模式验证错误

针对 XML 的 XSD 验证不会总是成功。
很多时候，我们会收到验证错误。
这些错误将作为 SAXException抛出。
因此，捕获此异常，它将具有验证失败的上下文。

例如，我已经使用此更改更新了架构文件。

<xs:element name="firstName" type="xs:string" minOccurs="0"/>
//to 
<xs:element name="firstName" type="xs:int" minOccurs="0"/>

现在看看验证错误。

javax.xml.bind.UnmarshalException
 - with linked exception:
[org.xml.sax.SAXParseException; systemId: file:/C:/Users/JackLi/workspace/App/employee.xml; lineNumber: 7; columnNumber: 34; 
cvc-datatype-valid.1.2.1: 'JackLi' is not a valid value for 'integer'.]
at javax.xml.bind.helpers.AbstractUnmarshallerImpl.createUnmarshalException(AbstractUnmarshallerImpl.java:335)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.createUnmarshalException(UnmarshallerImpl.java:563)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:249)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:214)
at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:157)
at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:162)
at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:171)
at javax.xml.bind.helpers.AbstractUnmarshallerImpl.unmarshal(AbstractUnmarshallerImpl.java:189)
at com.onitroad.demo.JaxbExample.jaxbXmlFileToObject(JaxbExample.java:45)
at com.onitroad.demo.JaxbExample.main(JaxbExample.java:23)
Caused by: org.xml.sax.SAXParseException; systemId: file:/C:/Users/JackLi/workspace/App/employee.xml; lineNumber: 7; columnNumber: 34;

XSD 验证后将 XML 转换为 Java 对象

package com.onitroad.demo;
import java.io.File;
import javax.xml.XMLConstants;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import org.xml.sax.SAXException;
import com.onitroad.demo.model.Employee;
public class JaxbExample 
{
	public static void main(String[] args) 
	{
		String xmlFile = "employee.xml";
		String xsdFile = "employee.xsd";

		jaxbXmlFileToObject(xmlFile, xsdFile);
	}
	private static void jaxbXmlFileToObject(String xmlFile, String xsdFile) {

		JAXBContext jaxbContext;

		try 
		{
			//获取 JAXBContext
			jaxbContext = JAXBContext.newInstance(Employee.class);

			//创建 Unmarshaller
			Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();

			// 设置验证器
			SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
			Schema employeeSchema = sf.newSchema(new File(xsdFile));
			jaxbUnmarshaller.setSchema(employeeSchema);

			//Unmarshal xml 文件 
			Employee employee = (Employee) jaxbUnmarshaller.unmarshal(new File(xmlFile));

			System.out.println(employee);
		}
		catch (JAXBException | SAXException e) 
		{
			e.printStackTrace();
		}
	}
}

测试使用的employee.xml和employee.xsd的内容如下。

<employees>
	<employee id="101">
		 <name>JackLi Gupta</name>
	    <title>Author</title>
	</employee>
	<employee id="102">
		 <name>BobRobert Lara</name>
	    <title>Cricketer</title>
	</employee>
</employees>

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<xs:schema version="1.0" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="department" type="department"/>
  <xs:element name="employee" type="employee"/>
  <xs:complexType name="employee">
    <xs:sequence>
      <xs:element ref="department" minOccurs="0"/>
      <xs:element name="firstName" type="xs:string" minOccurs="0"/>
      <xs:element name="id" type="xs:int" minOccurs="0"/>
      <xs:element name="lastName" type="xs:string" minOccurs="0"/>
    </xs:sequence>
  </xs:complexType>
  <xs:complexType name="department">
    <xs:sequence>
      <xs:element name="id" type="xs:int" minOccurs="0"/>
      <xs:element name="name" type="xs:string" minOccurs="0"/>
    </xs:sequence>
  </xs:complexType>
</xs:schema>