1 /* 2 * Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 /* 27 * This file is available under and governed by the GNU General Public 28 * License version 2 only, as published by the Free Software Foundation. 29 * However, the following notice accompanied the original version of this 30 * file, and Oracle licenses the original version of this file under the BSD 31 * license: 32 */ 33 /* 34 Copyright 2009-2013 Attila Szegedi 35 36 Redistribution and use in source and binary forms, with or without 37 modification, are permitted provided that the following conditions are 38 met: 39 * Redistributions of source code must retain the above copyright 40 notice, this list of conditions and the following disclaimer. 41 * Redistributions in binary form must reproduce the above copyright 42 notice, this list of conditions and the following disclaimer in the 43 documentation and/or other materials provided with the distribution. 44 * Neither the name of the copyright holder nor the names of 45 contributors may be used to endorse or promote products derived from 46 this software without specific prior written permission. 47 48 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 49 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 50 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 51 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER 52 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 53 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 54 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 55 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 56 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 57 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 58 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 59 */ 60 61 package jdk.dynalink.linker.support; 62 63 import java.util.LinkedList; 64 import java.util.List; 65 import java.util.Objects; 66 import jdk.dynalink.linker.GuardedInvocation; 67 import jdk.dynalink.linker.GuardingDynamicLinker; 68 import jdk.dynalink.linker.LinkRequest; 69 import jdk.dynalink.linker.LinkerServices; 70 71 /** 72 * A {@link GuardingDynamicLinker} that delegates sequentially to a list of 73 * other guarding dynamic linkers in its 74 * {@link #getGuardedInvocation(LinkRequest, LinkerServices)}. 75 */ 76 public class CompositeGuardingDynamicLinker implements GuardingDynamicLinker { 77 78 private final GuardingDynamicLinker[] linkers; 79 80 /** 81 * Creates a new composite linker. 82 * 83 * @param linkers a list of component linkers. 84 * @throws NullPointerException if {@code linkers} or any of its elements 85 * are null. 86 */ CompositeGuardingDynamicLinker(final Iterable<? extends GuardingDynamicLinker> linkers)87 public CompositeGuardingDynamicLinker(final Iterable<? extends GuardingDynamicLinker> linkers) { 88 final List<GuardingDynamicLinker> l = new LinkedList<>(); 89 for(final GuardingDynamicLinker linker: linkers) { 90 l.add(Objects.requireNonNull(linker)); 91 } 92 this.linkers = l.toArray(new GuardingDynamicLinker[0]); 93 } 94 95 /** 96 * Delegates the call to its component linkers. The first non-null value 97 * returned from a component linker is returned. If no component linker 98 * returns a non-null invocation, null is returned. 99 * @param linkRequest the object describing the request for linking a 100 * particular invocation 101 * @param linkerServices linker services 102 * @return the first non-null return value from a component linker, or null 103 * if none of the components returned a non-null. 104 */ 105 @Override getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices)106 public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices) 107 throws Exception { 108 for(final GuardingDynamicLinker linker: linkers) { 109 final GuardedInvocation invocation = linker.getGuardedInvocation(linkRequest, linkerServices); 110 if(invocation != null) { 111 return invocation; 112 } 113 } 114 return null; 115 } 116 } 117