从 java.io.Reader 读取 xml 而不是提供 xml 文件的路径时，saxreader 验证失败

Question

我有简单的 xml 文件 contacts.xml 位于实际文件夹的子文件夹 xml-files 中。

<contacts xsi:noNamespaceSchemaLocation="contacts.xsd"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> 
    <contact> 
        <firstname>AAA</firstname> 
        <lastname>BBB</lastname>
    </contact> 
</contacts>

架构文件也位于子文件夹 xml-files.

解析文件的代码：

  SAXParserFactory factory = SAXParserFactory.newInstance();
  factory.setValidating(true);

  SAXParser parser = factory.newSAXParser();                              
  parser.setProperty("http://java.sun.com/xml/jaxp/properties/schemaLanguage", "http://www.w3.org/2001/XMLSchema");

  SAXReader reader = new SAXReader(parser.getXMLReader());
  reader.setValidation(true);
  reader.read("xml-files/contacts.xml");

我想像这样使用 SAXReader 的读取方法，它以 java.io.Reader 作为参数

reader.read(new FileReader("xml-files/contacts.xml"));

但我遇到异常

org.dom4j.DocumentException：文档第 2 行错误：cvc-elt.1：找不到元素 'contacts' 的声明。嵌套异常：cvc-elt.1：找不到元素 'contacts'.

的声明

使用自定义实体解析器显示，在第一种情况下，xsd 文件是从路径 file:///e:/devel/xsd/xml-files/contacts.xsd 加载的，在第二种情况下，文件是：/ //e:/devel/xsd/contacts.xsd.

有什么方法可以将 xsd 文件所在的文件夹设置为 SAXReader？

Answer 1

未经测试，但根据我上面的评论，这就是我的想法：

    SAXParserFactory factory = SAXParserFactory.newInstance();
    factory.setValidating(true);

    SchemaFactory schemafactory =   SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);

    Source[] sources = new Source[] {
        new StreamSource(new File("path/to/schema1.xsd")),
        new StreamSource(new File("path/to/schema2.xsd")),
        new StreamSource(new File("path/to/schema3.xsd")),
        new StreamSource(new File("path/to/schema4.xsd")),
    };

    Schema sc = schemafactory.newSchema(sources);
    factory.setSchema(sc);

    SAXParser parser = factory.newSAXParser();
    parser.parse(file, handler);

Answer 2

受到Java: How to prevent 'systemId' in EntityResolver#resolveEntity(String publicId, String systemId) from being absolutized to current working directory的启发，我使用了自己的 EntityResolver2 实现

private static class EntityResolver2Impl implements EntityResolver2 {
    private File xmlFile;
    public EntityResolver2Impl(File xmlFile) {
        this.xmlFile = xmlFile;
    }

    @Override
    public InputSource getExternalSubset(String name, String baseURI) throws SAXException, IOException {
        return null;
    }

    @Override
    public InputSource resolveEntity(String name, String publicId, String baseURI, String systemId) throws SAXException, IOException {
        File entityPath = new File(xmlFile.getParent(), systemId);
        return new InputSource(new FileReader(entityPath));
    }

    @Override
    public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
        return null;
    }
}

调用代码如下所示

 File xmlFile = new File("xml-files/contacts.xml");
 SAXParserFactory factory = SAXParserFactory.newInstance();

 factory.setValidating(true);

 SAXParser parser = factory.newSAXParser();                              
 parser.setProperty("http://java.sun.com/xml/jaxp/properties/schemaLanguage", "http://www.w3.org/2001/XMLSchema");

 SAXReader reader = new SAXReader(parser.getXMLReader());
 reader.setEntityResolver(new EntityResolver2Impl(xmlFile));
 reader.setValidation(true);
 reader.read(new FileReader(xmlFile));

此代码还可以处理 xsd 的路径包含指向父文件夹 (../..) 等的相对路径的情况

从 java.io.Reader 读取 xml 而不是提供 xml 文件的路径时，saxreader 验证失败

saxreader validation fails when reading xml from java.io.Reader instead of providing path to xml file

java

xml

xml-validation