--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/jdk/internal/module/Resources.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,167 @@
+/*
+ * Copyright (c) 2016, 2017, 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. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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 jdk.internal.module;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.FileSystem;
+import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
+import java.nio.file.Path;
+import java.nio.file.attribute.BasicFileAttributes;
+
+/**
+ * A helper class to support working with resources in modules. Also provides
+ * support for translating resource names to file paths.
+ */
+public final class Resources {
+ private Resources() { }
+
+ /**
+ * Return true if a resource can be encapsulated. Resource with names
+ * ending in ".class" or "/" cannot be encapsulated. Resource names
+ * that map to a legal package name can be encapsulated.
+ */
+ public static boolean canEncapsulate(String name) {
+ int len = name.length();
+ if (len > 6 && name.endsWith(".class")) {
+ return false;
+ } else {
+ return Checks.isPackageName(toPackageName(name));
+ }
+ }
+
+ /**
+ * Derive a <em>package name</em> for a resource. The package name
+ * returned by this method may not be a legal package name. This method
+ * returns null if the the resource name ends with a "/" (a directory)
+ * or the resource name does not contain a "/".
+ */
+ public static String toPackageName(String name) {
+ int index = name.lastIndexOf('/');
+ if (index == -1 || index == name.length()-1) {
+ return "";
+ } else {
+ return name.substring(0, index).replace("/", ".");
+ }
+ }
+
+ /**
+ * Returns a resource name corresponding to the relative file path
+ * between {@code dir} and {@code file}. If the file is a directory
+ * then the name will end with a "/", except the top-level directory
+ * where the empty string is returned.
+ */
+ public static String toResourceName(Path dir, Path file) {
+ String s = dir.relativize(file)
+ .toString()
+ .replace(File.separatorChar, '/');
+ if (s.length() > 0 && Files.isDirectory(file))
+ s += "/";
+ return s;
+ }
+
+ /**
+ * Returns a file path to a resource in a file tree. If the resource
+ * name has a trailing "/" then the file path will locate a directory.
+ * Returns {@code null} if the resource does not map to a file in the
+ * tree file.
+ */
+ public static Path toFilePath(Path dir, String name) throws IOException {
+ boolean expectDirectory = name.endsWith("/");
+ if (expectDirectory) {
+ name = name.substring(0, name.length() - 1); // drop trailing "/"
+ }
+ Path path = toSafeFilePath(dir.getFileSystem(), name);
+ if (path != null) {
+ Path file = dir.resolve(path);
+ try {
+ BasicFileAttributes attrs;
+ attrs = Files.readAttributes(file, BasicFileAttributes.class);
+ if (attrs.isDirectory()
+ || (!attrs.isDirectory() && !expectDirectory))
+ return file;
+ } catch (NoSuchFileException ignore) { }
+ }
+ return null;
+ }
+
+ /**
+ * Map a resource name to a "safe" file path. Returns {@code null} if
+ * the resource name cannot be converted into a "safe" file path.
+ *
+ * Resource names with empty elements, or elements that are "." or ".."
+ * are rejected, as are resource names that translates to a file path
+ * with a root component.
+ */
+ private static Path toSafeFilePath(FileSystem fs, String name) {
+ // scan elements of resource name
+ int next;
+ int off = 0;
+ while ((next = name.indexOf('/', off)) != -1) {
+ int len = next - off;
+ if (!mayTranslate(name, off, len)) {
+ return null;
+ }
+ off = next + 1;
+ }
+ int rem = name.length() - off;
+ if (!mayTranslate(name, off, rem)) {
+ return null;
+ }
+
+ // convert to file path
+ Path path;
+ if (File.separatorChar == '/') {
+ path = fs.getPath(name);
+ } else {
+ // not allowed to embed file separators
+ if (name.contains(File.separator))
+ return null;
+ path = fs.getPath(name.replace('/', File.separatorChar));
+ }
+
+ // file path not allowed to have root component
+ return (path.getRoot() == null) ? path : null;
+ }
+
+ /**
+ * Returns {@code true} if the element in a resource name is a candidate
+ * to translate to the element of a file path.
+ */
+ private static boolean mayTranslate(String name, int off, int len) {
+ if (len <= 2) {
+ if (len == 0)
+ return false;
+ boolean starsWithDot = (name.charAt(off) == '.');
+ if (len == 1 && starsWithDot)
+ return false;
+ if (len == 2 && starsWithDot && (name.charAt(off+1) == '.'))
+ return false;
+ }
+ return true;
+ }
+
+}