<?xml version="1.0" encoding="utf-8" ?>
<!-- 
    1.书写根元素(因为xsd文件的引入是在根元素上进行的)
    2.在根元素上书写schemaLocation属性,填入命名空间,和xsd文件位置.(可以引入多个,没对之间用 空格/回车 隔开.)
    3.为引入的xsd定义一个前缀.xmlns="http://www.itcast.cn/xml"
    4.固定值. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 -->
 <students  xmlns="http://www.itcast.cn/xml" 
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
             xsi:schemaLocation="http://www.itcast.cn/xml students.xsd" >
         <student number="ITCAST_0001">
             <name>tom</name>
             <age>18</age>
             <sex>male</sex>
         </student>               
 </students>

<?xml version="1.0"?>
<xsd:schema xmlns="http://www.itcast.cn/xml"
        xmlns:xsd="http://www.w3.org/2001/XMLSchema"
        targetNamespace="http://www.itcast.cn/xml" elementFormDefault="qualified">
    <xsd:element name="students" type="studentsType"/>
    <xsd:complexType name="studentsType">
        <xsd:sequence>
            <xsd:element name="student" type="studentType" minOccurs="0" maxOccurs="unbounded"/>
        </xsd:sequence>
    </xsd:complexType>
    <xsd:complexType name="studentType">
        <xsd:sequence>
            <xsd:element name="name" type="xsd:string"/>
            <xsd:element name="age" type="ageType" />
            <xsd:element name="sex" type="sexType" />
        </xsd:sequence>
        <xsd:attribute name="number" type="numberType" use="required"/>
    </xsd:complexType>
    <xsd:simpleType name="sexType">
        <xsd:restriction base="xsd:string">
            <xsd:enumeration value="male"/>
            <xsd:enumeration value="female"/>
        </xsd:restriction>
    </xsd:simpleType>
    <xsd:simpleType name="ageType">
        <xsd:restriction base="xsd:integer">
            <xsd:minInclusive value="0"/>
            <xsd:maxInclusive value="120"/>
        </xsd:restriction>
    </xsd:simpleType>
    <xsd:simpleType name="numberType">
        <xsd:restriction base="xsd:string">
            <xsd:pattern value="ITCAST_\d{4}"/>
        </xsd:restriction>
    </xsd:simpleType>
</xsd:schema> 

c1 {
    font-size:200px;
    color:red;
}
c2 {
    font-size:100px;
    color:green;
}
c3 {
    font-size:10px;
    color:yellow;
}
c4 {
    font-size:150px;
    color:blue;
}

//country.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/css" href="http://www.mamicode.com/country.css"?>
<c>
    <c1>中国</c1>
    <c2>美国</c2>
    <c3>日本</c3>
    <c4>英国</c4>
</c>

<?xml version="1.0" encoding="gbk" ?>
<students>
    <!-- 下面是一个问题学生 
    -->
    <student number="itcast_0001" >
        <name>&lt;tom&gt;</name>
        <age>18</age>
        <sex>male</sex>
        <code><![CDATA[<><><><><<><><]]></code>
    </student>
</students>

<!ELEMENT students (student*) >
<!ELEMENT student (name,age,sex)>
<!ELEMENT name (#PCDATA) >
<!ELEMENT age (#PCDATA) >
<!ELEMENT sex (#PCDATA) >
<!ATTLIST student number ID #REQUIRED>