1 /*
   2  * Copyright (c) 2015, 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    Licensed under both the Apache License, Version 2.0 (the "Apache License")
  37    and the BSD License (the "BSD License"), with licensee being free to
  38    choose either of the two at their discretion.
  39 
  40    You may not use this file except in compliance with either the Apache
  41    License or the BSD License.
  42 
  43    If you choose to use this file in compliance with the Apache License, the
  44    following notice applies to you:
  45 
  46        You may obtain a copy of the Apache License at
  47 
  48            http://www.apache.org/licenses/LICENSE-2.0
  49 
  50        Unless required by applicable law or agreed to in writing, software
  51        distributed under the License is distributed on an "AS IS" BASIS,
  52        WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
  53        implied. See the License for the specific language governing
  54        permissions and limitations under the License.
  55 
  56    If you choose to use this file in compliance with the BSD License, the
  57    following notice applies to you:
  58 
  59        Redistribution and use in source and binary forms, with or without
  60        modification, are permitted provided that the following conditions are
  61        met:
  62        * Redistributions of source code must retain the above copyright
  63          notice, this list of conditions and the following disclaimer.
  64        * Redistributions in binary form must reproduce the above copyright
  65          notice, this list of conditions and the following disclaimer in the
  66          documentation and/or other materials provided with the distribution.
  67        * Neither the name of the copyright holder nor the names of
  68          contributors may be used to endorse or promote products derived from
  69          this software without specific prior written permission.
  70 
  71        THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  72        IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  73        TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  74        PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
  75        BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  76        CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  77        SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  78        BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  79        WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  80        OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  81        ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  82 */
  83 
  84 /**
  85  * <p>
  86  * Contains interfaces and classes needed by language runtimes to implement
  87  * their own language-specific object models and type conversions. The main
  88  * entry point is the
  89  * {@link jdk.dynalink.linker.GuardingDynamicLinker} interface. It needs to be
  90  * implemented in order to provide linking for the runtime's own object model.
  91  * A language runtime can have more than one guarding dynamic linker
  92  * implementation. When a runtime is configuring Dynalink for itself, it will
  93  * normally set these guarding linkers as the prioritized linkers in its
  94  * {@link jdk.dynalink.DynamicLinkerFactory} (and maybe some of them as fallback
  95  * linkers, for e.g. handling "method not found" and similar errors in a
  96  * language-specific manner if no other linker managed to handle the operation.)
  97  * </p><p>
  98  * A language runtime that wishes to make at least some of its linkers available
  99  * to other language runtimes for interoperability will need to declare the
 100  * class names of those linkers in
 101  * {@code /META-INF/services/jdk.dynalink.linker.GuardingDynamicLinker} file in
 102  * its distribution (typically, JAR file).
 103  * </p><p>
 104  * Most language runtimes will be able to implement their own linking logic by
 105  * implementing {@link jdk.dynalink.linker.TypeBasedGuardingDynamicLinker}
 106  * instead of {@link jdk.dynalink.linker.GuardingDynamicLinker}; it allows for
 107  * faster type-based linking dispatch.
 108  * </p><p>
 109  * Language runtimes that allow type conversions other than those provided by
 110  * Java will need to have their guarding dynamic linker (or linkers) also
 111  * implement the {@link jdk.dynalink.linker.GuardingTypeConverterFactory}
 112  * interface to provide the logic for these conversions.
 113  * </p>
 114  * @since 9
 115  */
 116 package jdk.dynalink.linker;