如何通过 XStream 在类中使用 HashMap 读取 xml答案

【问题标题】：How to read xml with HashMap inside the class via XStream如何通过 XStream 在类中使用 HashMap 读取 xml
【发布时间】：2017-03-04 11:30:34
【问题描述】：

这里是我的班级字段。

 @XStreamAlias("OrgEntity")
    public class OrgEntity implements Serializable {

    private static final long serialVersionUID = 2L;
    private static final int MAX_SHARE_PERCENTAGE = 100;
    private static final byte MIN_ORG_NAME_LENGTH = 2;
    public static Map<String, OrgEntity> allOrgMap;
    @XStreamAlias("entityName")
    @XStreamAsAttribute
    private String entityName;
    private OrgType type;
    private float sharesPortionHeldBy;
    private double authorisedCapital;
    private String parentCompanyName;
    private Human ceo;

    private Map<ShareHolder, Float> shareHoldersMap;
.... 
}

这是我需要阅读的xml：

<OrgEntity entityName="nonParentCompany">
  <type>ZAO</type>
  <sharesPortionHeldBy>13.0</sharesPortionHeldBy>
  <authorisedCapital>1000000.0</authorisedCapital>
  <ceo surname="Narishkin" firstName="Denis" middleName="Ven"/>
  <shareHoldersMap>
    <entry>
      <ShareHolder surname="Trump" firstName="Don" middleName="J">
        <shareHolderPortfolioMap>
          <shareHolderAsset>
            <entry>
              <string>nonParentCompany</string>
              <float>5.0</float>
            </entry>
          </shareHolderAsset>
          <outer-class reference="../.."/>
        </shareHolderPortfolioMap>
        <currCom reference="../../../.."/>
        <sharesNumberCurrComp>5.0</sharesNumberCurrComp>
      </ShareHolder>
      <float>5.0</float>
    </entry>
    <entry>
      <ShareHolder surname="Smith" firstName="Adam" middleName="A">
        <shareHolderPortfolioMap>
          <shareHolderAsset>
            <entry>
              <string>nonParentCompany</string>
              <float>8.0</float>
            </entry>
          </shareHolderAsset>
          <outer-class reference="../.."/>
        </shareHolderPortfolioMap>
        <currCom reference="../../../.."/>
        <sharesNumberCurrComp>8.0</sharesNumberCurrComp>
      </ShareHolder>
      <float>8.0</float>
    </entry>
  </shareHoldersMap>
</OrgEntity>

如何通过 XStream 读取此 xml？我尝试使用下面的代码，但失败了。我收到的例外是" Exception in thread "main" com.thoughtworks.xstream.InitializationException: No field "shareHoldersMap" for implicit collection " 你能给我一个建议，我应该怎么做才能读取xml。提前致谢。

public static void main(String[] args) {
        OrgEntity o = DataForRunners.createDataForBasicFile15OrgsWithShareHoldingsUpdateForXML().get(0);
        String xmlOrgObj = "src/main/java/com/.... ";
        new XStreamDecorator<OrgEntity>(o, xmlOrgObj);
        XStream xstream = new XStream(new DomDriver());
        xstream.alias("OrgEntity", OrgEntity.class);
        xstream.alias("entityName", OrgEntity.class);
        xstream.alias("type", OrgType.class);
        xstream.alias("ceo", Human.class);
        xstream.addImplicitCollection(HashMap.class, "shareHoldersMap");
        InputStream in = null;
        try {

            in = new FileInputStream(xmlOrgObj);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        OrgEntity var =(OrgEntity) xstream.fromXML(in);
        System.out.println(var);

    }

【问题讨论】：

标签： java xml xstream

【解决方案1】：

在 XStream 1.4.5 及以上版本你可以使用

命名映射转换器

所以在你的情况下，你可以尝试这样的事情：

XStream xstream = new XStream();
NamedMapConverter namedMapConverter = new NamedMapConverter(xstream.getMapper(), "entry", "key", ShareHolder.class, "value", Float.class);
xstream.registerConverter(namedMapConverter);

【讨论】：