Thoughts on how to do the modloading properly

fml/src/fml/Mod.java

@@ -0,0 +1,15 @@
+package fml;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Mod {
+  String name() default "";
+  String version() default "";
+  boolean wantsPreInit() default false;
+  boolean wantsPostInit() default false;
+  public @interface PreInit {}
+  public @interface Init {}
+  public @interface PostInit {}
+}

fml/src/fml/server/FMLModContainer.java

@@ -0,0 +1,49 @@
+package fml.server;
+
+import fml.Mod;
+
+public class FMLModContainer implements ModContainer {
+  private Mod modDescriptor;
+  private Object modInstance;
+  public FMLModContainer(Class<?> clazz) {
+    modDescriptor=clazz.getAnnotation(Mod.class);
+    
+    try {
+      modInstance=clazz.newInstance();
+    } catch (Exception e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  @Override
+  public boolean wantsPreInit() {
+    return modDescriptor.wantsPreInit();
+  }
+
+  @Override
+  public boolean wantsPostInit() {
+    return modDescriptor.wantsPostInit();
+  }
+
+  @Override
+  public void preInit() {
+    
+  }
+
+  @Override
+  public void init() {
+    // TODO Auto-generated method stub
+
+  }
+
+  @Override
+  public void postInit() {
+    // TODO Auto-generated method stub
+
+  }
+
+  public static ModContainer buildFor(Class<?> clazz) {
+    return new FMLModContainer(clazz);
+  }
+
+}

fml/src/fml/server/Loader.java

@@ -0,0 +1,193 @@
+package fml.server;
+
+import java.io.File;
+import java.io.FilenameFilter;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.logging.Logger;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
+
+import fml.Mod;
+import fml.stubs.mcpserver.BaseMod;
+
+public class Loader {
+  private enum State { NOINIT, LOADING, PREINIT, INIT, POSTINIT, UP, ERRORED };
+  private static State state;
+  private static Logger LOG = Logger.getLogger("ForgeModLoader.Loader");
+
+  private static List<ModContainer> mods;
+  
+  private static ModClassLoader modClassLoader;
+
+  private static Pattern zipJar = Pattern.compile("([\\w]+).(zip|jar)$");
+  private static Pattern modClass = Pattern.compile("(.*)(mod_[^\\s]+)\\.class$");
+
+  public static Loader instance;
+  
+  public static void run() {
+    instance=new Loader();
+  }
+  
+  private Loader() {
+    state=State.NOINIT;
+    load();
+    preModInit();
+    modInit();
+    postModInit();
+    state=State.UP;
+  }
+
+  private void preModInit() {
+    state=State.PREINIT;
+    for (ModContainer mod : mods) {
+      if (mod.wantsPreInit()) {
+        mod.preInit();
+      }
+    }
+  }
+
+  private void modInit() {
+    state=State.INIT;
+    for (ModContainer mod : mods) {
+       mod.init();
+    }
+  }
+
+  private void postModInit() {
+    state=State.POSTINIT;
+    for (ModContainer mod : mods) {
+      if (mod.wantsPostInit()) {
+        mod.postInit();
+      }
+    }
+  }
+
+  private void load() {
+    File modsDir = new File(".", "mods");
+    String canonicalModsPath;
+    try {
+      canonicalModsPath = modsDir.getCanonicalPath();
+    } catch (IOException ioe) {
+      LOG.severe(String.format("Failed to resolve mods directory mods %s",modsDir.getAbsolutePath()));
+      LOG.throwing("fml.server.Loader", "initialize", ioe);
+      throw new LoaderException(ioe);
+    }
+    if (!modsDir.exists()) {
+      LOG.fine(String.format("No mod directory found, creating one: %s", canonicalModsPath));
+      try {
+        modsDir.mkdir();
+      } catch (Exception e) {
+        LOG.throwing("fml.server.Loader", "initialize", e);
+        throw new LoaderException(e);
+      }
+    }
+    if (!modsDir.isDirectory()) {
+      LOG.severe(String.format("Attempting to load mods from %s, which is not a directory", canonicalModsPath));
+      LoaderException loaderException = new LoaderException();
+      LOG.throwing("fml.server.Loader", "initialize", loaderException);
+      throw loaderException;
+    }
+    File[] modList = modsDir.listFiles();
+    // Sort the files into alphabetical order first
+    Arrays.sort(modList);
+
+    state=State.LOADING;
+    for (File modFile : modList) {
+      if (modFile.isDirectory()) {
+        LOG.info(String.format("Found directory %s. Attempting load", modFile.getName()));
+        attemptDirLoad(modFile);
+      } else {
+        Matcher matcher = zipJar.matcher(modFile.getName());
+        if (matcher.find()) {
+          LOG.info(String.format("Found zip or jar file %s. Attempting load.", matcher.group(0)));
+          attemptFileLoad(modFile);
+        }
+      }
+    }
+    if (state==State.ERRORED) {
+      LOG.severe("A problem has occured during mod loading. Giving up now");
+      throw new RuntimeException("Giving up please");
+    }
+  }
+
+  private void attemptDirLoad(File modDir) {
+    extendClassLoader(modDir);
+    
+    File[] content=modDir.listFiles(new FilenameFilter() {
+      @Override
+      public boolean accept(File dir, String name) {
+        return modClass.matcher(name).find();
+      }
+    });
+    for (File modClassFile : content) {
+      LOG.fine(String.format("Found a mod class %s in directory %s. Attempting to load it",modClassFile.getName(),modDir.getName()));
+      String clazzName=modClass.matcher(modClassFile.getName()).group(2);
+      loadModClass(modDir, modClassFile.getName(), clazzName);
+      LOG.fine(String.format("Successfully loaded mod class %s",modClassFile.getName()));
+    }
+  }
+
+  private void loadModClass(File classSource, String classFileName, String clazzName) {
+    try {
+      Class<?> clazz=Class.forName(clazzName,true,modClassLoader);
+      if (clazz.isAnnotationPresent(Mod.class)) {
+        // an FML mod
+        mods.add(FMLModContainer.buildFor(clazz));
+      } else if (clazz.isAssignableFrom(BaseMod.class)) {
+        // a modloader mod
+      } else {
+        // Unrecognized
+      }
+    } catch (ClassNotFoundException e) {
+      LOG.warning(String.format("Failed to load mod class %s in %s",classFileName,classSource.getName()));
+      LOG.throwing("fml.server.Loader", "attemptDirLoad", e);
+      state=State.ERRORED;
+    }
+  }
+
+  private void extendClassLoader(File file) {
+    if (modClassLoader==null) {
+      modClassLoader=new ModClassLoader();
+    }
+    try {
+      modClassLoader.addFile(file);
+    } catch (MalformedURLException e) {
+      throw new LoaderException(e);
+    }
+  }
+
+  private void attemptFileLoad(File modFile) {
+    extendClassLoader(modFile);
+    
+    try {
+      ZipFile jar=new ZipFile(modFile);
+      for (ZipEntry ze : Collections.list(jar.entries())) {
+        Matcher match=modClass.matcher(ze.getName());
+        if (match.find()) {
+          String pkg=match.group(1).replace('/', '.');
+          String clazzName=pkg+match.group(2);
+          loadModClass(modFile, ze.getName(), clazzName);
+        }
+      }
+    } catch (Exception e) {
+      LOG.warning(String.format("Zip file %s failed to read properly", modFile.getName()));
+      LOG.throwing("fml.server.Loader", "attemptFileLoad", e);
+      state=State.ERRORED;
+    }
+  }
+
+  class LoaderException extends RuntimeException {
+    public LoaderException(Exception wrapped) {
+      super(wrapped);
+    }
+
+    public LoaderException() {
+    }
+  }
+}

