JaxB UNMarshalling问题

Question

我尝试在以下主题中运行相同的示例：

JAXB Annotations - Mapping interfaces and @XmlElementWrapper

但我收到以下例外：

  

意外元素（uri：“”，本地：“狗”）。预期元素是＆lt; {奇怪的问号符号}＆gt; catchAll＆gt;

...

知道我为什么会遇到这个例外吗？

Answer 1

我设法运行了这个例子，但是在使用带有java.uill.List的XmlElements标记之后 这是代码：

@XmlRootElement class Zoo {

@XmlElements({
        @XmlElement(name = "Dog" , type = Dog.class),
        @XmlElement(name = "Cat" , type = Cat.class)
})
private List<Animal> animals;

public static void main(String[] args) throws Exception {
    Zoo zoo = new Zoo();
    zoo.animals = new ArrayList<Animal>();

    Dog doggy = new Dog();
    doggy.setDogProp("Doggy");

    Cat catty = new Cat();
    catty.setCatProp("Catty");

    zoo.animals.add(doggy);
    zoo.animals.add(catty);

    JAXBContext jc = JAXBContext.newInstance(Zoo.class, Dog.class, Cat.class);
    Marshaller marshaller = jc.createMarshaller();

    ByteArrayOutputStream os = new ByteArrayOutputStream();
    marshaller.marshal(zoo, os);

    System.out.println(os.toString());

    Unmarshaller unmarshaller = jc.createUnmarshaller();

    unmarshaller.setEventHandler(new javax.xml.bind.helpers.DefaultValidationEventHandler());

    Zoo unmarshalledZoo = (Zoo) unmarshaller.unmarshal(new ByteArrayInputStream(os.toByteArray()));

    if (unmarshalledZoo.animals == null) {
        System.out.println("animals was null");
    } else if (unmarshalledZoo.animals.size() == 2) {
        System.out.println("it worked");
    } else {
        System.out.println("failed!");
    }
}

public interface Animal {
}

@XmlRootElement
public static class Dog implements Animal {

    private String dogProp;

    public String getDogProp() {
        return dogProp;
    }

    public void setDogProp(String dogProp) {
        this.dogProp = dogProp;
    }
}

@XmlRootElement
public static class Cat implements Animal {

    private String catProp;

    public String getCatProp() {
        return catProp;
    }

    public void setCatProp(String catProp) {
        this.catProp = catProp;
    }
}

@XmlElements({ @XmlElement(name = "Dog" , type = Dog.class), @XmlElement(name = "Cat" , type = Cat.class) }) private List<Animal> animals; public static void main(String[] args) throws Exception { Zoo zoo = new Zoo(); zoo.animals = new ArrayList<Animal>(); Dog doggy = new Dog(); doggy.setDogProp("Doggy"); Cat catty = new Cat(); catty.setCatProp("Catty"); zoo.animals.add(doggy); zoo.animals.add(catty); JAXBContext jc = JAXBContext.newInstance(Zoo.class, Dog.class, Cat.class); Marshaller marshaller = jc.createMarshaller(); ByteArrayOutputStream os = new ByteArrayOutputStream(); marshaller.marshal(zoo, os); System.out.println(os.toString()); Unmarshaller unmarshaller = jc.createUnmarshaller(); unmarshaller.setEventHandler(new javax.xml.bind.helpers.DefaultValidationEventHandler()); Zoo unmarshalledZoo = (Zoo) unmarshaller.unmarshal(new ByteArrayInputStream(os.toByteArray())); if (unmarshalledZoo.animals == null) { System.out.println("animals was null"); } else if (unmarshalledZoo.animals.size() == 2) { System.out.println("it worked"); } else { System.out.println("failed!"); } } public interface Animal { } @XmlRootElement public static class Dog implements Animal { private String dogProp; public String getDogProp() { return dogProp; } public void setDogProp(String dogProp) { this.dogProp = dogProp; } } @XmlRootElement public static class Cat implements Animal { private String catProp; public String getCatProp() { return catProp; } public void setCatProp(String catProp) { this.catProp = catProp; } }