Schema 校验XML某些属性不可重复

问题的提出：

当xml文件包含多个相同元素时，如果这些元素的字段在该属性值上有重复，则不能通过Schema验证。

问题的分类：

根据不能重复的元素或者属性所在位置，可以分为下面3种情况

1. 不同元素的某个属性不能重复

2. 不同元素的某个子元素不能重复

3. 一个元素的多个子元素不能重复

解决方法举例：

XML文件如下：

<?xml version="1.0" encoding="UTF-8"?>

<persons>

<person name="walnut"> -->不同person的name属性不能重复

<id>13130198201200770</id> -->不同person的id子元素不能重复

<children>

<child>aaa</child> -->children的不同child不能重复

<child>bbb</child>

<child>ccc</child>

</children>

</person>

<person name="daisy">

<id>13130198201200775</id>

<children>

<child>ccc</child>

</children>

</person>

</persons>

用于校验的XSD文件如下：

<?xml version="1.0" encoding="UTF-8"?>

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="qualified">

<xsd:element name="persons">

<xsd:complexType>

<xsd:sequence>

<xsd:element ref="person" minOccurs="0" maxOccurs="unbounded"/>

</xsd:sequence>

</xsd:complexType>

<xsd:unique name="nameUnique">

<xsd:selector xpath=".//person"/>

<xsd:field xpath="@name"/>

</xsd:unique>

<xsd:unique name="idUnique">

<xsd:selector xpath=".//person"/>

<xsd:field xpath="id"/>

</xsd:unique>

</xsd:element>

<xsd:element name="person">

<xsd:complexType>

<xsd:sequence>

<xsd:element name="id" type="xsd:string"/>

<xsd:element ref="children" minOccurs="0" maxOccurs="1"/>

</xsd:sequence>

<xsd:attribute name="name" type="xsd:string"/>

</xsd:complexType>

</xsd:element>

<xsd:element name="children">

<xsd:complexType>

<xsd:sequence>

<xsd:element name="child" type="xsd:string" minOccurs="0" maxOccurs="unbounded"/>

</xsd:sequence>

</xsd:complexType>

<xsd:unique name="childUnique">

<xsd:selector xpath=".//child"/>

<xsd:field xpath="."/>

</xsd:unique>

</xsd:element>

</xsd:schema>

利用xsd文件校验xml文件的java代码：

[code]

public class XMLValidateUtil {

private static Logger logger = Logger.getLogger(XMLValidateUtil.class);

public static boolean validateXMLByXSD(String xmlFileName, String xsdFileName) {

if (xmlFileName == null || xmlFileName.length() < 1) {

return false;

}

if (xsdFileName == null || xsdFileName.length() < 1) {

return false;

}

try {

XMLErrorHandler errorHandler = new XMLErrorHandler();

SAXParserFactory factory = SAXParserFactory.newInstance();

factory.setValidating(true);// 注意要设置有效，否则后面验证无用

// factory.setNamespaceAware(true);//XSD中有命名空间设置

SAXParser parser = factory.newSAXParser();

SAXReader xmlReader = new SAXReader();

org.dom4j.Document documentObject = (org.dom4j.Document) xmlReader

.read(new File(xmlFileName));// filename是对应符合XSD模式的具体xml文件绝对路径名

// String xsdpathfile = "e:\\schemaexample\\example.xsd";//xsdPathfile是绝对路径名

parser.setProperty(

"http://java.sun.com/xml/jaxp/properties/schemaLanguage",

"http://www.w3.org/2001/XMLSchema");

parser.setProperty(

"http://java.sun.com/xml/jaxp/properties/schemaSource",

"file:" + xsdFileName);

SAXValidator validator = new SAXValidator(parser.getXMLReader());

validator.setErrorHandler(errorHandler);

validator.validate(documentObject);

XMLWriter writer = new XMLWriter(OutputFormat.createPrettyPrint());

if (errorHandler.getErrors().hasContent()) {

writer.write(errorHandler.getErrors());

return false;

} else {

logger.info("xml validate success by xsd.");

return true;

}

} catch (Exception ex) {

logger.error("xml file: "+xmlFileName+" validate failed by xsd file:"+xsdFileName+" because "+ex.getMessage());

return false;

}

}

public static void main(String[] args) {

String xmlFile="C:\\myxml.xml";

String xsdFile="C:\\myxsd.xsd";

XMLValidateUtil.validateXMLByXSD(xmlFile,xsdFile);

}

}

[/code]