Question

我找到了如何流式传输整个文档的示例，但有没有办法按节点流式传输，所以如果文件太大，我不会遇到内存问题？

private Document document; 
private void stream(OutputStream out) {
    // write the doc into stream
    TransformerFactory transformerFactory = TransformerFactory.newInstance();
    Transformer transformer;
    DOMSource source = new DOMSource(document);
    StreamResult result = new StreamResult(out);

    try {
        transformer = transformerFactory.newTransformer();
        transformer.transform(source, result);
    } catch (TransformerException e) {
        throw new RuntimeException("couldn't stream result to output");
    }
}

Answer 1

您可以使用新的StAX（Streaming API for XML）API来完成任务并读取XML块。

Oracle Documentation提供了示例，我敢打赌，您也可以在线找到其他资源。

Answer 2

您可以随时使用递归来遍历Documents节点，如果这可以帮助您：

Element rootElement = document.getDocumentElement();
goThroughAllNodesOneByOne(rootElement);


goThroughAllNodesOneByOne(Node currentNode){
     // Do your logic with the node 
     // EX: currentNode.getNodeName(); currentNode.getNamespaceURI()  etc
     NodeList childNodes = currentNode.getChildNodes();
     for (int i = 0; i < childNodes.getLength(); i++) {
        Node currentNode = nodeList.item(i);
        if (currentNode.getNodeType() == Node.ELEMENT_NODE) {
          goThroughAllNodesOneByOne(currentNode);
        }
      }
}

逐节点地流XML

2 个答案: