| /* |
| * Copyright (c) 2016, 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.serviceprovider; |
| |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Modifier; |
| |
| /** |
| * Reflection based access to API introduced by JDK 9. This allows the API to be used in code that |
| * must be compiled on a JDK prior to 9. |
| */ |
| public final class JDK9Method { |
| |
| private static int getJavaSpecificationVersion() { |
| String value = System.getProperty("java.specification.version"); |
| if (value.startsWith("1.")) { |
| value = value.substring(2); |
| } |
| return Integer.parseInt(value); |
| } |
| |
| /** |
| * The integer value corresponding to the value of the {@code java.specification.version} system |
| * property after any leading {@code "1."} has been stripped. |
| */ |
| public static final int JAVA_SPECIFICATION_VERSION = getJavaSpecificationVersion(); |
| |
| public JDK9Method(Class<?> declaringClass, String name, Class<?>... parameterTypes) { |
| try { |
| this.method = declaringClass.getMethod(name, parameterTypes); |
| } catch (Exception e) { |
| throw new InternalError(e); |
| } |
| } |
| |
| /** |
| * Determines if the Java runtime is version 8 or earlier. |
| */ |
| public static final boolean Java8OrEarlier = JAVA_SPECIFICATION_VERSION <= 8; |
| |
| public final Method method; |
| |
| public Class<?> getReturnType() { |
| return method.getReturnType(); |
| } |
| |
| /** |
| * {@code Class.getModule()}. |
| */ |
| public static final JDK9Method getModule; |
| |
| /** |
| * {@code java.lang.Module.getPackages()}. |
| */ |
| public static final JDK9Method getPackages; |
| |
| /** |
| * {@code java.lang.Module.getResourceAsStream(String)}. |
| */ |
| public static final JDK9Method getResourceAsStream; |
| |
| /** |
| * {@code java.lang.Module.addOpens(String, Module)}. |
| */ |
| public static final JDK9Method addOpens; |
| |
| /** |
| * {@code java.lang.Module.isOpen(String, Module)}. |
| */ |
| public static final JDK9Method isOpenTo; |
| |
| /** |
| * 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) { |
| getModule = new JDK9Method(Class.class, "getModule"); |
| Class<?> moduleClass = getModule.getReturnType(); |
| getPackages = new JDK9Method(moduleClass, "getPackages"); |
| addOpens = new JDK9Method(moduleClass, "addOpens", String.class, moduleClass); |
| getResourceAsStream = new JDK9Method(moduleClass, "getResourceAsStream", String.class); |
| isOpenTo = new JDK9Method(moduleClass, "isOpen", String.class, moduleClass); |
| } else { |
| JDK9Method unavailable = new JDK9Method(); |
| getModule = unavailable; |
| getPackages = unavailable; |
| addOpens = unavailable; |
| getResourceAsStream = unavailable; |
| isOpenTo = unavailable; |
| } |
| } |
| |
| private JDK9Method() { |
| method = null; |
| } |
| } |