java - JAXB 注释

Question

我需要一些关于 JAXB 注释的帮助，但我找不到好的文档可以帮助我解决这个问题。

我有一个要编码为 XML 的类。我的类(class)看起来像这样:

@XmlRootElement(name="car")
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(propOrder = {
    "vid",
    "make",
    "model",
    "recalls",
    "engSpec"
})

public class Car {
    @XmlElement(name="vid", required=true)
    private String vid;
    @XmlElement(name="make", required=true)
    private String make;
    @XmlElement(name="model", required=true)
    private String model;
    @XmlElement(name="recalls", required=true)
    private ArrayList<Recall> recalls;
    @XmlElement(name="engSpec", required=true)
    private EngSpec engSpec;
...

召回类看起来像这样:

@XmlRootElement(name = "recall")
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(propOrder = {
        "type",
        "date"
})
public class Recall {
    @XmlElement(name="type", required=true)
    private String type;
    @XmlElement(name="date", required=true)
    private String date;
...

因此它产生了这个 XML 输出:

<car>
 <vid>vid</vid>
 <make>make</make>
 <model>model</model>

 <recalls>
   <type>Recall1</type>
   <date>01/01/11</date>
 </recalls>
 <recalls>
   <type>Recall2</type>
   <date>01/01/11</date>
 </recalls>

 <engSpec>
   <power>200HP</power>
   <size>size</size>
 </engSpec>
</car>

但我希望 ArrayList 以不同方式显示，如下所示:

<car>
 <vid>vid</vid>
 <make>make</make>
 <model>model</model>

 <recalls>
   <recall>
     <type>Recall1</type>
     <date>01/01/11</date>
   </recall>
   <recall>
     <type>Recall2</type>
     <date>01/01/11</date>
   </recall>
 </recalls>

 <engSpec>
   <power>200HP</power>
   <size>size</size>
 </engSpec>
</car>

知道我该怎么做吗？ 我认为问题出在我的架构上，但我将其用于编码:

JAXBContext jc = JAXBContext.newInstance(Car.class);
Marshaller marsh = jc.createMarshaller();
marsh.marshal(car, out);

有什么解决办法吗？谢谢!

Answer 1

试试这个:

@XmlRootElement(name="car")
...
public class Car {
   ...

   @XmlElementWrapper(name="recalls")  // this name=... can be omitted, as it
                                       // is the same as the field name
   @XmlElement(name="recall")
   private ArrayList<Recall> recalls;
}

来自documentation :

XmlElementWrapper: Generates a wrapper element around XML representation. This is primarily intended to be used to produce a wrapper XML element around collections.