Perspective "XML middleware"
XML and middleware are undoubtedly two popular technologies, then how are the two combined?
With XML and its related technologies, the development of applications, XML has become an important information publishing standard and representation of the technology, and more and more applications are exchanged. XML's cross-platform sex and strong adaptability quickly got an affirmation in the field of middleware, and therefore produced a large number of related research and related products. At the same time, with the continuous expansion of XML technology, a large number of XML-oriented applications have emerged, objectively put forward a lot of demand for XML-based intermediate services and tools, and some manufacturers and individuals have also put into XML services and tools. . XML Middleware (XML MiddleWare) came into being.
Strictly say that the XML middleware may not be seen as a concept, although some people try to make the next definition, but these definitions still have focused, and it is not good to cover the current existed XML middleware. Products, this may be a new concept to be born chaos, after all, the title of XML middleware has begun to be used everywhere. In general, we can understand the XML middleware as an interface of the database (in XML to query the database, return XML results) or an interface with a web browser (passing XML information, and displayed via XSL organization), of course, This understanding is not very exact. This article does not want to give the definition of the XML middleware, just to reveal the development status of the XML middleware, the comparative analysis of the various so-called XML middleware, the relationship between the intermediate parts and XML, hoping to play the role of torch jade.
According to the situation being grasped, the status of the current middleware and XML is divided into three categories according to the status of XML technology in the middleware implementation and its impact on the function and structure of the intermediate parts.
Old function, new technology - XML technology and traditional middleware function combination from the moment of birth, XML technology has thousands of relationships with data. To understand the relationship between XML and middleware, we can start with this feature, grab the main line of data. For traditional middleware systems, XML technology is most attractive place to describe any type of structural or semi-structural information and feature of rapid packaging and integration of resources, so XML is closely related to data. Applications in related middleware systems, such as database middleware, data integration middleware, and some MOM middleware systems. However, for these traditional middleware systems, XML technology has not changed its original purpose or primary function. For example, database middleware is still responsible for the connection and access of various database systems. The use of XML technology is just changing the original intermediate. Data representation, organization, and delivery of the system. For example, the XMLBLASTER product of the XMLBLASTER workgroup, which delivers messages between publishers and subscribers, but the main functionality of XMLBlaster is still in the MOM middleware system. It is not recognized that XML technology uses the implementation and use of this type of middleware, but its main function does not change, ie XML new technologies, but the old function is constant. New application, old technology - the powerful impact of XML technology XML technology causes the application of XML to XML, such as the spring, spring, the application objectively needs a small type of special intermediate system for its processing and XML Relevant square, including the corresponding XML development interface. For example, DOMPARSER, BML, JDOM, XML Security Suite, EasyXML, Saxon, SAX, Pyxie, XML2beans, DOM4J, COST, DT4DTD, and more. Some of them are modified by the original SGML or HTML tools. Some are parsers for XML documents and patterns (including XML DTD, XML Schema, XDR, SOX, Schematron, DSD, DCD, DDML, etc.) Or XPath's grammatical analyzer, or other technologies to XML development interface or converter, it is a variety of diversified. The collation of these systems is also different. From the perspective of middleware, some people are classified as a class of XML middleware. The intermediate parts that have been used, standards and other traditional middleware products have no essential differences. The real difference should be reflected. Application, strictly said that this is only a further application of middleware technology in the new field, namely, new application directions, old realizes technology. New features, new technology - XML technology and middleware deep binding XML technology impact on middleware technology is not limited thereto, currently, some studies have noticed the technical advantages of XML, and hope to Apply to the design and implementation of the middleware. For example, a large theme in the XML technology and software engineering XSE2001 (XML Technologies and Software Engineering) meeting in Canada is how to develop a new generation of distributed software framework structures and middleware systems through XML technology. It is concentrated in how to apply XML to achieve more flexible integration, security, and collaborative middleware or distributed software. Obviously, it is desirable to bring new vitality and new basic functions to middleware technology by using XML technology. Currently, some intermediate parts such as mobile and adaptive intermediate parts are using XML technology to improve the middleware technology itself. In principle, the research or application of such middleware is different from the two types we have discussed above, XML technology and middleware techniques are more closely coupled, and XML technology has brought functions in the middle part itself. Enhance or new features, so we define it as new features, new technologies. In a sense, the author is more preferred to refer to this type of intermediate unit system as an XML middleware.
To help further understand, the following so-called XML middleware is given below. XML middleware platform for developers to develop SAXMegginson TechnologiesJavaSAX2David MegginsonJavaJDOMThe JDOM ProjectJava SAXONMichael H. KayJavaXML GeneratorIBM alphaWorksJavaXML MasterIBM alphaWorksJavaXML Security SuiteIBM alphaWorksJavaPatMLIBM alphaWorksJavaXML Bean SuiteIBM alphaWorksJavaeasyXMLIBM alphaWorksJava XML Entity and URI ResolversSun MicrosystemsJavaMDSAXJXMLJava Parser FiltersJohn CowanJavaRelaxerAsami TomoharuJavaBMLAnders W. TellJavaXInclude EngineElliotte Rusty HaroldJavaXML TestbedSteve WithallJavaXML UtilitiesDavid BrownellJavaxmlBlasterThe xmlBlaster teamJavaXML :: GroveKen MacLeodPerlXML :: TwigMichel RodriguezPerlXML :: WriterDavid MegginsonPerlWrafThe Wraf TeamPerlCGI :: XMLFormMatt SergeantPerlPython XML packageThe Python XML-SIGPythonPyxieSean McGrathPythonPyXPathDieter MaurerPythonSAX in C Jez HigginsC ExCostJWaytclCostJoe Englishtcl
As can be seen from the above discussion, the XML middleware is actually not a mature concept, and even the concept of the concept. Perhaps it should be said that the XML middleware is an intermediate unit system based on XML technology or a middleware system for XML technology and XML applications. Lu Xun said, "There is no way in the world, but there are more people, but also a road." It is foreseeable that as XML MiddleWare is constantly used, more important is the continuous development of XML technology and middleware technology In-depth, perhaps one day XML middleware will become an exact concept, after all, the middleware and XML belong to two popular technology, and their combination should have greater significance, maybe it is also the same as the development of the middleware concept. Need to take a long way, let us wait and see.
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