Restore ability to run without jar (#1875)

* Change JAR_FILE_SYSTEM to allow running from IDE without jar

* Just grab /defaults/data

* Restore FileUtils.getPathsFromResource

src/main/java/emu/grasscutter/Grasscutter.java

@@ -2,7 +2,6 @@ package emu.grasscutter;
 
 import ch.qos.logback.classic.Level;
 import ch.qos.logback.classic.Logger;
-import com.google.gson.Gson;
 
 import emu.grasscutter.auth.AuthenticationSystem;
 import emu.grasscutter.auth.DefaultAuthentication;

src/main/java/emu/grasscutter/utils/FileUtils.java

@@ -5,17 +5,15 @@ import emu.grasscutter.Grasscutter;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
-import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.*;
-import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 public final class FileUtils {
-    private static final FileSystem JAR_FILE_SYSTEM;
     private static final Path DATA_DEFAULT_PATH;
     private static final Path DATA_USER_PATH = Path.of(Grasscutter.config.folderStructure.data);
     private static final Path PACKETS_PATH = Path.of(Grasscutter.config.folderStructure.packets);
@@ -24,22 +22,28 @@ public final class FileUtils {
     private static final Path SCRIPTS_PATH;
     static {
         FileSystem fs = null;
-        Path path = DATA_USER_PATH;
-        // Setup Data paths
-        // Get pathUri of the current running JAR
+        Path path = null;
+        // Setup access to jar resources
         try {
-            URI jarUri = Grasscutter.class.getProtectionDomain()
-                            .getCodeSource()
-                            .getLocation()
-                            .toURI();
-            fs = FileSystems.newFileSystem(Path.of(jarUri));
-            path = fs.getPath("/defaults/data");
+            var uri = Grasscutter.class.getResource("/defaults/data").toURI();
+            switch (uri.getScheme()) {
+                case "jar":  // When running normally, as a jar
+                case "zip":  // Honestly I have no idea what setup would result in this, but this should work regardless
+                    fs = FileSystems.newFileSystem(uri, Map.of());  // Have to mount zip filesystem. This leaks, but we want to keep it forever anyway.
+                    // Fall-through
+                case "file":  // When running in an IDE
+                    path = Path.of(uri);  // Can access directly
+                    break;
+                default:
+                Grasscutter.getLogger().error("Invalid URI scheme for class resources: "+uri.getScheme());
+                    break;
+            }
         } catch (URISyntaxException | IOException e) {
             // Failed to load this jar. How?
-            System.err.println("Failed to load jar?????????????????????");
+            Grasscutter.getLogger().error("Failed to load jar?!");
         } finally {
-            JAR_FILE_SYSTEM = fs;
             DATA_DEFAULT_PATH = path;
+            Grasscutter.getLogger().debug("Setting path for default data: "+path.toAbsolutePath());
         }
 
         // Setup Resources path
@@ -171,27 +175,22 @@ public final class FileUtils {
         }
     }
 
-    // From https://mkyong.com/java/java-read-a-file-from-resources-folder/
     public static List<Path> getPathsFromResource(String folder) throws URISyntaxException {
-        List<Path> result = null;
-
         try {
             // file walks JAR
-            result = Files.walk(JAR_FILE_SYSTEM.getPath(folder))
+            return Files.walk(Path.of(Grasscutter.class.getResource(folder).toURI()))
                     .filter(Files::isRegularFile)
                     .collect(Collectors.toList());
-        } catch (Exception e) {
+        } catch (IOException e) {
             // Eclipse puts resources in its bin folder
-            File f = new File(System.getProperty("user.dir") + folder);
-
-            if (!f.exists() || f.listFiles().length == 0) {
+            try {
+                return Files.walk(Path.of(System.getProperty("user.dir"), folder))
+                        .filter(Files::isRegularFile)
+                        .collect(Collectors.toList());
+            } catch (IOException ignored) {
                 return null;
             }
-
-            result = Arrays.stream(f.listFiles()).map(File::toPath).toList();
         }
-
-        return result;
     }
 
     @SuppressWarnings("ResultOfMethodCallIgnored")