学习DTD和Schema的几个例子

　　可以使用DTD（文档类型定义）来规定xml文档构建模块，可用起对xml文件进行验证。具体用法转：http://www.w3school.com.cn/dtd/dtd_intro.asp。同样也可以用Schema来实现DTD的功能，并且Schema因为其本身可以规定数据类型和其扩展性要优于DTD，并且将逐步取代DTD，具体用法转：http://www.w3school.com.cn/schema/index.asp

例子1：给xml文件编写对应的DTD文件

ex1.xml文件：

<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE game SYSTEM "game.dtd">
<!--
    Date:2016/1/26
    Writer:Wayne Ng
    Theme:MapleStory hero briefInstruction
-->
<game>
    <warrior>
        <hero>
            <name>英雄</name>
            <weapons>剑、斧、钝器</weapons>
            <skill>终极打击</skill>
        </hero>
        <hero>
            <name>圣骑士</name>
            <weapons>剑、钝器</weapons>
            <skill>神圣冲击</skill>
        </hero>
        <hero>
            <name>黑骑士</name>
            <weapons>长枪、矛</weapons>
            <skill>黑暗穿刺</skill>
        </hero>
    </warrior>
    <magician>
        <hero>
            <name>主教</name>
            <weapons>长杖、短仗</weapons>
            <skill>圣光普照</skill>
        </hero>
        <hero>
            <name>火毒法师</name>
            <weapons>长杖、短仗</weapons>
            <skill>末日火焰</skill>
        </hero>
        <hero>
            <name>冰雷法师</name>
            <weapons>长杖、短仗</weapons>
            <skill>冰咆哮</skill>
        </hero>
    </magician>
    <archer>
        <hero>
            <name>神射手</name>
            <weapons>弓</weapons>
            <skill>暴风箭雨</skill>
        </hero>
        <hero>
            <name>箭神</name>
            <weapons>弩</weapons>
            <skill>终极扫射</skill>
        </hero>
    </archer>
    <ranger>
        <hero>
            <name>侠盗</name>
            <weapons>短剑、短刀</weapons>
            <skill>暗杀</skill>
        </hero>
        <hero>
            <name>隐士</name>
            <weapons>拳套</weapons>
            <skill>四连镖</skill>
        </hero>
        <hero>
            <name>暗影双刀</name>
            <weapons>短剑、短刀</weapons>
            <skill>终极斩</skill>
        </hero>
    </ranger>
</game>

game.dtd文件：

<!ELEMENT warrior  (#PCDATA)>
<!ELEMENT hero  (#PCDATA)>
<!ELEMENT name  (#PCDATA)>
<!ELEMENT weapons  (#PCDATA)>
<!ELEMENT skill  (#PCDATA)>
<!ELEMENT magician  (#PCDATA)>
<!ELEMENT archer  (#PCDATA)>
<!ELEMENT ranger  (#PCDATA)>

例子2：使用Schema实现例1的功能

ex2.xml文件：

<?xml version = "1.0" encoding = "UTF-8"?>
<!--
    Date:2016/1/26
    Writer:Wayne Ng
    Theme:MapleStory hero briefInstruction
-->
<game xmlns="http://www.w3school.com.cn"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="game.xsd">
    <warrior>
        <hero>
            <name>英雄</name>
            <weapons>剑、斧、钝器</weapons>
            <skill>终极打击</skill>
        </hero>
        <hero>
            <name>圣骑士</name>
            <weapons>剑、钝器</weapons>
            <skill>神圣冲击</skill>
        </hero>
        <hero>
            <name>黑骑士</name>
            <weapons>长枪、矛</weapons>
            <skill>黑暗穿刺</skill>
        </hero>
    </warrior>
    <magician>
        <hero>
            <name>主教</name>
            <weapons>长杖、短仗</weapons>
            <skill>圣光普照</skill>
        </hero>
        <hero>
            <name>火毒法师</name>
            <weapons>长杖、短仗</weapons>
            <skill>末日火焰</skill>
        </hero>
        <hero>
            <name>冰雷法师</name>
            <weapons>长杖、短仗</weapons>
            <skill>冰咆哮</skill>
        </hero>
    </magician>
    <archer>
        <hero>
            <name>神射手</name>
            <weapons>弓</weapons>
            <skill>暴风箭雨</skill>
        </hero>
        <hero>
            <name>箭神</name>
            <weapons>弩</weapons>
            <skill>终极扫射</skill>
        </hero>
    </archer>
    <ranger>
        <hero>
            <name>侠盗</name>
            <weapons>短剑、短刀</weapons>
            <skill>暗杀</skill>
        </hero>
        <hero>
            <name>隐士</name>
            <weapons>拳套</weapons>
            <skill>四连镖</skill>
        </hero>
        <hero>
            <name>暗影双刀</name>
            <weapons>短剑、短刀</weapons>
            <skill>终极斩</skill>
        </hero>
    </ranger>
</game>

game.xsd文件：

<?xml version="1.0" encoding = "UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://www.w3school.com.cn"
xmlns="http://www.w3school.com.cn"
elementFormDefault="qualified" />
<!--简单元素的定义-->
<xs:element name = "name" type = "xs:string" />
<xs:element name = "weapons" type = "xs:string" />
<xs:element name = "skill" type = "xs:string" />
 
<!--复杂元素的定义-->
<xs:element name = "hero">
    <xs:complexType>
        <xs:sequence>
            <xs:element ref = "name" />
            <xs:element ref = "weapons" />
            <xs:element ref = "skill" />
        </xs:sequence>
    </xs:complexType>
</xs:element>
<xs:element name = "warrior">
    <xs:complexType>
        <xs:sequence>
            <xs:element ref = "hero" maxOccurs = "unbounded"/>
        </xs:sequence>
    </xs:complexType>
</xs:element>
<xs:element name = "magician">
    <xs:complexType>
        <xs:sequence>
            <xs:element ref = "hero" maxOccurs = "unbounded"/>
        </xs:sequence>
    </xs:complexType>
</xs:element>
<xs:element name = "archer">
    <xs:complexType>
        <xs:sequence>
            <xs:element ref = "hero" maxOccurs = "unbounded"/>
        </xs:sequence>
    </xs:complexType>
</xs:element>
<xs:element name = "ranger">
    <xs:complexType>
        <xs:sequence>
            <xs:element ref = "hero" maxOccurs = "unbounded"/>
        </xs:sequence>
    </xs:complexType>
</xs:element>
<xs:element name = "game">
    <xs:complexType>
        <xs:sequence>
            <xs:element ref = "warrior" />
            <xs:element ref = "magician" />
            <xs:element ref = "archer" />
            <xs:element ref = "ranger" />
        </xs:sequence>
    </xs:complexType>
</xs:element>

　　　　　　2016/1/27修订　　By野马菌