Add abstract State implementation.

diff --git a/src/main/java/net/pterodactylus/reactor/states/AbstractState.java b/src/main/java/net/pterodactylus/reactor/states/AbstractState.java
new file mode 100644 (file)
index 0000000..e35c933
--- /dev/null
+++ b/src/main/java/net/pterodactylus/reactor/states/AbstractState.java
@@ -0,0 +1,98 @@
+/*
+ * Reactor - AbstractState.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.states;
+
+import net.pterodactylus.reactor.State;
+
+/**
+ * Abstract implementation of a {@link State} that knows about the basic
+ * attributes of a {@link State}.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public abstract class AbstractState implements State {
+
+       /** Whether the state was successfully retrieved. */
+       private final boolean success;
+
+       /** The optional exception that occured while retrieving the state. */
+       private final Throwable exception;
+
+       /**
+        * Creates a new successful state.
+        */
+       protected AbstractState() {
+               this(true);
+       }
+
+       /**
+        * Creates a new state.
+        *
+        * @param success
+        *            {@code true} if the state is successful, {@code false}
+        *            otherwise
+        */
+       protected AbstractState(boolean success) {
+               this(success, null);
+       }
+
+       /**
+        * Creates a new non-successful state with the given exception.
+        *
+        * @param exception
+        *            The exception that occured while retrieving the state
+        */
+       protected AbstractState(Throwable exception) {
+               this(false, exception);
+       }
+
+       /**
+        * Creates a new state.
+        *
+        * @param success
+        *            {@code true} if the state is successful, {@code false}
+        *            otherwise
+        * @param exception
+        *            The exception that occured while retrieving the state
+        */
+       protected AbstractState(boolean success, Throwable exception) {
+               this.success = success;
+               this.exception = exception;
+       }
+
+       //
+       // STATE METHODS
+       //
+
+       /**
+        * {@inheritDoc}
+        */
+       @Override
+       public boolean success() {
+               return success;
+       }
+
+       /**
+        * {@inheritDoc}
+        */
+       @Override
+       public Throwable exception() {
+               return exception;
+       }
+
+}