defines an XML-based binding language that can be used to customize the WSDL to Java bindings. The wsdl2java tool implements this feature using the -b option. Listing 4 shows how to specify a JAX-WS binding file for customization.
You can ask the tool to generate an Ant build file for use in your application. To do so, use the -ant option as shown in Listing 5:
Or you can define your own Ant macro. A sample of such a macro is included in the CXF distribution. Listing 6 shows a modified version of it.
|kuldeep_saini83 08/29/09 08:33:00 PM EDT|
|yogesh 10/06/08 02:27:38 PM EDT|
Avnet, Inc. has announced that it ranked No. 4 on the InformationWeek Elite 100 – a list of the top business technology innovators in the U.S. Avnet was recognized for the development of an innovative cloud-based training system that serves as the foundation for Avnet Academy – the company’s education and training organization focused on technical training around top IT vendor technologies. The development of this system allowed Avnet to quickly expand its IT-related training capabilities around the world, while creating a new service that Avnet and its IT solution providers can offer to their...
May. 4, 2015 01:30 PM EDT Reads: 540
The Internet of Things Maturity Model (IoTMM) is a qualitative method to gauge the growth and increasing impact of IoT capabilities in an IT environment from both a business and technology perspective. In his session at @ThingsExpo, Tony Shan will first scan the IoT landscape and investigate the major challenges and barriers. The key areas of consideration are identified to get started with IoT journey. He will then pinpoint the need of a tool for effective IoT adoption and implementation, which leads to IoTMM in which five maturity levels are defined: Advanced, Dynamic, Optimized, Primitive,...
May. 4, 2015 12:00 PM EDT Reads: 1,053
SYS-CON Events announced today that B2Cloud, a provider of enterprise resource planning software, will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. B2cloud develops the software you need. They have the ideal tools to help you work with your clients. B2Cloud’s main solutions include AGIS – ERP, CLOHC, AGIS – Invoice, and IZUM
May. 4, 2015 12:00 PM EDT Reads: 4,410
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo in Silicon Valley. 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 Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal an...
May. 4, 2015 11:22 AM EDT Reads: 457
Enterprise IoT is an exciting and chaotic space with a lot of potential to transform how the enterprise resources are managed. In his session at @ThingsExpo, Hari Srinivasan, Sr Product Manager at Cisco, will describe the challenges in enabling mass adoption of IoT, and share perspectives and insights on architectures/standards/protocols that are necessary to build a healthy ecosystem and lay the foundation to for a wide variety of exciting IoT use cases in the years to come.
May. 4, 2015 11:00 AM EDT Reads: 1,203
The world's leading Cloud event, Cloud Expo has launched Microservices Journal on the SYS-CON.com portal, featuring over 19,000 original articles, news stories, features, and blog entries. DevOps Journal is focused on this critical enterprise IT topic in the world of cloud computing. Microservices Journal 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. Follow new article posts on Twitter at @MicroservicesE
May. 4, 2015 11:00 AM EDT Reads: 2,861
Containers and microservices have become topics of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 16th Cloud Expo at the Javits Center in New York June 9-11 will find fresh new content in a new track called PaaS | Containers & Microservices Containers are not being considered for the first time by the cloud community, but a current era of re-consideration has pushed them to the top of the cloud agenda. With the launch of Docker's initial release in March of 2013, interest was revved up several notches. Then late last...
May. 4, 2015 11:00 AM EDT Reads: 3,808
There is no doubt that Big Data is here and getting bigger every day. Building a Big Data infrastructure today is no easy task. There are an enormous number of choices for database engines and technologies. To make things even more challenging, requirements are getting more sophisticated, and the standard paradigm of supporting historical analytics queries is often just one facet of what is needed. As Big Data growth continues, organizations are demanding real-time access to data, allowing immediate and actionable interpretation of events as they happen. Another aspect concerns how to deliver ...
May. 4, 2015 11:00 AM EDT Reads: 5,695
WebRTC defines no default signaling protocol, causing fragmentation between WebRTC silos. SIP and XMPP provide possibilities, but come with considerable complexity and are not designed for use in a web environment. In his session at @ThingsExpo, Matthew Hodgson, technical co-founder of the Matrix.org, discussed how Matrix is a new non-profit Open Source Project that defines both a new HTTP-based standard for VoIP & IM signaling and provides reference implementations.
May. 4, 2015 10:45 AM EDT Reads: 4,262
So I guess we’ve officially entered a new era of lean and mean. I say this with the announcement of Ubuntu Snappy Core, “designed for lightweight cloud container hosts running Docker and for smart devices,” according to Canonical. “Snappy Ubuntu Core is the smallest Ubuntu available, designed for security and efficiency in devices or on the cloud.” This first version of Snappy Ubuntu Core features secure app containment and Docker 1.6 (1.5 in main release), is available on public clouds, and for ARM and x86 devices on several IoT boards. It’s a Trend! This announcement comes just as...
