java - 如何在运行时在 java 的 xpath 中禁用 dtd？

Question

我的文件中有 dtd，但我无法删除它。当我尝试用 Java 解析它时，我得到“Caused by: java.net.SocketException: Network is unreachable: connect”，因为它的远程 dtd。我可以以某种方式禁用 dtd 检查吗？

Answer 1

您应该能够指定您自己的 EntityResolver，或者使用您的解析器的特定功能？参见 here对于某些方法。

一个更完整的例子:

<?xml version="1.0"?>
<!DOCTYPE foo PUBLIC "//FOO//" "foo.dtd">
<foo>
    <bar>Value</bar>
</foo>

和xpath用法:

import java.io.File;
import java.io.IOException;
import java.io.StringReader;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

public class Main {

    public static void main(String[] args) throws Exception {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();

        builder.setEntityResolver(new EntityResolver() {

            @Override
            public InputSource resolveEntity(String publicId, String systemId)
                    throws SAXException, IOException {
                System.out.println("Ignoring " + publicId + ", " + systemId);
                return new InputSource(new StringReader(""));
            }
        });
        Document document = builder.parse(new File("src/foo.xml"));
        XPathFactory xpathFactory = XPathFactory.newInstance();
        XPath xpath = xpathFactory.newXPath();
        String content = xpath.evaluate("/foo/bar/text()", document
                .getDocumentElement());
        System.out.println(content);
    }
}

希望这有助于...