| /* |
| * Copyright (c) 2016, 2017, 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. |
| * |
| * 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 org.graalvm.compiler.core.common.util; |
| |
| import static org.graalvm.compiler.core.common.util.Util.JAVA_SPECIFICATION_VERSION; |
| |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Modifier; |
| |
| /** |
| * Reflection based access to the Module API introduced by JDK 9. This allows the API to be used in |
| * code that must be compiled on a JDK prior to 9. Use of this class must be guarded by a test for |
| * JDK 9 or later. For example: |
| * |
| * <pre> |
| * if (Util.JAVA_SPECIFICATION_VERSION >= 9) { |
| * // Use of ModuleAPI |
| * } |
| * </pre> |
| */ |
| public final class ModuleAPI { |
| |
| private ModuleAPI(Method method) { |
| this.method = method; |
| } |
| |
| private final Method method; |
| |
| /** |
| * {@code Class.getModule()}. |
| */ |
| public static final ModuleAPI getModule; |
| |
| /** |
| * {@code java.lang.Module.getResourceAsStream(String)}. |
| */ |
| public static final ModuleAPI getResourceAsStream; |
| |
| /** |
| * {@code java.lang.Module.canRead(Module)}. |
| */ |
| public static final ModuleAPI canRead; |
| |
| /** |
| * {@code java.lang.Module.isExported(String)}. |
| */ |
| public static final ModuleAPI isExported; |
| |
| /** |
| * {@code java.lang.Module.isExported(String, Module)}. |
| */ |
| public static final ModuleAPI isExportedTo; |
| |
| /** |
| * Invokes the static Module API method represented by this object. |
| */ |
| @SuppressWarnings("unchecked") |
| public <T> T invokeStatic(Object... args) { |
| checkAvailability(); |
| assert Modifier.isStatic(method.getModifiers()); |
| try { |
| return (T) method.invoke(null, args); |
| } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) { |
| throw new InternalError(e); |
| } |
| } |
| |
| /** |
| * Invokes the non-static Module API method represented by this object. |
| */ |
| @SuppressWarnings("unchecked") |
| public <T> T invoke(Object receiver, Object... args) { |
| checkAvailability(); |
| assert !Modifier.isStatic(method.getModifiers()); |
| try { |
| return (T) method.invoke(receiver, args); |
| } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) { |
| throw new InternalError(e); |
| } |
| } |
| |
| private void checkAvailability() throws InternalError { |
| if (method == null) { |
| throw new InternalError("Cannot use Module API on JDK " + JAVA_SPECIFICATION_VERSION); |
| } |
| } |
| |
| static { |
| if (JAVA_SPECIFICATION_VERSION >= 9) { |
| try { |
| getModule = new ModuleAPI(Class.class.getMethod("getModule")); |
| Class<?> moduleClass = getModule.method.getReturnType(); |
| getResourceAsStream = new ModuleAPI(moduleClass.getMethod("getResourceAsStream", String.class)); |
| canRead = new ModuleAPI(moduleClass.getMethod("canRead", moduleClass)); |
| isExported = new ModuleAPI(moduleClass.getMethod("isExported", String.class)); |
| isExportedTo = new ModuleAPI(moduleClass.getMethod("isExported", String.class, moduleClass)); |
| } catch (NoSuchMethodException | SecurityException e) { |
| throw new InternalError(e); |
| } |
| } else { |
| ModuleAPI unavailable = new ModuleAPI(null); |
| getModule = unavailable; |
| getResourceAsStream = unavailable; |
| canRead = unavailable; |
| isExported = unavailable; |
| isExportedTo = unavailable; |
| } |
| } |
| } |