我在谷歌上能找到的只有 3 条信息，最详细的是设计文档，如下 URL
http://wiki.eclipse.org/EclipseLink/DesignDocs/317962/Phase2.1#.40XmlProperty
它确实提到“xml-property 元数据标记将用于配置属性”。并且给出了两个没有编组结果的示例如下：
Example: type-level property
The following example will demonstrate how a type-level property can be applied.
Setting xml-property on a type via EclipseLink XML metadata can be accomplished as follows:
<java-type name="org.example.Employee">
<xml-properties>
<xml-property name="identifier" value="101" value-type="java.lang.Integer" />
<xml-property name="isTrue" value="false" value-type="java.lang.Boolean" />
</xml-properties>
</java-type>
Setting @XmlProperty on a type via annotations can be accomplished as follows:
org.example.Employee.java
@XmlProperties({@XmlProperty(name="identifier", value="101", valueType=Integer.class),
@XmlProperty(name="isTrue", value="false", valueType=Boolean.class)})
public class Employee {
...
}
Example: property-level property
The following example will demonstrate how a property-level property can be applied.
Setting xml-property on a property via EclipseLink XML metadata can be accomplished as follows:
<java-type name="org.example.Employee">
<java-attributes>
<xml-element java-attribute="myelement">
<xml-properties>
<xml-property name="isAttribute" value="false" value-type="java.lang.Boolean" />
<xml-property name="comment" value="this is an element" />
</xml-properties>
</xml-element>
</java-attributes>
</java-type>
Setting @XmlProperty on a property via annotations can be accomplished as follows:
org.example.Employee.java
public class Employee {
@XmlProperties({@XmlProperty(name="isAttribute", value="false", valueType=Boolean.class),
@XmlProperty(name="comment", value="this is an element")}
public String myelement;
}
我也尝试了我的示例，但我无法区分使用和不使用 xml-property 的东西。
谁能向我解释 XmlProperty 是做什么的？它会产生什么样的效果？或何时使用 XmlProperty？是否有任何带有封送结果的示例代码？
<?xml version="1.0"?>
<xml-bindings xmlns="http://www.eclipse.org/eclipselink/xsds/persistence/oxm"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.eclipse.org/eclipselink/xsds/persistence/oxm http://www.eclipse.org/eclipselink/xsds/eclipselink_oxm_2_4.xsd"
version="2.1">
<xml-schema element-form-default="QUALIFIED">
<xml-ns prefix="ns1" namespace-uri="http://www.example.org/customer" />
<xml-ns prefix="ns2" namespace-uri="http://www.example.org/phone" />
<xml-ns prefix="ns3" namespace-uri="http://www.example.org/addr" />
</xml-schema>
<java-types>
<java-type name="example.gettingstarted.demo1.Customer">
<xml-root-element />
<xml-type namespace="http://www.example.org/customer"
prop-order="name address phoneNumbers" />
<xml-properties>
<xml-property name="hello" value="false" value-type="java.lang.String" />
<xml-property name="world" value="this is an element"
value-type="java.lang.String" />
</xml-properties>
<java-attributes>
<xml-attribute java-attribute="name" xml-path="@name" />
<xml-element java-attribute="address">
</xml-element>
<xml-element java-attribute="phoneNumbers" xml-path="contact-info/phone-number" />
</java-attributes>
</java-type>
<java-type name="example.gettingstarted.demo1.PhoneNumber">
<xml-root-element />
<xml-type namespace="http://www.example.org/phone"></xml-type>
<java-attributes>
<xml-attribute java-attribute="type" />
<xml-value java-attribute="value" />
</java-attributes>
</java-type>
<java-type name="example.gettingstarted.demo1.Address">
</java-type>
</java-types>
</xml-bindings>
Java 文件：
package example.gettingstarted.demo5;
import java.util.HashMap;
import java.util.Map;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.transform.Source;
import javax.xml.transform.stream.StreamSource;
import org.eclipse.persistence.jaxb.JAXBContextFactory;
import example.gettingstarted.demo1.Address;
import example.gettingstarted.demo1.Customer;
import example.gettingstarted.demo1.PhoneNumber;
/**
* @author barry
* make Customer.Address.street as Customer.@street
*/
public class Demo {
@SuppressWarnings({ "rawtypes", "deprecation" })
public static void main(String[] args) throws JAXBException {
// Step 1 - Create the Domain Model
Customer customer = new Customer();
customer.setName("Jane Doe");
Address address = new Address();
address.setStreet("123 Any Street");
address.setCity("My Town");
customer.setAddress(address);
PhoneNumber workPhoneNumber = new PhoneNumber();
workPhoneNumber.setType("work");
workPhoneNumber.setValue("613-555-1111");
customer.getPhoneNumbers().add(workPhoneNumber);
PhoneNumber cellPhoneNumber = new PhoneNumber();
cellPhoneNumber.setType("cell");
cellPhoneNumber.setValue("613-555-2222");
customer.getPhoneNumbers().add(cellPhoneNumber);
// Step 2 - Convert the Domain Model to XML
final Map<String, Source> metadataSourceMap = new HashMap<String, Source>();
metadataSourceMap.put("example.gettingstarted.demo1", new StreamSource("./example/gettingstarted/demo5/eclipselink-oxm.xml"));
final Map<String, Object> properties = new HashMap<String, Object>();
properties.put(JAXBContextFactory.ECLIPSELINK_OXM_XML_KEY, metadataSourceMap);
final Class[] classes = new Class[1];
classes[0] = Customer.class;
JAXBContext jaxbContext = (JAXBContext) JAXBContext.newInstance(classes, properties);
Marshaller marshaller = jaxbContext.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.marshal(customer, System.out);
}
}
无论是否应用了 xml-property，我的输出如下。
My Town 123 Any Street 613-555-1111 613-555-2222