java - XMLRootElement 在 Jersey 中将类转换为 XML

Question

我非常擅长将模型类转换为 JSON 数组或对象。

但在 XML 方面我是个菜鸟。

我希望我的最终输出是这样的

<Response>
<Say voice="alice">Thanks for trying our documentation. Enjoy!</Say>
</Response>

为了实现它，我创建了一个模型类

@XmlRootElement(name = "Response")
public class Response {

    private Say say = new Say();

    public Say getSay() {
        return say;
    }

    public void setSay(Say say) {
        this.say = say;
    }

    @XmlRootElement(name = "Say")
    static class Say {

        @XmlAttribute
        private String voice = "alice";

        private String string = "Thanks for trying our documentation. Enjoy!";

        public String getString() {
            return string;
        }

        public void setString(String string) {
            this.string = string;
        }
    }   
}

现在用 Jersey 将它转换为 XML 后，我的输出是

<Response>
<say voice="alice">
<string>Thanks for trying our documentation. Enjoy!</string>
</say>
</Response>

我有一个额外的字符串标签。我不确定要为字符串设置什么属性，以便它出现在正文中。？还是有其他办法？

也为说。 “S”没有大写。我怎样才能让它成为大写字母？

提前致谢

Answer 1

默认情况下，属性和公共(public)字段将映射到元素。你想要做的是使用 @XmlValue将字段映射到元素的值。

@XmlRootElement(name = "Say")
@XmlAccessorType(XmlAccessType.FIELD)
static class Say {

    @XmlAttribute
    private String voice = "alice";

    @XmlValue
    private String string = "Thanks for trying our documentation. Enjoy!";

    public String getString() {
        return string;
    }

    public void setString(String string) {
        this.string = string;
    }
} 

注意 @XmlAccessorType(XmlAccessType.FIELD) 的使用。这样默认行为就不会“双重”尝试映射由 getter 和 setter 定义的属性。或者，您可以将注释放在 getter 上，并省略 @XmlAccessorType

结果:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Response>
    <say voice="alice">Thanks for trying our documentation. Enjoy!</say>
</Response>

public class ResponseTest {
    public static void main(String[] args) throws Exception {
        JAXBContext context = JAXBContext.newInstance(Response.class);
        Marshaller marshaller = context.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        Response response = new Response();
        marshaller.marshal(response, System.out);
    }
}

---

更新

but can i know why the 'S' in Say is not capitalised even though @XmlRootElement(name = "Say") is specified?

您需要在属性上使用 @XmlElement(name = "Say") 指定名称。如果您不这样做，默认命名将生效。

@XmlElement(name = "Say")
public Say getSay() {
    return say;
}

XmlRootElement(name = "Say") 仅适用于元素用作根元素的情况。比如这个:

Response.Say response = new Response.Say();
marshaller.marshal(response, System.out);

会给你这个输出

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Say voice="alice">Thanks for trying our documentation. Enjoy!</Say>