| /* |
| * Copyright (c) 2010, 2013, 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 |
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| * 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 |
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| * questions. |
| */ |
| |
| /* |
| * This file is available under and governed by the GNU General Public |
| * License version 2 only, as published by the Free Software Foundation. |
| * However, the following notice accompanied the original version of this |
| * file, and Oracle licenses the original version of this file under the BSD |
| * license: |
| */ |
| /* |
| Copyright 2009-2013 Attila Szegedi |
| |
| Licensed under both the Apache License, Version 2.0 (the "Apache License") |
| and the BSD License (the "BSD License"), with licensee being free to |
| choose either of the two at their discretion. |
| |
| You may not use this file except in compliance with either the Apache |
| License or the BSD License. |
| |
| If you choose to use this file in compliance with the Apache License, the |
| following notice applies to you: |
| |
| You may obtain a copy of the Apache License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
| implied. See the License for the specific language governing |
| permissions and limitations under the License. |
| |
| If you choose to use this file in compliance with the BSD License, the |
| following notice applies to you: |
| |
| 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 the copyright holder nor the names of |
| 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 COPYRIGHT HOLDER |
| 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. |
| */ |
| |
| package jdk.dynalink.linker; |
| |
| import java.lang.invoke.MethodHandles; |
| import java.util.function.Supplier; |
| import jdk.dynalink.SecureLookupSupplier; |
| import jdk.dynalink.beans.BeansLinker; |
| import jdk.dynalink.linker.support.TypeUtilities; |
| |
| /** |
| * Optional interface that can be implemented by {@link GuardingDynamicLinker} |
| * implementations to provide language-specific type conversion capabilities. |
| * Note that if you implement this interface, you will very likely want to |
| * implement {@link ConversionComparator} interface too, as your additional |
| * language-specific conversions, in absence of a strategy for prioritizing |
| * these conversions, will cause more ambiguity for {@link BeansLinker} in |
| * selecting the correct overload when trying to link to an overloaded Java |
| * method. |
| */ |
| public interface GuardingTypeConverterFactory { |
| /** |
| * Returns a guarded type conversion that receives a value of the specified |
| * source type and returns a value converted to the specified target type. |
| * Value types can be either primitives or reference types, including |
| * interfaces, so you can even provide converters for converting your |
| * language's objects to Java interfaces and classes by generating adapters |
| * for them. |
| * <p> |
| * The type of the invocation is <tt>(sourceType)→targetType</tt>, while the |
| * type of the guard is <tt>(sourceType)→boolean</tt>. You are allowed to |
| * return unconditional invocations (with no guard) if the source type is |
| * specific to your runtime and your runtime only. |
| * <p>Note that this method will never be invoked for |
| * {@link TypeUtilities#isMethodInvocationConvertible(Class, Class) method |
| * invocation conversions} as those can be automatically applied by |
| * {@link java.lang.invoke.MethodHandle#asType(MethodType)}. |
| * An implementation can assume it is never requested to produce a |
| * converter for those conversions. If a language runtime needs to customize |
| * method invocation conversions, it should |
| * {@link jdk.dynalink.DynamicLinkerFactory#setAutoConversionStrategy(MethodTypeConversionStrategy) |
| * set an autoconversion strategy in the dynamic linker factory} instead. |
| * <p>Dynalink is at liberty to either cache some of the returned converters |
| * or to repeatedly request the converter factory to create the same |
| * conversion. |
| * |
| * @param sourceType source type |
| * @param targetType the target type. |
| * @param lookupSupplier a supplier for retrieving the lookup of the class |
| * on whose behalf a type converter is requested. When a converter is |
| * requested as part of linking an {@code invokedynamic} instruction the |
| * supplier will return the lookup passed to the bootstrap method, otherwise |
| * if the method is invoked from within a |
| * {@link LinkerServices#getWithLookup(Supplier, jdk.dynalink.SecureLookupSupplier)} |
| * it will delegate to the secure lookup supplier. In any other case, |
| * it will return the public lookup. A typical case where the lookup might |
| * be needed is when the converter creates a Java adapter class on the fly |
| * (e.g. to convert some object from the dynamic language into a Java |
| * interface for interoperability). Invoking the {@link Supplier#get()} |
| * method on the passed supplier will be subject to the same security checks |
| * as {@link SecureLookupSupplier#getLookup()}. An implementation should avoid |
| * retrieving the lookup if it is not needed so as to avoid the expense of |
| * {@code AccessController.doPrivileged} call. |
| * @return a guarded invocation that can take an object (if it passes guard) |
| * and return another object that is its representation coerced into the |
| * target type. In case the factory is certain it is unable to handle a |
| * conversion, it can return null. In case the factory is certain that it |
| * can always handle the conversion, it can return an unconditional |
| * invocation (one whose guard is null). |
| * @throws Exception if there was an error during creation of the converter |
| * @see LinkerServices#getWithLookup(Supplier, SecureLookupSupplier) |
| */ |
| public GuardedInvocation convertToType(Class<?> sourceType, Class<?> targetType, Supplier<MethodHandles.Lookup> lookupSupplier) throws Exception; |
| } |