Fixes #160

Plugin Cubot/src/main/java/net/simon987/cubotplugin/CubotPlugin.java

@@ -34,6 +34,6 @@ public class CubotPlugin extends ServerPlugin {
         registry.registerHardware(CubotShield.class);
         registry.registerHardware(CubotCore.class);
 
-        LogManager.LOGGER.info("Initialised Cubot plugin");
+        LogManager.LOGGER.info("(Cubot Plugin) Initialised Cubot plugin");
     }
 }

Plugin Misc HW/src/main/java/net/simon987/mischwplugin/MiscHWPlugin.java

@@ -19,6 +19,6 @@ public class MiscHWPlugin extends ServerPlugin {
         registry.registerHardware(RandomNumberGenerator.class);
         registry.registerHardware(Clock.class);
 
-        LogManager.LOGGER.info("Initialised Misc Hardware Plugin");
+        LogManager.LOGGER.info("(Mist HW Plugin) Initialised Misc Hardware Plugin");
     }
 }

Plugin NPC/src/main/java/net/simon987/npcplugin/NpcPlugin.java

@@ -44,7 +44,7 @@ public class NpcPlugin extends ServerPlugin {
 
         radioTowers = new ArrayList<>(32);
 
-        LogManager.LOGGER.info("Initialised NPC plugin");
+        LogManager.LOGGER.info("(NPC Plugin) Initialised NPC plugin");
     }
 
     public static ArrayList<RadioTower> getRadioTowers() {

Plugin Plant/src/main/java/net/simon987/biomassplugin/BiomassPlugin.java

@@ -14,14 +14,10 @@ public class BiomassPlugin extends ServerPlugin {
 
     @Override
     public void init(ServerConfiguration config, GameRegistry registry) {
+
         listeners.add(new WorldCreationListener());
         listeners.add(new WorldUpdateListener(config));
-
-        if (registry.isGameObjectRegistered("net.simon987.npcplugin.HarvesterNPC")) {
         listeners.add(new ObjectDeathListener(config));
-        } else {
-            LogManager.LOGGER.severe("(BiomassPlugin) NPC plugin is not loaded so biomass will not spawn on death of HarvesterNPC");
-        }
 
         registry.registerGameObject(BiomassBlob.class);
         registry.registerItem(ItemBiomass.ID, ItemBiomass.class);

Plugin Plant/src/main/java/net/simon987/biomassplugin/event/ObjectDeathListener.java

@@ -19,7 +19,6 @@ public class ObjectDeathListener implements GameEventListener {
 
     public ObjectDeathListener(ServerConfiguration config) {
         biomassDropCount = config.getInt("harvester_biomass_drop_count");
-
     }
 
     @Override

Plugin Plant/src/main/resources/plugin.properties

@@ -1,3 +1,4 @@
 classpath=net.simon987.biomassplugin.BiomassPlugin
 name=Biomass Plugin
 version=1.0
+depend=NPC Plugin

Plugin Radioactive Cloud/src/main/java/net/simon987/pluginradioactivecloud/RadioactiveCloudPlugin.java

@@ -10,6 +10,6 @@ public class RadioactiveCloudPlugin extends ServerPlugin {
     @Override
     public void init(ServerConfiguration config, GameRegistry registry) {
 
-        LogManager.LOGGER.info("Initialised Radioactive cloud plugin.");
+        LogManager.LOGGER.info("(Radioactive cloud Plugin) Initialised Radioactive cloud plugin.");
     }
 }

Server/src/main/java/net/simon987/server/GameServer.java

@@ -24,7 +24,6 @@ import net.simon987.server.user.UserStatsHelper;
 import net.simon987.server.websocket.SocketServer;
 import org.bson.Document;
 
-import java.io.File;
 import java.util.ArrayList;
 
 public class GameServer implements Runnable {
@@ -68,8 +67,8 @@ public class GameServer implements Runnable {
 
         gameUniverse = new GameUniverse(config);
         gameUniverse.setMongo(mongo);
-        pluginManager = new PluginManager();
         gameRegistry = new GameRegistry();
+        pluginManager = new PluginManager(config, gameRegistry);
 
         maxExecutionTime = config.getInt("user_timeout");
 
@@ -84,21 +83,8 @@ public class GameServer implements Runnable {
             config.setString("secret_key", secretKey);
         }
 
-        //Load all plugins in plugins folder, if it doesn't exist, create it
+        if (!pluginManager.loadInFolder("plugins/")) {
-        File pluginDir = new File("plugins/");
+            System.exit(-1);
-        File[] pluginDirListing = pluginDir.listFiles();
-
-        if (pluginDirListing != null) {
-            for (File pluginFile : pluginDirListing) {
-
-                if (pluginFile.getName().endsWith(".jar")) {
-                    pluginManager.load(pluginFile, config, gameRegistry);
-                }
-            }
-        } else {
-            if (!pluginDir.mkdir()) {
-                LogManager.LOGGER.severe("Couldn't create plugin directory");
-            }
         }
 
         eventDispatcher = new GameEventDispatcher(pluginManager);

Server/src/main/java/net/simon987/server/plugin/PluginManager.java

@@ -5,30 +5,40 @@ import net.simon987.server.game.objects.GameRegistry;
 import net.simon987.server.logging.LogManager;
 
 import java.io.File;
+import java.io.IOException;
 import java.io.InputStream;
 import java.lang.reflect.Constructor;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
 import java.util.Properties;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
 public class PluginManager {
 
-    private ArrayList<ServerPlugin> plugins;
+    private ArrayList<ServerPlugin> loadedPlugins;
+    private ArrayList<ServerPlugin> toLoadPlugins;
+    private ServerConfiguration config;
+    private GameRegistry gameRegistry;
 
