graphdb/src/main/java/com/orientechnologies/orient/graph/graphml/OGraphMLReader.java
public OGraphMLReader inputGraph(final String filename) throws IOException {
    return inputGraph(this.graph, filename, batchSize, this.vertexIdKey, this.edgeIdKey, this.edgeLabelKey);
  }
public OGraphMLReader inputGraph(final String filename) throws IOException {
    return inputGraph(this.graph, filename, batchSize, this.vertexIdKey, this.edgeIdKey, this.edgeLabelKey);
  }
Input the GraphML stream data into the graph. In practice, usually the provided graph is empty.

@param filename
name of a file containing GraphML data
@throws IOException
thrown when the GraphML data is not correctly formatted