/*

 * Copyright (c) 1998, 2010, 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 sun.misc;

import java.io.File;

import java.io.IOException;

import java.io.FilePermission;

import java.net.URL;

import java.net.URLClassLoader;

import java.net.MalformedURLException;

import java.net.URLStreamHandler;

import java.net.URLStreamHandlerFactory;

import java.util.HashSet;

import java.util.StringTokenizer;

import java.util.Set;

import java.util.Vector;

import java.security.AccessController;

import java.security.AllPermission;

import java.security.PrivilegedAction;

import java.security.PrivilegedExceptionAction;

import java.security.AccessControlContext;

import java.security.PermissionCollection;

import java.security.Permissions;

import java.security.Permission;

import java.security.ProtectionDomain;

import java.security.CodeSource;

import sun.security.util.SecurityConstants;

import sun.net.www.ParseUtil;

/**

 * This class is used by the system to launch the main application.

Launcher */

public class Launcher {

    private static URLStreamHandlerFactory factory = new Factory();

    private static Launcher launcher = new Launcher();

    private static String bootClassPath =

        System.getProperty("sun.boot.class.path");

    public static Launcher getLauncher() {

        return launcher;

    }

    private ClassLoader loader;

    public Launcher() {

        // Create the extension class loader

        ClassLoader extcl;

        try {

            extcl = ExtClassLoader.getExtClassLoader();

        } catch (IOException e) {

            throw new InternalError(

                "Could not create extension class loader");

        }

        // Now create the class loader to use to launch the application

        try {

            loader = AppClassLoader.getAppClassLoader(extcl);

        } catch (IOException e) {

            throw new InternalError(

                "Could not create application class loader");

        }

        // Also set the context class loader for the primordial thread.

        Thread.currentThread().setContextClassLoader(loader);

        // Finally, install a security manager if requested

        String s = System.getProperty("java.security.manager");

        if (s != null) {

            SecurityManager sm = null;

            if ("".equals(s) || "default".equals(s)) {

                sm = new java.lang.SecurityManager();

            } else {

                try {

                    sm = (SecurityManager)loader.loadClass(s).newInstance();

                } catch (IllegalAccessException e) {

                } catch (InstantiationException e) {

                } catch (ClassNotFoundException e) {

                } catch (ClassCastException e) {

                }

            }

            if (sm != null) {

                System.setSecurityManager(sm);

            } else {

                throw new InternalError(

                    "Could not create SecurityManager: " + s);

            }

        }

    }

    /*

     * Returns the class loader used to launch the main application.

     */

    public ClassLoader getClassLoader() {

        return loader;

    }

    public static void addURLToAppClassLoader(URL u) {

        AccessController.checkPermission(new AllPermission());

        ClassLoader loader = Launcher.getLauncher().getClassLoader();

        ((Launcher.AppClassLoader) loader).addAppURL(u);

    }

    public static void addURLToExtClassLoader(URL u) {

        AccessController.checkPermission(new AllPermission());

        ClassLoader loader = Launcher.getLauncher().getClassLoader();

        ((Launcher.ExtClassLoader) loader.getParent()).addExtURL(u);

    }

    /*

     * The class loader used for loading installed extensions.

     */

    static class ExtClassLoader extends URLClassLoader {

        static {

            ClassLoader.registerAsParallelCapable();

        }

        /**

         * create an ExtClassLoader. The ExtClassLoader is created

         * within a context that limits which files it can read

         */

        public static ExtClassLoader getExtClassLoader() throws IOException

        {

            final File[] dirs = getExtDirs();

            try {

                // Prior implementations of this doPrivileged() block supplied

                // aa synthesized ACC via a call to the private method

                // ExtClassLoader.getContext().

                return AccessController.doPrivileged(

                    new PrivilegedExceptionAction<ExtClassLoader>() {

                        public ExtClassLoader run() throws IOException {

                            int len = dirs.length;

                            for (int i = 0; i < len; i++) {

                                MetaIndex.registerDirectory(dirs[i]);

                            }

                            return new ExtClassLoader(dirs);

                        }

                    });

            } catch (java.security.PrivilegedActionException e) {

                throw (IOException) e.getException();

            }

        }

        void addExtURL(URL url) {

            super.addURL(url);

        }

        /*

         * Creates a new ExtClassLoader for the specified directories.

