1 /*
2 * Copyright (c) 2015, 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.nashorn.tools.jjs;
27
28 import java.io.IOException;
29 import java.io.File;
30 import java.util.ArrayList;
31 import java.util.Collections;
32 import java.util.EnumSet;
33 import java.util.HashSet;
34 import java.util.LinkedHashMap;
35 import java.util.List;
36 import java.util.Map;
37 import java.util.Set;
38 import java.util.stream.Collectors;
39 import java.util.stream.Stream;
40 import javax.tools.JavaCompiler;
41 import javax.tools.JavaFileManager.Location;
42 import javax.tools.JavaFileObject;
43 import javax.tools.StandardJavaFileManager;
44 import javax.tools.StandardLocation;
45 import javax.tools.ToolProvider;
46
47 /**
48 * A helper class to compute properties of a Java package object. Properties of
49 * package object are (simple) top level class names in that java package and
50 * immediate subpackages of that package.
51 */
52 final class PackagesHelper {
53 // JavaCompiler may be null on certain platforms (eg. JRE)
54 private static final JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
55
56 /**
57 * Is Java package properties helper available?
58 *
59 * @return true if package properties support is available
60 */
61 static boolean isAvailable() {
62 return compiler != null;
63 }
64
65 private final StandardJavaFileManager fm;
66 private final Set<JavaFileObject.Kind> fileKinds;
67
68 /**
69 * Construct a new PackagesHelper.
70 *
71 * @param classPath Class path to compute properties of java package objects
72 */
73 PackagesHelper(final String classPath) throws IOException {
74 assert isAvailable() : "no java compiler found!";
75
76 fm = compiler.getStandardFileManager(null, null, null);
77 fileKinds = EnumSet.of(JavaFileObject.Kind.CLASS);
78
79 if (classPath != null && !classPath.isEmpty()) {
80 fm.setLocation(StandardLocation.CLASS_PATH, getFiles(classPath));
81 } else {
82 // no classpath set. Make sure that it is empty and not any default like "."
83 fm.setLocation(StandardLocation.CLASS_PATH, Collections.<File>emptyList());
84 }
85 }
86
87 // LRU cache for java package properties lists
88 private final LinkedHashMap<String, List<String>> propsCache =
89 new LinkedHashMap<>(32, 0.75f, true) {
90 private static final int CACHE_SIZE = 100;
91 private static final long serialVersionUID = 1;
92
93 @Override
94 protected boolean removeEldestEntry(final Map.Entry<String, List<String>> eldest) {
95 return size() > CACHE_SIZE;
96 }
97 };
98
99 /**
100 * Return the list of properties of the given Java package or package prefix
101 *
102 * @param pkg Java package name or package prefix name
103 * @return the list of properties of the given Java package or package prefix
104 */
105 List<String> getPackageProperties(final String pkg) {
106 // check the cache first
107 if (propsCache.containsKey(pkg)) {
108 return propsCache.get(pkg);
109 }
110
111 try {
112 // make sorted list of properties
113 final List<String> props = new ArrayList<>(listPackage(pkg));
114 Collections.sort(props);
115 propsCache.put(pkg, props);
116 return props;
117 } catch (final IOException exp) {
118 if (Main.DEBUG) {
119 exp.printStackTrace();
120 }
121 return Collections.<String>emptyList();
122 }
123 }
124
125 public void close() throws IOException {
126 fm.close();
127 }
128
129 private Set<String> listPackage(final String pkg) throws IOException {
130 final Set<String> props = new HashSet<>();
131 listPackage(StandardLocation.PLATFORM_CLASS_PATH, pkg, props);
132 listPackage(StandardLocation.CLASS_PATH, pkg, props);
133 return props;
134 }
135
136 private void listPackage(final Location loc, final String pkg, final Set<String> props)
137 throws IOException {
138 for (JavaFileObject file : fm.list(loc, pkg, fileKinds, true)) {
139 final String binaryName = fm.inferBinaryName(loc, file);
140 // does not start with the given package prefix
141 if (!binaryName.startsWith(pkg + ".")) {
142 continue;
143 }
144
145 final int nextDot = binaryName.indexOf('.', pkg.length() + 1);
146 final int start = pkg.length() + 1;
147
148 if (nextDot != -1) {
149 // subpackage - eg. "regex" for "java.util"
150 props.add(binaryName.substring(start, nextDot));
151 } else {
152 // class - filter out nested, inner, anonymous, local classes.
153 // Dynalink supported public nested classes as properties of
154 // StaticClass object anyway. We don't want to expose those
155 // "$" internal names as properties of package object.
156
157 final String clsName = binaryName.substring(start);
158 if (clsName.indexOf('$') == -1) {
159 props.add(clsName);
160 }
161 }
162 }
163 }
164
165 // return list of File objects for the given class path
166 private static List<File> getFiles(final String classPath) {
167 return Stream.of(classPath.split(File.pathSeparator))
168 .map(File::new)
169 .collect(Collectors.toList());
170 }
171 }