/* * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.lang; /** * A resource that must be closed when it is no longer needed. * * @author Josh Bloch * @since 1.7 */ public interface AutoCloseable { /** * Closes this resource, relinquishing any underlying resources. * This method is invoked automatically on objects managed by the * {@code try}-with-resources statement. * *

While this interface method is declared to throw {@code * Exception}, implementers are strongly encouraged to * declare concrete implementations of the {@code close} method to * throw more specific exceptions, or to throw no exception at all * if the close operation cannot fail. * *

Implementers of this interface are also strongly advised * to not have the {@code close} method throw {@link * InterruptedException}. * * This exception interacts with a thread's interrupted status, * and runtime misbehavior is likely to occur if an {@code * InterruptedException} is {@linkplain Throwable#addSuppressed * suppressed}. * * More generally, if it would cause problems for an * exception to be suppressed, the {@code AutoCloseable.close} * method should not throw it. * *

Note that unlike the {@link java.io.Closeable#close close} * method of {@link java.io.Closeable}, this {@code close} method * is not required to be idempotent. In other words, * calling this {@code close} method more than once may have some * visible side effect, unlike {@code Closeable.close} which is * required to have no effect if called more than once. * * However, implementers of this interface are strongly encouraged * to make their {@code close} methods idempotent. * * @throws Exception if this resource cannot be closed */ void close() throws Exception; }