Java - 使用DOM解析xml

Question

我试图解析以下xml.我可以轻松访问WeekNumber但无法访问EmployeeRatesLevelA和EmployeeRatesLevelB的子项.目标是将这些保存到具有字段WeekNumber和ArrayLists,EmployeeRatesLevelA和EmployeeRatesLevelB的类DataSet.谢谢.

<DataSet ActiveFrom="2011/04/06">  
    <WeekNumber>8</WeekNumber>  
    <EmployeeRatesLevelA>  
        <Rate>0</Rate>  
        <Rate>0.12</Rate>  
    </EmployeeRatesLevelA>  
    <EmployeeRatesLevelB>  
        <Rate>0.15</Rate>  
        <Rate>0.20</Rate>  
    </EmployeeRatesLevelB>  
</DataSet>  


    Document doc = loadXml("data.xml");  
    NodeList nodeList = doc.getElementsByTagName("DataSet");  
    for (int i = 0; i < nodeList.getLength(); i++) {  
        Node node = nodeList.item(i);  
        if (node.getNodeType() == Node.ELEMENT_NODE) {  
            Element element = (Element) node;  
            NodeList weekNumberList = element.getElementsByTagName("WeekNumber");  
            Element weekElement = (Element) weekNumberList.item(0);  
            NodeList textElementList = weekElement.getChildNodes();
            System.out.println("Weeknumber:"+ ((Node)textElementList.item(0)).getNodeValue().trim());
    }

    public static Document loadXml(String file) {
        try {
           return (DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new File(file)));
        } catch (SAXException e) {
        e.printStackTrace();
        } catch (IOException e) {
        e.printStackTrace();
        } catch (ParserConfigurationException e) {
        e.printStackTrace();
        }
        return null;
    }

这给了我Weeknumber但我无法访问EmployeeRatesLevelA和EmployeeRatesLevelB.

想学习其他很酷的东西,但由于我是Java的新手并且xml文档非常小,DOM应该足够了.

Answer 1

如评论中所述,请向我们展示您的Java代码.您可能还需要考虑查看JAXB - 用于XML绑定的Java体系结构.这特别适合将XML表示为Java对象.无论出于何种原因,您的解决方案可能都不可行,但绝对要看一下:

http://jaxb.java.net/tutorial/

数据集

以下域对象是您在问题中描述的内容:

目标是将这些保存到具有字段WeekNumber和ArrayLists,EmployeeRatesLevelA和EmployeeRatesLevelB的类DataSet.

package forum8345529;

import java.util.List;
import javax.xml.bind.annotation.*;

@XmlRootElement(name="DataSet")
@XmlAccessorType(XmlAccessType.FIELD)
public class DataSet {

    @XmlElement(name="WeekNumber")
    private int weekNumber;

    @XmlElementWrapper(name="EmployeeRatesLevelA")
    @XmlElement(name="Rate")
    private List<Float> employeeRatesLevelA;

    @XmlElementWrapper(name="EmployeeRatesLevelB")
    @XmlElement(name="Rate")
    private List<Float> employeeRatesLevelB;

}

演示

以下代码演示了如何使用JAXB运行时将XML转换为域对象或从域对象转换XML:

package forum8345529;

import java.io.File;
import javax.xml.bind.*;

public class Demo {

    public static void main(String[] args) throws Exception{
        JAXBContext jc = JAXBContext.newInstance(DataSet.class);

        Unmarshaller unmarshaller = jc.createUnmarshaller();
        File xml = new File("src/forum8345529/input.xml");
        DataSet dataSet = (DataSet) unmarshaller.unmarshal(xml);

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(dataSet, System.out);
    }

}