From 6cd724b33ff7c745f663c6784842ebba362d61dc Mon Sep 17 00:00:00 2001
From: =?utf8?q?David=20=E2=80=98Bombe=E2=80=99=20Roden?=
 <bombe@pterodactylus.net>
Date: Sun, 6 Jan 2013 11:54:15 +0100
Subject: [PATCH] Add manager for state (uses Jackson to read/write JSON).

---
 pom.xml                                            |  15 +++
 .../pterodactylus/reactor/states/StateManager.java | 121 +++++++++++++++++++++
 2 files changed, 136 insertions(+)
 create mode 100644 src/main/java/net/pterodactylus/reactor/states/StateManager.java

diff --git a/pom.xml b/pom.xml
index a6ca554..28d464d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -55,5 +55,20 @@
 			<artifactId>jaxb</artifactId>
 			<version>2.1.9</version>
 		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-core</artifactId>
+			<version>2.1.2</version>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-annotations</artifactId>
+			<version>2.1.2</version>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+			<version>2.1.2</version>
+		</dependency>
 	</dependencies>
 </project>
diff --git a/src/main/java/net/pterodactylus/reactor/states/StateManager.java b/src/main/java/net/pterodactylus/reactor/states/StateManager.java
new file mode 100644
index 0000000..cd0af2c
--- /dev/null
+++ b/src/main/java/net/pterodactylus/reactor/states/StateManager.java
@@ -0,0 +1,121 @@
+/*
+ * Reactor - StateManager.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 java.io.File;
+import java.io.IOException;
+
+import net.pterodactylus.reactor.State;
+
+import org.apache.log4j.Logger;
+
+import com.fasterxml.jackson.core.JsonGenerationException;
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * Loads and saves {@link State}s.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class StateManager {
+
+	/** The logger. */
+	private static final Logger logger = Logger.getLogger(StateManager.class);
+
+	/** Jackson object mapper. */
+	private final ObjectMapper objectMapper = new ObjectMapper();
+
+	/** The directory in which to store states. */
+	private final String directory;
+
+	/**
+	 * Creates a new state manager. The given directory is assumed to exist.
+	 *
+	 * @param directory
+	 *            The directory to store states in
+	 */
+	public StateManager(String directory) {
+		this.directory = directory;
+	}
+
+	//
+	// ACTIONS
+	//
+
+	/**
+	 * Loads the state with the given name.
+	 *
+	 * @param reactionName
+	 *            The name of the reaction
+	 * @return The loaded state, or {@code null} if the state could not be
+	 *         loaded
+	 */
+	public State loadState(String reactionName) {
+		File stateFile = stateFile(reactionName);
+		try {
+			State state = objectMapper.readValue(stateFile, AbstractState.class);
+			return state;
+		} catch (JsonParseException jpe1) {
+			logger.warn(String.format("State for Reaction “%s” could not be parsed.", reactionName), jpe1);
+		} catch (JsonMappingException jme1) {
+			logger.warn(String.format("State for Reaction “%s” could not be parsed.", reactionName), jme1);
+		} catch (IOException ioe1) {
+			logger.info(String.format("State for Reaction “%s” could not be found.", reactionName));
+		}
+		return null;
+	}
+
+	/**
+	 * Saves the given state under the given name.
+	 *
+	 * @param reactionName
+	 *            The name of the reaction
+	 * @param state
+	 *            The state to save
+	 */
+	public void saveState(String reactionName, State state) {
+		try {
+			File stateFile = stateFile(reactionName);
+			objectMapper.writeValue(stateFile, state);
+		} catch (JsonGenerationException jge1) {
+			logger.warn(String.format("State for Reaction “%s” could not be generated.", reactionName), jge1);
+		} catch (JsonMappingException jme1) {
+			logger.warn(String.format("State for Reaction “%s” could not be generated.", reactionName), jme1);
+		} catch (IOException ioe1) {
+			logger.warn(String.format("State for Reaction “%s” could not be written.", reactionName));
+		}
+	}
+
+	//
+	// PRIVATE METHODS
+	//
+
+	/**
+	 * Returns the file for the state with the given name.
+	 *
+	 * @param reactionName
+	 *            The name of the reaction
+	 * @return The file for the state
+	 */
+	private File stateFile(String reactionName) {
+		return new File(directory, reactionName + ".json");
+	}
+
+}
-- 
2.7.4