XML Schema allows us to define the elements and attributes that are present within
an XML file and allows the XML file to be machine validated for correctness. This
second part is important, because XML schema allows us to machine validate XML
files. This means that applications can check that data is valid before they attempt to
process the data.
XML Schema is a W3C Recommendation which was first recommended in May 2001
(http://www.w3.org/TR/2001/REC-xmlschema-0-20010502/). The W3C describes
XML Schema (http://www.w3.org/TR/NOTE-xml-schema-req) as follows:
The XML schema language can be used to define, describe, and catalogue
XML vocabularies for classes of XML documents. Any application of XML
can use the Schema formalism to express syntactic, structural, and value
constraints applicable to its document instances.
Given this knowledge of XML schema, we could define a simple XML schema
(airport.xsd) and XML file (airport.xml) for our airport data structure as follows:
//airport.xsd
targetNamespace="http://xml.netbeans.org/schema/airport"
xmlns:tns="http://xml.netbeans.org/schema/airport"
elementFormDefault="qualified">
??? ??? ??? ???
XML Schema Designer
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//airport.
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