How to parse specific information from a XML-file into objects in java?

Question

i´m quite new to programming and especially new to XML parsing and i´m currently having issues with xml-parsing in java. I´ve tried several things to get specific information from a xml-file and writing it into an object, which later on will be put into an arraylist and sorted. Here´sa short cut from my XML-file (i changed names and values as i´m not sure if i´m allowed to share it.):

    <things>
      <code V="123"/>
      <region V="38"/>
      <hl_list>
        <hl>
          <stuff_hmv V="XXX" DN="some other stuff"/>
          <secondary_code V="Z98"/>
          <infotext V="max 12 units"/>
          <kl_list>
            <kl V="I" DN="some other stuff">
              <diag_list>
                <diag V="WS1" DN="illness 1"/>
                <diag V="WS2" DN="illness 2"/>
                <diag V="EX1" DN="illness 3"/>

              </diag_list>
            </kl>
          </kl_list>
        </hl>
      </hl_list>
    </things>
    <things>
      <code V="456"/>
      <region V="45"/>
      <hl_list>
        <hl>
          <stuff_hmv V="X1X" DN="some other stuff"/>
          <infotext V="max 13 units"/>
          <kl_list>
            <kl V="II" DN="some other stuff">
              <diag_list>
                <diag V="WS1" DN="illness 3"/>
                <diag V="WS2" DN="illness 2"/>
                <diag V="EX1" DN="illness 4"/>

              </diag_list>
            </kl>
          </kl_list>
        </hl>
      </hl_list>
    </things>

This is basically what i´m working with. I have several "thing-blocks" and i need the following information (if existing) in my objects. If the object is filled it should be put into an arraylist and the next block continues. Information from xml:

• code
• region
• stuff_hmv
• secondary_code
• infotext
• kl
• every diag entry (i tried to put them into an arraylist in my object)

so far i´ve tried to get the information with getElementsByTagName and getters/setters for my object.

Answer 1

JAXB could be the solution for you

@XmlRootElement
public class Things {
  private String code;
  private String region;

  @XmlElement
  public void setCode(String code) {
    this.code = code;
  }

  @XmlElement
  public void setCode(String region) {
    this.region = region;
  }
}

JAXBContext jaxbContext = JAXBContext.newInstance(Things.class);
Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
Customer customer = (Customer) jaxbUnmarshaller.unmarshal(new File("C:\\file.xml"));

for more information check jaxb and how to parse xml to java object?

Answer 2

File fXmlFile = new File("/Users/mkyong/staff.xml");
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(fXmlFile);

//optional, but recommended
//read this - http://stackoverflow.com/questions/13786607/normalization-in-dom-parsing-with-java-how-does-it-work
doc.getDocumentElement().normalize();

System.out.println("Root element :" + doc.getDocumentElement().getNodeName());

NodeList nList = doc.getElementsByTagName("staff");

System.out.println("----------------------------");

for (int temp = 0; temp < nList.getLength(); temp++) {

    Node nNode = nList.item(temp);

    System.out.println("\nCurrent Element :" + nNode.getNodeName());

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

        Element eElement = (Element) nNode;

        System.out.println("Staff id : " + eElement.getAttribute("id"));
        System.out.println("First Name : " + eElement.getElementsByTagName("firstname").item(0).getTextContent());
        System.out.println("Last Name : " + eElement.getElementsByTagName("lastname").item(0).getTextContent());
        System.out.println("Nick Name : " + eElement.getElementsByTagName("nickname").item(0).getTextContent());
        System.out.println("Salary : " + eElement.getElementsByTagName("salary").item(0).getTextContent());

    }
}

SIMPLY REPLACE THE STAFF MARKEUP TAG WITH CODE OR THINGS WHICH ONENODE YOU WANT TO PICKUP