-    public PluginManager() {
+    public PluginManager(ServerConfiguration config, GameRegistry registry) {
-        this.plugins = new ArrayList<>(10);
+        this.config = config;
+        this.gameRegistry = registry;
+        this.toLoadPlugins = new ArrayList<>(10);
+        this.loadedPlugins = new ArrayList<>(10);
     }
 
-    public void load(File pluginFile, ServerConfiguration config, GameRegistry gameRegistry) {
+    private ServerPlugin load(File pluginFile) {
 
         LogManager.LOGGER.info("Loading plugin file " + pluginFile.getName());
 
+        ZipFile zipFile = null;
         try {
             //Get the plugin config file from the archive
-            ZipFile zipFile = new ZipFile(pluginFile);
+            zipFile = new ZipFile(pluginFile);
 
             ZipEntry configEntry = zipFile.getEntry("plugin.properties");
 
@@ -38,7 +48,6 @@ public class PluginManager {
                 Properties pluginConfig = new Properties();
                 pluginConfig.load(stream);
 
-                //Load the plugin
                 ClassLoader loader = URLClassLoader.newInstance(new URL[]{pluginFile.toURI().toURL()});
                 Class<?> aClass = Class.forName(pluginConfig.getProperty("classpath"), true, loader);
                 Class<? extends ServerPlugin> pluginClass = aClass.asSubclass(ServerPlugin.class);
@@ -48,26 +57,115 @@ public class PluginManager {
                 plugin.setName(pluginConfig.getProperty("name"));
                 plugin.setVersion(pluginConfig.getProperty("version"));
 
-                LogManager.LOGGER.info("Loaded " + plugin.name + " V" + plugin.version);
+                String dependStr = pluginConfig.getProperty("depend");
+                if (dependStr != null) {
+                    for (String dep : dependStr.split(",")) {
+                        plugin.dependencies.add(dep.trim());
+                    }
+                }
 
-                //Add it to the list
+                return plugin;
-                plugins.add(plugin);
-
-                //Init the plugin
-                plugin.init(config, gameRegistry);
 
             } else {
                 LogManager.LOGGER.severe("Couldn't find plugin.properties in " + pluginFile.getName());
             }
-            zipFile.close();
-
 
         } catch (Exception e) {
             e.printStackTrace();
+
+        } finally {
+            try {
+                if (zipFile != null) {
+                    zipFile.close();
+                }
+            } catch (IOException e) {
+                e.printStackTrace();
             }
         }
 
+        return null;
+    }
+
+    /**
+     * Load all plugins in plugins folder, if it doesn't exist, create it
+     *
+     * @return true if all the plugins could be loaded
+     */
+    public boolean loadInFolder(String dir) {
+
+        File pluginDir = new File(dir);
+        File[] pluginDirListing = pluginDir.listFiles();
+
+        if (pluginDirListing == null) {
+            if (!pluginDir.mkdir()) {
+                LogManager.LOGGER.severe("Couldn't create plugin directory");
+            }
+            return false;
+        }
+
+        for (File pluginFile : pluginDirListing) {
+            if (pluginFile.getName().endsWith(".jar")) {
+                toLoadPlugins.add(load(pluginFile));
+            }
+        }
+
+        while (toLoadPlugins.size() > 0) {
+
+            ServerPlugin plugin = toLoadPlugins.get(0);
+
+            if (!initWithDependencies(plugin)) {
+                LogManager.LOGGER.severe("Plugin " + plugin.name + " has unmet dependencies: " +
+                        Arrays.toString(plugin.dependencies.toArray()));
+                return false;
+            }
+        }
+
+        toLoadPlugins.clear();
+        return true;
+    }
+
+    private boolean initWithDependencies(ServerPlugin plugin) {
+
+        for (String depName : plugin.dependencies) {
+
+            if (!isLoaded(depName)) {
+                ServerPlugin dep = getPluginByName(depName, toLoadPlugins);
+
+                if (dep != null) {
+                    initWithDependencies(dep);
+                } else {
+                    return false;
+                }
+            }
+        }
+
+        initPlugin(plugin);
+        return true;
+    }
+
+    private static ServerPlugin getPluginByName(String name, List<ServerPlugin> plugins) {
+
+        for (ServerPlugin p : plugins) {
+            if (p.name.equals(name)) {
+                return p;
+            }
+        }
+
+        return null;
+    }
+
+    private boolean isLoaded(String name) {
+        return getPluginByName(name, loadedPlugins) != null;
+    }
+
+    private void initPlugin(ServerPlugin plugin) {
+
+        toLoadPlugins.remove(plugin);
+        loadedPlugins.add(plugin);
+        plugin.init(config, gameRegistry);
+    }
+
     public ArrayList<ServerPlugin> getPlugins() {
-        return plugins;
+        return loadedPlugins;
     }
 }

Server/src/main/java/net/simon987/server/plugin/ServerPlugin.java

@@ -5,6 +5,7 @@ import net.simon987.server.event.GameEventListener;
 import net.simon987.server.game.objects.GameRegistry;
 
 import java.util.ArrayList;
+import java.util.List;
 
 public abstract class ServerPlugin {
 
@@ -21,7 +22,9 @@ public abstract class ServerPlugin {
     /**
      * List of event listeners
      */
-    protected ArrayList<GameEventListener> listeners = new ArrayList<>(5);
+    protected List<GameEventListener> listeners = new ArrayList<>(5);
+
+    protected List<String> dependencies = new ArrayList<>();
 
     /**
      * Called when the plugin is loaded
@@ -44,7 +47,7 @@ public abstract class ServerPlugin {
         this.version = version;
     }
 
-    public ArrayList<GameEventListener> getListeners() {
+    public List<GameEventListener> getListeners() {
         return listeners;
     }
 }