java - 如何使用RDFBean和Apache Jena反序列化Java对象

问题/问题

我已经很容易地通过简单的属性（例如String类型）反序列化对象。但是，当存在到另一个类型的链接时，它不会自动解决，并且会出现异常。似乎该链接未解析，而是作为简单的URI属性处理。

如何自动反序列化整个对象图？

更新1

通过调试，我知道可以通过查询三元存储中的某个谓词来解析元素，因此在读取文件之前手动添加这些行时，可以将SubGeographicalRegion取消编组为JavaBean。

  Class<SubGeographicalRegion> class1 = SubGeographicalRegion.class;
  URI class1RdfType = RDFBeanInfo.get(class1).getRDFType();
  PlainLiteral class1Literal = model.createPlainLiteral(class1.getName());
  model.addStatement(class1RdfType, RDFBeanManager.BINDINGCLASS_PROPERTY, class1Literal);

但是，即使仅引用一个相同的SubGeographicalRegion，似乎也创建了一个新对象。

更新2

根据元素的ID实现hashCode()和equals()解决了多个实例的问题！

码

RDF / XML文件（节选）：

<?xml version="1.0" encoding="UTF-8" ?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:cim="http://iec.ch/TC57/2010/CIM-schema-cim15#">
 <cim:SubGeographicalRegion rdf:ID="_93ed4cbc90fe424caa7f572e9652997">
  <cim:IdentifiedObject.name>SubRegion</cim:IdentifiedObject.name>
  <cim:SubGeographicalRegion.Region rdf:resource="#_a56f739020054bcd826f675918ab2df"/>
 </cim:SubGeographicalRegion>
 <cim:Substation rdf:ID="_da9f289336dd46bdac22c961b7b525f3">
  <cim:IdentifiedObject.name>73109E0009</cim:IdentifiedObject.name>
  <cim:Substation.Region rdf:resource="#_93ed4cbc90fe424caa7f572e9652997"/>
 </cim:Substation>
 <cim:Substation rdf:ID="_e66d0514110841c285b7956c98e52b32">
  <cim:IdentifiedObject.name>73019J0003</cim:IdentifiedObject.name>
  <cim:Substation.Region rdf:resource="#_93ed4cbc90fe424caa7f572e9652997"/>
 </cim:Substation>
</rdf:RDF>

Substation.java：

@RDFBean("http://iec.ch/TC57/2010/CIM-schema-cim15#Substation")
public class Substation {

  private String id;
  private String name;
  private SubGeographicalRegion subRegion;

  @RDFSubject
  public String getId() {
    return id;
  }

  public void setId(String id) {
    this.id = id;
  }

  @RDF("http://iec.ch/TC57/2010/CIM-schema-cim15#IdentifiedObject.name")
  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  @RDF("http://iec.ch/TC57/2010/CIM-schema-cim15#Substation.Region")
  public SubGeographicalRegion getSubRegion() {
    return subRegion;
  }

  public void setSubRegion(SubGeographicalRegion subRegion) {
    this.subRegion = subRegion;
  }
}

SubGeographicalRegion.java：

@RDFBean("http://iec.ch/TC57/2010/CIM-schema-cim15#SubGeographicalRegion")
public class SubGeographicalRegion {

  private String id;
  private String name;

  private Collection<Substation> substations;

  @RDF("http://iec.ch/TC57/2010/CIM-schema-cim15#IdentifiedObject.name")
  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  @RDFSubject(prefix = "http://www.w3.org/1999/02/22-rdf-syntax-ns#ID")
  public String getId() {
    return id;
  }

  public void setId(String id) {
    this.id = id;
  }

  // this works, but returns a HashSet<URI>
  @RDF(inverseOf = "http://iec.ch/TC57/2010/CIM-schema-cim15#Substation.Region")
  public Collection<Substation> getSubstations() {
    return substations;
  }

  public void setSubstations(Collection<Substation> substations) {
    this.substations = substations;
  }
}

提示：方法SubGeographicalRegion.getSubstations()返回一个HashSet<URI>（尽管已声明为Collection<Substation>）

这是我启动引擎的方式：

org.ontoware.rdf2go.model.Model model = RDF2Go.getModelFactory().createModel();
model.open();

// try-catch omitted for readability
model.readFrom(getClass().getResourceAsStream(RDF_XML_INPUT_FILENAME), Syntax.RdfXml);

RDFBeanManager rdfBeanManager = new RDFBeanManager(model);
ClosableIterator<Substation> substationIterator = rdfBeanManager.getAll(Substation.class);
while (substationIterator.hasNext()) {
  logger.info("substation.name: ", substationIterator.next().getName());
}

model.close();

最佳答案

您可以考虑直接使用Jena或Sesame代替RDF2Go，后者似乎不再维护。

如果您不介意使用（某些）芝麻API，则可以尝试Pinto。