fml/src/fml/server/ModClassLoader.java

@@ -0,0 +1,18 @@
+package fml.server;
+
+import java.io.File;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+
+public class ModClassLoader extends URLClassLoader {
+
+  public ModClassLoader() {
+    super(new URL[0]);
+  }
+
+  public void addFile(File modFile) throws MalformedURLException {
+    URL url=modFile.toURI().toURL();
+    super.addURL(url);
+  }
+}

fml/src/fml/server/ModContainer.java

@@ -0,0 +1,9 @@
+package fml.server;
+
+public interface ModContainer {
+  boolean wantsPreInit();
+  boolean wantsPostInit();
+  void preInit();
+  void init();
+  void postInit();
+}

fml/src/fml/server/ModLoaderModContainer.java

@@ -0,0 +1,30 @@
+package fml.server;
+
+public class ModLoaderModContainer implements ModContainer {
+  public boolean wantsPreInit() {
+    return false;
+  }
+
+  public boolean wantsPostInit() {
+    return false;
+  }
+
+  @Override
+  public void preInit() {
+    // TODO Auto-generated method stub
+
+  }
+
+  @Override
+  public void init() {
+    // TODO Auto-generated method stub
+
+  }
+
+  @Override
+  public void postInit() {
+    // TODO Auto-generated method stub
+
+  }
+
+}

fml/src/fml/stubs/mcpserver/BaseMod.java

@@ -2,12 +2,16 @@ package fml.stubs.mcpserver;
 
 import java.util.Random;
 
+import fml.Mod;
+
+
 import net.minecraft.src.EntityPlayer;
 import net.minecraft.src.IInventory;
 import net.minecraft.src.ItemStack;
 import net.minecraft.src.Packet250CustomPayload;
 import net.minecraft.src.World;
 
+@Mod(name="blah",version="blah")
 public interface BaseMod {
   int addFuel(int id, int metadata);
 
@@ -25,8 +29,10 @@ public interface BaseMod {
   abstract String getVersion();
 
   // void keyboardEvent(KeyBinding event);
+  @Mod.PreInit
   abstract void load();
 
+  @Mod.Init
   void modsLoaded();
 
   void onItemPickup(EntityPlayer player, ItemStack item);