Class JSONEventDrivenImporter

  • All Implemented Interfaces:
    EventDrivenImporter<java.lang.String,​Triple<java.lang.String,​java.lang.String,​java.lang.Double>>

    public class JSONEventDrivenImporter
    extends BaseEventDrivenImporter<java.lang.String,​Triple<java.lang.String,​java.lang.String,​java.lang.Double>>
    implements EventDrivenImporter<java.lang.String,​Triple<java.lang.String,​java.lang.String,​java.lang.Double>>
    Imports a graph from a JSON file. Below is a small example of a graph in JSON format.
     {
       "nodes": [
         { "id": "1" },
         { "id": "2", "label": "Node 2 label" },
         { "id": "3" }
       ],
       "edges": [
         { "source": "1", "target": "2", "weight": 2.0, "label": "Edge between 1 and 2" },
         { "source": "2", "target": "3", "weight": 3.0, "label": "Edge between 2 and 3" }
       ]
     }
     

    In case the graph is weighted then the importer also reads edge weights. Otherwise the default edge weight is returned. The importer also supports reading additional string attributes such as label or custom user attributes.

    The parser completely ignores elements from the input that are not related to vertices or edges of the graph. Moreover, complicated nested structures which are inside vertices or edges are simply returned as a whole. For example, in the following graph

     {
       "nodes": [
         { "id": "1" },
         { "id": "2" }
       ],
       "edges": [
         { "source": "1", "target": "2", "points": { "x": 1.0, "y": 2.0 } }
       ]
     }
     
    the points attribute of the edge is returned as a string containing {"x":1.0,"y":2.0}. The same is done for arrays or any other arbitrary nested structure.
    Author:
    Dimitrios Michail
    • Field Detail

      • DEFAULT_VERTICES_COLLECTION_NAME

        public static final java.lang.String DEFAULT_VERTICES_COLLECTION_NAME
        Default name for the vertices collection
        See Also:
        Constant Field Values
      • DEFAULT_EDGES_COLLECTION_NAME

        public static final java.lang.String DEFAULT_EDGES_COLLECTION_NAME
        Default name for the edges collection
        See Also:
        Constant Field Values
    • Constructor Detail

      • JSONEventDrivenImporter

        public JSONEventDrivenImporter()
        Constructs a new importer.
      • JSONEventDrivenImporter

        public JSONEventDrivenImporter​(boolean notifyVertexAttributesOutOfOrder,
                                       boolean notifyEdgeAttributesOutOfOrder)
        Constructs a new importer.
        Parameters:
        notifyVertexAttributesOutOfOrder - whether to notify for vertex attributes out-of-order even if they appear together in the input
        notifyEdgeAttributesOutOfOrder - whether to notify for edge attributes out-of-order even if they appear together in the input
    • Method Detail

      • getVerticesCollectionName

        public java.lang.String getVerticesCollectionName()
        Get the name used for the vertices collection in the file.
        Returns:
        the name used for the vertices collection in the file.
      • setVerticesCollectionName

        public void setVerticesCollectionName​(java.lang.String verticesCollectionName)
        Set the name used for the vertices collection in the file.
        Parameters:
        verticesCollectionName - the name
      • getEdgesCollectionName

        public java.lang.String getEdgesCollectionName()
        Get the name used for the edges collection in the file.
        Returns:
        the name used for the edges collection in the file.
      • setEdgesCollectionName

        public void setEdgesCollectionName​(java.lang.String edgesCollectionName)
        Set the name used for the edges collection in the file.
        Parameters:
        edgesCollectionName - the name
      • importInput

        public void importInput​(java.io.Reader input)
        Description copied from interface: EventDrivenImporter
        Import a graph
        Specified by:
        importInput in interface EventDrivenImporter<java.lang.String,​Triple<java.lang.String,​java.lang.String,​java.lang.Double>>
        Parameters:
        input - the input reader