Question

我遇到了在另一个JAXB对象中映射JAXB对象集合的麻烦，有人看到我的结构问题在下面吗？我使用以下代码获得一个空的formerUsers ArrayList：

 String test="<SSO-Request><User-Id>3119043033121014002</User-Id><Former-User-Ids><User-Id>3119043033121014999</User-Id><User-Id>3119043033121014555</User-Id></Former-User-Ids></SSO-Request>";
        SSORequest ssoRequest=null;
        try{
            JAXBContext jaxbContext = JAXBContext.newInstance(SSORequest.class);
            Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
            ssoRequest = (SSORequest) unmarshaller.unmarshal(new StringReader(test));
        }
        catch(Exception e){
            e.printStackTrace();
        }

    @XmlAccessorType(XmlAccessType.FIELD)
    @XmlRootElement(name="SSO-Request")
    public class SSORequest {
        @XmlElement(name="User-Id")
        String userId;
        @XmlElementWrapper(name="Former-User-Ids")
        List<FormerUser> formerUsers;
    }

    @XmlAccessorType(XmlAccessType.FIELD)
    @XmlRootElement(name="Former-User-Ids")
    public class FormerUser {
    @XmlElement(name="User-Id")
    String userId;
}

Answer 1

您的映射过于复杂，这就是您所需要的：

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name="SSO-Request")
public class SSORequest {

    @XmlElement(name="User-Id")
    String userId;

    @XmlElementWrapper(name="Former-User-Ids")
    @XmlElement(name="User-Id")
    List<String> formerUserIds;
}

Answer 2

您应该像skaffman建议的那样更改映射，或者您应该更改xml：

<SSO-Request><User-Id>3119043033121014002</User-Id><Former-User-Ids><Former-User><User-Id>3119043033121014999</User-Id></Former-User><Former-User><User-Id>3119043033121014555</User-Id></Former-User></Former-User-Ids></SSO-Request>

并更改FormerUser xml元素的名称：

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name="Former-User")
public class FormerUser {
    @XmlElement(name="User-Id")
    String userId;
 }

Answer 3

如果属性应为List＆lt; FormerUser＆gt;那么你需要一种方法来告诉JAXB ID对应的内容。如果FormerUsers的数据将出现在文档中，那么您可以使用@XmlID和@XmlIDREF进行此映射：

http://bdoughan.blogspot.com/2010/10/jaxb-and-shared-references-xmlid-and.html

如果FormerUsers的数据发生在文档之外，那么您可以使用我在下面的答案中描述的策略：

Using JAXB to cross reference XmlIDs from two XML files

JAXB嵌套集合

3 个答案: