Add JavaLangAccess utility and basic test

Introduce `JavaLangAccessUtils` to centralize access to JavaLangAccess internals across JDK versions by resolving `sun.misc.JavaLangAccess` first and falling back to `jdk.internal.access.JavaLangAccess`. Add `JavaLangAccessUtilsTest` to verify the class-name constants and resolved class are available.

Author: mercyblitz

microsphere-java-core/src/main/java/io/microsphere/internal/access/JavaLangAccessUtils.java

@@ -0,0 +1,61 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 io.microsphere.internal.access;
+
+import io.microsphere.annotation.Nonnull;
+import io.microsphere.util.Utils;
+
+import static io.microsphere.util.ClassLoaderUtils.loadClass;
+import static io.microsphere.util.ObjectUtils.defaultIfNull;
+import static java.lang.ClassLoader.getSystemClassLoader;
+
+/**
+ * The utility class for {@link sun.misc.JavaLangAccess} or {@link jdk.internal.access.JavaLangAccess}
+ *
+ * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
+ * @see sun.misc.JavaLangAccess
+ * @see jdk.internal.access.JavaLangAccess
+ * @since 1.0.0
+ */
+public abstract class JavaLangAccessUtils implements Utils {
+
+    /**
+     * The class name of {@link sun.misc.JavaLangAccess}
+     */
+    public static final String LEGACY_JAVA_LANG_ACCESS_CLASS_NAME = "sun.misc.JavaLangAccess";
+
+    /**
+     * The class name of {@link jdk.internal.access.JavaLangAccess}
+     */
+    public static final String JAVA_LANG_ACCESS_CLASS_NAME = "jdk.internal.access.JavaLangAccess";
+
+    /**
+     * The {@link Class} of {@link sun.misc.JavaLangAccess} or {@link jdk.internal.access.JavaLangAccess}
+     */
+    @Nonnull
+    public static final Class<?> JAVA_LANG_ACCESS_CLASS = loadJavaLangAccessClass();
+
+    private static Class<?> loadJavaLangAccessClass() {
+        ClassLoader classLoader = getSystemClassLoader();
+        Class<?> javaLangAccessClass = loadClass(classLoader, LEGACY_JAVA_LANG_ACCESS_CLASS_NAME);
+        return defaultIfNull(javaLangAccessClass, () -> loadClass(classLoader, JAVA_LANG_ACCESS_CLASS_NAME));
+    }
+
+    private JavaLangAccessUtils() {
+    }
+}

microsphere-java-core/src/test/java/io/microsphere/internal/access/JavaLangAccessUtilsTest.java

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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 io.microsphere.internal.access;
+
+
+import org.junit.jupiter.api.Test;
+
+import static io.microsphere.internal.access.JavaLangAccessUtils.JAVA_LANG_ACCESS_CLASS;
+import static io.microsphere.internal.access.JavaLangAccessUtils.JAVA_LANG_ACCESS_CLASS_NAME;
+import static io.microsphere.internal.access.JavaLangAccessUtils.LEGACY_JAVA_LANG_ACCESS_CLASS_NAME;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+/**
+ * {@link JavaLangAccessUtils} Test
+ *
+ * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
+ * @see JavaLangAccessUtils
+ * @since 1.0.0
+ */
+class JavaLangAccessUtilsTest {
+
+    @Test
+    void testConstants() {
+        assertNotNull(LEGACY_JAVA_LANG_ACCESS_CLASS_NAME);
+        assertNotNull(JAVA_LANG_ACCESS_CLASS_NAME);
+        assertNotNull(JAVA_LANG_ACCESS_CLASS);
+    }
+}