xml 入门 dtd

xml dtd的格式：

<?xml version="1.0" encoding="UTF-8"?><!ELEMENT classroom (className,grade,students)><!ATTLIST classroom id ID #REQUIRED><!ELEMENT className (#PCDATA)><!ELEMENT grade (#PCDATA)><!ELEMENT students (student+)><!ELEMENT student (id,name,age)><!ELEMENT id (#PCDATA)><!ELEMENT name (#PCDATA)><!ELEMENT age (#PCDATA)>

相应的xml文件：

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE classroom SYSTEM "classroom.dtd"><!--<!DOCTYPE classroom PUBLIC "http://www.zizhu.com/classroom">--><classroom id="p1">    <className>2010计算机应用技术</className>    <grade>2010</grade>    <students>        <student>            <id>11</id>            <name>zizhu8</name>            <age>20</age>        </student>        <student>             <id>12</id>            <name>zizhu3</name>            <age>20</age>        </student>    </students></classroom>