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you're conversant in the JDBC API, or at least SQL. If you're not familiar with JDBC,see Database Programming with JDBCTM and Java M 2 Edition, by George Reese One of Java's most important features is platform independence. Since it was first eleased, Java has been marketed as"write once, run anywhere. While the hype has got ten a little heavy-handed at times, code written with Sun's Java programming language is remarkably platform independent. Enterprise Java Beans isn't just platform independent- it's also implementation independent. If you've worked with JDBC, you know a little about what this means Not only can the JDBC API run on a Windows machine or on a Unix machine, it can also access relational databases of many different vendors(dB2, Oracle Sybase, SQLServer, etc. by using different JDBC drivers. You dont have to code to a particular database implementation; just change JDBC drivers and you change database It's the same with Enterprise JavaBeans. Ideally, an Enterprise JavaBeans component,an enterprise bean, can run in any application server that implements the Enterprise JavaBeans(EJB)specification. This means that you can develop and deploy your EJB business system in one server, such as Orion, and later move it to a different EJB server such as Pramati, BEAs WebLogic, IBMs WebSphere, or open source projects like OpenEJB, JOnAS, and JBoss. Implementation independence means that your business components are not dependent on the brand of server, which means there are more Setting the Stage Before defining Enterprise Java Beans more precisely, lets set the stage by discussing a number of important concepts: distributed objects, business objects, and component transaction monitors and asynchronous messaging Distributed objects Distributed computing allows a business system to be more accessible. Distributed sys- tems allow parts of the system to be located on separate computers, possibly in many dif- ferent locations, where they make the most sense. In other words, distributed computing allows business logic and data to be reached from remote locations. Customers, business partners, and other remote parties can use a business system at any time from almost any- where. The most recent development in distributed computing is distributed objects. DiS- I Provided that the bean components and EJB servers comply with the specification and no proprietary functionality is used in development. Copyright(c)2001 OReilly AssociatesDRAFT 10/21/0107/06/01 Copyright (c) 2001 O'Reilly & Associates you’re conversant in the JDBC API, or at least SQL. If you’re not familiar with JDBC, see Database Programming with JDBC™ and Java™, 2nd Edition, by George Reese. One of Java’s most important features is platform independence. Since it was first released, Java has been marketed as “write once, run anywhere.” While the hype has got￾ten a little heavy-handed at times, code written with Sun’s Java programming language is remarkably platform independent. Enterprise JavaBeans isn’t just platform independent— it’s also implementation independent. If you’ve worked with JDBC, you know a little about what this means. Not only can the JDBC API run on a Windows machine or on a Unix machine, it can also access relational databases of many different vendors (DB2, Oracle, Sybase, SQLServer, etc.) by using different JDBC drivers. You don’t have to code to a particular database implementation; just change JDBC drivers and you change databases. It’s the same with Enterprise JavaBeans. Ideally, an Enterprise JavaBeans component, an enterprise bean, can run in any application server that implements the Enterprise JavaBeans (EJB) specification.1 This means that you can develop and deploy your EJB business system in one server, such as Orion , and later move it to a different EJB server, such as Pramati, BEA’s WebLogic, IBM’s WebSphere, or open source projects like OpenEJB, JOnAS, and JBoss. Implementation independence means that your business components are not dependent on the brand of server, which means there are more options before you begin development, during development, and after deployment. Setting the Stage Before defining Enterprise JavaBeans more precisely, let’s set the stage by discussing a number of important concepts: distributed objects, business objects, and component transaction monitors and asynchronous messaging. Distributed Objects Distributed computing allows a business system to be more accessible. Distributed sys￾tems allow parts of the system to be located on separate computers, possibly in many dif￾ferent locations, where they make the most sense. In other words, distributed computing allows business logic and data to be reached from remote locations. Customers, business partners, and other remote parties can use a business system at any time from almost any￾where. The most recent development in distributed computing is distributed objects. Dis- 1 Provided that the bean components and EJB servers comply with the specification and no proprietary functionality is used in development
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