         */

        public ExtClassLoader(File[] dirs) throws IOException {

            super(getExtURLs(dirs), null, factory);

        }

        private static File[] getExtDirs() {

            String s = System.getProperty("java.ext.dirs");

            File[] dirs;

            if (s != null) {

                StringTokenizer st =

                    new StringTokenizer(s, File.pathSeparator);

                int count = st.countTokens();

                dirs = new File[count];

                for (int i = 0; i < count; i++) {

                    dirs[i] = new File(st.nextToken());

                }

            } else {

                dirs = new File[0];

            }

            return dirs;

        }

        private static URL[] getExtURLs(File[] dirs) throws IOException {

            Vector<URL> urls = new Vector<URL>();

            for (int i = 0; i < dirs.length; i++) {

                String[] files = dirs[i].list();

                if (files != null) {

                    for (int j = 0; j < files.length; j++) {

                        if (!files[j].equals("meta-index")) {

                            File f = new File(dirs[i], files[j]);

                            urls.add(getFileURL(f));

                        }

                    }

                }

            }

            URL[] ua = new URL[urls.size()];

            urls.copyInto(ua);

            return ua;

        }

        /*

         * Searches the installed extension directories for the specified

         * library name. For each extension directory, we first look for

         * the native library in the subdirectory whose name is the value

         * of the system property <code>os.arch</code>. Failing that, we

         * look in the extension directory itself.

         */

        public String findLibrary(String name) {

            name = System.mapLibraryName(name);

            URL[] urls = super.getURLs();

            File prevDir = null;

            for (int i = 0; i < urls.length; i++) {

                // Get the ext directory from the URL

                File dir = new File(urls[i].getPath()).getParentFile();

                if (dir != null && !dir.equals(prevDir)) {

                    // Look in architecture-specific subdirectory first

                    // Read from the saved system properties to avoid deadlock

                    String arch = VM.getSavedProperty("os.arch");

                    if (arch != null) {

                        File file = new File(new File(dir, arch), name);

                        if (file.exists()) {

                            return file.getAbsolutePath();

                        }

                    }

                    // Then check the extension directory

                    File file = new File(dir, name);

                    if (file.exists()) {

                        return file.getAbsolutePath();

                    }

                }

                prevDir = dir;

            }

            return null;

        }

        protected Class findClass(String name) throws ClassNotFoundException {

            BootClassLoaderHook.preLoadClass(name);

            return super.findClass(name);

        }

        private static AccessControlContext getContext(File[] dirs)

            throws IOException

        {

            PathPermissions perms =

                new PathPermissions(dirs);

            ProtectionDomain domain = new ProtectionDomain(

                new CodeSource(perms.getCodeBase(),

                    (java.security.cert.Certificate[]) null),

                perms);

            AccessControlContext acc =

                new AccessControlContext(new ProtectionDomain[] { domain });

            return acc;

        }

    }

    /**

     * The class loader used for loading from java.class.path.

     * runs in a restricted security context.

     */

    static class AppClassLoader extends URLClassLoader {

        static {

            ClassLoader.registerAsParallelCapable();

        }

        public static ClassLoader getAppClassLoader(final ClassLoader extcl)

            throws IOException

        {

            final String s = System.getProperty("java.class.path");

            final File[] path = (s == null) ? new File[0] : getClassPath(s);

            // Note: on bugid 4256530

            // Prior implementations of this doPrivileged() block supplied

            // a rather restrictive ACC via a call to the private method

            // AppClassLoader.getContext(). This proved overly restrictive

            // when loading  classes. Specifically it prevent

            // accessClassInPackage.sun.* grants from being honored.

            //

            return AccessController.doPrivileged(

                new PrivilegedAction<AppClassLoader>() {

                    public AppClassLoader run() {

                    URL[] urls =

                        (s == null) ? new URL[0] : pathToURLs(path);

                    return new AppClassLoader(urls, extcl);

                }

            });

        }

        /*

         * Creates a new AppClassLoader

         */

        AppClassLoader(URL[] urls, ClassLoader parent) {

            super(urls, parent, factory);

        }

        /**

         * Override loadClass so we can checkPackageAccess.

         */

        public Class loadClass(String name, boolean resolve)

            throws ClassNotFoundException

        {

            BootClassLoaderHook.preLoadClass(name);

            int i = name.lastIndexOf('.');

            if (i != -1) {

                SecurityManager sm = System.getSecurityManager();

                if (sm != null) {

                    sm.checkPackageAccess(name.substring(0, i));

                }

            }

            return (super.loadClass(name, resolve));

        }

        /**

         * allow any classes loaded from classpath to exit the VM.

         */

        protected PermissionCollection getPermissions(CodeSource codesource)

        {

            PermissionCollection perms = super.getPermissions(codesource);

            perms.add(new RuntimePermission("exitVM"));

            return perms;

        }

        /**

         * This class loader supports dynamic additions to the class path

         * at runtime.

         *

         * @see java.lang.instrument.Instrumentation#appendToSystemClassPathSearch

         */

        private void appendToClassPathForInstrumentation(String path) {

            assert(Thread.holdsLock(this));

            // addURL is a no-op if path already contains the URL

            super.addURL( getFileURL(new File(path)) );

        }

        /**

         * create a context that can read any directories (recursively)

         * mentioned in the class path. In the case of a jar, it has to

         * be the directory containing the jar, not just the jar, as jar

         * files might refer to other jar files.

