好吧，我自己解决了这个问题。简而言之，我必须创建一个实现接口的类 LSResourceResolver 并重写该方法 resolveResource .
答案很长：
首先我创建了类 XsdReceiver 并让它实现接口 LSResourceResolver . 还有方法 resolveResource 现在必须被覆盖。这个方法最终负责查询丢失的xsd文件并将它们作为资源返回 LSInput . (就像 LSResourceResolver , LSInput 是一个接口，因此必须作为一个单独的类实现。我只是叫它 Input ). 最后我用了这个方法 setResourceResolver 并示例化为创建的类的参数 XsdReceiver .
功能：
方法 isValid 应该检查xml模式的有效性。必要的模式文件可以在根标记中找到。它还必须手动传递给 SchemaFactory 班级。调用该方法并读取主模式文件后，每个引用的xml或xsd文件都会自动传递给该方法 resolveResource . 这个 SchemaFactory 全班为我们做这件事。
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;
    }
}