Locator for the configuration file.

diff --git a/src/de/todesbaum/jsite/main/ConfigurationLocator.java b/src/de/todesbaum/jsite/main/ConfigurationLocator.java
new file mode 100644 (file)
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+++ b/src/de/todesbaum/jsite/main/ConfigurationLocator.java
@@ -0,0 +1,179 @@
+/*
+ * jSite - ConfigurationLocator.java - Copyright © 2011 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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+package de.todesbaum.jsite.main;
+
+import java.io.File;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Locator for configuration files in different places.
+ *
+ * @author David ‘Bombe’ Roden <bombe@freenetproject.org>
+ */
+public class ConfigurationLocator {
+
+       /**
+        * The location of the configuration directory.
+        *
+        * @author David ‘Bombe’ Roden <bombe@freenetproject.org>
+        */
+       public enum ConfigurationLocation {
+
+               /** The configuration is in the same directory as the JAR file. */
+               NEXT_TO_JAR_FILE,
+
+               /**
+                * The configuration is in the user’s home directory. This is the
+                * pre-0.9.3 default.
+                */
+               HOME_DIRECTORY,
+
+               /** Custom location. */
+               CUSTOM,
+
+       }
+
+       /** The possible configuration locations. */
+       private final Map<ConfigurationLocation, String> configurationFiles = new HashMap<ConfigurationLocation, String>();
+
+       /**
+        * Creates a new configuration locator. If this class is loaded from a JAR
+        * file, {@link ConfigurationLocation#NEXT_TO_JAR_FILE} is added to the
+        * list of possible configuration file locations.
+        * {@link ConfigurationLocation#HOME_DIRECTORY} is always added to this
+        * list, {@link ConfigurationLocation#CUSTOM} has to be enabled by calling
+        * {@link #setCustomLocation(String)}.
+        */
+       public ConfigurationLocator() {
+               /* are we executed from a JAR file? */
+               String resource = getClass().getResource("/" + getClass().getName().replace(".", "/") + ".class").toString();
+               if (resource.startsWith("jar:")) {
+                       String jarFileLocation = resource.substring(9, resource.indexOf(".jar!") + 4);
+                       String jarFileDirectory = new File(jarFileLocation).getParent();
+                       File configurationFile = new File(jarFileDirectory, "jSite.conf");
+                       configurationFiles.put(ConfigurationLocation.NEXT_TO_JAR_FILE, configurationFile.getPath());
+               }
+               File homeDirectoryFile = new File(System.getProperty("user.home"), ".jSite/config7");
+               configurationFiles.put(ConfigurationLocation.HOME_DIRECTORY, homeDirectoryFile.getPath());
+       }
+
+       //
+       // ACCESSORS
+       //
+
+       /**
+        * Sets the location of the custom configuration file.
+        *
+        * @param customFile
+        *            The custom location of the configuration file
+        */
+       public void setCustomLocation(String customFile) {
+               configurationFiles.put(ConfigurationLocation.CUSTOM, customFile);
+       }
+
+       /**
+        * Returns whether the given location is valid. Certain locations (such as
+        * {@link ConfigurationLocation#NEXT_TO_JAR_FILE}) may be invalid in
+        * certain circumstances (such as the application not being run from a JAR
+        * file). A location being valid does not imply that a configuration file
+        * does exist at the given location, use
+        * {@link #hasFile(ConfigurationLocation)} to check for a configuration
+        * file at the desired location.
+        *
+        * @param configurationLocation
+        *            The configuration location
+        * @return {@code true} if the location is valid, {@code false} otherwise
+        */
+       public boolean isValidLocation(ConfigurationLocation configurationLocation) {
+               return configurationFiles.containsKey(configurationLocation);
+       }
+
+       /**
+        * Checks whether a configuration file exists at the given location.
+        *
+        * @param configurationLocation
+        *            The configuration location
+        * @return {@code true} if a configuration file exists at the given
+        *         location, {@code false} otherwise
+        */
+       public boolean hasFile(ConfigurationLocation configurationLocation) {
+               if (!isValidLocation(configurationLocation)) {
+                       return false;
+               }
+               return new File(configurationFiles.get(configurationLocation)).exists();
+       }
+
+       /**
+        * Returns the configuration file for the given location.
+        *
+        * @param configurationLocation
+        *            The location to get the file for
+        * @return The name of the configuration file at the given location, or
+        *         {@code null} if the given location is invalid
+        */
+       public String getFile(ConfigurationLocation configurationLocation) {
+               return configurationFiles.get(configurationLocation);
+       }
+
+       //
+       // ACTIONS
+       //
+
+       /**
+        * Finds the preferred location of the configuration file.
+        *
+        * @see #findPreferredLocation(ConfigurationLocation)
+        * @return The preferred location of the configuration file
+        */
+       public ConfigurationLocation findPreferredLocation() {
+               return findPreferredLocation(ConfigurationLocation.NEXT_TO_JAR_FILE);
+       }
+
+       /**
+        * Finds the preferred location of the configuration file. The following
+        * checks are performed: if a custom configuration location has been defined
+        * (by calling {@link #setCustomLocation(String)})
+        * {@link ConfigurationLocation#CUSTOM} is returned. If the application is
+        * run from a JAR file and a configuration file is found next to the JAR
+        * file (i.e. in the same directory),
+        * {@link ConfigurationLocation#NEXT_TO_JAR_FILE} is returned. If a
+        * configuration file exists in the user’s home directory,
+        * {@link ConfigurationLocation#HOME_DIRECTORY} is returned. Otherwise, the
+        * given {@code defaultLocation} is returned.
+        *
+        * @param defaultLocation
+        *            The default location to return if no other configuration file
+        *            is found
+        * @return The configuration location to load the configuration from
+        */
+       public ConfigurationLocation findPreferredLocation(ConfigurationLocation defaultLocation) {
+               if (hasFile(ConfigurationLocation.CUSTOM)) {
+                       return ConfigurationLocation.CUSTOM;
+               }
+               if (hasFile(ConfigurationLocation.NEXT_TO_JAR_FILE)) {
+                       return ConfigurationLocation.NEXT_TO_JAR_FILE;
+               }
+               if (hasFile(ConfigurationLocation.HOME_DIRECTORY)) {
+                       return ConfigurationLocation.HOME_DIRECTORY;
+               }
+               return defaultLocation;
+       }
+
+}