1、英文原文:Title: Business Applications of Java. Author: Erbschloe, Michael, Business Applications of Java - Research Starters Business, 2008DataBase: Research Starters - BusinessBusiness Applications of Java This article examines the growing use of Java technology in business applications. The history of
2、 Java is briefly reviewed along with the impact of open standards on the growth of the World Wide Web. Key components and concepts of the Java programming language are explained including the Java Virtual Machine. Examples of how Java is being used by e-commerce leaders is provided along with an exp
3、lanation of how Java is used to develop data warehousing, data mining, and industrial automation applications. The concept of metadata modeling and the use of Extendable Markup Language (XML) are also explained.Keywords Application Programming Interfaces (APIs); Enterprise JavaBeans (EJB); Extendabl
4、e Markup Language (XML); HyperText Markup Language (HTML); HyperText Transfer Protocol (HTTP); Java Authentication and Authorization Service (JAAS); Java Cryptography Architecture (JCA); Java Cryptography Extension (JCE); Java Programming Language; Java Virtual Machine (JVM); Java2 Platform, Enterpr
5、ise Edition (J2EE); MetadataBusiness Information Systems Business Applications of Java Overview Open standards have driven the e-business revolution. Networking protocol standards, such as Transmission Control Protocol/Internet Protocol (TCP/IP), HyperText Transfer Protocol (HTTP), and the HyperText
6、 Markup Language (HTML) Web standards have enabled universal communication via the Internet and the World Wide Web. As e-business continues to develop, various computing technologies help to drive its evolution.The Java programming language and platform have emerged as major technologies for perform
7、ing e-business functions. Java programming standards have enabled portability of applications and the reuse of application components across computing platforms. Sun Microsystems Java Community Process continues to be a strong base for the growth of the Java infrastructure and language standards. Th
8、is growth of open standards creates new opportunities for designers and developers of applications and services (Smith, 2001).Creation of Java Technology Java technology was created as a computer programming tool in a small, secret effort called the Green Project at Sun Microsystems in 1991. The Gre
9、en Team, fully staffed at 13 people and led by James Gosling, locked themselves away in an anonymous office on Sand Hill Road in Menlo Park, cut off from all regular communications with Sun, and worked around the clock for 18 months. Their initial conclusion was that at least one significant trend w
10、ould be the convergence of digitally controlled consumer devices and computers. A device-independent programming language code-named Oak was the result.To demonstrate how this new language could power the future of digital devices, the Green Team developed an interactive, handheld home-entertainment
11、 device controller targeted at the digital cable television industry. But the idea was too far ahead of its time, and the digital cable television industry wasnt ready for the leap forward that Java technology offered them. As it turns out, the Internet was ready for Java technology, and just in tim
12、e for its initial public introduction in 1995, the team was able to announce that the Netscape Navigator Internet browser would incorporate Java technology (Learn about Java, 2007).Applications of Java Java uses many familiar programming concepts and constructs and allows portability by providing a
13、common interface through an external Java Virtual Machine (JVM). A virtual machine is a self-contained operating environment, created by a software layer that behaves as if it were a separate computer. Benefits of creating virtual machines include better exploitation of powerful computing resources
14、and isolation of applications to prevent cross-corruption and improve security (Matlis, 2006).The JVM allows computing devices with limited processors or memory to handle more advanced applications by calling up software instructions inside the JVM to perform most of the work. This also reduces the
15、size and complexity of Java applications because many of the core functions and processing instructions were built into the JVM. As a result, software developers no longer need to re-create the same application for every operating system. Java also provides security by instructing the application to
16、 interact with the virtual machine, which served as a barrier between applications and the core system, effectively protecting systems from malicious code.Among other things, Java is tailor-made for the growing Internet because it makes it easy to develop new, dynamic applications that could make th
17、e most of the Internets power and capabilities. Java is now an open standard, meaning that no single entity controls its development and the tools for writing programs in the language are available to everyone. The power of open standards like Java is the ability to break down barriers and speed up
18、progress.Today, you can find Java technology in networks and devices that range from the Internet and scientific supercomputers to laptops and cell phones, from Wall Street market simulators to home game players and credit cards. There are over 3 million Java developers and now there are several ver
19、sions of the code. Most large corporations have in-house Java developers. In addition, the majority of key software vendors use Java in their commercial applications (Lazaridis, 2003).Applications Java on the World Wide Web Java has found a place on some of the most popular websites in the world and
20、 the uses of Java continues to grow. Java applications not only provide unique user interfaces, they also help to power the backend of websites. Two e-commerce giants that everybody is probably familiar with (eBay and Amazon) have been Java pioneers on the World Wide Web.eBay Founded in 1995, eBay e
21、nables e-commerce on a local, national and international basis with an array of Web sites-including the eBay marketplaces, PayPal, Skype, R and S-that bring together millions of buyers and sellers every day. You can find it on eBay, even if you didnt know it existed. On a typical day, more than 100
22、million items are listed on eBay in tens of thousands of categories. Recent listings have included a tunnel boring machine from the Chunnel project, a cup of water that once belonged to Elvis, and the Volkswagen that Pope Benedict XVI owned before he moved up to the Popemobile. More than one hundred
23、 million items are available at any given time, from the massive to the miniature, the magical to the mundane, on eBay; the worlds largest online marketplace.eBay uses Java almost everywhere. To address some security issues, eBay chose Sun Microsystems Java System Identity Manager as the platform fo
24、r revamping its identity management system. The task at hand was to provide identity management for more than 12,000 eBay employees and contractors.Now more than a thousand eBay software developers work daily with Java applications. Javas inherent portability allows eBay to move to new hardware to t
25、ake advantage of new technology, packaging, or pricing, without having to rewrite Java code (eBay drives explosive growth, 2007).Amazon A (a large seller of books, CDs, and other products) has created a Web Service application that enables users to browse their product catalog and place orders. A us
