1/* 2 * Copyright (c) 2016, 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 */ 25package java.lang; 26 27import java.lang.module.Configuration; 28import java.lang.module.ModuleReference; 29import java.net.URI; 30 31/** 32 * A NamedPackage represents a package by name in a specific module. 33 * 34 * A class loader will automatically create NamedPackage for each 35 * package when a class is defined. Package object is lazily 36 * defined until Class::getPackage, Package::getPackage(s), or 37 * ClassLoader::getDefinedPackage(s) method is called. 38 * 39 * NamedPackage allows ClassLoader to keep track of the runtime 40 * packages with minimal footprint and avoid constructing Package 41 * object. 42 */ 43class NamedPackage { 44 private final String name; 45 private final Module module; 46 47 NamedPackage(String pn, Module module) { 48 if (pn.isEmpty() && module.isNamed()) { 49 throw new InternalError("unnamed package in " + module); 50 } 51 this.name = pn.intern(); 52 this.module = module; 53 } 54 55 /** 56 * Returns the name of this package. 57 */ 58 String packageName() { 59 return name; 60 } 61 62 /** 63 * Returns the module of this named package. 64 */ 65 Module module() { 66 return module; 67 } 68 69 /** 70 * Returns the location of the module if this named package is in 71 * a named module; otherwise, returns null. 72 */ 73 URI location() { 74 if (module.isNamed() && module.getLayer() != null) { 75 Configuration cf = module.getLayer().configuration(); 76 ModuleReference mref 77 = cf.findModule(module.getName()).get().reference(); 78 return mref.location().orElse(null); 79 } 80 return null; 81 } 82 83 /** 84 * Creates a Package object of the given name and module. 85 */ 86 static Package toPackage(String name, Module module) { 87 return new Package(name, module); 88 } 89} 90