What is XML and what can it do? -- To the XML Publisher

XML can be used to extend the markup language (Extensible Markup Language ). A tag is an information symbol that a computer can understand. Through this tag, a computer can process articles that contain various information. To define these tags, you can select an international markup language, such as HTML, or use a markup language that is freely determined by people like XML. This is the scalability of the language. XML is simplified from SGML. It mainly uses XML, XSL, and XPath.

The above section is a basic definition of XML, a widely accepted description. Simply put, XML is a descriptive language for data. Although it is a language, it generally does not have the basic functions of common languages-it is recognized and executed by computers. There is also a language that can be used to explain it, so that it can achieve the desired effect or be accepted by computers.

If you are new to XML, you may not be able to understand what XML is. Perhaps, you can understand what XML is from another angle; understand XML from the application side, and know what XML can do to understand it. This should be more helpful to you than the more empty definition.

XML applications are mainly divided into two types: document and data. The following describes several common XML applications:

1. Customize XML + XSLT => HTML, one of the most common document applications. XML stores the XML data of the entire document. Then, XSLT converts and parses the XML, and combines the HTML tags in XSLT into HTML, which is finally displayed on the browser. A typical example is the post on csdn.

2. XML, as a micro-database, is one of the most common data-type applications. We use the relevant XML APIs (MSXML Dom, Java Dom, etc.) to access and query XML. In the implementation of message boards, XML is often used as a database. At the same time, we want to tell new people, databases and database systems. These two concepts are different. The impact of XML on the database system is introduced here. In traditional database systems with new versions, XML becomes a data type. Compared with "traditional", it is a new form of database, which is based entirely on XML-related technologies. Exist, which is more famous than exist.

3. As the carrier of information transmission. Why is it a carrier? Although these applications are still in XML format, they have developed a specific format. The most typical is the Web service, which encapsulates data into XML for transmission, but the XML here already has a specific specification, that is, soap. I still have to say That Ajax and Ajax applications, I believe some of them use their own XML as data, but they have not become the industrial standard. I will not go into detail here.

4. Application configuration data. The most typical web. XML is used when J2EE configures webserver. This application is expected to be easy to understand. We only need to store the required data into XML, and then load the data in our application, and perform corresponding operations based on different data. In fact, it is a bit similar to Application 2. The difference is that the data changes in the database are normal, and the configuration information is often relatively static and lacks changes.

5. XML format of other documents. Such as Word and Excel.

6. Save the ing between data. Such as hibernate.

In these common applications, we can also customize XML and specific XML based on the wide range of applications. 1 and 2 are the categories of custom XML; 3 to 6 are specific XML, or XML extensions.

The six applications described here basically cover the main usage of XML. In short, XML is an abstract language, which is not as detailed as traditional programming languages. To understand it in depth, you should first start with its application, select a purpose you need, and then learn how to use it.

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Sank orange

What is XML and what can it do? -- To the XML Publisher