/* * Copyright (c) 2013, 2021, Oracle and/or its affiliates. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Oracle or the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ import java.util.function.Consumer; public class LambdaScopeTest { public int x = 0; class FirstLevel { public int x = 1; void methodInFirstLevel(int x) { int z = 2; Consumer myConsumer = (y) -> { // The following statement causes the compiler to generate // the error "Local variable z defined in an enclosing scope // must be final or effectively final" // // z = 99; System.out.println("x = " + x); System.out.println("y = " + y); System.out.println("z = " + z); System.out.println("this.x = " + this.x); System.out.println("LambdaScopeTest.this.x = " + LambdaScopeTest.this.x); }; myConsumer.accept(x); } } public static void main(String... args) { LambdaScopeTest st = new LambdaScopeTest(); LambdaScopeTest.FirstLevel fl = st.new FirstLevel(); fl.methodInFirstLevel(23); } }