001/*
002 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     bstefanescu
018 *
019 * $Id$
020 */
021
022package org.nuxeo.osgi.application;
023
024import java.io.File;
025import java.io.IOException;
026import java.util.Collection;
027import java.util.List;
028import java.util.jar.JarFile;
029
030import org.nuxeo.osgi.BundleFile;
031import org.nuxeo.osgi.DirectoryBundleFile;
032import org.nuxeo.osgi.JarBundleFile;
033
034/**
035 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
036 */
037public class ClassPathScanner {
038
039    protected boolean scanForNestedJARs = true;
040
041    protected final Callback callback;
042
043    /**
044     * If set points to a set of path prefixes to be excluded form bundle processing
045     */
046    protected String[] blackList;
047
048    public ClassPathScanner(Callback callback) {
049        this.callback = callback;
050    }
051
052    public ClassPathScanner(Callback callback, boolean scanForNestedJars, String[] blackList) {
053        this.callback = callback;
054        scanForNestedJARs = scanForNestedJars;
055        this.blackList = blackList;
056    }
057
058    public void setScanForNestedJARs(boolean scanForNestedJars) {
059        scanForNestedJARs = scanForNestedJars;
060    }
061
062    /**
063     * FIXME: this javadoc is not correct.
064     * <p>
065     * Scans the given class path and put found OSGi bundles in bundles, regular JARs in jars and append any nested jar
066     * or bundle into the given class loader.
067     *
068     * @param classPath
069     */
070    public void scan(List<File> classPath) {
071        for (File file : classPath) {
072            scan(file);
073        }
074    }
075
076    public void scan(File file) {
077        String path = file.getAbsolutePath();
078        if (!(path.endsWith(".jar") || path.endsWith(".rar") || path.endsWith(".sar") || path.endsWith("_jar")
079                || path.endsWith("_rar") || path.endsWith("_sar"))) {
080            return;
081        }
082        if (blackList != null) {
083            for (String prefix : blackList) {
084                if (path.startsWith(prefix)) {
085                    return;
086                }
087            }
088        }
089        try {
090            BundleFile bf;
091            if (file.isFile()) {
092                JarFile jar = new JarFile(file);
093                bf = new JarBundleFile(jar);
094            } else if (file.isDirectory()) {
095                bf = new DirectoryBundleFile(file);
096            } else {
097                return;
098            }
099            File nestedJARsDir;
100            if (bf.getSymbolicName() == null) { // a regular jar
101                nestedJARsDir = callback.handleJar(bf);
102            } else { // an osgi bundle
103                nestedJARsDir = callback.handleBundle(bf);
104            }
105            if (nestedJARsDir != null) {
106                Collection<BundleFile> nested = extractNestedJars(bf, nestedJARsDir);
107                if (nested != null) {
108                    for (BundleFile nestedJar : nested) {
109                        callback.handleNestedJar(nestedJar);
110                    }
111                }
112            }
113        } catch (IOException e) {
114            // ignore exception since some manifest may be invalid (invalid ClassPath entries) etc.
115        }
116    }
117
118    public Collection<BundleFile> extractNestedJars(BundleFile bf, File nestedBundlesDir) throws IOException {
119        Collection<BundleFile> bundles = null;
120        if (scanForNestedJARs) {
121            bundles = bf.findNestedBundles(nestedBundlesDir);
122        } else { // use manifest to find nested jars
123            bundles = bf.getNestedBundles(nestedBundlesDir);
124        }
125        if (bundles != null && bundles.isEmpty()) {
126            bundles = null;
127        }
128        return bundles;
129    }
130
131    public interface Callback {
132
133        /**
134         * A nested JAR was found on the class path. Usually a callback should handle this by adding the JAR to a class
135         * loader
136         * <p>
137         * The callback should return a directory to be used to extract nested JARs from this JAR.
138         * <p>
139         * The callback may return null to skip nested JAR extraction
140         *
141         * @param bf the JAR found
142         */
143        void handleNestedJar(BundleFile bf);
144
145        /**
146         * A JAR was found on the class path. Usually a callback should handle this by adding the JAR to a class loader.
147         * <p>
148         * The callback should return a directory to be used to extract nested JARs from this JAR.
149         * <p>
150         * The callback may return null to skip nested JAR extraction.
151         *
152         * @param bf the JAR found
153         * @return the folder to be used to extract JARs or null to skip extraction
154         */
155        File handleJar(BundleFile bf);
156
157        /**
158         * A Bundle was found on the class path. Usually a callback should handle this by adding the Bundle to a class
159         * loader and installing it in an OSGi framework
160         * <p>
161         * The callback should return a directory to be used to extract nested JARs from this JAR.
162         * <p>
163         * The callback may return null to skip nested JAR extraction.
164         *
165         * @param bf the JAR found
166         * @return the folder to be used to extract JARs or null to skip extraction
167         */
168        File handleBundle(BundleFile bf);
169
170    }
171
172}