Вместо да използвате JAXB RI (Metro), можете да използвате внедряването на MOXy JAXB (аз съм техническият ръководител). Има някои разширения, които ще направят картографирането на този сценарий доста лесно.
jaxb.properties
За да използвате MOXy като ваша реализация на JAXB, трябва да добавите файл с име jaxb.properties в същия пакет като вашите моделни класове със следния запис:
javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory
Корен
import javax.xml.bind.annotation.*;
@XmlRootElement(name="ROOT")
@XmlAccessorType(XmlAccessType.FIELD)
public class Root {
@XmlElement(name="ELEM_A")
private ElemA elemA;
@XmlElement(name="ELEM_B")
private ElemB elemB;
}
ElemA
Можем да използваме @XmlTransformation. Той е подобен по концепция на XmlAdapter, но по-лесен за споделяне между съпоставяния.
import java.util.Date;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import org.eclipse.persistence.oxm.annotations.XmlReadTransformer;
import org.eclipse.persistence.oxm.annotations.XmlTransformation;
import org.eclipse.persistence.oxm.annotations.XmlWriteTransformer;
import org.eclipse.persistence.oxm.annotations.XmlWriteTransformers;
@XmlAccessorType(XmlAccessType.FIELD)
public class ElemA {
@XmlTransformation
@XmlReadTransformer(transformerClass=DateAttributeTransformer.class)
@XmlWriteTransformers({
@XmlWriteTransformer(xpath="A_DATE/text()", transformerClass=DateFieldTransformer.class),
@XmlWriteTransformer(xpath="A_TIME/text()", transformerClass=TimeFieldTransformer.class),
})
public Date aDate;
@XmlElement(name="STRING")
private String string;
}
ElemB
import java.util.Date;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import org.eclipse.persistence.oxm.annotations.XmlReadTransformer;
import org.eclipse.persistence.oxm.annotations.XmlTransformation;
import org.eclipse.persistence.oxm.annotations.XmlWriteTransformer;
import org.eclipse.persistence.oxm.annotations.XmlWriteTransformers;
@XmlAccessorType(XmlAccessType.FIELD)
public class ElemB {
@XmlTransformation
@XmlReadTransformer(transformerClass=DateAttributeTransformer.class)
@XmlWriteTransformers({
@XmlWriteTransformer(xpath="B_DATE/text()", transformerClass=DateFieldTransformer.class),
@XmlWriteTransformer(xpath="B_TIME/text()", transformerClass=TimeFieldTransformer.class),
})
private Date bDate;
@XmlElement(name="NUM")
private int num;
@XmlTransformation
@XmlReadTransformer(transformerClass=DateAttributeTransformer.class)
@XmlWriteTransformers({
@XmlWriteTransformer(xpath="C_DATE/text()", transformerClass=DateFieldTransformer.class),
@XmlWriteTransformer(xpath="C_TIME/text()", transformerClass=TimeFieldTransformer.class),
})
private Date cDate;
}
DateAttributeTransformer
Трансформаторът на атрибути отговаря за демаршалирането на обекта Date.
import java.text.ParseException;
import java.text.SimpleDateFormat;
import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.mappings.foundation.AbstractTransformationMapping;
import org.eclipse.persistence.mappings.transformers.AttributeTransformer;
import org.eclipse.persistence.sessions.Record;
import org.eclipse.persistence.sessions.Session;
public class DateAttributeTransformer implements AttributeTransformer {
private AbstractTransformationMapping mapping;
private SimpleDateFormat yyyyMMddHHmmss = new SimpleDateFormat("yyyyMMddHHmmss");
public void initialize(AbstractTransformationMapping mapping) {
this.mapping = mapping;
}
public Object buildAttributeValue(Record record, Object instance, Session session) {
try {
String dateString = null;
String timeString = null;
for(DatabaseField field : mapping.getFields()) {
if(field.getName().contains("DATE")) {
dateString = (String) record.get(field);
} else {
timeString = (String) record.get(field);
}
}
return yyyyMMddHHmmss.parseObject(dateString + timeString);
} catch(ParseException e) {
throw new RuntimeException(e);
}
}
}
DateFieldTransformer
Полевите трансформатори са отговорни за сортирането на обекта Date.
import java.text.SimpleDateFormat;
import java.util.Date;
import org.eclipse.persistence.mappings.foundation.AbstractTransformationMapping;
import org.eclipse.persistence.mappings.transformers.FieldTransformer;
import org.eclipse.persistence.sessions.Session;
public class DateFieldTransformer implements FieldTransformer {
private AbstractTransformationMapping mapping;
private SimpleDateFormat yyyyMMdd = new SimpleDateFormat("yyyyMMdd");
public void initialize(AbstractTransformationMapping mapping) {
this.mapping = mapping;
}
public Object buildFieldValue(Object instance, String xPath, Session session) {
Date date = (Date) mapping.getAttributeValueFromObject(instance);
return yyyyMMdd.format(date);
}
}
TimeFieldTransformer
import java.text.SimpleDateFormat;
import java.util.Date;
import org.eclipse.persistence.mappings.foundation.AbstractTransformationMapping;
import org.eclipse.persistence.mappings.transformers.FieldTransformer;
import org.eclipse.persistence.sessions.Session;
public class TimeFieldTransformer implements FieldTransformer {
private AbstractTransformationMapping mapping;
private SimpleDateFormat HHmmss = new SimpleDateFormat("HHmmss");
public void initialize(AbstractTransformationMapping mapping) {
this.mapping = mapping;
}
public Object buildFieldValue(Object instance, String xPath, Session session) {
Date date = (Date) mapping.getAttributeValueFromObject(instance);
return HHmmss.format(date);
}
}
Примерна програма
import java.io.File;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
public class Demo {
public static void main(String[] args) throws Exception {
JAXBContext jc = JAXBContext.newInstance(Root.class);
System.out.println(jc);
Unmarshaller unmarshaller = jc.createUnmarshaller();
File xml = new File("src/forum41/input.xml");
Root root = (Root) unmarshaller.unmarshal(xml);
Marshaller marshaller = jc.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.marshal(root, System.out);
}
}
XML документ
<ROOT>
<ELEM_A>
<A_DATE>20100825</A_DATE>
<A_TIME>141500</A_TIME>
<!-- other elements, maybe also other or date/time combinations -->
<STRING>ABC</STRING>
</ELEM_A>
<ELEM_B>
<B_DATE>20100825</B_DATE>
<B_TIME>153000</B_TIME>
<NUM>123</NUM>
<C_DATE>20100825</C_DATE>
<C_TIME>154500</C_TIME>
</ELEM_B>
</ROOT>
Кодът, както е показано по-горе, изисква EclipseLink 2.2, който в момента е в процес на разработка. Тук са налични нощни компилации:
Текущата издадена версия на EclipseLink 2.1 поддържа горното, но с малко по-различна конфигурация. Можем да обсъдим подходящата настройка, ако се интересувате от проучването на тази опция.
person
bdoughan
schedule
25.08.2010