Dépôt officiel du code source de l'ERP OpenConcerto

/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

 *

 * Copyright 2011 OpenConcerto, by ILM Informatique. All rights reserved.

 *

 * The contents of this file are subject to the terms of the GNU General Public License Version 3

 * only ("GPL"). You may not use this file except in compliance with the License. You can obtain a

 * copy of the License at http://www.gnu.org/licenses/gpl-3.0.html See the License for the specific

 * language governing permissions and limitations under the License.

 *

 * When distributing the software, include this License Header Notice in each file.

 */

 package org.openconcerto.utils.tools;

import org.openconcerto.utils.Log;

import org.openconcerto.utils.StreamUtils;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.MalformedURLException;

import java.net.URL;

import java.net.URLClassLoader;

import java.net.URLConnection;

import java.security.CodeSigner;

import java.security.CodeSource;

import java.security.SecureClassLoader;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import java.util.logging.Level;

/**

 * Class loader which supports any URL. {@link URLClassLoader} only supports directories and jar

 * files, but is more optimized (e.g. for finding which URL contains a resource)

 *

 * @author sylvain

 */

public class SimpleURLClassLoader extends SecureClassLoader {

    static public final URL toURL(final File f) {

        try {

            return f.toURI().toURL();

        } catch (MalformedURLException e) {

            // shouldn't happen since constructed from a file

            throw new IllegalStateException("Couldn't transform file to URL " + f, e);

        }

    }

    static public class URLCollector {

        private final List<URL> urls = new ArrayList<>();

        public final List<URL> copyToUnmodifiableList() {

            return Collections.unmodifiableList(new ArrayList<>(this.urls));

        }

        public final URLCollector add(final URL url) {

            this.urls.add(url);

            return this;

        }

        public final URLCollector addDirectory(final File dir) {

            if (!dir.isDirectory())

                throw new IllegalArgumentException("Not a directory : " + dir);

            return this.add(toURL(dir));

        }

        public final URLCollector addJar(final File jar) {

            if (!jar.isFile())

                throw new IllegalArgumentException("Not a file : " + jar);

            return this.addJar(toURL(jar));

        }

        public final URLCollector addJar(final URL u) {

            return this.add(org.openconcerto.utils.protocol.Helper.intoJar(u));

        }

        public final URLCollector addJars(final Iterable<URL> jars) {

            for (final URL jar : jars)

                this.addJar(jar);

            return this;

        }

    }

    // from ResourceBundle.Control

    static public final String toResourceName(String bundleName, String suffix) {

        StringBuilder sb = new StringBuilder(bundleName.length() + 1 + suffix.length());

        sb.append(bundleName.replace('.', '/')).append('.').append(suffix);

        return sb.toString();

    }

    static public final String toClassFile(String bundleName) {

        return toResourceName(bundleName, "class");

    }

    private final List<URL> urls;

    public SimpleURLClassLoader(final URLCollector urls) {

        super();

        this.urls = urls.copyToUnmodifiableList();

    }

    public SimpleURLClassLoader(final URLCollector urls, final ClassLoader parent) {

        super(parent);

        this.urls = urls.copyToUnmodifiableList();

    }

    protected URL createURL(final URL url, final String spec) throws MalformedURLException {

        return new URL(url, spec);

    }

    @Override

    protected Class<?> findClass(String name) throws ClassNotFoundException {

        for (final URL baseURL : this.urls) {

            try {

                final URL url = createURL(baseURL, toClassFile(name));

                try (final InputStream ins = url.openConnection().getInputStream()) {

                    try {

                        final byte[] bytes = StreamUtils.read(ins);

                        return this.defineClass(name, bytes, 0, bytes.length, new CodeSource(url, (CodeSigner[]) null));

                    } catch (IOException readExn) {

                        // same behaviour as URLClassLoader.findClass()

                        throw new ClassNotFoundException(name, readExn);

                    }

                }

            } catch (IOException connectExn) {

                Log.get().log(Level.FINE, connectExn, () -> "Couldn't connect to " + baseURL + " for " + name);

                // next

            }

        }

        return super.findClass(name);

    }

    @Override

    protected URL findResource(String name) {

        for (final URL baseURL : this.urls) {

            try {

                final URL url = createURL(baseURL, name);

                boolean exists = false;

                if (url.getProtocol().equals("file")) {

                    exists = new File(url.toURI()).exists();

                } else {

                    // From sun.misc.URLClassPath.Loader

                    URLConnection uc = url.openConnection();

                    if (uc instanceof HttpURLConnection) {

                        HttpURLConnection hconn = (HttpURLConnection) uc;

                        hconn.setRequestMethod("HEAD");

                        exists = hconn.getResponseCode() < HttpURLConnection.HTTP_BAD_REQUEST;

                    } else {

                        // our best guess for the other cases

                        uc.setUseCaches(false);

                        try (final InputStream ins = uc.getInputStream()) {

                            exists = true;

                        } catch (IOException e) {

                            exists = false;

                        }

                    }

                }

                if (exists)

                    return url;

            } catch (Exception e) {

                // next

            }

        }

        return super.findResource(name);

    }

}