java - 使用 XSD 架构解析 XML 文件时出现 SAXException

Question

我有以下 XSD 文件:

<xs:schema xmlns:xs='http://www.w3.org/2001/XMLSchema'
           targetNamespace='http://www.wvf.com/schemas'
           xmlns='http://www.wvf.com/schemas'
           xmlns:acmewvf='http://www.wvf.com/schemas'>

 <xs:element name='loft'>
 </xs:element>
</xs:schema>

和以下 XML 文件:

<?xml version="1.0"?>

<acmewvf:loft xmlns:acmewvf="http://www.wvf.com/schemas"
               xmlns="http://www.wvf.com/schemas">
</acmewvf:loft>

当我执行以下 Java 代码时:

public void parse(InputStream constraints) {
    final SchemaFactory schemaFactory = new XMLSchemaFactory();
    final URL resource = 
        ClassLoader.getSystemClassLoader().getResource(SCHEMA_PATH);
    final DocumentBuilderFactory factory = 
        DocumentBuilderFactory.newInstance();
    Document doc = null;
    factory.setSchema(schemaFactory.newSchema(resource));
    final DocumentBuilder builder = factory.newDocumentBuilder();
    doc = builder.parse(constraints);

我得到以下 SAXException(在代码的最后一行):

cvc-elt.1: Cannot find the declaration of element 'acmewvf:loft'.

(请注意，SCHEMA_PATH 指向上面给出内容的 XSD 文件，constraints 是上面也给出内容的 XML 文件的输入流。)

这里出了什么问题？

Answer 1

参见 Using the Validating Parser .也许，您应该尝试添加以下内容以生成命名空间感知的验证解析器:

  factory.setNamespaceAware(true);
  factory.setValidating(true);
try {
  factory.setAttribute(JAXP_SCHEMA_LANGUAGE, W3C_XML_SCHEMA);
} 
catch (IllegalArgumentException x) {
  // Happens if the parser does not support JAXP 1.2
  ...
} 

不要忘记定义:

static final String JAXP_SCHEMA_LANGUAGE =
    "http://java.sun.com/xml/jaxp/properties/schemaLanguage";

static final String W3C_XML_SCHEMA =
    "http://www.w3.org/2001/XMLSchema";