Fix deprecated method in sun.misc.Unsafe has been called #2808

Author: Vincent Potucek

lib/src/main/java/com/diffplug/spotless/java/ModuleHelper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2025 DiffPlug
+ * Copyright 2016-2026 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,10 @@
  */
 package com.diffplug.spotless.java;
 
-import java.lang.invoke.MethodHandle;
+import static java.lang.Class.forName;
+import static java.lang.invoke.MethodHandles.privateLookupIn;
+
 import java.lang.invoke.MethodHandles;
-import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.util.ArrayList;
@@ -26,15 +27,12 @@
 import java.util.List;
 import java.util.Map;
 
-import javax.annotation.Nullable;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import com.diffplug.spotless.Jvm;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
-import sun.misc.Unsafe;
 
 final class ModuleHelper {
 	private static final Logger LOGGER = LoggerFactory.getLogger(ModuleHelper.class);
@@ -86,7 +84,7 @@ private static List<String> unavailableRequiredPackages() {
 			final String key = e.getKey();
 			final String value = e.getValue();
 			try {
-				final Class<?> clazz = Class.forName(key + "." + value);
+				final Class<?> clazz = forName(key + "." + value);
 				if (clazz.isEnum()) {
 					clazz.getMethod("values").invoke(null);
 				} else {
@@ -103,42 +101,34 @@ private static List<String> unavailableRequiredPackages() {
 
 	@SuppressWarnings("unchecked")
 	private static void openPackages(Collection<String> packagesToOpen) throws Throwable {
-		final Collection<?> modules = allModules();
-		if (modules == null) {
-			return;
-		}
-		final Field unsafeField = Unsafe.class.getDeclaredField("theUnsafe");
-		unsafeField.setAccessible(true);
-		final Unsafe unsafe = (Unsafe) unsafeField.get(null);
-		final Field implLookupField = MethodHandles.Lookup.class.getDeclaredField("IMPL_LOOKUP");
-		final MethodHandles.Lookup lookup = (MethodHandles.Lookup) unsafe.getObject(
-				unsafe.staticFieldBase(implLookupField),
-				unsafe.staticFieldOffset(implLookupField));
-		final MethodHandle modifiers = lookup.findSetter(Method.class, "modifiers", Integer.TYPE);
-		final Method exportMethod = Class.forName("java.lang.Module").getDeclaredMethod("implAddOpens", String.class);
-		modifiers.invokeExact(exportMethod, Modifier.PUBLIC);
-		for (Object module : modules) {
-			final Collection<String> packages = (Collection<String>) module.getClass().getMethod("getPackages").invoke(module);
-			for (String name : packages) {
+		// Use MethodHandles.privateLookupIn for accessing private fields in JDK 9+
+		// Get the IMPL_LOOKUP field using MethodHandles
+		MethodHandles.Lookup.class.getDeclaredField("IMPL_LOOKUP").setAccessible(true);
+		// Use MethodHandles to modify method accessibility
+		var exportMethod = forName("java.lang.Module").getDeclaredMethod("implAddOpens", String.class);
+		// Set method to public using MethodHandle
+		privateLookupIn(MethodHandles.Lookup.class, MethodHandles.lookup())
+				.findSetter(Method.class, "modifiers", int.class)
+				.invokeExact(exportMethod, Modifier.PUBLIC);
+		for (var module : allModules()) {
+			for (var name : (Collection<String>) module.getClass().getMethod("getPackages").invoke(module)) {
 				if (packagesToOpen.contains(name)) {
 					exportMethod.invoke(module, name);
 				}
 			}
 		}
 	}
 
-	@Nullable @SuppressFBWarnings("REC_CATCH_EXCEPTION") // workaround JDK11
+	@SuppressFBWarnings("REC_CATCH_EXCEPTION") // workaround JDK11
 	private static Collection<?> allModules() {
 		// calling ModuleLayer.boot().modules() by reflection
 		try {
-			final Object boot = Class.forName("java.lang.ModuleLayer").getMethod("boot").invoke(null);
-			if (boot == null) {
-				return null;
-			}
-			final Object modules = boot.getClass().getMethod("modules").invoke(boot);
-			return (Collection<?>) modules;
+			var boot = forName("java.lang.ModuleLayer").getMethod("boot").invoke(null);
+			return boot != null
+					? (Collection<?>) boot.getClass().getMethod("modules").invoke(boot)
+					: List.of();
 		} catch (Exception ignore) {
-			return null;
+			return List.of();
 		}
 	}
 }