java - 如何使用 FasterXML 反序列化带有注释的 XML

Question

我有以下 XML 架构:

<Courses semester="1">
    <Course code="A231" credits="3">Intermediate A</Course>
    <Course code="A105" credits="2">Intro to A</Course>
    <Course code="B358" credits="4">Advanced B</Course>
</Courses>

我需要将其转换为 POJO 为:

public class Schedule
{
   public int semester;
   public Course[] courses;
}

public class Course
{
   public String code;
   public int credits;
   public String name;
}

这里有两点需要注意:

1. 类(class)对象未包含在标签中
2. 一些属性是属性

我需要如何注释我的对象才能让 FasterXML 反序列化此 xml？

Answer 1

您必须将jackson-dataformat-xml 依赖项添加到您的项目中:

<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-xml</artifactId>
    <version>2.3.3</version>
</dependency>

之后就可以这样使用XML注解了:

@JacksonXmlRootElement(localName = "Courses")
class Schedule {

    @JacksonXmlProperty(isAttribute = true)
    private int semester;

    @JacksonXmlProperty(localName = "Course")
    private Course[] courses;

    // getters, setters, toString, etc
}

class Course {

    @JacksonXmlProperty(isAttribute = true)
    private String code;

    @JacksonXmlProperty(isAttribute = true)
    private int credits;

    @JacksonXmlText(value = true)
    private String name;

    // getters, setters, toString, etc
}

现在，您必须使用 XmlMapper 而不是 ObjectMapper:

JacksonXmlModule module = new JacksonXmlModule();
module.setDefaultUseWrapper(false);
XmlMapper xmlMapper = new XmlMapper(module);

System.out.println(xmlMapper.readValue(xml, Schedule.class));

以上脚本打印:

Schedule [semester=1, courses=[[code=A231, credits=3, name=Intermediate A], [code=A105, credits=2, name=Intro to A], [code=B358, credits=4, name=Advanced B]]]