JBoss is an alternative open source software. It broke the old concept of open source software and could not make money, and won the development return by providing commercial services. This is an innovation of open source software development. JBoss is an alternative open source software that breaks people's understanding: Open source software cannot make money. However, JBoss organizational chief architect Bill Burke said: "JBoss is different from other open source software, which provides commercial services for open source software. And other open source software does not provide such services." That is, you can free Get JBoss source code or installation package, but if you have a technical problem, you will pay for the JBoss organization or you want to get training. About JBoss JBoss is written with pure Java, open source, follow the J2EE specification application server software, which follows the LGPL Open Source Protocol. JBoss was originally just an EJB container, which later gradually developed into a computer with complex function. Now, the highest version is 4.0. It has been created to the present and experienced a four-year development process.
JBoss architecture
JBoss is a very important project. It reflects the open source of JBoss, unrelated to the platform, fully follow the J2EE specification and easy installation. It contains built-in web server (support JSP, Servlet, and HTML), EJB2.0 container, built-in relational database Hypersonic, Java Message Service (JMS), JavaMail, Java Transaction Interface / Java Transaction Service (JTA / JTS) support. In addition, JBoss4.0 previous versions, only Tomcat acts as a built-in web server. However, starting from JBoss4.0, another optional JBoss Web server - Jetty is available. The characteristic of the JBoss architecture is the core of the Micronarian JBoss complies with Sun's JMX specification. JMX is equivalent to a soft bus, its main job is to support hot-swap service components, manage the living components' life. Hot-swappable service component JBoss contains a series of micro-kernel-based service components. These service components can be transaction components, message queue components, mail service components, secure service components, or connection service components. It draws on the essence of plug-in, allowing these service components to be hot deployed in the form of packaging. The interface layer interface is implemented with the AOP framework. It allows the system to easily access service components, any way to any object. It is worth mentioning that the EJB container in jboss is implemented in this way. The application layer application layer is where the application is deployed. JBoss supports thermal deployment features. You don't have to restart the server, you can dynamically add or delete such as EJB services, making developing new applications easier. JBoss popular reasons can be used to get a variety of benefits: you can get free software, even if it is used for commercial purposes; 100% pure Java, easy installation, small system resources, starting time than standard J2EE server is 10 times fast; deployment The new application is very convenient and highly scalable; can be widely supported, and is currently included in J2EE standard services by SUN. Not only that, if you use a download amount to measure the popularity of a software, it can be said that JBoss is very popular. According to statistics, JBoss was approximately 2 million JBoss in 2002. So far, its downloads are continuously rising. It is currently one of the world's most popular J2EE application server software, with 25% market share. JBoss's power, its installation is also very simple: After decompressing the downloaded file, modify several environment variables (not required) can run. Since JBoss is based on JMX microcalence, it can dynamically manage those components that are deployed. With the management console provided by JBoss, the components can be arbitrarily modified. For example, if an EJB is deployed, JBOSS will automatically generate a deployment MBean and will be displayed on the management console. By this MBean, this EJB is dynamically deleted or deployed, and you can view or modify its status. Since JBoss is open source, it can be extended as long as you need to extend its management console and add some interface elements. Maybe in some people, open source means no quality assurance. But that is not the case. Open source software is facing users with better quality. Since the operation of JBoss organizations is to charge service costs, it has financial resources to develop software and new versions. Therefore, JBoss is higher than other commercial application server software costs. In addition, it is worth mentioning that JBoss's technical support is directly exchanged with customers directly. Therefore, the quality of service will be better, and can even do JBoss for the customer. The latest version of JBoss 4.0 in the JBoss4.0 version, JBoss absorbed some good design concepts to .NET.
For example, support in the Meta tag in the source code. It can be considered that the JBoss organization is similar to Borland. It is not only absorbing good technical experience, regardless of the other party is mircrosoft or sun. In JBoss4.0, the JBoss organizes Fleury, Fleury, decided to gradually detach this version from J2EE specification and add some new features. Fleury pointed out: "We have some trip to J2EE standard, but we will still support it, we will let developers have a simpler, deeper development environment-AOP (style-oriented programming)" AOP for JBoss organizations, A very important innovation. Because it is not only a feature of JBoss, but an impact on program design methods. If you use it, AOP allows you to find their common features from different classes, which is similar to multiple inheritance. Therefore, AOP can bring a lot of benefits, such as adding a behavior to a class without having to change its source code, which gives the project's post-maintenance. The AOP framework defines some unique concepts such as Interceptor, Pointcut, etc. Interceptor meaning interceptor, it can intercept a method of the object, thus adding controls such as security, transaction, permissions check, as in Windows in WINDOWS. JBOSS allows yourself to define your own interceptor, which interceptor and Pointcut are you determined by an object. The so-called PointCut is an XML configuration file. It is used to configure interceptor, and very flexible, and can specify any interceptor for any method of any kind. At present, JBoss4.0 has only launched a development version, and its production version is coming soon. The release of the release will directly support JDO (an alternative method of java data objects, EJB), in addition, enhanced JMS allows cluster functions and supports distributed transactions. More importantly, it fully follows J2EE 1.4 specification. About JBoss organization JBoss organizations is a commercial service organization located in Atlanta, USA. They provide technical support and consultants for JBoss application servers. JBoss organizes the Chief Soft Square of JBS, said they provide services to our customers with hours, and different from traditional fixed-charge mode. However, JBoss's own development and maintenance is free. "In our CVS server, updated bugs and patches are free, and any new features are added free, but if we want to customize a feature, then they will charge." Burke said. JBoss organizations will give bonuses or dividends for those contributors. Marc Fleury, chairman of JBoss organization, said: "We will give material encouragement for participants who contribute to JBoss," JBoss and J2EE specification In 1999, Marc Fleury established JBoss open source project, now it has 100 active Developers, 30 core developers, up to 350,000 downloads per month. Since JBoss3.0 has joined cluster technology, cluster management, such as session, EJB, etc. in JDI, JSP, etc. JBoss is an application server built on the J2EE specification. The J2EE (Java2 SDK Enterprise Edition) specification is made by Sun. It defines components based on components, develops, assembles, and deploys all components of the enterprise application system.