May. 4, 2015 10:45 AM EDT Reads: 2,178
The security devil is always in the details of the attack: the ones you've endured, the ones you prepare yourself to fend off, and the ones that, you fear, will catch you completely unaware and defenseless. The Internet of Things (IoT) is nothing if not an endless proliferation of details. It's the vision of a world in which continuous Internet connectivity and addressability is embedded into a growing range of human artifacts, into the natural world, and even into our smartphones, appliances, and physical persons. In the IoT vision, every new "thing" - sensor, actuator, data source, data con...
May. 4, 2015 10:30 AM EDT Reads: 5,303
It's time to put the "Thing" back in IoT. Whether it’s drones, robots, self-driving cars, ... There are multiple incredible examples of the power of IoT nowadays that are shadowed by announcements of yet another twist on statistics, databases, .... Sorry, I meant, Big Data(TM), tiered storage(TM), complex systems(TM), smart nations(TM), .... In his session at WebRTC Summit, Dr Alex Gouaillard, CTO and Co-Founder of Temasys, will discuss the concrete, cool, examples of IoT already happening today, and how mixing all those different sources of visual and audio input can make your life happier ...
May. 4, 2015 10:04 AM EDT Reads: 451
SYS-CON Events announced today the IoT Bootcamp – Jumpstart Your IoT Strategy, being held June 9–10, 2015, in conjunction with 16th Cloud Expo and Internet of @ThingsExpo at the Javits Center in New York City. This is your chance to jumpstart your IoT strategy. Combined with real-world scenarios and use cases, the IoT Bootcamp is not just based on presentations but includes hands-on demos and walkthroughs. We will introduce you to a variety of Do-It-Yourself IoT platforms including Arduino, Raspberry Pi, BeagleBone, Spark and Intel Edison. You will also get an overview of cloud technologies s...
May. 4, 2015 10:00 AM EDT Reads: 3,878
The Internet of Things is not new. Historically, smart businesses have used its basic concept of leveraging data to drive better decision making and have capitalized on those insights to realize additional revenue opportunities. So, what has changed to make the Internet of Things one of the hottest topics in tech? In his session at @ThingsExpo, Chris Gray, Director, Embedded and Internet of Things, discussed the underlying factors that are driving the economics of intelligent systems. Discover how hardware commoditization, the ubiquitous nature of connectivity, and the emergence of Big Data a...
May. 4, 2015 10:00 AM EDT Reads: 5,474
Scott Jenson leads a project called The Physical Web within the Chrome team at Google. Project members are working to take the scalability and openness of the web and use it to talk to the exponentially exploding range of smart devices. Nearly every company today working on the IoT comes up with the same basic solution: use my server and you'll be fine. But if we really believe there will be trillions of these devices, that just can't scale. We need a system that is open a scalable and by using the URL as a basic building block, we open this up and get the same resilience that the web enjoys.
May. 4, 2015 09:45 AM EDT Reads: 5,819
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
May. 4, 2015 09:45 AM EDT Reads: 3,359
The WebRTC Summit 2015 New York, to be held June 9-11, 2015, at the Javits Center in New York, NY, announces that its Call for Papers is open. Topics include all aspects of improving IT delivery by eliminating waste through automated business models leveraging cloud technologies. WebRTC Summit is co-located with 16th International Cloud Expo, @ThingsExpo, Big Data Expo, and DevOps Summit.
May. 4, 2015 09:15 AM EDT Reads: 3,101
There are lots of challenges in IoT around secure, scalable and business friendly infrastructure for enterprises. For large corporations, IoT implementations are one of the top priorities of the decade. All industries are seeing a competitive need to sustain by investing in IoT initiatives. The value addition comes from improved customer service, innovative product and additional revenue streams. The data from these IP-connected devices can be leveraged for a variety of business applications as well as responsive action controls. The various architectural building blocks of an IoT ...
May. 4, 2015 09:00 AM EDT Reads: 1,117
Chuck Piluso will present a study of cloud adoption trends and the power and flexibility of IBM Power and Pureflex cloud solutions. Speaker Bio: Prior to Data Storage Corporation (DSC), Mr. Piluso founded North American Telecommunication Corporation, a facilities-based Competitive Local Exchange Carrier licensed by the Public Service Commission in 10 states, serving as the company's chairman and president from 1997 to 2000. Between 1990 and 1997, Mr. Piluso served as chairman & founder of International Telecommunications Corporation, a facilities-based international carrier licensed by t...
May. 4, 2015 09:00 AM EDT Reads: 782
Recent technology advances in miniaturization has positioned the wearables as the pinnacle of technology convergence with the human body. We inquire if wearables are mere standard miniaturized devices extended with the connectivity and present our views on considerations like design, applications, performance, efficiency, interoperability, usage scenarios, human device interaction and consequent trade-offs enabling wearables to impart optimal value.
May. 4, 2015 08:00 AM EDT Reads: 1,736