Support for Java 22+ (#91)

Fix #80

Problem indeed introduced in this change. Despite code comment MagicAccessorImpl is not prevent bytecode verification anymore.

Also added separate build configuration for jdk 23

.github/workflows/build-and-test.yml

@@ -20,9 +20,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        jdk: [8, 11, 17, 19, 21]
-    env:
-      main_jdk: 8
+        jdk: [8, 11, 17, 19, 21, 23]
 
     steps:
       - uses: actions/checkout@v3

src/one/nio/serial/gen/DelegateGenerator.java

@@ -23,7 +23,6 @@
 import one.nio.serial.NotSerial;
 import one.nio.serial.Repository;
 import one.nio.serial.SerializeWith;
-import one.nio.util.Hex;
 import one.nio.util.JavaFeatures;
 import one.nio.util.JavaInternals;
 import one.nio.util.MethodHandlesReflection;
@@ -59,7 +58,7 @@ public class DelegateGenerator extends BytecodeGenerator {
     private static final AtomicInteger index = new AtomicInteger();
 
     // Allows to bypass security checks when accessing private members of other classes
-    private static final String MAGIC_CLASS = "sun/reflect/MagicAccessorImpl";
+    static final String MAGIC_CLASS = "sun/reflect/MagicAccessorImpl";
 
     // In JDK 9+ there is no more sun.reflect.MagicAccessorImpl class.
     // Instead there is package private jdk.internal.reflect.MagicAccessorImpl, which is not visible
@@ -76,18 +75,17 @@ public class DelegateGenerator extends BytecodeGenerator {
                 }
 
                 // public jdk.internal.reflect.MagicAccessorBridge extends jdk.internal.reflect.MagicAccessorImpl
-                defineBootstrapClass(m, "cafebabe00000033000a0a000300070700080700090100063c696e69743e010003282956010004436f64650c000400050100286a646b2f696e7465726e616c2f7265666c6563742f4d616769634163636573736f724272696467650100266a646b2f696e7465726e616c2f7265666c6563742f4d616769634163636573736f72496d706c042100020003000000000001000100040005000100060000001100010001000000052ab70001b1000000000000");
+                defineBootstrapClass(m, MagicAccessor.magicAccessorBridge());
                 // public sun.reflect.MagicAccessorImpl extends jdk.internal.reflect.MagicAccessorBridge
-                defineBootstrapClass(m, "cafebabe00000033000a0a000300070700080700090100063c696e69743e010003282956010004436f64650c0004000501001d73756e2f7265666c6563742f4d616769634163636573736f72496d706c0100286a646b2f696e7465726e616c2f7265666c6563742f4d616769634163636573736f72427269646765042100020003000000000001000100040005000100060000001100010001000000052ab70001b1000000000000");
+                defineBootstrapClass(m, MagicAccessor.sunMagicAccessor());
             } catch (Exception e) {
                 throw new IllegalStateException(e);
             }
         }
     }
 
     // Defines a new class by the bootstrap ClassLoader
-    private static void defineBootstrapClass(Method m, String classData) throws ReflectiveOperationException {
-        byte[] code = Hex.parseBytes(classData);
+    private static void defineBootstrapClass(Method m, byte[] code) throws ReflectiveOperationException {
         m.invoke(null, null, null, code, 0, code.length, null, null);
     }
 

src/one/nio/serial/gen/MagicAccessor.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2025 VK
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package one.nio.serial.gen;
+
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+
+public class MagicAccessor {
+
+    public static byte[] magicAccessorBridge() {
+        String superClass;
+        if (useSerializationConstructorAccessor()) {
+            superClass = "jdk/internal/reflect/SerializationConstructorAccessorImpl";
+        } else {
+            superClass = "jdk/internal/reflect/MagicAccessorImpl";
+        }
+
+        return generateClass("jdk/internal/reflect/MagicAccessorBridge", superClass);
+    }
+
+    public static byte[] sunMagicAccessor() {
+        return generateClass(DelegateGenerator.MAGIC_CLASS, "jdk/internal/reflect/MagicAccessorBridge");
+    }
+
+    private static boolean useSerializationConstructorAccessor() {
+        String javaVersion = System.getProperty("java.version");
+        int majorVersion = Integer.parseInt(javaVersion.substring(0, javaVersion.indexOf(".")));
+        return majorVersion >= 22;
+    }
+
+    private static byte[] generateClass(String name, String superClass) {
+        ClassWriter cv = new ClassWriter(ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);
+        cv.visit(Opcodes.V1_6, Opcodes.ACC_PUBLIC, name, null, superClass, new String[]{});
+        MethodVisitor mv = cv.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "()V", null, null);
+        mv.visitCode();
+
+        mv.visitVarInsn(Opcodes.ALOAD, 0);
+        mv.visitMethodInsn(Opcodes.INVOKESPECIAL, superClass, "<init>", "()V", false);
+        mv.visitInsn(Opcodes.RETURN);
+        mv.visitEnd();
+        cv.visitEnd();
+        return cv.toByteArray();
+    }
+
+}