Stop using reflection, update to latest

src/main/java/net/minestom/server/extensions/DiscoveredExtension.java

@@ -11,6 +11,7 @@ import org.slf4j.LoggerFactory;
 
 import java.io.File;
 import java.net.URL;
+import java.nio.file.Path;
 import java.util.LinkedList;
 import java.util.List;
 
@@ -75,6 +76,8 @@ public final class DiscoveredExtension {
     /** The original jar this is from. */
     transient private File originalJar;
 
+    transient private Path dataDirectory;
+
     /** The class loader that powers it. */
     transient private MinestomExtensionClassLoader minestomExtensionClassLoader;
 
@@ -130,6 +133,15 @@ public final class DiscoveredExtension {
         return originalJar;
     }
 
+    @NotNull
+    public Path getDataDirectory() {
+        return dataDirectory;
+    }
+
+    public void setDataDirectory(@NotNull Path dataDirectory) {
+        this.dataDirectory = dataDirectory;
+    }
+
     MinestomExtensionClassLoader removeMinestomExtensionClassLoader() {
         MinestomExtensionClassLoader oldClassLoader = getMinestomExtensionClassLoader();
         setMinestomExtensionClassLoader(null);

src/main/java/net/minestom/server/extensions/Extension.java

@@ -1,11 +1,19 @@
 package net.minestom.server.extensions;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
 
+import java.io.IOException;
+import java.io.InputStream;
 import java.lang.ref.Reference;
 import java.lang.ref.ReferenceQueue;
 import java.lang.ref.WeakReference;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardCopyOption;
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Consumer;
@@ -77,6 +85,122 @@ public abstract class Extension {
         return logger;
     }
 
+    @NotNull
+    public Path getDataDirectory() {
+        return getOrigin().getDataDirectory();
+    }
+
+    /**
+     * Gets a resource from the extension directory, or from inside the jar if it does not
+     * exist in the extension directory.
+     * <p>
+     * If it does not exist in the extension directory, it will be copied from inside the jar.
+     * <p>
+     * The caller is responsible for closing the returned {@link InputStream}.
+     *
+     * @param fileName The file to read
+     * @return The file contents, or null if there was an issue reading the file.
+     */
+    @Nullable
+    public InputStream getResource(@NotNull String fileName) {
+        return getResource(Paths.get(fileName));
+    }
+
+    /**
+     * Gets a resource from the extension directory, or from inside the jar if it does not
+     * exist in the extension directory.
+     * <p>
+     * If it does not exist in the extension directory, it will be copied from inside the jar.
+     * <p>
+     * The caller is responsible for closing the returned {@link InputStream}.
+     *
+     * @param target The file to read
+     * @return The file contents, or null if there was an issue reading the file.
+     */
+    @Nullable
+    public InputStream getResource(@NotNull Path target) {
+        final Path targetFile = getDataDirectory().resolve(target);
+        try {
+            // Copy from jar if the file does not exist in the extension data directory.
+            if (!Files.exists(targetFile)) {
+                savePackagedResource(target);
+            }
+
+            return Files.newInputStream(targetFile);
+        } catch (IOException ex) {
+            getLogger().info("Failed to read resource {}.", target, ex);
+            return null;
+        }
+    }
+
+    /**
+     * Gets a resource from inside the extension jar.
+     * <p>
+     * The caller is responsible for closing the returned {@link InputStream}.
+     *
+     * @param fileName The file to read
+     * @return The file contents, or null if there was an issue reading the file.
+     */
+    public InputStream getPackagedResource(@NotNull String fileName) {
+        return getPackagedResource(Paths.get(fileName));
+    }
+
+    /**
+     * Gets a resource from inside the extension jar.
+     * <p>
+     * The caller is responsible for closing the returned {@link InputStream}.
+     *
+     * @param target The file to read
+     * @return The file contents, or null if there was an issue reading the file.
+     */
+    @Nullable
+    public InputStream getPackagedResource(@NotNull Path target) {
+        try {
+            final URL url = getOrigin().getMinestomExtensionClassLoader().getResource(target.toString());
+            if (url == null) {
+                getLogger().debug("Resource not found: {}", target);
+                return null;
+            }
+
+            return url.openConnection().getInputStream();
+        } catch (IOException ex) {
+            getLogger().debug("Failed to load resource {}.", target, ex);
+            return null;
+        }
+    }
+
+    /**
+     * Copies a resource file to the extension directory, replacing any existing copy.
+     *
+     * @param fileName The resource to save
+     * @return True if the resource was saved successfully, null otherwise
+     */
+    public boolean savePackagedResource(@NotNull String fileName) {
+        return savePackagedResource(Paths.get(fileName));
+    }
+
+    /**
+     * Copies a resource file to the extension directory, replacing any existing copy.
+     *
+     * @param target The resource to save
+     * @return True if the resource was saved successfully, null otherwise
+     */
+    public boolean savePackagedResource(@NotNull Path target) {
+        final Path targetFile = getDataDirectory().resolve(target);
+        try (InputStream is = getPackagedResource(target)) {
+            if (is == null) {
+                return false;
+            }
+
+            Files.createDirectories(targetFile.getParent());
+            Files.copy(is, targetFile, StandardCopyOption.REPLACE_EXISTING);
+            return true;
+        } catch (IOException ex) {
+            getLogger().debug("Failed to save resource {}.", target, ex);
+            return false;
+        }
+    }
+
     /**
      * Adds a new observer to this extension.
      * Will be kept as a WeakReference.

src/main/java/net/minestom/server/extensions/ExtensionManager.java

@@ -24,6 +24,8 @@ import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.net.URL;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.*;
 import java.util.stream.Collectors;
 import java.util.zip.ZipFile;
@@ -44,6 +46,7 @@ public class ExtensionManager {
 
     private final File extensionFolder = new File("extensions");
     private final File dependenciesFolder = new File(extensionFolder, ".libs");
+    private Path extensionDataRoot = extensionFolder.toPath();
     private boolean loaded;
 
     // Option
@@ -336,6 +339,7 @@ public class ExtensionManager {
                 DiscoveredExtension extension = GSON.fromJson(reader, DiscoveredExtension.class);
                 extension.files.add(new File(extensionClasses).toURI().toURL());
                 extension.files.add(new File(extensionResources).toURI().toURL());
+                extension.setDataDirectory(getExtensionDataRoot().resolve(extension.getName()));
 
                 // Verify integrity and ensure defaults
                 DiscoveredExtension.verifyIntegrity(extension);
@@ -365,6 +369,7 @@ public class ExtensionManager {
             DiscoveredExtension extension = GSON.fromJson(reader, DiscoveredExtension.class);
             extension.setOriginalJar(file);
             extension.files.add(file.toURI().toURL());
+            extension.setDataDirectory(getExtensionDataRoot().resolve(extension.getName()));
 
             // Verify integrity and ensure defaults
             DiscoveredExtension.verifyIntegrity(extension);
@@ -569,6 +574,15 @@ public class ExtensionManager {
         return extensionFolder;
     }
 
+    @NotNull
+    public Path getExtensionDataRoot() {
+        return extensionDataRoot;
+    }
+
+    public void setExtensionDataRoot(@NotNull Path dataRoot) {
+        this.extensionDataRoot = dataRoot;
+    }
+
     @NotNull
     public Collection<Extension> getExtensions() {
         return immutableExtensions.values();