26、es a Java application that searches the Amazon catalog for books whose subject matches a user-selected topic. The application displays ten books that match the chosen topic, and shows the author name, book title, list price, Amazon discount price, and the cover icon. The user may optionally view one
27、 review per displayed title and make a buying decision (Stearns & Garishakurthi, 2003).Java in Data Warehousing & Mining Although many companies currently benefit from data warehousing to support corporate decision making, new business intelligence approaches continue to emerge that can be powered b
28、y Java technology. Applications such as data warehousing, data mining, Enterprise Information Portals (EIPs), and Knowledge Management Systems (which can all comprise a business intelligence application) are able to provide insight into customer retention, purchasing patterns, and even future buying
29、 behavior.These applications can not only tell what has happened but why and what may happen given certain business conditions; allowing for what if scenarios to be explored. As a result of this information growth, people at all levels inside the enterprise, as well as suppliers, customers, and othe
30、rs in the value chain, are clamoring for subsets of the vast stores of information such as billing, shipping, and inventory information, to help them make business decisions. While collecting and storing vast amounts of data is one thing, utilizing and deploying that data throughout the organization
31、 is another.The technical challenges inherent in integrating disparate data formats, platforms, and applications are significant. However, emerging standards such as the Application Programming Interfaces (APIs) that comprise the Java platform, as well as Extendable Markup Language (XML) technologie
32、s can facilitate the interchange of data and the development of next generation data warehousing and business intelligence applications. While Java technology has been used extensively for client side access and to presentation layer challenges, it is rapidly emerging as a significant tool for devel
33、oping scaleable server side programs. The Java2 Platform, Enterprise Edition (J2EE) provides the object, transaction, and security support for building such systems.Metadata Issues One of the key issues that business intelligence developers must solve is that of incompatible metadata formats. Metada
34、ta can be defined as information about data or simply data about data. In practice, metadata is what most tools, databases, applications, and other information processes use to define, relate, and manipulate data objects within their own environments. It defines the structure and meaning of data obj
35、ects managed by an application so that the application knows how to process requests or jobs involving those data objects. Developers can use this schema to create views for users. Also, users can browse the schema to better understand the structure and function of the database tables before launchi
36、ng a query.To address the metadata issue, a group of companies (including Unisys, Oracle, IBM, SAS Institute, Hyperion, Inline Software and Sun) have joined to develop the Java Metadata Interface (JMI) API. The JMI API permits the access and manipulation of metadata in Java with standard metadata se
37、rvices. JMI is based on the Meta Object Facility (MOF) specification from the Object Management Group (OMG). The MOF provides a model and a set of interfaces for the creation, storage, access, and interchange of metadata and metamodels (higher-level abstractions of metadata). Metamodel and metadata
38、interchange is done via XML and uses the XML Metadata Interchange (XMI) specification, also from the OMG. JMI leverages Java technology to create an end-to-end data warehousing and business intelligence solutions framework.Enterprise JavaBeans A key tool provided by J2EE is Enterprise JavaBeans (EJB
39、), an architecture for the development of component-based distributed business applications. Applications written using the EJB architecture are scalable, transactional, secure, and multi-user aware. These applications may be written once and then deployed on any server platform that supports J2EE.
40、The EJB architecture makes it easy for developers to write components, since they do not need to understand or deal with complex, system-level details such as thread management, resource pooling, and transaction and security management. This allows for role-based development where component assemble
41、rs, platform providers and application assemblers can focus on their area of responsibility further simplifying application development.EJBs in the Travel Industry A case study from the travel industry helps to illustrate how such applications could function. A travel company amasses a great deal of
42、 information about its operations in various applications distributed throughout multiple departments. Flight, hotel, and automobile reservation information is located in a database being accessed by travel agents worldwide. Another application contains information that must be updated with credit a
43、nd billing history from a financial services company. Data is periodically extracted from the travel reservation system databases to spreadsheets for use in future sales and marketing analysis.Utilizing J2EE, the company could consolidate application development within an EJB container, which can ru
44、n on a variety of hardware and software platforms allowing existing databases and applications to coexist with newly developed ones. EJBs can be developed to model various data sets important to the travel reservation business including information about customer, hotel, car rental agency, and other
45、 attributes.Data Storage & Access Data stored in existing applications can be accessed with specialized connectors. Integration and interoperability of these data sources is further enabled by the metadata repository that contains metamodels of the data contained in the sources, which then can be ac
46、cessed and interchanged uniformly via the JMI API. These metamodels capture the essential structure and semantics of business components, allowing them to be accessed and queried via the JMI API or to be interchanged via XML. Through all of these processes, the J2EE infrastructure ensures the securi
47、ty and integrity of the data through transaction management and propagation and the underlying security architecture.To consolidate historical information for analysis of sales and marketing trends, a data warehouse is often the best solution. In this example, data can be extracted from the operatio
48、nal systems with a variety of Extract, Transform and Load tools (ETL). The metamodels allow EJBs designed for filtering, transformation, and consolidation of data to operate uniformly on data from diverse data sources as the bean is able to query the metamodel to identify and extract the pertinent f
49、ields. Queries and reports can be run against the data warehouse that contains information from numerous sources in a consistent, enterprise-wide fashion through the use of the JMI API (Mosher & Oh, 2007).Java in Industrial Settings Many people know Java only as a tool on the World Wide Web that enables sites to perform some of their fancier functions such as interactivity and animation. However, the actual uses for Java are much more widesprea