java - 使用 Java 和 XML 创建具有属性的对象(解码)

Question

以下代码根据我的 XSD 文件 (SQL.xsd) 创建 Java 文件 (QUERY.java)。

String directory = "D:/PROJEKTE/2016/";

SchemaCompiler sc = XJC.createSchemaCompiler();
sc.forcePackageName("de.example.jaxb");

File myXsd = new File("SQL.xsd");
InputSource source = new InputSource(myXsd.toURI().toString());

sc.parseSchema(source);
S2JJAXBModel model = sc.bind();
JCodeModel jCodeModel = model.generateCode(null, null);
jCodeModel.build(new File(directory));

QUERY.java:

public class QUERY {

@XmlElement(name = "SELECT", required = true)
protected QUERY.SELECT select;
@XmlElement(name = "TABLE")
protected List<QUERY.TABLE> table;
@XmlElement(name = "JOIN")
protected List<QUERY.JOIN> join;
@XmlElement(name = "WHERE", required = true)
protected String where;
@XmlElement(name = "GROUP", required = true)
protected QUERY.GROUP group;
@XmlElement(name = "ORDER", required = true)
protected QUERY.ORDER order;
@XmlAttribute(name = "author")
protected String author;

public QUERY.SELECT getSELECT() {
    return select;
}

public void setSELECT(QUERY.SELECT value) {
    this.select = value;
}

public List<QUERY.TABLE> getTABLE() {
    if (table == null) {
        table = new ArrayList<QUERY.TABLE>();
    }
    return this.table;
}

public List<QUERY.JOIN> getJOIN() {
    if (join == null) {
        join = new ArrayList<QUERY.JOIN>();
    }
    return this.join;
}

public String getWHERE() {
    return where;
}

public void setWHERE(String value) {
    this.where = value;
}

public QUERY.GROUP getGROUP() {
    return group;
}

public void setGROUP(QUERY.GROUP value) {
    this.group = value;
}

public QUERY.ORDER getORDER() {
    return order;
}

public void setORDER(QUERY.ORDER value) {
    this.order = value;
}

public String getAuthor() {
    return author;
}

public void setAuthor(String value) {
    this.author = value;
}

...

不幸的是，我不知道如何将其保存在内存中(而不是构建)。但至关重要的是，我使用相应的 XML 文件来赋予对象其属性(解码!)。

SQL.xml:

<?xml version="1.0" encoding="UTF-8"?>
<QUERY author='Test'>
<SELECT>
    <COLUMN alias="id">
        <ATTRIBUTE table="orders">OrderID</ATTRIBUTE>
    </COLUMN>
    <COLUMN>
        <ATTRIBUTE table="customers">CustomerName</ATTRIBUTE>
    </COLUMN>
    <COLUMN>
        <ATTRIBUTE table="orders">OrderDate</ATTRIBUTE>
    </COLUMN>
    <COLUMN alias="group">'Bestellungen'</COLUMN>
</SELECT>
<TABLE alias="orders">Orders</TABLE>
<TABLE alias="customers">Customers</TABLE>
<TABLE alias="product">Product</TABLE>
<JOIN type="INNER">
    <LEFT table="orders">CustomerID</LEFT>
    <RIGHT table="customers">CustomerID</RIGHT>
</JOIN>
<JOIN type="LEFT">
    <LEFT table="orders">ProductID</LEFT>
    <RIGHT table="product">ProductID</RIGHT>
</JOIN>
<WHERE>
    CustomerName='Test'
</WHERE>
<GROUP>
    <ATTRIBUTE>CustomerName</ATTRIBUTE>
    <HAVING>SUM(Units)>30</HAVING>
</GROUP>
<ORDER>
    <COLUMN>OrderID</COLUMN>
    <SORT>DESC</SORT>
</ORDER>
</QUERY>

Answer 1

解决方案:

File myXml = new File("SQL.xml");

DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(myXml);
doc.getDocumentElement().normalize();

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

for (int i = 0; i < nList.getLength(); i++)
{
    Node nNode = nList.item(i);

    Element eElement = (Element) nNode;
    System.out.println("SELECT " + eElement.getElementsByTagName("SELECT").item(0).getTextContent());
    System.out.println("FROM " + eElement.getElementsByTagName("TABLE").item(0).getTextContent());
    System.out.println("JOIN " + eElement.getElementsByTagName("JOIN").item(0).getTextContent());
    System.out.println("WHERE " + eElement.getElementsByTagName("WHERE").item(0).getTextContent());
    System.out.println("GROUP " + eElement.getElementsByTagName("GROUP").item(0).getTextContent());
    System.out.println("ORDER " + eElement.getElementsByTagName("ORDER").item(0).getTextContent());
}

无论如何谢谢你!