Add all the A tasks

Task/Accumulator-factory/Java/accumulator-factory-2.java

@@ -0,0 +1,19 @@
+import com.google.common.base.Function;
+
+public class AccumulatorFactory {
+	private static Function<Double, Double> accumulator(final Double elem) {
+		return new Function<Double, Double>() {
+			Double sum = elem;
+			@Override public Double apply(Double val) {
+				return sum += val;
+			}
+		};
+	}
+
+	public static void main(String[] args) {
+		Function<Double, Double> x = accumulator(1d);
+		x.apply(5d);
+		System.out.println(accumulator(3d));		
+		System.out.println(x.apply(2.3));
+	}
+}