47 lines
1.2 KiB
Java
47 lines
1.2 KiB
Java
package docs.cluster;
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import java.math.BigInteger;
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import java.util.concurrent.Callable;
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import scala.concurrent.Future;
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import akka.actor.UntypedActor;
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import akka.dispatch.Mapper;
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import static akka.dispatch.Futures.future;
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import static akka.pattern.Patterns.pipe;
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//#backend
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public class FactorialBackend extends UntypedActor {
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@Override
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public void onReceive(Object message) {
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if (message instanceof Integer) {
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final Integer n = (Integer) message;
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Future<BigInteger> f = future(new Callable<BigInteger>() {
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public BigInteger call() {
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return factorial(n);
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}
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}, getContext().dispatcher());
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Future<FactorialResult> result = f.map(
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new Mapper<BigInteger, FactorialResult>() {
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public FactorialResult apply(BigInteger factorial) {
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return new FactorialResult(n, factorial);
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}
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}, getContext().dispatcher());
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pipe(result, getContext().dispatcher()).to(getSender());
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} else {
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unhandled(message);
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}
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}
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BigInteger factorial(int n) {
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BigInteger acc = BigInteger.ONE;
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for (int i = 1; i <= n; ++i) {
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acc = acc.multiply(BigInteger.valueOf(i));
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}
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return acc;
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}
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}
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//#backend
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