java - Jackson XML 列表元素匹配它们的根名称

Question

使用杰克逊的XmlMapper，有没有办法让对象列表的元素名称与localName给定的匹配@JacksonXmlRootElement？

例如，给定以下类

interface Foo {}

@JacksonXmlRootElement(localName = "bar")
class Bar implements Foo {}

@JacksonXmlRootElement(localName = "baz")
class Baz implements Foo {}

@JacksonXmlRootElement(localName = "container")
class FooContainer {
    @JacksonXmlElementWrapper(useWrapping = false)
    private List<Foo> foos;

    FooContainer(List<Foo> foos) {
        this.foos = foos;
    }

    public List<Foo> getFoos() {
        return foos;
    }
}

使用XmlMapper

FooContainer container = new FooContainer(Arrays.asList(new Bar(), new Baz()));
XmlMapper xmlMapper = new XmlMapper();
xmlMapper.writeValueAsString(container);

我们得到以下 XML

<container>
  <foos/>
  <foos/>
</container>

有没有办法得到这个？

<container>
  <bar/>
  <baz/>
</container>

Answer 1

我无法在杰克逊找到一种方法来做到这一点，但在 JAXB 中这几乎是微不足道的。

interface Foo {}

class Bar implements Foo {}

class Baz implements Foo {}

@XmlRootElement(name = "container")
@XmlAccessorType(XmlAccessType.FIELD)
class FooContainer {
    @XmlElements({
        @XmlElement(name = "bar", type = Bar.class),
        @XmlElement(name = "baz", type = Baz.class)
    })
    private List<Foo> foos;

    FooContainer() {}

    FooContainer(List<Foo> foos) {
        this.foos = foos;
    }

    public List<Foo> getFoos() {
        return foos;
    }
}

解组：

FooContainer container = new FooContainer(Arrays.asList(new Bar(), new Baz()));

JAXBContext jaxbContext = JAXBContext.newInstance(FooContainer.class);
Marshaller marshaller = jaxbContext.createMarshaller();
marshaller.marshal(container, System.out);