如何将 XML 文件正确转换为字符串？

Question

我下面有一个XML签名验证码：

public static boolean isXmlDigitalSignatureValid(String xmlString) throws Exception {
    boolean validFlag = false;
    String pubicKeyFilePath = "src/main/resources/keys/publickey.key";
    Document doc = convertStringToDocument(xmlString);
    NodeList nl = doc.getElementsByTagNameNS(XMLSignature.XMLNS, "Signature");
    if (nl.getLength() == 0) {
        throw new Exception("No XML Digital Signature Found, document is discarded");
    }
    PublicKey publicKey = new CryptoUtil().getStoredPublicKey(pubicKeyFilePath);
    DOMValidateContext valContext = new DOMValidateContext(publicKey, nl.item(0));
    XMLSignatureFactory fac = XMLSignatureFactory.getInstance("DOM");
    XMLSignature signature = fac.unmarshalXMLSignature(valContext);
    validFlag = signature.validate(valContext);
    return validFlag;
}

但是有个问题。我确定 doc 文件有签名部分，因为我正在打印它。但是

 NodeList nl = doc.getElementsByTagNameNS(XMLSignature.XMLNS, "Signature");

找不到签名部分所以

n1.item(0)

为空，我在 header.

中提到了异常

Answer 1

我明白是怎么回事了。我的 XMLReader 方法工作不正常。是的，它准确地返回字符串，但缺少字节中的一些点。所以我稍微改一下。

首先我阅读并转换为 Doc 文件

public static Document getXmlDocument(String xmlFilePath) {
    Document doc = null;
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    dbf.setNamespaceAware(true);
    try {
        doc = dbf.newDocumentBuilder().parse(new FileInputStream(xmlFilePath));
    } catch (ParserConfigurationException ex) {
        ex.printStackTrace();
    } catch (FileNotFoundException ex) {
        ex.printStackTrace();
    } catch (SAXException ex) {
        ex.printStackTrace();
    } catch (IOException ex) {
        ex.printStackTrace();
    }
    return doc;
}

然后我将 doc 转换为字符串。

public static Document convertStringToDocument(String xmlStr) {
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    factory.setNamespaceAware(true);
    DocumentBuilder builder;
    try
    {
        builder = factory.newDocumentBuilder();
        Document doc = builder.parse( new InputSource( new StringReader( xmlStr ) ) );
        return doc;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

我最终的 xmlReader 函数是：

public static String xmlReader(String path){
    return convertDocumentToString(XmlDigitalSignatureGenerator.getXmlDocument(path));
}

这是我将 XML 文件正确转换为字符串的唯一方法

如何将 XML 文件正确转换为字符串？

How to convet XML file to string properly?

java

xml

document

nodelist

xml-signature