@Override public void initialize(MapReduceTaskContext<byte[], Put> context) throws Exception { InputContext inputContext = context.getInputContext(); Preconditions.checkArgument(PARTITIONED.equals(inputContext.getInputName())); Preconditions.checkArgument(inputContext instanceof PartitionedFileSetInputContext); this.pfsInputcontext = (PartitionedFileSetInputContext) inputContext; Preconditions.checkNotNull(pfsInputcontext.getInputPartitionKey()); Preconditions.checkArgument( pfsInputcontext.getInputPartitionKeys().contains(pfsInputcontext.getInputPartitionKey()) ); Map<String, String> dsArguments = RuntimeArguments.extractScope(Scope.DATASET, PARTITIONED, context.getRuntimeArguments()); PartitionFilter inputPartitionFilter = PartitionedFileSetArguments.getInputPartitionFilter(dsArguments); Preconditions.checkNotNull(inputPartitionFilter); // verify that the partition matches the partition filter for this MapReduce Preconditions.checkArgument(inputPartitionFilter.match(pfsInputcontext.getInputPartitionKey())); }