Subgraph object not available in the subgraph compute constructor

[dipkakwani]

The subgraph object can only be accessed after the compute class is instantiated. So a call to getSubgraph() inside constructor of compute class throws a NullPointerException.

Relevant code snippets:

Example where subgraph object might be used inside a constructor (full code):

        /**
         * Input has <num_clusters>,<max_edge_cuts>,<max_iters>
         *
         * @param initMsg
        */
        public KMeans(String initMsg) {
                String[] inp = initMsg.split(",");
                //SubgraphValue value = new SubgraphValue();
                value.k = Integer.parseInt(inp[0]);
                value.maxEdgeCrossing = Long.parseLong(inp[1]);
                value.maxIterations = Integer.parseInt(inp[2]);
                // NOTE: Subgraph state is not available in the constructor.
                //getSubgraph().setSubgraphValue(value);

        }

Framework code snippet which creates subgraphCompute Object and assigns subgraph object to it (full code):

    /*
     * Creating SubgraphCompute objects
     */
    for (ISubgraph<S, V, E, I, J, K> subgraph : partition.getSubgraphs()) {
      Class<? extends AbstractSubgraphComputation<S, V, E, M, I, J, K>> subgraphComputeClass;
      subgraphComputeClass = (Class<? extends AbstractSubgraphComputation<S, V, E, M, I, J, K>>) conf
              .getClass(GraphJob.SUBGRAPH_COMPUTE_CLASS_ATTR, null);
      if (subgraphComputeClass == null)
        throw new RuntimeException("Could not load subgraph compute class");

      AbstractSubgraphComputation<S, V, E, M, I, J, K> abstractSubgraphComputeRunner;

      if (initialValue != null) {
        Object []params = {initialValue};
        abstractSubgraphComputeRunner = ReflectionUtils.newInstance(subgraphComputeClass, params);
      }
      else
        abstractSubgraphComputeRunner = ReflectionUtils.newInstance(subgraphComputeClass);

      // FIXME: Subgraph value is not available to user in the subgraph-compute's constructor,
      // since it is added only after the object is created (using setSubgraph).
      SubgraphCompute<S, V, E, M, I, J, K> subgraphComputeRunner = new SubgraphCompute<S, V, E, M, I, J, K>();
      subgraphComputeRunner.setAbstractSubgraphCompute(abstractSubgraphComputeRunner);
      abstractSubgraphComputeRunner.setSubgraphPlatformCompute(subgraphComputeRunner);
      subgraphComputeRunner.setSubgraph(subgraph);
      subgraphComputeRunner.init(this);
      subgraphs.add(subgraphComputeRunner);
    }