[Java] 寫入及讀取 XML 檔案

CenterInfo.java

@XmlRootElement(name = "centerInfo")
@XmlAccessorType(XmlAccessType.FIELD)
public class CenterInfo extends BaseXmlConfig {

    @XmlAttribute(name = "Id")
    private String id;

    @XmlAttribute(name = "Name")
    private String name;

    @XmlAttribute(name = "status")
    private String status;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }
}

CenterList.java

@XmlRootElement(name = "centerList")
@XmlAccessorType(XmlAccessType.FIELD)
public class CenterList extends BaseXmlConfig {

    @XmlElement(name = "centerInfo")
    private List<CenterInfo> centerInfo;

    public List<CenterInfo> getCenterInfo() {
        return centerInfo;
    }

    public void setCenterInfo(List<CenterInfo> centerInfo) {
        this.centerInfo = centerInfo;
    }
}

xmlWriterTest001.java

    /**
     * https://www.mkyong.com/java/how-to-create-xml-file-in-java-dom/
     */
    @Test
    public void testWriteXmlUseDocument() {

        final String ROOT_ELEMENT = "centerList";
        final String CHILDREN_ELEMENT = "centerInfo";
        final String ID = "Id";
        final String NAME = "Name";
        final String STATUS = "status";

        try {
            DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder docBuilder = docFactory.newDocumentBuilder();

            // root element
            Document doc = docBuilder.newDocument();
            Element rootElement = doc.createElement(ROOT_ELEMENT);
            doc.appendChild(rootElement);

            // centerInfo elements
            Element centerInfo = doc.createElement(CHILDREN_ELEMENT);
            rootElement.appendChild(centerInfo);

            Element centerInfo2 = doc.createElement(CHILDREN_ELEMENT);
            rootElement.appendChild(centerInfo2);

            Attr attrId = doc.createAttribute(ID);
            attrId.setValue("777");
            centerInfo.setAttributeNode(attrId);

            Attr attrName = doc.createAttribute(NAME);
            attrName.setValue("測試");
            centerInfo.setAttributeNode(attrName);

            Attr attrStatus = doc.createAttribute(STATUS);
            attrStatus.setValue("0");
            centerInfo.setAttributeNode(attrStatus);

            Attr attrId2 = doc.createAttribute(ID);
            attrId2.setValue("6000");
            centerInfo2.setAttributeNode(attrId2);

            Attr attrName2 = doc.createAttribute(NAME);
            attrName2.setValue("測試二");
            centerInfo2.setAttributeNode(attrName2);

            Attr attrStatus2 = doc.createAttribute(STATUS);
            attrStatus2.setValue("1");
            centerInfo2.setAttributeNode(attrStatus2);

            // write the content into xml file
            TransformerFactory transformerFactory = TransformerFactory.newInstance();
            Transformer transformer = transformerFactory.newTransformer();
            DOMSource source = new DOMSource(doc);
            StreamResult result = new StreamResult(new File("test.xml"));

            transformer.transform(source, result);

            Assert.assertNotNull(result);

        } catch (ParserConfigurationException | TransformerException e) {
            e.printStackTrace();
        }
    }

xmlWriterTest002.java

    private CenterList centerList;
    private CenterInfo centerInfo;
    private CenterInfo centerInfo2;
    private List<CenterInfo> centerInfos;

    @Before
    public void setUp() {
        prepareCenterConfig();
    }

    /**
     * http://www.journaldev.com/1234/jaxb-example-tutorial
     * http://blog.bdoughan.com/2011/06/jaxb-and-complex-types-with-simple.html
     */
    @Test
    public void testWriteXmlUseJaxb() {

        centerList.setCenterInfo(centerInfos);

        jaxbObjectToXML(centerList);

        CenterList centerList1 = jaxbXMLToObject();

        Assert.assertNotNull(centerList1);
    }

    private void jaxbObjectToXML(CenterList centerList) {
        try {
            JAXBContext context = JAXBContext.newInstance(CenterList.class);
            Marshaller m = context.createMarshaller();
            m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
            m.marshal(centerList, new File("test.xml"));
        } catch (JAXBException e) {
            e.printStackTrace();
        }
    }

    private CenterList jaxbXMLToObject() {
        try {
            JAXBContext context = JAXBContext.newInstance(CenterList.class);
            Unmarshaller un = context.createUnmarshaller();
            CenterList centerList = (CenterList) un.unmarshal(new File("test.xml"));
            return centerList;
        } catch (JAXBException e) {
            e.printStackTrace();
        }
        return null;
    }

    private void prepareCenterConfig() {
        centerList = new CenterList();
        centerInfo = new CenterInfo();
        centerInfo.setId("777");
        centerInfo.setName("測試");
        centerInfo.setStatus("1");
        centerInfo2 = new CenterInfo();
        centerInfo2.setId("7778");
        centerInfo2.setName("測試2");
        centerInfo2.setStatus("0");
        centerInfos = new ArrayList<>();
        centerInfos.add(centerInfo);
        centerInfos.add(centerInfo2);
        centerList.setCenterInfo(centerInfos);
    }