Adds basic plugin dependencies, courtesy of Raphfrk

By: Dinnerbone <dinnerbone@dinnerbone.com>

paper-api/src/main/java/org/bukkit/fillr/Getter.java

@@ -8,6 +8,7 @@ import org.bukkit.*;
 import org.bukkit.command.CommandSender;
 import org.bukkit.plugin.InvalidDescriptionException;
 import org.bukkit.plugin.InvalidPluginException;
+import org.bukkit.plugin.UnknownDependencyException;
 
 public class Getter {
     private Server server;
@@ -40,6 +41,8 @@ public class Getter {
         File plugin = new File(DIRECTORY, name + ".jar");
         try {
             server.getPluginManager().loadPlugin(plugin);
+        } catch (UnknownDependencyException ex) {
+            server.getLogger().log(Level.SEVERE, null, ex);
         } catch (InvalidPluginException ex) {
             server.getLogger().log(Level.SEVERE, null, ex);
         } catch (InvalidDescriptionException ex) {

paper-api/src/main/java/org/bukkit/fillr/Updater.java

@@ -98,6 +98,8 @@ public class Updater {
         File plugin = new File(DIRECTORY, name + ".jar");
         try {
             server.getPluginManager().loadPlugin(plugin);
+        } catch (UnknownDependencyException ex) {
+            server.getLogger().log(Level.SEVERE, null, ex);
         } catch (InvalidPluginException ex) {
             server.getLogger().log(Level.SEVERE, null, ex);
         } catch (InvalidDescriptionException ex) {

paper-api/src/main/java/org/bukkit/plugin/PluginDescriptionFile.java

@@ -7,6 +7,7 @@ import java.io.Writer;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
 import org.yaml.snakeyaml.Yaml;
 import org.yaml.snakeyaml.constructor.SafeConstructor;
@@ -18,6 +19,7 @@ public final class PluginDescriptionFile {
     private static final Yaml yaml = new Yaml(new SafeConstructor());
     private String name = null;
     private String main = null;
+    private ArrayList<String> depend = null;
     private String version = null;
     private Object commands = null;
     private String description = null;
@@ -99,6 +101,10 @@ public final class PluginDescriptionFile {
         return commands;
     }
 
+    public Object getDepend() {
+        return depend;
+    }
+
     /**
      * Gets the description of this plugin
      *
@@ -149,6 +155,14 @@ public final class PluginDescriptionFile {
             }
         }
 
+        if (map.containsKey("depend")) {
+            try {
+                depend = (ArrayList<String>)map.get("depend");
+            } catch (ClassCastException ex) {
+                throw new InvalidDescriptionException(ex, "depend is of wrong type");
+            }
+        }
+
         if (map.containsKey("website")) {
             try {
                 website = (String)map.get("website");
@@ -191,6 +205,7 @@ public final class PluginDescriptionFile {
         map.put("version", version);
 
         if (commands != null) map.put("command", commands);
+        if (depend != null) map.put("depend", depend);
         if (website != null) map.put("website", website);
         if (description != null) map.put("description", description);
 

paper-api/src/main/java/org/bukkit/plugin/PluginLoader.java

@@ -20,7 +20,7 @@ public interface PluginLoader {
      * unsuccessful
      * @throws InvalidPluginException Thrown when the specified file is not a plugin
      */
-    public Plugin loadPlugin(File file) throws InvalidPluginException, InvalidDescriptionException;
+    public Plugin loadPlugin(File file) throws InvalidPluginException, InvalidDescriptionException, UnknownDependencyException;
 
     /**
      * Returns a list of all filename filters expected by this PluginLoader

paper-api/src/main/java/org/bukkit/plugin/PluginManager.java

@@ -65,7 +65,7 @@ public interface PluginManager {
      * @throws InvalidPluginException Thrown when the specified file is not a valid plugin
      * @throws InvalidDescriptionException Thrown when the specified file contains an invalid description
      */
-    public Plugin loadPlugin(File file) throws InvalidPluginException, InvalidDescriptionException;
+    public Plugin loadPlugin(File file) throws InvalidPluginException, InvalidDescriptionException, UnknownDependencyException;
 
