Java - 添加到 DOM XML 文件

Question

我有以下 XML，我想向该 xml 添加另一个“产品”。

<?xml version="1.0" encoding="ISO-8859-1"?>
<products>
    <product>
        <name>Computer</name>
        <code>PC1003</code>
        <description>Basic Computer</description>
        <price>399.99</price>
    </product>
    <product>
        <name>Monitor</name>
        <code>MN1003</code>
        <description>LCD Monitor</description>
        <price>99.99</price>
    </product>
    <product>
        <name>Printer</name>
        <code>PR1003x</code>
        <description>Inkjet Printer</description>
        <price>54.23</price>
    </product>
</products>

这是我到目前为止的代码:

        // Variables
        File file = new File("db_products.xml"); // set xml to parse

        // Create builders
        DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
        Document doc = dBuilder.parse(file); // load xml file
        doc.getDocumentElement().normalize();

        doc.createElement("product");

我并不关心新的“产品”部分添加到哪里。我似乎无法理解节点和元素之间的区别。我假设添加新“产品”部分的正确方法是将子项添加到“产品”，然后将子项(名称、代码等)添加到“产品”。

任何有关如何轻松执行此操作的帮助或简单教程的链接将不胜感激。

Answer 1

您需要做的是首先检索products 元素，然后对该元素调用appendChild。像这样的事情:

Element productElement = doc.createElement("product");
productElement.setAttribute("name", "value");
//Other name value pairs...

//Append the products element to the right spot.
Element productsElement = (Element) doc.getElementByTagName("products").item(0);
productsElement.appendChild(productElement);

//Convert doc to xml string
DOMSource domSource = new DOMSource(doc);
StringWriter writer = new StringWriter();
StreamResult result = new StreamResult(writer);
TransformerFactory tf = TransformerFactory.newInstance();
Transformer transformer = tf.newTransformer();
transformer.transform(domSource, result);
String xmlAsString = writer.toString();