MapReduce Reducer Assignment

Motivation

Collector is fundamental to the MapReduce Framework lab.

Background

interface Collector<T,A,R>

class MutableInt

Mythical Reducer:

public class CollectorReducerAdapter<V, A, R> implements Reducer<V, A, R> {
	private final Collector<V,A,R> collector;
	public CollectorReducerAdapter(Collector<V,A,R> collector) {
		this.collector = collector;
	}
	@Override
	public A createMutableContainer() {
		return collector.supplier().get();
	}
	@Override
	public void accumulate(A container, V item) {
		collector.accumulator().accept(container, item);
	}
	@Override
	public A combine(A containerA, A containerB) {
		return collector.combiner().apply(containerA, containerB);
	}
	@Override
	public R reduce(A container) {
		return collector.finisher().apply(container);
	}
}

Code To Implement

ClassicReducer

class:	ClassicReducer.java
methods:	supplier accumulator combiner
package:	mapreduce.collector.studio
source folder:	student/src/main/java

IntSumCollector

class:	IntSumCollector.java
methods:	supplier accumulator combiner finisher
package:	mapreduce.collector.intsum.studio
source folder:	student/src/main/java

Testing Your Solution

Correctness

class:	CollectorStudioTestSuite.java
package:	mapreduce
source folder:	testing/src/test/java