以下是如何使用EclipseLink JAXB (MOXy)支持此用例:
布尔字符串适配器
AnXmlAdapter
允许您将一种类型的对象编组为另一种类型(请参阅http://blog.bdoughan.com/2010/07/xmladapter-jaxbs-secret-weapon.html)。在此示例中,我们希望将String
值视为Boolean
1。
package forum11451880;
import javax.xml.bind.annotation.adapters.XmlAdapter;
public class BooleanStringAdapter extends XmlAdapter<Boolean, String> {
@Override
public String unmarshal(Boolean v) throws Exception {
return v.toString();
}
@Override
public Boolean marshal(String v) throws Exception {
return Boolean.valueOf(v);
}
}
oxm.xml
我们可以利用 MOXy 的外部映射文档来增加通过注释提供的元数据以挂钩我们XmlAadapter
(请参阅http://blog.bdoughan.com/2010/12/extending-jaxb-representing-annotations.html)。
<?xml version="1.0"?>
<xml-bindings
xmlns="http://www.eclipse.org/eclipselink/xsds/persistence/oxm"
package-name="forum11451880">
<java-types>
<java-type name="LifeSpan">
<java-attributes>
<xml-element java-attribute="end">
<xml-java-type-adapter value="forum11451880.BooleanStringAdapter"/>
</xml-element>
</java-attributes>
</java-type>
</java-types>
</xml-bindings>
寿命
下面是具有end
type 属性的域模型String
。
package forum11451880;
import javax.xml.bind.annotation.*;
import javax.xml.bind.annotation.adapters.*;
@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class LifeSpan {
protected String begin;
protected String end;
@XmlJavaTypeAdapter(CollapsedStringAdapter.class)
protected String ended;
}
jaxb.properties
要将 MOXy 指定为您的 JAXB 提供程序,您需要包含一个jaxb.properties
使用以下条目调用的文件(请参阅http://blog.bdoughan.com/2011/05/specifying-eclipselink-moxy-as-your.html):
javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory
演示
下面的演示代码演示了如何利用外部映射文档。
package forum11451880;
import java.util.*;
import javax.xml.bind.*;
import org.eclipse.persistence.jaxb.JAXBContextProperties;
import org.eclipse.persistence.jaxb.MarshallerProperties;
public class Demo {
public static void main(String[] args) throws Exception {
Map<String, Object> properties = new HashMap<String, Object>(1);
properties.put(JAXBContextProperties.OXM_METADATA_SOURCE, "forum11451880/oxm.xml");
JAXBContext jc = JAXBContext.newInstance(new Class[] {LifeSpan.class}, properties);
LifeSpan lifeSpan = new LifeSpan();
lifeSpan.begin = "1999-04";
lifeSpan.end = "true";
Marshaller marshaller = jc.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.marshal(lifeSpan, System.out);
marshaller.setProperty(MarshallerProperties.MEDIA_TYPE, "application/json");
marshaller.marshal(lifeSpan, System.out);
}
}
输出
下面是运行示例的输出。如您所见,该true
值不带引号出现:
<?xml version="1.0" encoding="UTF-8"?>
<lifeSpan>
<begin>1999-04</begin>
<end>true</end>
</lifeSpan>
{
"lifeSpan" : {
"begin" : "1999-04",
"end" : true
}
}