Java：读取具有许多嵌套元素的xml

Question

我有看起来与以下内容类似的xml。 我需要从属性和标签中获取值并存储它们。 但是我不明白如何到达2（3,4等）嵌套元素。 我使用以下代码在Internet上找到，它使用DOM，但是我无法获取正确的RegNumber及其属性。 提前致谢。

 nodeList = xmldocument.getElementsByTagName("Header"); if (nodeList != null && nodeList.getLength() > 0) { for (int i = 0; i < nodeList.getLength(); i++) { //get the header element Element header = (Element) nodeList.item(i); System.out.println("Element: " + ((Element)nodeList.item(i)).getNodeName()); System.out.println(header.getAttribute("time")); } } nodeList = xmldocument.getElementsByTagName("Document"); if (nodeList != null && nodeList.getLength() > 0) { for (int i = 0; i < nodeList.getLength(); i++) { //get the document element Element document = (Element) nodeList.item(i); System.out.println("Element: " + ((Element)nodeList.item(i)).getNodeName()); System.out.println(document.getAttribute("Id")); nodeList = document.getElementsByTagName("RegNumber"); for (int j = 0; j < nodeList.getLength(); j++) { //get the RegNumber element Element regNumber = (Element) nodeList.item(j); System.out.println("Element: " + ((Element)nodeList.item(j)).getNodeName()); System.out.println(regNumber.getAttribute("regpoint")); } } } 

xml：

<XML xsi:schemaLocation="http://www.codetools.it XSD2.xsd" xmlns="http://www.codetools.it" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
            <Header time="2001-12-17T09:30:47Z" />
            <Document Id="456">
                <RegNumber regpoint="" regdate="2001-12-17T09:30:47Z">123/456</RegNumber>
                <Confident flag="0"/>
                <DocNumber kind="">
                    <RegNumber RegPoint="" regdate="2001-12-17T09:30:47Z">456/789</RegNumber>
                    <Organization fullname="lol" shortname="" ownership="lol" ogrn="78945612" inn="">
                        <OfficialPerson>
                            <Name  Firstname="John"/>
                            <Official Department="" post=""/>
                            <SignDate>2001-12-17T09:30:47Z</SignDate>
                        </OfficialPerson>
                        <Econtact type="1">test@test.com.ua</Econtact>
                        <Address street="" settlement="" postcode="" postbox="" flat="" district="" region="" country="" nontypical="" house=""/>
                    </Organization>
                </DocNumber>
                <DocTransfer os="Windows" type=".docx" type_ver="" char_set="" description="kkkk">
    </DocTransfer>
            <Reghistory idnumber="">
                <RegNumber RegPoint="" regdate=""/>
                <Organization fullname="" shortname="" ownership="" ogrn="" inn="">
                    <Econtact type=""/>
                    <Address street="" settlement="" postcode="" postbox="" flat="" district="" region="" country="" nontypical="" house=""/>
                </Organization>
            </Reghistory>
            <Author>
                <Organization fullname="" shortname="" ownership="" ogrn="12345678" inn="">
                    <OfficialPerson>
                        <Name  Firstname="" />
                        <Official Department="" post=""/>
                        <SignDate>2011-12-17T09:30:47Z</SignDate>
                    </OfficialPerson>
                    <Econtact type="Рї">smirnov@test.com</Econtact>
                    <Address street=""  postcode="1234" postbox="" flat="" district="" region="" country="" nontypical="" house="12"/>
                </Organization>
                <PrivatePerson>
                    <Name Surname="" Firstname="" Fathername=""/>
                    <Econtact type=""/>
                    <Address street="" settlement="" postcode="" postbox="" flat="" district="" region="" country="" nontypical="" house=""/>
                    <SignDate/>
                    <Rank privilege="" socialposition="" sex=""/>
                </PrivatePerson>
            </Author>
            <Validator attestation="0">
                <DocNumber kind="наказ">
                    <RegNumber RegPoint="" regdate="2001-12-17T09:30:47Z"/>
                    <Organization fullname="" shortname="" ownership="" ogrn="14725836" inn="">
                        <Econtact type="Рї">kmu@test.com</Econtact>
                        <Address street="" settlement="" postcode="" postbox="" flat="" district="" region="" country="" nontypical="" house=""/>
                    </Organization>
                </DocNumber>
                <Organization fullname="" shortname="РљРњРЈ" ownership="" ogrn="96325878" inn="">
                    <Econtact type="String">kmu@test.com</Econtact>
                    <Address street="Пушкіна" settlement="" postcode="4563" postbox="" flat="" district="" region="" country="" nontypical="" house="23"/>
                    <OfficialPerson>
                        <Name Surname="" Firstname="" Fathername=""/>
                        <Official Department="" post=""/>
                        <SignDate>2011-12-17T09:30:47Z</SignDate>
                    </OfficialPerson>
                </Organization>
                <PrivatePerson>
                    <Name Surname="" Firstname="" Fathername=""/>
                    <Econtact type=""></Econtact>
                    <Address street="" settlement="" postcode="" postbox="" flat="" district="" region="" country="" nontypical="" house=""/>
                    <SignDate></SignDate>
                    <Rank privilege="" socialposition="" sex=""/>
                </PrivatePerson>
            </Validator>
            <Addressee>
                <Referred id="" retype="">
                    <RegNumber regdate="" regpoint=""/>
                    <TaskNumber taskDate=""/>
                </Referred>
                <Organization fullname="String" shortname="" ownership="" ogrn="85236974" inn="">
                    <OfficialPerson>
                        <Name Surname="" Firstname="" Fathername=""/>
                        <Official Department="" post=""/>
                    </OfficialPerson>
                    <Econtact type="Рї">sofki@test.com</Econtact>
                    <Address street="" settlement="" postcode="" postbox="" flat="" district="" region="" country="" nontypical="" type="" house=""/>
                </Organization>
                <PrivatePerson>
                    <Name Surname="" Firstname="" Fathername=""/>
                    <Econtact type=""></Econtact>
                    <Address street="" settlement="" postcode="" postbox="" flat="" district="" region="" country="" nontypical="" house=""/>
                    <Rank privilege="" socialposition="" sex=""/>
                </PrivatePerson>
            </Addressee>
            <Writer>
                <Organization fullname="" shortname="" ownership="" ogrn="" inn="">
                    <OfficialPerson>
                        <Name Surname="" Firstname="" Fathername=""/>
                        <Econtact type=""></Econtact>
                    </OfficialPerson>
                </Organization>
                <PrivatePerson>
                    <Name Surname="" Firstname="" Fathername=""/>
                    <Econtact type=""></Econtact>
                </PrivatePerson>
            </Writer>
        </Document>

