XML 使用非本地模式进行验证

Question

目前我参与了一个项目，其中我必须验证 XML 文件。这些文件将由用户通过 REST API 上传，REST API 用 Spring 框架编写在 Java 中。架构文件作为属性“schemaLocation”位于 XML 文件 [2] 中的 URL[1]。 XSD 文件也可能包含多个其他模式文件。用户上传的文件是 IO-Link 设备描述 (IODD) 文件。

所以，我当前的问题是在主模式中加载包含的验证方案。下载模式并使用它们进行验证不是我的目标。整个过程必须是动态的。我也不想使用 IO-Link 本身提供的 IODDDchecker。

我读到这可以通过 ResourceResolver 接口完成，但我找不到任何实现来通过 URL 或类似的方式从主模式加载包含的模式。

那么，你能帮我找到解决这个问题的方法吗？

提前致谢！

这是验证文件的方法：

public boolean isValid(String file) {
    if (file == null || file.isEmpty() || !Files.exists(Path.of(file)) || !Files.isReadable(Path.of(file)))
        return false;
    else if (this.getStamp() == null || this.getStamp().getChecker() == null)
        return false;
    else if (this.getStamp().getCrc().isEmpty())
        return false;

    try {
        SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);

        factory.setErrorHandler(new LineNumberErrorHandler());

        Schema schema = factory.newSchema(XsdReceiver.receive(this.schemaLocation));
        Validator validator = schema.newValidator();
        //validator.validate(new StreamSource(new ByteArrayInputStream(data)));

        validator.setResourceResolver(factory.getResourceResolver());
        validator.validate(new StreamSource(new File(file)));
    } catch (Exception e) {
        return false;
    }

    return true;
}

这是模式接收器方法。它可以工作，但是当模式包含时，验证过程将失败。（此代码下方的错误消息。

public static Source receive(String url) {
    url = url.contains(" ") ? url.replace(" ", "/") : url;

    try {
        URL u = new URL(url);
        HttpURLConnection c = (HttpURLConnection)u.openConnection();
        int status = c.getResponseCode();

        if (status == HttpURLConnection.HTTP_MOVED_TEMP
                || status == HttpURLConnection.HTTP_MOVED_PERM
                || status == HttpURLConnection.HTTP_SEE_OTHER
        )
            c = (HttpURLConnection) new URL(c.getHeaderField("Location")).openConnection();


        return new StreamSource(c.getInputStream());
    } catch (IOException e) {
        e.printStackTrace();
    }

    return null;
}

我从验证器收到的错误消息。

Line: 3) schema_reference.4: Failed to read schema document 'IODD-Primitives1.1.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
Line: 4) schema_reference.4: Failed to read schema document 'IODD-Datatypes1.1.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
Line: 5) schema_reference.4: Failed to read schema document 'IODD-Variables1.1.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
Line: 6) schema_reference.4: Failed to read schema document 'IODD-Events1.1.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
Line: 7) schema_reference.4: Failed to read schema document 'IODD-UserInterface1.1.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
Line: 8) schema_reference.4: Failed to read schema document 'IODD-Communication1.1.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.
Line: 180) src-resolve: Cannot resolve the name 'DeviceIdT' to a(n) 'type definition' component.
Line: 180) src-resolve: Cannot resolve the name 'DeviceIdT' to a(n) 'simpleType definition' component.
Line: 191) src-resolve: Cannot resolve the name 'DeviceIdT' to a(n) 'type definition' component.
Line: 228) src-resolve: Cannot resolve the name 'CollectionT' to a(n) 'type definition' component.
Line: 292) src-resolve: Cannot resolve the name 'ObjectT' to a(n) 'type definition' component.
Line: 303) src-resolve: Cannot resolve the name 'CollectionT' to a(n) 'type definition' component.
Line: 312) src-resolve: Cannot resolve the name 'DataItemT' to a(n) 'type definition' component.
Line: 12) src-resolve: Cannot resolve the name 'DocumentInfoT' to a(n) 'type definition' component.
Line: 15) src-resolve: Cannot resolve the name 'CommNetworkProfileT' to a(n) 'type definition' component.
Line: 16) src-resolve: Cannot resolve the name 'ExternalTextCollectionT' to a(n) 'type definition' component.
Line: 22) src-resolve: Cannot resolve the name 'StampT' to a(n) 'type definition' component.
Line: 152) src-resolve: Cannot resolve the name 'TextRefT' to a(n) 'type definition' component.
Line: 153) src-resolve: Cannot resolve the name 'TextRefT' to a(n) 'type definition' component.
Line: 168) src-resolve: Cannot resolve the name 'TextRefT' to a(n) 'type definition' component.
Line: 169) src-resolve: Cannot resolve the name 'TextRefT' to a(n) 'type definition' component.
Line: 195) src-resolve: Cannot resolve the name 'TextRefT' to a(n) 'type definition' component.
Line: 196) src-resolve: Cannot resolve the name 'TextRefT' to a(n) 'type definition' component.
Line: 238) src-resolve: Cannot resolve the name 'DatatypeCollectionT' to a(n) 'type definition' component.
Line: 239) src-resolve: Cannot resolve the name 'VariableCollectionT' to a(n) 'type definition' component.
Line: 250) src-resolve: Cannot resolve the name 'ErrorTypeCollectionT' to a(n) 'type definition' component.
Line: 257) src-resolve: Cannot resolve the name 'EventCollectionT' to a(n) 'type definition' component.
Line: 263) src-resolve: Cannot resolve the name 'UserInterfaceT' to a(n) 'type definition' component.

[1] https://www.io-link.com/IODD/2010/10/IODD1.1.xsd
[2] https://ioddfinder.io-link.com/productvariants/search/11765（IO-Link 产品 TV7105 示例）

Answer 1

好的，我自己解决了这个问题。简而言之，我必须创建一个 class 来实现接口 LSResourceResolver 并覆盖方法 resolveResource.