         */

        private static AccessControlContext getContext(File[] cp)

            throws java.net.MalformedURLException

        {

            PathPermissions perms =

                new PathPermissions(cp);

            ProtectionDomain domain =

                new ProtectionDomain(new CodeSource(perms.getCodeBase(),

                    (java.security.cert.Certificate[]) null),

                perms);

            AccessControlContext acc =

                new AccessControlContext(new ProtectionDomain[] { domain });

            return acc;

        }

        void addAppURL(URL url) {

            super.addURL(url);

        }

    }

    private static class BootClassPathHolder {

        static final URLClassPath bcp;

        static {

            URL[] urls;

            if (bootClassPath != null) {

                urls = AccessController.doPrivileged(

                    new PrivilegedAction<URL[]>() {

                        public URL[] run() {

                            File[] classPath = getClassPath(bootClassPath);

                            int len = classPath.length;

                            Set<File> seenDirs = new HashSet<File>();

                            for (int i = 0; i < len; i++) {

                                File curEntry = classPath[i];

                                // Negative test used to properly handle

                                // nonexistent jars on boot class path

                                if (!curEntry.isDirectory()) {

                                    curEntry = curEntry.getParentFile();

                                }

                                if (curEntry != null && seenDirs.add(curEntry)) {

                                    MetaIndex.registerDirectory(curEntry);

                                }

                            }

                            return pathToURLs(classPath);

                        }

                    }

                );

            } else {

                urls = new URL[0];

            }

            bcp = new URLClassPath(urls, factory);

        }

    }

    public static URLClassPath getBootstrapClassPath() {

        URLClassPath bcp = BootClassPathHolder.bcp;

        // if DownloadManager is installed, return the bootstrap class path

        // maintained by the Java kernel

        BootClassLoaderHook hook = BootClassLoaderHook.getHook();

        return hook == null ? bcp : hook.getBootstrapClassPath(bcp, factory);

    }

    private static URL[] pathToURLs(File[] path) {

        URL[] urls = new URL[path.length];

        for (int i = 0; i < path.length; i++) {

            urls[i] = getFileURL(path[i]);

        }

        // DEBUG

        //for (int i = 0; i < urls.length; i++) {

        //  System.out.println("urls[" + i + "] = " + '"' + urls[i] + '"');

        //}

        return urls;

    }

    private static File[] getClassPath(String cp) {

        File[] path;

        if (cp != null) {

            int count = 0, maxCount = 1;

            int pos = 0, lastPos = 0;

            // Count the number of separators first

            while ((pos = cp.indexOf(File.pathSeparator, lastPos)) != -1) {

                maxCount++;

                lastPos = pos + 1;

            }

            path = new File[maxCount];

            lastPos = pos = 0;

            // Now scan for each path component

            while ((pos = cp.indexOf(File.pathSeparator, lastPos)) != -1) {

                if (pos - lastPos > 0) {

                    path[count++] = new File(cp.substring(lastPos, pos));

                } else {

                    // empty path component translates to "."

                    path[count++] = new File(".");

                }

                lastPos = pos + 1;

            }

            // Make sure we include the last path component

            if (lastPos < cp.length()) {

                path[count++] = new File(cp.substring(lastPos));

            } else {

                path[count++] = new File(".");

            }

            // Trim array to correct size

            if (count != maxCount) {

                File[] tmp = new File[count];

                System.arraycopy(path, 0, tmp, 0, count);

                path = tmp;

            }

        } else {

            path = new File[0];

        }

        // DEBUG

        //for (int i = 0; i < path.length; i++) {

        //  System.out.println("path[" + i + "] = " + '"' + path[i] + '"');

        //}

        return path;

    }

    private static URLStreamHandler fileHandler;

    static URL getFileURL(File file) {

        try {

            file = file.getCanonicalFile();

        } catch (IOException e) {}

        try {

            return ParseUtil.fileToEncodedURL(file);

        } catch (MalformedURLException e) {

            // Should never happen since we specify the protocol...

            throw new InternalError();

        }

    }

    /*

     * The stream handler factory for loading system protocol handlers.

     */

    private static class Factory implements URLStreamHandlerFactory {

        private static String PREFIX = "sun.net.www.protocol";

        public URLStreamHandler createURLStreamHandler(String protocol) {

            String name = PREFIX + "." + protocol + ".Handler";

            try {

                Class c = Class.forName(name);

                return (URLStreamHandler)c.newInstance();

            } catch (ClassNotFoundException e) {

                e.printStackTrace();

            } catch (InstantiationException e) {

                e.printStackTrace();

            } catch (IllegalAccessException e) {

                e.printStackTrace();

            }

            throw new InternalError("could not load " + protocol +

                                    "system protocol handler");

        }

    }

}

class PathPermissions extends PermissionCollection {