1 /* 2 * Copyright (c) 2017, 2018, 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 package jdk.internal.module; 27 28 import java.lang.module.ModuleDescriptor; 29 import java.lang.module.ModuleFinder; 30 import java.lang.module.ModuleReference; 31 import java.util.Set; 32 import java.util.stream.Collectors; 33 34 /** 35 * Defines methods to compute the default set of root modules for the unnamed 36 * module. 37 */ 38 39 public final class DefaultRoots { 40 private DefaultRoots() { } 41 42 /** 43 * Returns the default set of root modules for the unnamed module from the 44 * modules observable with the intersection of two module finders. 45 * 46 * The first module finder should be the module finder that finds modules on 47 * the upgrade module path or among the system modules. The second module 48 * finder should be the module finder that finds all modules on the module 49 * path, or a subset of when using --limit-modules. 50 */ 51 static Set<String> compute(ModuleFinder finder1, ModuleFinder finder2) { 52 return finder1.findAll().stream() 53 .filter(mref -> !ModuleResolution.doNotResolveByDefault(mref)) 54 .map(ModuleReference::descriptor) 55 .filter(descriptor -> finder2.find(descriptor.name()).isPresent() 56 && exportsAPI(descriptor)) 57 .map(ModuleDescriptor::name) 58 .collect(Collectors.toSet()); 59 } 60 61 /** 62 * Returns the default set of root modules for the unnamed module from the 63 * modules observable with the given module finder. 64 * 65 * This method is used by the jlink system modules plugin. 66 */ 67 public static Set<String> compute(ModuleFinder finder) { 68 return compute(finder, finder); 69 } 70 71 /** 72 * Returns true if the given module exports a package to all modules 73 */ 74 private static boolean exportsAPI(ModuleDescriptor descriptor) { 75 return descriptor.exports() 76 .stream() 77 .filter(e -> !e.isQualified()) 78 .findAny() 79 .isPresent(); 80 } 81 }