+act #3770 Added Java 8 friendly APIs for Actor and FSM

akka-actor/src/main/java/akka/japi/pf/UnitMatch.java

@@ -0,0 +1,79 @@
+/**
+ * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
+ */
+
+package akka.japi.pf;
+
+import scala.MatchError;
+import scala.PartialFunction;
+import scala.runtime.BoxedUnit;
+
+/**
+ * Version of {@link scala.PartialFunction} that can be built during
+ * runtime from Java.
+ * This is a specialized version of {@link UnitMatch} to map java
+ * void methods to {@link scala.runtime.BoxedUnit}.
+ *
+ * @param <I> the input type, that this PartialFunction will be applied to
+ */
+public class UnitMatch<I> extends AbstractMatch<I, BoxedUnit> {
+
+  /**
+   * Convenience function to create a {@link UnitPFBuilder} with the first
+   * case statement added.
+   *
+   * @param type  a type to match the argument against
+   * @param apply  an action to apply to the argument if the type matches
+   * @return a builder with the case statement added
+   * @see UnitPFBuilder#match(Class, FI.UnitApply)
+   */
+  public static final <F, P> UnitPFBuilder<F> match(final Class<P> type, FI.UnitApply<P> apply) {
+    return new UnitPFBuilder<F>().match(type, apply);
+  }
+
+  /**
+   * Convenience function to create a {@link UnitPFBuilder} with the first
+   * case statement added.
+   *
+   * @param type  a type to match the argument against
+   * @param predicate  a predicate that will be evaluated on the argument if the type matches
+   * @param apply  an action to apply to the argument if the type and predicate matches
+   * @return a builder with the case statement added
+   * @see UnitPFBuilder#match(Class, FI.TypedPredicate, FI.UnitApply)
+   */
+  public static <F, P> UnitPFBuilder<F> match(final Class<P> type,
+                                              final FI.TypedPredicate<P> predicate,
+                                              final FI.UnitApply<P> apply) {
+    return new UnitPFBuilder<F>().match(type, predicate, apply);
+  }
+
+  /**
+   * Create a {@link UnitMatch} from the builder.
+   *
+   * @param builder  a builder representing the partial function
+   * @return a {@link UnitMatch} that can be reused
+   */
+  public static <F> UnitMatch<F> create(UnitPFBuilder<F> builder) {
+    return new UnitMatch<F>(builder.build());
+  }
+
+  private UnitMatch(PartialFunction<I, BoxedUnit> statements) {
+    super(statements);
+  }
+
+  /**
+   * Convenience function to make the Java code more readable.
+   *
+   * <pre><code>
+   *   UnitMatcher&lt;X&gt; matcher = UnitMatcher.create(...);
+   *
+   *   matcher.match(obj);
+   * </code></pre>
+   *
+   * @param i  the argument to apply the match to
+   * @throws scala.MatchError  if there is no match
+   */
+  public void match(I i) throws MatchError {
+    statements.apply(i);
+  }
+}