1 /* 2 * Copyright (c) 2017, 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 package jdk.internal.module; 26 27 import java.lang.module.ModuleDescriptor; 28 import java.lang.module.ModuleFinder; 29 import java.lang.module.ModuleReference; 30 import java.util.HashSet; 31 import java.util.Set; 32 33 /** 34 * Defines methods to compute the default set of root modules for the unnamed 35 * module. 36 */ 37 38 public final class DefaultRoots { 39 private static final String JAVA_SE = "java.se"; 40 41 private DefaultRoots() { } 42 43 /** 44 * Returns the default set of root modules for the unnamed module computed from 45 * the system modules observable with the given module finder. 46 */ 47 static Set<String> compute(ModuleFinder systemModuleFinder, ModuleFinder finder) { 48 Set<String> roots = new HashSet<>(); 49 50 boolean hasJava = false; 51 if (systemModuleFinder.find(JAVA_SE).isPresent()) { 52 if (finder == systemModuleFinder || finder.find(JAVA_SE).isPresent()) { 53 // java.se is a system module 54 hasJava = true; 55 roots.add(JAVA_SE); 56 } 57 } 58 59 for (ModuleReference mref : systemModuleFinder.findAll()) { 60 String mn = mref.descriptor().name(); 61 if (hasJava && mn.startsWith("java.")) { 62 // not a root 63 continue; 64 } 65 66 if (ModuleResolution.doNotResolveByDefault(mref)) { 67 // not a root 68 continue; 69 } 70 71 if ((finder == systemModuleFinder || finder.find(mn).isPresent())) { 72 // add as root if exports at least one package to all modules 73 ModuleDescriptor descriptor = mref.descriptor(); 74 for (ModuleDescriptor.Exports e : descriptor.exports()) { 75 if (!e.isQualified()) { 76 roots.add(mn); 77 break; 78 } 79 } 80 } 81 } 82 83 return roots; 84 } 85 86 /** 87 * Returns the default set of root modules for the unnamed module from the 88 * modules observable with the given module finder. 89 */ 90 public static Set<String> compute(ModuleFinder finder) { 91 return compute(finder, finder); 92 } 93 }