From 2b8aecff333e65cc5b44d01bbc31a16ca12280b2 Mon Sep 17 00:00:00 2001
From: =?utf8?q?David=20=E2=80=98Bombe=E2=80=99=20Roden?=
 <bombe@pterodactylus.net>
Date: Wed, 2 Jan 2013 02:36:32 +0100
Subject: [PATCH] Add state interface.

---
 src/main/java/net/pterodactylus/reactor/State.java | 50 ++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 src/main/java/net/pterodactylus/reactor/State.java

diff --git a/src/main/java/net/pterodactylus/reactor/State.java b/src/main/java/net/pterodactylus/reactor/State.java
new file mode 100644
index 0000000..9e2face
--- /dev/null
+++ b/src/main/java/net/pterodactylus/reactor/State.java
@@ -0,0 +1,50 @@
+/*
+ * Reactor - State.java - Copyright © 2013 David Roden
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.reactor;
+
+/**
+ * Defines the current state of a system.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public interface State {
+
+	/**
+	 * Whether the state was successfully retrieved. This method should only
+	 * return {@code true} if a meaningful result could be retrieved; if e. g. a
+	 * service is currently not reachable, this method should return false
+	 * instead of emulating success by using empty lists or similar constructs.
+	 *
+	 * @return {@code true} if the state could be retrieved successfully,
+	 *         {@code false} otherwise
+	 */
+	boolean success();
+
+	/**
+	 * If {@link #success()} returns {@code false}, this method may return a
+	 * {@link Throwable} to give some details for the reason why retrieving the
+	 * state was not possible. For example, network-based {@link Query}s might
+	 * return any exception that were encountered while communicating with the
+	 * remote service.
+	 *
+	 * @return An exception that occured, may be {@code null} in case an
+	 *         exception can not be meaningfully returned
+	 */
+	Throwable exception();
+
+}
-- 
2.7.4