用Java替換XML元素

Question

在下面的XML中，我想使用Java更改<Password>元素的值。

<?xml version="1.0" encoding="UTF-8"?>
<ns1:Envelope xmlns:ns1="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns2="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd">
    <ns1:Header>
        <ns2:Security>
            <ns2:UsernameToken xmlns:ns3="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">
            <ns2:Username>ADMIN</ns2:Username>
            <ns2:Password Type="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordText">abcd</ns2:Password>
            <ns3:Created>2016-09-08T17:47:05.079Z</ns3:Created>
            </ns2:UsernameToken>
        </ns2:Security>
    </ns1:Header>
    <ns1:Body>
    </ns1:Body>
</ns1:Envelope>

我嘗試使用以下代碼：

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(new File("D:/test.xml"));  
Element root = doc.getDocumentElement();
root.getElementsByTagName("Password").item(0).setTextContent("efgh");

但我得到NullPointerException。 這是因為getElementsByTagName返回一個包含0個元素的NodeList。 我嘗試使用getElementsByTagNameNS，但結果仍然相同。

root.getElementsByTagNameNS("http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd", "Password").item(0).setTextContent("efgh");

我還可以做些什么？ 提前致謝。

Answer 1

您需要將DocumentBuilderFactory設置為名稱空間感知：

public static void main(String[] args) throws Exception {
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    factory.setNamespaceAware(true);
    DocumentBuilder builder = factory.newDocumentBuilder();
    Document doc = builder.parse(new File("D:/test.xml"));
    Element root = doc.getDocumentElement();
    root.getElementsByTagNameNS("http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd", "Password").item(0).setTextContent("efgh");

    // Write out result to check it
    TransformerFactory tFactory = TransformerFactory.newInstance();
    Transformer transformer = tFactory.newTransformer();
    DOMSource source = new DOMSource(doc);
    StreamResult result = new StreamResult(System.out);
    transformer.transform(source, result);
}