长答案是：
首先我创建了 class XsdReceiver 并让它实现接口 LSResourceResolver。此外，方法 resolveResource 现在必须被覆盖。该方法最终负责查询丢失的 XSD 个文件并将它们作为资源 LSInput 返回。（与 LSResourceResolver 一样，LSInput 是一个接口，因此必须作为单独的 class 实现。我只是将其称为 Input）。最后我使用方法 setResourceResolver 并将创建的 class XsdReceiver.

实例化为参数

功能：
isValid 方法应该检查 XML 模式的有效性等。必要的模式文件可以在根标签中找到。它还必须手动传递给 SchemaFactory class。在调用该方法并读取主架构文件后，每个引用的 XML 或 XSD 文件都会自动传递给方法 resolveResource。 SchemaFactory class 为我们做了这个。

玩得开心:D

public boolean isValid(byte[] data) {
    if (this.getStamp() == null || this.getStamp().getChecker() == null)
        return false;
    else if (this.getStamp().getCrc().isEmpty())
        return false;

    try {
        SchemaFactory factory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);

        factory.setErrorHandler(new LineNumberErrorHandler());
        factory.setResourceResolver(new XsdReceiver());

        Schema schema = factory.newSchema(XsdReceiver.receive(this.schemaLocation));
        Validator validator = schema.newValidator();

        validator.setResourceResolver(factory.getResourceResolver());
        validator.validate(new StreamSource(new ByteArrayInputStream(data)));
    } catch (Exception e) {
        e.printStackTrace();
        return false;
    }

    return true;
}

public class XsdReceiver implements LSResourceResolver {
    public static Source receive(String url) {
        url = url.contains(" ") ? url.replace(" ", "/") : url;
        HttpURLConnection c = XsdReceiver.followRedirection(url);

        if (c == null)
            return null;

        try {
            return new StreamSource(c.getInputStream());
        } catch (IOException e) {
            return null;
        }
    }

    private static HttpURLConnection followRedirection(String url) {
        HttpURLConnection c = null;

        try {
            URL u = new URL(url);
            c = (HttpURLConnection)u.openConnection();
            int status = c.getResponseCode();

            if (status == HttpURLConnection.HTTP_MOVED_TEMP
                    || status == HttpURLConnection.HTTP_MOVED_PERM
                    || status == HttpURLConnection.HTTP_SEE_OTHER
            )
                c = (HttpURLConnection) new URL(c.getHeaderField("Location")).openConnection();
        } catch (IOException e) {
            return null;
        }

        return c;
    }

    @Override
    public LSInput resolveResource(String type, String namespaceURI, String publicId, String systemId, String baseURI) {
        if (namespaceURI == null || type.equals("http://www.w3.org/TR/REC-xml"))
            return null;

        if (systemId.equals("xml.xsd")) {
            try {
                File f = ResourceUtils.getFile("classpath:data/xml.xsd");

                return new Input(StandardCharsets.UTF_8.name(), new FileInputStream(f), null, systemId, publicId, namespaceURI, true, null);
            } catch (IOException e) {
                return null;
            }
        }

        String file = String.join("/", namespaceURI, systemId);
        HttpURLConnection connection;
        Input i = null;

        connection = XsdReceiver.followRedirection(file);

        if (connection == null)
            return null;

        try {
            i = new Input(StandardCharsets.UTF_8.name(), connection.getInputStream(), null, systemId, publicId, namespaceURI, true, null);
        } catch (IOException e) {
            return null;
        }

        return i;
    }
}

public class Input implements LSInput {
    private String encoding;
    private InputStream byteStream;
    private String stringData;
    private String systemId;
    private String publicId;
    private String baseUri;
    boolean certifiedText;
    private Reader characterStream;

    public Input(String encoding, InputStream byteStream, String stringData, String systemId, String publicId, String baseUri, boolean certifiedText, Reader characterStream) {
        this.encoding = encoding;
        this.byteStream = byteStream;
        this.stringData = stringData;
        this.systemId = systemId;
        this.publicId = publicId;
        this.baseUri = baseUri;
        this.certifiedText = certifiedText;
        this.characterStream = characterStream;
    }

    @Override
    public Reader getCharacterStream() {
        return this.characterStream;
    }

    @Override
    public void setCharacterStream(Reader characterStream) {
        this.characterStream = characterStream;
    }

    @Override
    public InputStream getByteStream() {
        return this.byteStream;
    }

    @Override
    public void setByteStream(InputStream byteStream) {
        this.byteStream = byteStream;
    }

    @Override
    public String getStringData() {
        return this.stringData;
    }

    @Override
    public void setStringData(String stringData) {
        this.stringData = stringData;
    }

    @Override
    public String getSystemId() {
        return this.systemId;
    }

    @Override
    public void setSystemId(String systemId) {
        this.systemId = systemId;
    }

    @Override
    public String getPublicId() {
        return this.publicId;
    }

    @Override
    public void setPublicId(String publicId) {
        this.publicId = publicId;
    }

    @Override
    public String getBaseURI() {
        return this.baseUri;
    }

    @Override
    public void setBaseURI(String baseURI) {
        this.baseUri = baseURI;
    }

    @Override
    public String getEncoding() {
        return this.encoding;
    }

    @Override
    public void setEncoding(String encoding) {
        this.encoding = encoding;
    }

    @Override
    public boolean getCertifiedText() {
        return this.certifiedText;
    }

    @Override
    public void setCertifiedText(boolean certifiedText) {
        this.certifiedText = certifiedText;
    }
}

XML 使用非本地模式进行验证

XML Validation with non local schemas

java

xml

validation

xsd