下面显示的 JUnit 测试使用 MOXy 失败（在我的环境中），但适用于 JAXB 参考实现。
预期生成的 XML 是：
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<itemManager>
<items>
<value>2</value>
</items>
</itemManager>
但打开 MOXy - jaxb.properties 包含：
javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory
生成的 XML 字符串为空。
这种行为的原因可能是什么以及需要做些什么来解决它？
我已经尝试过 EclipseLink MOXy 版本 2.5.1 和 2.4.2 - 请参阅下面的 pom.xml 片段。依赖项是 pom.xml 中的第一个依赖项，然后是许多其他依赖项（这也可能破坏了节目）。
<!-- Eclipselink moxy -->
<dependency>
<groupId>org.eclipse.persistence</groupId>
<artifactId>org.eclipse.persistence.moxy</artifactId>
<version>2.4.2</version>
<!-- <version>2.5.1</version> -->
<scope>test</scope>
</dependency>
JUnit 测试的 Java 代码：
package com.bitplan.storage.moxy;
import static org.junit.Assert.*;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;
import org.junit.Test;
/**
* show problem with empty xml result for Jaxb Marshaller
*
* @author wf
*
*/
public class TestEmptyXml {
public interface Copyable<T> {
/**
* copy me from the copyable
*
* @param othe
* - the source copyaqble to copy from
*/
public void copyFrom(T other);
}
public interface BO<BO_T> extends Copyable<BO_T> {
}
public interface ItemInterface {
}
@XmlRootElement
public static class Item implements ItemInterface {
int value;
/**
* @return the value
*/
public int getValue() {
return value;
}
/**
* @param value
* the value to set
*/
public void setValue(int value) {
this.value = value;
}
public Item() {
}
public Item(int pValue) {
value = pValue;
}
}
public interface ItemManagerInterface {
public void setItems(List<Item> pItems);
public List<Item> getItems();
}
public interface MoxyList<BO_T> extends Collection<BO_T> {
}
public interface MoxyManager<BO_T> extends MoxyList<BO_T> {
}
public static class MoxyManagerImpl<BO_T> implements MoxyManager<BO_T> {
public transient List<BO_T> bolist = new ArrayList<BO_T>();
@Override
public boolean add(BO_T arg0) {
boolean result = bolist.add(arg0);
return result;
}
@Override
public boolean addAll(Collection<? extends BO_T> arg0) {
boolean result = bolist.addAll(arg0);
return result;
}
@Override
public void clear() {
bolist.clear();
}
@Override
public boolean contains(Object arg0) {
boolean result = bolist.contains(arg0);
return result;
}
@Override
public boolean containsAll(Collection<?> arg0) {
boolean result = bolist.containsAll(arg0);
return result;
}
@Override
public boolean isEmpty() {
boolean result = bolist.isEmpty();
return result;
}
@Override
public Iterator<BO_T> iterator() {
Iterator<BO_T> result = bolist.iterator();
return result;
}
@Override
public boolean remove(Object arg0) {
boolean result = bolist.remove(arg0);
return result;
}
@Override
public boolean removeAll(Collection<?> arg0) {
boolean result = bolist.removeAll(arg0);
return result;
}
@Override
public boolean retainAll(Collection<?> arg0) {
boolean result = bolist.retainAll(arg0);
return result;
}
@Override
public int size() {
int result = bolist.size();
return result;
}
@Override
public Object[] toArray() {
Object[] result = bolist.toArray();
return result;
}
@Override
public <T> T[] toArray(T[] arg0) {
T[] result = bolist.toArray(arg0);
return result;
}
}
@XmlAccessorType(XmlAccessType.NONE)
@XmlTransient
public static abstract class MyMoxyManager<BO_T> extends
MoxyManagerImpl<BO_T> {
public abstract Class<? extends BO<?>> getEntityType();
}
@XmlRootElement
public static class ItemManager extends MyMoxyManager<Item> implements
ItemManagerInterface {
public ItemManager() {
}
private List<Item> items = new ArrayList<Item>();
@Override
@XmlElement
public void setItems(List<Item> pItems) {
items = pItems;
}
@Override
public List<Item> getItems() {
return items;
}
@SuppressWarnings("unchecked")
@Override
public Class<? extends BO<?>> getEntityType() {
return (Class<? extends BO<?>>) Item.class;
}
}
/**
* convert the target to XML Format
*
* @param target
* @return
* @throws Exception
*/
public String asXML(Object target) throws Exception {
JAXBContext jaxbContext = JAXBContext.newInstance(target.getClass());
Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
// output pretty printed
jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
StringWriter sw = new StringWriter();
jaxbMarshaller.marshal(target, sw);
String result = sw.toString();
return result;
}
@Test
public void testMarshall() throws Exception {
ItemManager im = new ItemManager();
im.items.add(new Item(2));
String xml = asXML(im);
System.out.println(xml);
assertNotEquals("xml should not be empty", "", xml);
}
}