将新的XML节点保存到文件

时间:2015-11-26 10:06:06

标签: java xml dom nodelist

我正在尝试将包含XML的{​​{1}}节点保存为新文件,以下是获取新XML文档并拆分为较小XMLs的节点列表:

public void split(Document inDocument) throws ParserConfigurationException,
            SAXException, IOException {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        SaveXML savePerJob = new SaveXML();
        // Load the input XML document, parse it and return an instance of the
        // Document class.
        Document document = inDocument;
        //all elements
        //jobs
        NodeList nodes = document.getDocumentElement().getChildNodes();
        NodeList jobs = nodes.item(7).getChildNodes();
        for(int j =0; j<jobs.getLength(); j++){
            Node itm = jobs.item(j);
            String itmName = itm.getFirstChild().getNodeName();
            String itmID = itm.getFirstChild().getTextContent();
            System.out.println("name: " + itmName + " value: " + itmID);
            //here I want to save the node as a new .xml file
        }
    }

输出是一个很长的列表,如:

name: id value: 9496425

现在我想将节点itm保存为新的新.xml文件,但我没有找到按原样返回节点的函数。 感谢。

2 个答案:

答案 0 :(得分:6)

您可以将节点转换为字符串,并将此字符串保存到.xml文件中。

将节点转换为字符串

以下方法将节点转换为xml字符串。它只是一个JDK解决方案,不需要依赖。

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import java.io.StringWriter;

public static String toString(Node node, boolean omitXmlDeclaration, boolean prettyPrint) {
    if (node == null) {
        throw new IllegalArgumentException("node is null.");
    }

    try {
        // Remove unwanted whitespaces
        node.normalize();
        XPath xpath = XPathFactory.newInstance().newXPath();
        XPathExpression expr = xpath.compile("//text()[normalize-space()='']");
        NodeList nodeList = (NodeList)expr.evaluate(node, XPathConstants.NODESET);

        for (int i = 0; i < nodeList.getLength(); ++i) {
            Node nd = nodeList.item(i);
            nd.getParentNode().removeChild(nd);
        }

        // Create and setup transformer
        Transformer transformer =  TransformerFactory.newInstance().newTransformer();
        transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");

        if (omitXmlDeclaration == true) {
           transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        }

        if (prettyPrint == true) {
           transformer.setOutputProperty(OutputKeys.INDENT, "yes");
           transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
        }

        // Turn the node into a string
        StringWriter writer = new StringWriter();
        transformer.transform(new DOMSource(node), new StreamResult(writer));
        return writer.toString();
    } catch (TransformerException e) {
        throw new RuntimeException(e);
    } catch (XPathExpressionException e) {
        throw new RuntimeException(e);
    }
}

答案 1 :(得分:1)

这是一种可能性:

void save(Node node, OutputStream stream) throws Exception {
    DOMImplementationLS ls = (DOMImplementationLS) node.getOwnerDocument().getImplementation();
    LSOutput out = ls.createLSOutput();
    out.setByteStream(stream);
    LSSerializer ser = ls.createLSSerializer();
    ser.write(node, out);
}

也许你应该确保node真的是Element,但我把它留作了一个例外。