/** * Copyright (c) 2024 Araf Karsh Hamid *

* Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: *

* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. *

* This program and the accompanying materials are dual-licensed under * either the terms of the Eclipse Public License v1.0 as published by * the Eclipse Foundation *

* or (per the licensee's choosing) *

* under the terms of the Apache 2 License version 2.0 * as published by the Apache Software Foundation. */ package java18; import java.lang.invoke.MethodHandle; import java.lang.invoke.MethodHandles; import java.lang.invoke.MethodType; import java.lang.reflect.Method; import static java.lang.System.out; /** * JavaExamples / ReflectionExample * * JEP 416: Reimplement Core Reflection with Method Handles * * Java 18 reimplements parts of the core reflection using MethodHandles to improve performance * and reduce the maintenance burden. * * @author: Araf Karsh Hamid * @version: 0.1 * @date: 2024-09-29T21:29 */ public class ReflectionExample { public static void main(String[] args) throws Throwable { // Java 18 out.println("JAVA 18 >>>>>--------------------------------------------------------"); oldModel(); newModel(); } /** * Old API Model * @throws Throwable */ public static void oldModel() throws Throwable { out.println("Old Reflection Model... "); // Obtain the Class object for String Class stringClass = String.class; // Get the method reference to `toUpperCase` with no parameters Method toUpperCaseMethod = stringClass.getMethod("toUpperCase"); // Invoke the method on an instance of String String result = (String) toUpperCaseMethod.invoke("hello"); System.out.println(result); // Outputs: HELLO } /** * New Much Simpler high performance API * @throws Throwable */ public static void newModel() throws Throwable { out.println("New Reflection Model... "); MethodHandles.Lookup lookup = MethodHandles.lookup(); MethodHandle handle = lookup.findVirtual(String.class, "toUpperCase", MethodType.methodType(String.class)); String result = (String) handle.invoke("hello"); System.out.println(result); } }