com.datastax.driver.dse.graph.PropertyGraphNode Maven / Gradle / Ivy

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/*
 * Copyright DataStax, Inc.
 *
 * This software can be used solely with DataStax Enterprise. Please consult the license at
 * http://www.datastax.com/terms/datastax-dse-driver-license-terms
 */
package com.datastax.driver.dse.graph;

import com.datastax.driver.core.exceptions.DriverException;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.TreeTraversingParser;
import com.google.common.reflect.TypeToken;

/**
 * A node that represents a Graph property.
 *
 * Such nodes can only appear as fields inside JSON objects, and this implementation allows to
 * retrieve its parent element and its corresponding property name (which corresponds to the field
 * name in the parent JSON object).
 *
 * @see DefaultPropertyDeserializer
 * @see DefaultVertexPropertyDeserializer
 */
class PropertyGraphNode extends DefaultGraphNode {

  private final String propertyName;

  private final Element parent;

  PropertyGraphNode(
      JsonNode delegate, ObjectMapper objectMapper, String propertyName, Element parent) {
    super(delegate, objectMapper);
    this.propertyName = propertyName;
    this.parent = parent;
  }

  @Override
  public  T as(Class clazz) {
    return as(TypeToken.of(clazz));
  }

  @Override
  public  T as(TypeToken type) {
    try {
      final TreeTraversingParser parser =
          new PropertyGraphNodeParser(delegate, objectMapper, propertyName, parent);
      JavaType javaType = objectMapper.constructType(type.getType());
      return objectMapper.readValue(parser, javaType);
    } catch (Exception e) {
      throw new DriverException("Cannot deserialize result as " + type, e);
    }
  }
}