     /**
      * Loads the plugins contained within the specified directory

paper-api/src/main/java/org/bukkit/plugin/SimplePluginManager.java

@@ -12,6 +12,9 @@ import java.util.Map;
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.Iterator;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.regex.Matcher;
@@ -88,19 +91,45 @@ public final class SimplePluginManager implements PluginManager {
         List<Plugin> result = new ArrayList<Plugin>();
         File[] files = directory.listFiles();
 
-        for (File file : files) {
+        boolean allFailed = false;
+        boolean finalPass = false;
+
+        LinkedList<File> filesList = new LinkedList(Arrays.asList(files));
+
+        while(!allFailed || finalPass) {
+            allFailed = true;
+            Iterator<File> itr = filesList.iterator();
+            while(itr.hasNext()) {
+                File file = itr.next();
                 Plugin plugin = null;
 
                 try {
                     plugin = loadPlugin(file);
+                    itr.remove();
+                } catch (UnknownDependencyException ex) {
+                    if(finalPass) {
+                        server.getLogger().log(Level.SEVERE, "Could not load " + file.getPath() + " in " + directory.getPath() + ": " + ex.getMessage(), ex);
+                        itr.remove();
+                    } else {
+                        plugin = null;
+                    }
                 } catch (InvalidPluginException ex) {
                     server.getLogger().log(Level.SEVERE, "Could not load " + file.getPath() + " in " + directory.getPath() + ": " + ex.getMessage(), ex);
+                    itr.remove();
                 } catch (InvalidDescriptionException ex) {
                     server.getLogger().log(Level.SEVERE, "Could not load " + file.getPath() + " in " + directory.getPath() + ": " + ex.getMessage(), ex);
+                    itr.remove();
                 }
 
                 if (plugin != null) {
                     result.add(plugin);
+                    allFailed = false;
+                }
+            }
+            if(finalPass) {
+                break;
+            } else if(allFailed) {
+                finalPass = true;
             }
         }
 
@@ -117,7 +146,7 @@ public final class SimplePluginManager implements PluginManager {
      * @throws InvalidPluginException Thrown when the specified file is not a valid plugin
      * @throws InvalidDescriptionException Thrown when the specified file contains an invalid description
      */
-    public Plugin loadPlugin(File file) throws InvalidPluginException, InvalidDescriptionException {
+    public Plugin loadPlugin(File file) throws InvalidPluginException, InvalidDescriptionException, UnknownDependencyException {
         Set<Pattern> filters = fileAssociations.keySet();
         Plugin result = null;
 

paper-api/src/main/java/org/bukkit/plugin/UnknownDependencyException.java

@@ -0,0 +1,63 @@
+
+package org.bukkit.plugin;
+
+/**
+ * Thrown when attempting to load an invalid Plugin file
+ */
+public class UnknownDependencyException extends Exception {
+
+    private static final long serialVersionUID = 5721389371901775894L;
+    private final Throwable cause;
+    private final String message;
+
+    /**
+     * Constructs a new UnknownDependencyException based on the given Exception
+     *
+     * @param throwable Exception that triggered this Exception
+     */
+    public UnknownDependencyException(Throwable throwable) {
+        this(throwable, "Unknown dependency");
+    }
+
+    /**
+     * Constructs a new UnknownDependencyException with the given message
+     *
+     * @param message Brief message explaining the cause of the exception
+     */
+    public UnknownDependencyException(final String message) {
+        this(null, message);
+    }
+
+    /**
+     * Constructs a new UnknownDependencyException based on the given Exception
+     *
+     * @param message Brief message explaining the cause of the exception
+     * @param throwable Exception that triggered this Exception
+     */
+    public UnknownDependencyException(final Throwable throwable, final String message) {
+        this.cause = null;
+        this.message = message;
+    }
+
+    /**
+     * Constructs a new UnknownDependencyException
+     */
+    public UnknownDependencyException() {
+        this(null, "Unknown dependency");
+    }
+
+    /**
+     * If applicable, returns the Exception that triggered this Exception
+     *
+     * @return Inner exception, or null if one does not exist
+     */
+    @Override
+    public Throwable getCause() {
+        return cause;
+    }
+
+    @Override
+    public String getMessage() {
+        return message;
+    }
+}