编辑 。 按照建议，我尝试找出JAXB的问题。 xjc工具生成了3个类：ObjectFactory，package-info，XML。 我发现以下代码可从xml创建对象：

public static void main(String[] args) {
        try {

            File file = new File("F:\\Untitled3.xml");
            JAXBContext jaxbContext = JAXBContext.newInstance(XML.class);

            Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
            XML xml = (XML) jaxbUnmarshaller.unmarshal(file);
            System.out.println(xml);

        } catch (JAXBException e) {
            e.printStackTrace();
        }
    }

这是正确的方法，还是我需要使用ObjectFactory？

ObjectFactory f =new ObjectFactory();
            XML xml1 = f.createXML();

如何创建具有所有标签和属性的对象，然后从中创建xml文件？ 我是Java和jaxb的新手，请耐心等待。

Answer 1

它对于让您访问特定深度的节点的方法通常没有意义或通常没有用。 这不仅与Java有关，而且与DOM规范有关，我相信这是正确的决定。

人们通常通过许多有意义的方式之一来访问节点：

1. 通过标签名，而标签名通常表示节点的含义。
2. XPath-文档的完整含义。
3. 绑定，例如JAXB（基本上，您不再处理XML，而是Java类）
4. 有旧的SAX（不是DOM）和StAX（DOM和SAX的混合物）

查找xpath，这将非常有帮助。

Answer 2

在每个节点上再次使用“ getElementsByTagName”功能，以按标签名称获取元素。 明显...

这是我的示例代码，深入了几个层次：

DocumentBuilder db = dbf.newDocumentBuilder();
        Document doc = db.parse(acpFile);
        Element docEle = doc.getDocumentElement();
        NodeList series = docEle.getElementsByTagName("dod:recordSeries");

        if(series != null && series.getLength()>0) 
        {
            for(int i=0; i<series.getLength(); i++) 
            {
                Element serie = (Element)series.item(i);
                System.out.println("S -- "+serie.getAttribute("view:childName"));
                NodeList categories = serie.getElementsByTagName("dod:recordCategory");

                for(int j=0; j<categories.getLength(); j++)
                {
                    Element category = (Element)categories.item(j);
                    System.out.println("C ---- "+category.getAttribute("view:childName"));
                    NodeList recordFolders = category.getElementsByTagName("rma:recordFolder");

                    for(int k=0; k<recordFolders.getLength(); k++)
                    {
                        Element folder = (Element)recordFolders.item(k);
                        System.out.println("F ------ "+folder.getAttribute("view:childName"));
                    }
                }
            }
        }