编组在MarkLogic中不使用MarkLogic

Question

我想将下面的对象存储到MarkLogic中。

@XmlRootElement(name = "trainModel")
@XmlAccessorType(XmlAccessType.FIELD)
public class TrainedModel implements Serializable {

    private static final long serialVersionUID = 1L;

    private String modelName;
    private CrossValidatorModel crossValidatorModel;

    public String getModelName() {
        return modelName;
    }

    public void setModelName(String modelName) {
        this.modelName = modelName;
    }

    public CrossValidatorModel getCrossValidatorModel() {
        return crossValidatorModel;
    }

    public void setCrossValidatorModel(CrossValidatorModel crossValidatorModel) {
        this.crossValidatorModel = crossValidatorModel;
    }

    @Override
    public String toString() {
        return "TrainedModel [modelName=" + modelName + ", crossValidatorModel=" + crossValidatorModel + "]";
    }
}

我使用JAXBHandle来完成我的需求，但是在将TrainedModel对象存储到MarkLogic中时，CrossValidatorModel变得空了。

CrossValidatorModel是org.apache.spark.ml.tuning.CrossValidatorModel提供的外部对象。

我试过了下面的代码

    CrossValidatorModel crossValidatorModel = createDataFrame(null);
    TrainedModel trainedModel = new TrainedModel();
    trainedModel.setModelName("sample");
    trainedModel.setCrossValidatorModel(crossValidatorModel);
    
    JAXBContext context = JAXBContext.newInstance(TrainedModel.class);  
    JAXBHandle<TrainedModel> jaxbHandle = new JAXBHandle<TrainedModel>(context);
    jaxbHandle.set(trainedModel);
    
    GenericDocumentManager docMgr = client.newDocumentManager();
    docMgr.writeAs("/shivling.xml", null, jaxbHandle);

这是我得到的xml结果，

<?xml  version="1.0" encoding="UTF-8"?>
<trainModel>
    <modelName>sample</modelName>
    <crossValidatorModel>
    </crossValidatorModel>
</trainModel>

crossValidatorModel在这里是空的，请帮我解决这个问题。

Answer 1

NULL (在代码中)与XML中的 result ：您的结果表明代码中存在语义问题。

JAXB框架可以通过适当的MarkLogic文档管理器或旧的POJO方式来传递:一个简单的MarkLogic JAXB注释(您可以在批量读写事务中使用DMSDK )：

代码片段：

        XMLDocumentManager docMgr = marklogic.newXMLDocumentManager();

        TrainedModel trainedModel = new TrainedModel();
            
        trainedModel.setModelName("History and Psychology");
        trainedModel.setCrossValidatorModel("Biology");

        String docId = "/train-model.xml";

        docMgr.writeAs(docId, trainedModel);

结果：

次等IO方法：

    TrainedModel trainedModel = new TrainedModel();
            
        trainedModel.setModelName("History and Current Affairs");
        trainedModel.setCrossValidatorModel("Psychology");
        
        // initialize JAXB 
        JAXBContext context = JAXBContext.newInstance(TrainedModel.class);
        
        // POJO Handle
        JAXBHandle<TrainedModel> writeHandle = new JAXBHandle<TrainedModel>(context);
        
        // Marshalling
        Marshaller jaxMar = context.createMarshaller();
            
        String docId = "/train-model.xml";

        // IsMarshalled
        jaxMar.marshal(trainedModel, System.out);

        // set Handle
        writeHandle.set(trainedModel);

       // write POJO to MarkLogic
        docMgr.write(docId, writeHandle);