got rid of dependency injection, it doesn't add anything at this point and only slows down things and makes a mess. Also some refactoring.

src/yugecin/opsudance/core/Environment.java

@@ -0,0 +1,62 @@
+/*
+ * opsu!dance - fork of opsu! with cursordance auto
+ * Copyright (C) 2017 yugecin
+ *
+ * opsu!dance 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * opsu!dance 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 opsu!dance.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package yugecin.opsudance.core;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Paths;
+import java.util.jar.JarFile;
+
+import static yugecin.opsudance.core.Constants.PROJECT_NAME;
+
+public class Environment {
+
+	public final boolean isJarRunning;
+	public final File workingdir;
+	public final JarFile jarfile;
+
+	public Environment() {
+		Class thiz = Environment.class;
+		String thisClassLocation = thiz.getResource(thiz.getSimpleName() + ".class").toString();
+		this.isJarRunning = thisClassLocation.startsWith("jar:");
+		if (!isJarRunning) {
+			this.workingdir = Paths.get(".").toAbsolutePath().normalize().toFile();
+			this.jarfile = null;
+		} else {
+			String wdir = thisClassLocation.substring(6); // remove the jar://
+			String separator = "!/";
+			int separatorIdx = wdir.indexOf(separator);
+			int lastSeparatorIdx = wdir.lastIndexOf(separator);
+			if (separatorIdx != lastSeparatorIdx) {
+				String msg = String.format("%s cannot run from paths containing '!/', please move the file. Current directory: %s",
+					PROJECT_NAME, thisClassLocation.substring(0, lastSeparatorIdx));
+				throw new RuntimeException(msg);
+			}
+			File jar = new File(wdir.substring(0, separatorIdx));
+			this.workingdir = jar.getParentFile();
+			try {
+				this.jarfile = new JarFile(jar);
+			} catch (IOException e) {
+				String msg = String.format("Cannot read from jarfile (%s): %s", jar.getAbsolutePath(),
+					e.getMessage());
+				throw new RuntimeException(msg, e);
+			}
+		}
+	}
+
+}