001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 */
017package org.apache.xbean.finder.archive;
018
019import static java.util.Arrays.asList;
020
021import java.io.IOException;
022import java.io.InputStream;
023import java.util.HashMap;
024import java.util.Map;
025import java.util.jar.Attributes;
026import java.util.jar.Manifest;
027
028// helper to share the multijar release logic in a single place and avoid to impl it in all archives
029public class MJarSupport {
030    private static final boolean SUPPORT_MJAR = asList("true", "force")
031            .contains(System.getProperty("jdk.util.jar.enableMultiRelease", "true"));
032    private static final int MJAR_VERSION = findMJarVersion();
033
034    private static int findMJarVersion() {
035        if (!SUPPORT_MJAR) {
036            return -1;
037        }
038        final int version = major(System.getProperty("java.version"));
039        final int jarVersion = major(System.getProperty("jdk.util.jar.version"));
040        if (jarVersion > 0) {
041            return Math.min(version, jarVersion);
042        }
043        return Math.min(7/*unexpected but just in case*/, version);
044    }
045
046    private static int major(final String version) {
047        if (version == null) {
048            return -1;
049        }
050        final String[] parts = version.split("\\.");
051        try {
052            final int i = Integer.parseInt(parts[0]);
053            if (i == 1 && parts.length > 1) {
054                return Integer.parseInt(parts[1]);
055            }
056            return i;
057        } catch (final NumberFormatException nfe) {
058            // unexpected
059            return -1;
060        }
061    }
062
063    private boolean mjar;
064    private final Map<String, Clazz> classes = new HashMap<String, Clazz>();
065
066    public boolean isMjar() {
067        return mjar;
068    }
069
070    public Map<String, Clazz> getClasses() {
071        return classes;
072    }
073
074    public void load(final InputStream is) throws IOException {
075        if (!SUPPORT_MJAR) {
076            return;
077        }
078        load(new Manifest(is));
079    }
080
081    public void load(final Manifest manifest) {
082        if (!SUPPORT_MJAR) {
083            return;
084        }
085        final Attributes mainAttributes = manifest.getMainAttributes();
086        if (mainAttributes != null) {
087            mjar = Boolean.parseBoolean(mainAttributes.getValue("Multi-Release"));
088        }
089    }
090
091    // for exploded dirs since jars are handled by the JVM
092    public void visit(final String name) {
093        String normalized = name.replace('/', '.');
094        if (normalized.startsWith("/")) {
095            normalized = normalized.substring(1);
096        }
097        if (normalized.startsWith("META-INF.versions.")) {
098            final String version = normalized.substring("META-INF.versions.".length());
099            final int nextSep = version.indexOf('.');
100            if (nextSep < 0) {
101                return;
102            }
103            final String vStr = version.substring(0, nextSep);
104            final int major;
105            try {
106                if ((major = Integer.parseInt(vStr)) > MJAR_VERSION) {
107                    return;
108                }
109            } catch (final NumberFormatException nfe) {
110                return;
111            }
112            if (nextSep < version.length()) {
113                final String cname = version.substring(nextSep + 1);
114                final Clazz existing = classes.get(cname);
115                if (existing == null || existing.version < major) {
116                    classes.put(cname, new Clazz(name + (!version.endsWith(".class") ? ".class" : ""), major));
117                }
118            }
119        }
120    }
121
122    public static class Clazz {
123        private final String path;
124        private final int version;
125
126        private Clazz(final String path, final int version) {
127            this.path = path;
128            this.version = version;
129        }
130
131        public String getPath() {
132            return path;
133        }
134    }
135}