针对模式验证 XML - 找不到元素的声明

Question

我对 XML 验证很陌生，很抱歉这个基本问题。我有以下文件：

<tincan xmlns="http://projecttincan.com/tincan.xsd">
  <activities>
    <activity id="TestActivity" type="course">
      <name lang="und">MyCourse</name>
      <description lang="und"/>
      <launch lang="und">start.html</launch>
    </activity>
    <activity id="p001" type="objective">
      <name lang="und">First Page</name>
      <description lang="und">First Page</description>
    </activity>
  </activities>
</tincan>

我正在尝试根据以下架构对其进行验证：http://projecttincan.com/tincan.xsd（我还尝试从我的 XML 中删除架构并在外部提供它）。

我总是遇到以下异常：cvc-elt.1: Cannot find the declaration of element 'tincan'

通过查看架构，我看到tincan 元素在那里定义，并且它也存在于我的 XML 中，所以我不明白这个异常的来源是什么。如果有人能解释验证应该如何工作，我会很高兴。

编辑：我的验证代码：

DocumentBuilder parser = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document document = parser.parse(stream);

// create a SchemaFactory capable of understanding WXS schemas
SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);

// load a WXS schema, represented by a Schema instance
Source schemaFile = new StreamSource(getClass().getClassLoader().getResource("tincan.xsd").getFile());
Schema schema = factory.newSchema(schemaFile);

// create a Validator instance, which can be used to validate an instance document
Validator validator = schema.newValidator();

// validate the DOM tree
validator.validate(new DOMSource(document));

EDIT2：架构已链接到此处，但为了清楚起见，我将再次将其发布在这里：

<xs:schema xmlns="http://projecttincan.com/tincan.xsd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:tc="http://projecttincan.com/tincan.xsd" targetNamespace="http://projecttincan.com/tincan.xsd" elementFormDefault="qualified">
<xs:element name="tincan" type="tincan"></xs:element>
<xs:complexType name="tincan">
<xs:sequence>
<xs:element name="activities" type="activities" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="activity">
<xs:sequence>
<xs:element name="name" type="langstring" maxOccurs="unbounded"/>
<xs:element name="description" type="langstring" maxOccurs="unbounded"/>
<xs:element name="launch" type="langURI" maxOccurs="unbounded" minOccurs="0"/>
<xs:element name="resource" type="langURI" maxOccurs="unbounded" minOccurs="0"/>
<xs:element name="interactionType" type="xs:string" minOccurs="0"/>
<!--  CMI Interaction fields  -->
<xs:element name="correctResponsePatterns" type="correctResponsePatternList" minOccurs="0"/>
<xs:element name="choices" type="interactionComponentList" minOccurs="0"/>
<xs:element name="scale" type="interactionComponentList" minOccurs="0"/>
<xs:element name="source" type="interactionComponentList" minOccurs="0"/>
<xs:element name="target" type="interactionComponentList" minOccurs="0"/>
<xs:element name="steps" type="interactionComponentList" minOccurs="0"/>
<!--  Extensions -->
<xs:element name="extensions" type="extensions" minOccurs="0"/>
</xs:sequence>
<xs:attribute name="id" type="xs:anyURI"/>
<xs:attribute name="type" type="xs:string"/>
</xs:complexType>
<xs:complexType name="activities">
<xs:sequence>
<xs:sequence>
<xs:element name="activity" type="activity" maxOccurs="unbounded"/>
<xs:element name="provider" type="provider" minOccurs="0"/>
</xs:sequence>
</xs:sequence>
</xs:complexType>
<xs:complexType name="provider">
<xs:all>
<xs:element name="name" type="langstring"/>
<xs:element name="id" type="xs:string"/>
<xs:element name="secret" type="xs:string" minOccurs="0"/>
<xs:element name="public_key" type="xs:string" minOccurs="0"/>
<xs:element name="info" type="xs:anyURI" minOccurs="0"/>
</xs:all>
</xs:complexType>
<xs:complexType name="correctResponsePatternList">
<xs:sequence>
<xs:element name="correctResponsePattern" type="xs:string" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="interactionComponentList">
<xs:sequence>
<xs:element name="component" type="interactionComponentType" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="interactionComponentType">
<xs:sequence>
<xs:element name="id" type="xs:string"/>
<xs:element name="description" type="langstring" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="langstring">
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute name="lang" type="xs:language"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<xs:complexType name="extensions">
<xs:sequence>
<xs:element name="extension" type="extension" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="extension">
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute name="key" type="xs:string" use="required"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<xs:complexType name="langURI">
<xs:simpleContent>
<xs:extension base="xs:anyURI">
<xs:attribute name="lang" type="xs:language"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:schema>

Answer 1

让您的文档构建器“namespaceAware”应该修复它！

  DocumentBuilderFactory f=DocumentBuilderFactory.newInstance();          
  f.setNamespaceAware(true);

您也可以直接对 Source 对象进行操作，这样代码会更短一些，而且速度可能更快并且使用更少的内存。

两种变体的示例

package stack43324079;

import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Source;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.Schema;
import javax.xml.validation.SchemaFactory;
import javax.xml.validation.Validator;

import org.junit.Test;
import org.w3c.dom.Document;

public class HowToValidateXml {
    @Test
    public void validate1() throws Exception {
        DocumentBuilderFactory f=DocumentBuilderFactory.newInstance();
        f.setNamespaceAware(true);
        DocumentBuilder parser = f.newDocumentBuilder();
        Document document = parser.parse(Thread.currentThread().getContextClassLoader().getResourceAsStream("43324079.xml"));
        SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
        Source schemaFile = new StreamSource(Thread.currentThread().getContextClassLoader().getResourceAsStream("tincan.xsd"));
        Schema schema = factory.newSchema(schemaFile);
        Validator validator = schema.newValidator();
        validator.validate(new DOMSource(document));
    }

    @Test
    public void validate2() throws Exception {
        Source xmlFile = new StreamSource(Thread.currentThread().getContextClassLoader().getResourceAsStream("43324079.xml"));
        SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
        Schema schema = factory.newSchema(Thread.currentThread().getContextClassLoader().getResource("tincan.xsd"));
        Validator validator = schema.newValidator();
        validator.validate(xmlFile);
    }
}

Answer 2

你没有向我们展示架构，所以我们只能猜测出了什么问题，但我的猜测是元素在错误的命名空间中声明。

如果这是一个错误的猜测，那么下次你问一个问题时要记住，当人们不向你展示代码时，很难在代码中找到错误。