paper-api/src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java

@@ -9,6 +9,9 @@ import java.net.URL;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
+import java.util.Arrays;
+import java.util.Map;
+import java.util.ArrayList;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.regex.Pattern;
@@ -36,12 +39,13 @@ public final class JavaPluginLoader implements PluginLoader {
             Pattern.compile("\\.jar$"),
     };
     private final Map<String, Class<?>> classes = new HashMap<String, Class<?>>();
+    private final Map<String, File> files = new HashMap<String, File>();
 
     public JavaPluginLoader(Server instance) {
         server = instance;
     }
 
-    public Plugin loadPlugin(File file) throws InvalidPluginException, InvalidDescriptionException {
+    public Plugin loadPlugin(File file) throws InvalidPluginException, InvalidDescriptionException, UnknownDependencyException {
         JavaPlugin result = null;
         PluginDescriptionFile description = null;
 
@@ -67,8 +71,37 @@ public final class JavaPluginLoader implements PluginLoader {
 
         File dataFolder = getDataFolder(file);
 
+        ArrayList<String> depend;
         try {
-            ClassLoader loader = new PluginClassLoader(this, new URL[]{file.toURI().toURL()}, getClass().getClassLoader());
+            depend = (ArrayList)description.getDepend();
+            if(depend == null) {
+                depend = new ArrayList<String>();
+            }
+        } catch (ClassCastException ex) {
+             throw new InvalidPluginException(ex);
+        }
+
+        ArrayList<File> dependFiles = new ArrayList<File>();
+
+        for(String pluginName : depend) {
+            if(files == null) {
+                throw new UnknownDependencyException(pluginName);
+            }
+            File current = files.get(pluginName);
+            if(current == null) {
+                throw new UnknownDependencyException(pluginName);
+            }
+            dependFiles.add(current);
+        }
+
+        try {
+            URL[] urls = new URL[dependFiles.size() + 1];
+            urls[0] = file.toURI().toURL();
+            int cnt = 1;
+            for(File f : dependFiles) {
+                urls[cnt++] = f.toURI().toURL();
+            }
+            ClassLoader loader = new PluginClassLoader(this, urls, getClass().getClassLoader());
             Class<?> jarClass = Class.forName(description.getMain(), true, loader);
             Class<? extends JavaPlugin> plugin = jarClass.asSubclass(JavaPlugin.class);
 
@@ -80,6 +113,8 @@ public final class JavaPluginLoader implements PluginLoader {
             throw new InvalidPluginException(ex);
         }
 
+        files.put(description.getName(), file);
+
         return (Plugin)result;
     }
 
@@ -112,8 +147,10 @@ public final class JavaPluginLoader implements PluginLoader {
     }
 
     public void setClass(final String name, final Class<?> clazz) {
+        if(!classes.containsKey(name)) {
             classes.put(name, clazz);
         }
+    }
 
     public EventExecutor createExecutor( Event.Type type, Listener listener ) {
         // TODO: remove multiple Listener type and hence casts
@@ -429,6 +466,8 @@ public final class JavaPluginLoader implements PluginLoader {
 
             server.getPluginManager().callEvent(new PluginEvent(Event.Type.PLUGIN_DISABLE, plugin));
 
+            files.remove(jPlugin.getDescription().getName());
+
             if (cloader instanceof PluginClassLoader) {
                 PluginClassLoader loader = (PluginClassLoader)cloader;
                 Set<String> names = loader.getClasses();

paper-api/src/main/java/org/bukkit/plugin/java/PluginClassLoader.java

@@ -24,17 +24,25 @@ public class PluginClassLoader extends URLClassLoader {
         Class<?> result = classes.get(name);
 
         if (result == null) {
-            result = loader.getClassByName(name);
+            ClassNotFoundException ex = null;
 
-            if (result == null) {
+            try {
                 result = super.findClass(name);
+            } catch (ClassNotFoundException e) {
+                ex = e;
+            }
 
             if (result != null) {
                 loader.setClass(name, result);
-                }
+            } else {
+                result = loader.getClassByName(name);
             }
 
+            if (result != null ) {
                 classes.put(name, result);
+            } else {
+                throw ex;
+            }
         }
 
         return result;