Java all child element reading in XML

问题

I want to read all link and title at the same time to array list?

<rootNode>
    <image>
        <link>http://imagelink/</link>
        <title>This is the title</title>
    </image>
    <movie>
        <link>http://movielink/</link>
        <title>This is the title</title>
    </movie>
</rootNode>

Code below works fine but, where there are different child nodes it can make code too big.

I don't want multiple for, I want something that looks clean!

    ArrayList XTimeStamp = new ArrayList();
    Node libraryTagNode, libraryDataNode;
    Element libraryTagElement, libraryDataElement;
    NodeList libraryTagList,libraryDataList;

    try {
        File file = new File("computer.txt");
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = dbf.newDocumentBuilder();
        Document doc = db.parse(file);
        doc.getDocumentElement().normalize();

        NodeList imageLst = doc.getElementsByTagName("image");
        NodeList movieLst = doc.getElementsByTagName("movie");  

        for (int s = 0; s < imageLst.getLength(); s++) {
            libraryTagNode=bookLst.item(s);


            if (libraryTagNode.getNodeType() == Node.ELEMENT_NODE) {

                libraryTagElement = (Element) libraryTagNode;

                libraryTagList = libraryTagElement.getElementsByTagName("link");
                libraryDataElement = (Element) libraryTagList.item(0);

                libraryDataList = libraryDataElement.getChildNodes();
                String timeStampX=libraryDataList.item(0).getNodeValue();

                libraryTagList = libraryTagElement.getElementsByTagName("title");
                libraryDataElement = (Element) libraryTagList.item(0);

                libraryDataList = libraryDataElement.getChildNodes();
                String timeStampY=libraryDataList.item(0).getNodeValue();

                XTimeStamp.add(timeStampX+" "+timeStampY);

            }

        }
    for (int s = 0; s < movieLst.getLength(); s++) {
            libraryTagNode=bookLst.item(s);


            if (libraryTagNode.getNodeType() == Node.ELEMENT_NODE) {

                libraryTagElement = (Element) libraryTagNode;

                libraryTagList = libraryTagElement.getElementsByTagName("link");
                libraryDataElement = (Element) libraryTagList.item(0);

                libraryDataList = libraryDataElement.getChildNodes();
                String timeStampX=libraryDataList.item(0).getNodeValue();

                libraryTagList = libraryTagElement.getElementsByTagName("title");
                libraryDataElement = (Element) libraryTagList.item(0);

                libraryDataList = libraryDataElement.getChildNodes();
                String timeStampY=libraryDataList.item(0).getNodeValue();

                XTimeStamp.add(timeStampX+" "+timeStampY);

            }

        }

回答1:

I'm guessing you want to roll the two loops into one somehow as this is certainly a cumbersome way to do it as it is now.

The answer is to use XPath. I would suggest you search for <title> elements whose parent holds a <link> element.

回答2:

Use XPATH - see http://www.ibm.com/developerworks/library/x-javaxpathapi/index.html

回答3:

Not 100% sure on what your asking but if you want to get all the link nodes in a NodeList and all the title nodes in a different nodelist you could try XPath using "//link" and "//title" as your XPath expression

来源：https://stackoverflow.com/questions/8578455/java-all-child-element-reading-in-xml