用简单的例子无法让JAXB处理接口 [英] Can't get JAXB to handle interfaces with simple example

问题描述

我正在尝试在非官方的JAXB指南 - 映射接口 - 项目Kenai ，第3.2.1节，它对我不起作用。我是最新的JDK 1.8_70并没有使用任何特殊的库。完整性代码：

I'm trying the simple example for JAXB Interfaces shown at Unofficial JAXB Guide - Mapping interfaces — Project Kenai, section 3.2.1 and it won't work for me. I'm in latest JDK 1.8_70 and not using any special libraries. Code for completeness sake:

@XmlRootElement
class Zoo {
  @XmlAnyElement
  public List<Animal> animals;
}

interface Animal {
  void sleep();
  void eat();
  ...
}

@XmlRootElement
class Dog implements Animal { ... }

@XmlRootElement
class Lion implements Animal { ... }

对此有何帮助？我得到的错误是：

Any help on this? The error I'm getting is:

[com.sun.istack.internal.SAXException2: class testjaxb.Cat nor any of its super class is known to this context.
javax.xml.bind.JAXBException: class testjaxb.Cat nor any of its super class is known to this context.]

编辑：发布JAXBContext.newInstance代码：

Posted JAXBContext.newInstance code:

Zoo zoo = new Zoo();
zoo.animals = new ArrayList<Animal>();
zoo.animals.add( new Cat() );
zoo.animals.add( new Dog() );
zoo.animals.add( new Dog() );

JAXBContext ctx = JAXBContext.newInstance(Zoo.class);
Marshaller marshaller = ctx.createMarshaller();
marshaller.marshal(zoo, System.out);

推荐答案

尝试在您提供的列表中指定其他类 JAXBContext.newInstance（）。

Try specifying the other classes in the list you provide to JAXBContext.newInstance().

JAXBContext ctx = JAXBContext.newInstance(Zoo.class, Cat.class, Dog.class);

将 @XmlSeeAlso 注释应用于 Zoo 类也应该有效。

Applying the @XmlSeeAlso annotation to your Zoo class should also work.

@XmlRootElement
@XmlSeeAlso({Cat.class, Dog.class})
class Zoo {
    ...
}

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