Add class enumerator for future class stuff

common/mekanism/common/classloading/ClassEnumerator.java

@@ -0,0 +1,115 @@
+package mekanism.common.classloading;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+public class ClassEnumerator
+{
+	private static Class<?> loadClass(String className)
+	{
+		try {
+			return Class.forName(className);
+		} catch(ClassNotFoundException e) {
+			throw new RuntimeException("Unexpected ClassNotFoundException loading class '" + className + "'");
+		}
+	}
+
+	private static void processDir(File directory, String pkgname, ArrayList<Class<?>> classes)
+	{
+		String[] files = directory.list();
+		
+		for(int i = 0; i < files.length; i++)
+		{
+			String fileName = files[i];
+			String className = null;
+			
+			if(fileName.endsWith(".class"))
+			{
+				className = pkgname + '.' + fileName.substring(0, fileName.length() - 6);
+			}
+			
+			if(className != null)
+			{
+				classes.add(loadClass(className));
+			}
+			
+			File subdir = new File(directory, fileName);
+			
+			if(subdir.isDirectory())
+			{
+				processDir(subdir, pkgname + '.' + fileName, classes);
+			}
+		}
+	}
+
+	private static void processJar(URL resource, String pkgname, ArrayList<Class<?>> classes)
+	{
+		String relPath = pkgname.replace('.', '/');
+		String resPath = resource.getPath();
+		String jarPath = resPath.replaceFirst("[.]jar[!].*", ".jar").replaceFirst("file:", "");
+		
+		JarFile jarFile;
+		
+		try {
+			jarFile = new JarFile(jarPath);
+		} catch(IOException e) {
+			throw new RuntimeException("Unexpected IOException reading JAR File '" + jarPath + "'", e);
+		}
+		
+		Enumeration<JarEntry> entries = jarFile.entries();
+		
+		while(entries.hasMoreElements())
+		{
+			JarEntry entry = entries.nextElement();
+			String entryName = entry.getName();
+			String className = null;
+			
+			if(entryName.endsWith(".class") && entryName.startsWith(relPath) && entryName.length() > (relPath.length() + "/".length()))
+			{
+				className = entryName.replace('/', '.').replace('\\', '.').replace(".class", "");
+			}
+			
+			if(className != null)
+			{
+				classes.add(loadClass(className));
+			}
+		}
+	}
+
+	public static ArrayList<Class<?>> getClassesForPackage(Package pkg)
+	{
+		ArrayList<Class<?>> classes = new ArrayList<Class<?>>();
+
+		try {
+			String pkgname = pkg.getName();
+			String relPath = pkgname.replace('.', '/');
+	
+			URL resource = ClassLoader.getSystemClassLoader().getResource(relPath);
+			
+			if(resource == null)
+			{
+				throw new RuntimeException("Unexpected problem: No resource for " + relPath);
+			}
+	
+			resource.getPath();
+			
+			if(resource.toString().startsWith("jar:"))
+			{
+				processJar(resource, pkgname, classes);
+			}
+			else {
+				processDir(new File(resource.getPath()), pkgname, classes);
+			}
+		} catch(Exception e) {
+			System.err.println("[Mekanism] Error while loading classes in package " + pkg);
+			e.printStackTrace();
+		}
+
+		return classes;
+	}
+}