public class RexsterLongDoubleFloatVertexInputFormat
  extends RexsterVertexInputFormat<LongWritable, DoubleWritable,
          FloatWritable> {

  @Override
  public RexsterVertexReader createVertexReader(
    InputSplit split, TaskAttemptContext context) throws IOException {

    return new RexsterLongDoubleFloatVertexReader();
  }

  /**
   * Rexster vertex reader
   */
  protected class RexsterLongDoubleFloatVertexReader
    extends RexsterVertexReader {

    @Override
    protected Vertex<LongWritable, DoubleWritable, FloatWritable> parseVertex(
      JSONObject jsonVertex) throws JSONException {

      /* create the actual vertex */
      Vertex<LongWritable, DoubleWritable, FloatWritable> vertex =
        getConf().createVertex();

      Long id;
      try {
        id = jsonVertex.getLong("_id");
      } catch (JSONException ex) {
        /* OrientDB compatibility; try to transform it as long */
        String idString = jsonVertex.getString("_id");
        String[] splits = idString.split(":");
        id = Long.parseLong(splits[1]);
      }
      vertex.initialize(new LongWritable(id), new DoubleWritable(0));
      return vertex;
    }
  }
}
    

public class RexsterLongFloatEdgeInputFormat
  extends RexsterEdgeInputFormat<LongWritable, FloatWritable> {

  @Override
  public RexsterEdgeReader createEdgeReader(
      InputSplit split, TaskAttemptContext context) throws IOException {

    return new RexsterLongFloatEdgeReader();
  }

  protected class RexsterLongFloatEdgeReader extends RexsterEdgeReader {

    /** source vertex of the edge */
    private LongWritable sourceId;

    @Override
    public LongWritable getCurrentSourceId()
      throws IOException, InterruptedException {

      return this.sourceId;
    }

    @Override
    protected Edge<LongWritable, FloatWritable> parseEdge(JSONObject jsonEdge)
      throws JSONException {

      Long value = jsonEdge.getLong("weight");
      Long dest;
      try {
        dest = jsonEdge.getLong("_outV");
      } catch (JSONException ex) {
        /* OrientDB compatibility; try to transform it as long */
        String idString = jsonEdge.getString("_outV");
        String[] splits = idString.split(":");
        dest = Long.parseLong(splits[1]);
      }
      Edge<LongWritable, FloatWritable> edge =
        EdgeFactory.create(new LongWritable(dest), new FloatWritable(value));

      Long sid;
      try {
        sid = jsonEdge.getLong("_inV");
      } catch (JSONException ex) {
        /* OrientDB compatibility; try to transform it as long */
        String sidString = jsonEdge.getString("_inV");
        String[] splits = sidString.split(":");
        sid = Long.parseLong(splits[1]);
      }
      this.sourceId = new LongWritable(sid);
      return edge;
    }
  }
}
    

hadoop jar /path/to/giraph/giraph-examples/target/giraph-examples-*-jar-with-dependencies.jar \
  org.apache.giraph.GiraphRunner \
  -libjars /path/to/giraph/giraph-rexster/giraph-rexster-io/target/giraph-rexster-io*-jar-with-dependencies.jar \
  org.apache.giraph.examples.SimpleShortestPathsComputation \
  -vif org.apache.giraph.rexster.io.formats.RexsterLongDoubleFloatVertexInputFormat \
  -eif org.apache.giraph.rexster.io.formats.RexsterLongFloatEdgeInputFormat \
  -vof org.apache.giraph.io.formats.JsonLongDoubleFloatDoubleVertexOutputFormat \
  -op output \
  -w 1
    

public class RexsterLongDoubleFloatVertexOutputFormat
  extends RexsterVertexOutputFormat<LongWritable, DoubleWritable,
          FloatWritable> {

  @Override
  public RexsterVertexWriter createVertexWriter(
      TaskAttemptContext context) throws IOException,
      InterruptedException {

    return new RexsterLongDoubleFloatVertexWriter();
  }

  /**
   * Rexster vertex writer.
   */
  protected class RexsterLongDoubleFloatVertexWriter
    extends RexsterVertexWriter {

    /** current vertex ID */
    private LongWritable vertexId;

    @Override
    protected JSONObject getVertex(
      Vertex<LongWritable, DoubleWritable, FloatWritable> vertex)
      throws JSONException {

      vertexId = vertex.getId();

      double value = vertex.getValue().get();
      JSONObject jsonVertex = new JSONObject();
      jsonVertex.accumulate("value", value);

      return jsonVertex;
    }

    @Override
    protected LongWritable getVertexId() {
      return vertexId;
    }
  }
}
      

public class RexsterLongDoubleFloatEdgeOutputFormat
  extends RexsterEdgeOutputFormat<LongWritable, DoubleWritable,
          FloatWritable> {

  @Override
  public RexsterEdgeWriter createEdgeWriter(
      TaskAttemptContext context) throws IOException,
      InterruptedException {

    return new RexsterLongDoubleFloatEdgeWriter();
  }

  /**
   * Rexster edge writer.
   */
  protected class RexsterLongDoubleFloatEdgeWriter
    extends RexsterEdgeWriter {

    @Override
    protected JSONObject getEdge(LongWritable srcId, DoubleWritable srcValue,
      Edge<LongWritable, FloatWritable> edge) throws JSONException {

      long outId = srcId.get();
      long inId = edge.getTargetVertexId().get();
      float value = edge.getValue().get();
      JSONObject jsonEdge = new JSONObject();
      jsonEdge.accumulate("_outV", outId);
      jsonEdge.accumulate("_inV",  inId);
      jsonEdge.accumulate("value", value);

      return jsonEdge;
    }
  }
}
      

hadoop jar /path/to/giraph/giraph-examples/target/giraph-examples-*-jar-with-dependencies.jar \
  org.apache.giraph.GiraphRunner \
  -libjars /path/to/giraph/giraph-rexster/giraph-rexster-io/target/giraph-rexster-io*-jar-with-dependencies.jar \
  org.apache.giraph.examples.SimpleShortestPathsComputation \
  -vif org.apache.giraph.io.formats.JsonLongDoubleFloatDoubleVertexInputFormat \
  -vof org.apache.giraph.rexster.io.formats.RexsterVertexOutputFormat \
  -eof org.apache.giraph.rexster.io.formats.RexsterEdgeOutputFormat \
  -vip input/ \
  -w 1