The following contrived example will hopefully communicate its use + * more clearly than the previous paragraph of flowery prose: + * + *
+ * public void doSomeStuff (IntResultListener listener)
+ * {
+ * Runnable run = new Runnable () {
+ * public void run () {
+ * try {
+ * // do our thing
+ * listener.requestCompleted(42);
+ * } catch (Exception e) {
+ * listener.requestFailed(e);
+ * }
+ * }
+ * };
+ * new Thread(run).start();
+ * }
+ *
+ *
+ * This interface is a convenience-variation on the plain old {@link
+ * ResultListener}, which communicates the result back in the form of an
+ * {@link Object} rather than an integer.
+ */
+public interface IntResultListener
+{
+ /**
+ * Called to communicate that the request succeeded and that the
+ * result is available.
+ */
+ public void requestCompleted (int result);
+
+ /**
+ * Called to communicate that the request failed and to provide the
+ * reason for failure.
+ */
+ public void requestFailed (Exception cause);
+}
diff --git a/projects/samskivert/src/java/com/samskivert/util/ResultListener.java b/projects/samskivert/src/java/com/samskivert/util/ResultListener.java
new file mode 100644
index 00000000..b93ad587
--- /dev/null
+++ b/projects/samskivert/src/java/com/samskivert/util/ResultListener.java
@@ -0,0 +1,50 @@
+//
+// $Id: ResultListener.java,v 1.1 2002/03/20 07:07:48 mdb Exp $
+
+package com.samskivert.util;
+
+/**
+ * Provides access to a future result, or the exception associated with
+ * failure. In the trying course of implementing a method, one is often
+ * left with no choice but to foist control off onto another thread or
+ * generally postpone things beyond the lifetime of the current call. In
+ * such circumstances, it is handy to have a general purpose mechanism for
+ * leting the caller know when things are done and whether or not the
+ * succeeded; this class serves that purpose.
+ *
+ * The following contrived example will hopefully communicate its use + * more clearly than the previous paragraph of flowery prose: + * + *
+ * public void doSomeStuff (ResultListener listener)
+ * {
+ * Runnable run = new Runnable () {
+ * public void run () {
+ * try {
+ * // do our thing
+ * listener.requestCompleted("Elvis!");
+ * } catch (Exception e) {
+ * listener.requestFailed(e);
+ * }
+ * }
+ * };
+ * new Thread(run).start();
+ * }
+ *
+ *
+ * @see IntResultListener
+ */
+public interface ResultListener
+{
+ /**
+ * Called to communicate that the request succeeded and that the
+ * result is available.
+ */
+ public void requestCompleted (Object result);
+
+ /**
+ * Called to communicate that the request failed and to provide the
+ * reason for failure.
+ */
+ public void requestFailed (Exception cause);
+}