JXTA

Project JXTA [36], an industry-wide research project led by Sun Microsystems, was launched on April 25th, 2001. The goal of Project JXTA is to develop protocols for cross-platform communication that provide direct access from one node to another without any centralized server control, and to create a simple, open, lightweight layer of standards that ensures interoperability and scalability when existing software stacks are integrated. Even though current JXTA is developed on top of Java technology, JXTA supposed to be independent from programming platforms, systems platforms, and networking platforms. The claim is that it can be embraced by all developers, independent of their preferred programming languages, existing development environments, or targeted deployment platforms. Currently existing software technologies such as Java, Jini, and Extensible Markup Language (XML) are used by JXTA technology. The goal is a P2P system that is familiar to developers and easy to use. The benefit of using Java technology is the ability to compute on different machines without worrying about operating system limitations. Jini network technology enables spontaneous networking of a wide variety of hardware, and services. XML technology allows data to move across a network in a widely used format. JXTA is developed with the Java 2 Platform, Micro Edition (J2ME) environment. The core classes of JXTA are packed into a jar file of about 250Kbytes. Hence JXTA can easily be stored in many different wireless mobile devices such as Personal Data Assistants, cell phones, and laptops, which can thus be nodes on a P2P network. This makes it possible to access information directly from a PDA to a laptop without going through a centralized server. JXTA has a limited number of concepts at it core. Here we overview some important concepts. A peer is any network device that implements one or more of the JXTA protocols. A collection of peers which have common interests can organize into a peer group. We can identify each peer group by a unique peer group id. Two peers can send and receive message using pipes--currently unidirectional virtual communication channels. All network resources, such as peers, peer groups, pipes and services are represented by an advertisement, which is JXTA's language neutral metadata structure for describing such resources. Along with Jini technology, JXTA technology may become a very useful tool for our pure Java version of HPJava runtime environment.