Akka/Scala example source code file (FSMStopBuilder.java)

This example Akka source code file (FSMStopBuilder.java) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

actor, akka, boxedunit, class, d, exception, fsmstopbuilder, japi, override, p, runtime, s, suppresswarnings

The FSMStopBuilder.java Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */

package akka.japi.pf;

import akka.actor.FSM;
import scala.PartialFunction;
import scala.runtime.BoxedUnit;

/**
 * Builder used to create a partial function for {@link akka.actor.FSM#onTermination}.
 *
 * @param <S> the state type
 * @param <D> the data type
 *
 * This is an EXPERIMENTAL feature and is subject to change until it has received more real world testing.
 */
public class FSMStopBuilder<S, D> {

  private UnitPFBuilder<FSM.StopEvent<S, D>> builder =
    new UnitPFBuilder<FSM.StopEvent<S, D>>();

  /**
   * Add a case statement that matches on an {@link FSM.Reason}.
   *
   * @param reason  the reason for the termination
   * @param apply  an action to apply to the event and state data if there is a match
   * @return the builder with the case statement added
   */
  public FSMStopBuilder<S, D> stop(final FSM.Reason reason,
                                   final FI.UnitApply2<S, D> apply) {
    builder.match(FSM.StopEvent.class,
      new FI.TypedPredicate<FSM.StopEvent>() {
        @Override
        public boolean defined(FSM.StopEvent e) {
          return reason.equals(e.reason());
        }
      },
      new FI.UnitApply<FSM.StopEvent>() {
        public void apply(FSM.StopEvent e) throws Exception {
          @SuppressWarnings("unchecked")
          S s = (S) e.currentState();
          @SuppressWarnings("unchecked")
          D d = (D) e.stateData();
          apply.apply(s, d);
        }
      }
    );

    return this;
  }

  /**
   * Add a case statement that matches on a reason type.
   *
   * @param reasonType  the reason type to match on
   * @param apply  an action to apply to the reason, event and state data if there is a match
   * @param <P>  the reason type to match on
   * @return the builder with the case statement added
   */
  public <P extends FSM.Reason> FSMStopBuilder<S, D> stop(final Class<P> reasonType,
                                                          final FI.UnitApply3<P, S, D> apply) {
    return this.stop(reasonType,
      new FI.TypedPredicate<P>() {
        @Override
        public boolean defined(P p) {
          return true;
        }
      }, apply);
  }

  /**
   * Add a case statement that matches on a reason type and a predicate.
   *
   * @param reasonType  the reason type to match on
   * @param apply  an action to apply to the reason, event and state data if there is a match
   * @param predicate  a predicate that will be evaluated on the reason if the type matches
   * @param <P>  the reason type to match on
   * @return the builder with the case statement added
   */
  public <P extends FSM.Reason> FSMStopBuilder<S, D> stop(final Class<P> reasonType,
                                                          final FI.TypedPredicate<P> predicate,
                                                          final FI.UnitApply3<P, S, D> apply) {
    builder.match(FSM.StopEvent.class,
      new FI.TypedPredicate<FSM.StopEvent>() {
        @Override
        public boolean defined(FSM.StopEvent e) {
          if (reasonType.isInstance(e.reason())) {
            @SuppressWarnings("unchecked")
            P p = (P) e.reason();
            return predicate.defined(p);
          } else {
            return false;
          }
        }
      },
      new FI.UnitApply<FSM.StopEvent>() {
        public void apply(FSM.StopEvent e) throws Exception {
          @SuppressWarnings("unchecked")
          P p = (P) e.reason();
          @SuppressWarnings("unchecked")
          S s = (S) e.currentState();
          @SuppressWarnings("unchecked")
          D d = (D) e.stateData();
          apply.apply(p, s, d);
        }
      }
    );

    return this;
  }

  /**
   * Build a {@link scala.PartialFunction} from this builder.
   * After this call the builder will be reset.
   *
   * @return  a PartialFunction for this builder.
   */
  public PartialFunction<FSM.StopEvent<S, D>, BoxedUnit> build() {
    return builder.build();
  }
}