/*

 * Copyright (c) 1999, 2012, 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 javax.management.loading;

// Java import

import com.sun.jmx.defaults.JmxProperties;

import com.sun.jmx.defaults.ServiceName;

import com.sun.jmx.remote.util.EnvHelp;

import java.io.Externalizable;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.ObjectInput;

import java.io.ObjectInputStream;

import java.io.ObjectOutput;

import java.lang.reflect.Constructor;

import java.net.MalformedURLException;

import java.net.URL;

import java.net.URLStreamHandlerFactory;

import java.nio.file.Files;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.logging.Level;

import java.util.Map;

import java.util.Set;

import java.util.StringTokenizer;

import javax.management.InstanceAlreadyExistsException;

import javax.management.InstanceNotFoundException;

import javax.management.MBeanException;

import javax.management.MBeanRegistration;

import javax.management.MBeanRegistrationException;

import javax.management.MBeanServer;

import javax.management.NotCompliantMBeanException;

import javax.management.ObjectInstance;

import javax.management.ObjectName;

import javax.management.ReflectionException;

import static com.sun.jmx.defaults.JmxProperties.MLET_LIB_DIR;

import static com.sun.jmx.defaults.JmxProperties.MLET_LOGGER;

import com.sun.jmx.defaults.ServiceName;

import javax.management.ServiceNotFoundException;

/**

 * Allows you to instantiate and register one or several MBeans in the MBean server

 * coming from a remote URL. M-let is a shortcut for management applet. The m-let service does this

 * by loading an m-let text file, which specifies information on the MBeans to be obtained.

 * The information on each MBean is specified in a single instance of a tag, called the MLET tag.

 * The location of the m-let text file is specified by a URL.

 * <p>

 * The <CODE>MLET</CODE> tag has the following syntax:

 * <p>

 * &lt;<CODE>MLET</CODE><BR>

 *      <CODE>CODE = </CODE><VAR>class</VAR><CODE> | OBJECT = </CODE><VAR>serfile</VAR><BR>

 *      <CODE>ARCHIVE = &quot;</CODE><VAR>archiveList</VAR><CODE>&quot;</CODE><BR>

 *      <CODE>[CODEBASE = </CODE><VAR>codebaseURL</VAR><CODE>]</CODE><BR>

 *      <CODE>[NAME = </CODE><VAR>mbeanname</VAR><CODE>]</CODE><BR>

 *      <CODE>[VERSION = </CODE><VAR>version</VAR><CODE>]</CODE><BR>

 * &gt;<BR>

 *      <CODE>[</CODE><VAR>arglist</VAR><CODE>]</CODE><BR>

 * &lt;<CODE>/MLET</CODE>&gt;

 * <p>

 * where:

 * <DL>

 * <DT><CODE>CODE = </CODE><VAR>class</VAR></DT>

 * <DD>

 * This attribute specifies the full Java class name, including package name, of the MBean to be obtained.

 * The compiled <CODE>.class</CODE> file of the MBean must be contained in one of the <CODE>.jar</CODE> files specified by the <CODE>ARCHIVE</CODE>

 * attribute. Either <CODE>CODE</CODE> or <CODE>OBJECT</CODE> must be present.

 * </DD>

 * <DT><CODE>OBJECT = </CODE><VAR>serfile</VAR></DT>

 * <DD>

 * This attribute specifies the <CODE>.ser</CODE> file that contains a serialized representation of the MBean to be obtained.

 * This file must be contained in one of the <CODE>.jar</CODE> files specified by the <CODE>ARCHIVE</CODE> attribute. If the <CODE>.jar</CODE> file contains a directory hierarchy, specify the path of the file within this hierarchy. Otherwise  a match will not be found. Either <CODE>CODE</CODE> or <CODE>OBJECT</CODE> must be present.

 * </DD>

 * <DT><CODE>ARCHIVE = &quot;</CODE><VAR>archiveList</VAR><CODE>&quot;</CODE></DT>

 * <DD>

 * This mandatory attribute specifies one or more <CODE>.jar</CODE> files

 * containing MBeans or other resources used by

 * the MBean to be obtained. One of the <CODE>.jar</CODE> files must contain the file specified by the <CODE>CODE</CODE> or <CODE>OBJECT</CODE> attribute.

 * If archivelist contains more than one file:

 * <UL>

 * <LI>Each file must be separated from the one that follows it by a comma (,).

 * <LI><VAR>archivelist</VAR> must be enclosed in double quote marks.

 * </UL>

 * All <CODE>.jar</CODE> files in <VAR>archivelist</VAR> must be stored in the directory specified by the code base URL.

 * </DD>

 * <DT><CODE>CODEBASE = </CODE><VAR>codebaseURL</VAR></DT>

 * <DD>

 * This optional attribute specifies the code base URL of the MBean to be obtained. It identifies the directory that contains

 * the <CODE>.jar</CODE> files specified by the <CODE>ARCHIVE</CODE> attribute. Specify this attribute only if the <CODE>.jar</CODE> files are not in the same

 * directory as the m-let text file. If this attribute is not specified, the base URL of the m-let text file is used.

 * </DD>

 * <DT><CODE>NAME = </CODE><VAR>mbeanname</VAR></DT>

 * <DD>

 * This optional attribute specifies the object name to be assigned to the

 * MBean instance when the m-let service registers it. If

 * <VAR>mbeanname</VAR> starts with the colon character (:), the domain

 * part of the object name is the default domain of the MBean server,

 * as returned by {@link javax.management.MBeanServer#getDefaultDomain()}.

 * </DD>

 * <DT><CODE>VERSION = </CODE><VAR>version</VAR></DT>

 * <DD>

 * This optional attribute specifies the version number of the MBean and

 * associated <CODE>.jar</CODE> files to be obtained. This version number can

 * be used to specify that the <CODE>.jar</CODE> files are loaded from the

 * server to update those stored locally in the cache the next time the m-let

 * text file is loaded. <VAR>version</VAR> must be a series of non-negative

 * decimal integers each separated by a period from the one that precedes it.

 * </DD>

 * <DT><VAR>arglist</VAR></DT>

 * <DD>

 * This optional attribute specifies a list of one or more parameters for the

 * MBean to be instantiated. This list describes the parameters to be passed the MBean's constructor.

 * Use the following syntax to specify each item in

 * <DL>

 * <DT>&lt;<CODE>ARG TYPE=</CODE><VAR>argumentType</VAR> <CODE>VALUE=</CODE><VAR>value</VAR>&gt;</DT>

 * <UL>

 * <LI><VAR>argumentType</VAR> is the type of the argument that will be passed as parameter to the MBean's constructor.</UL>

 * </DL>

 * <P>The arguments' type in the argument list should be a Java primitive type or a Java basic type

 * (<CODE>java.lang.Boolean, java.lang.Byte, java.lang.Short, java.lang.Long, java.lang.Integer, java.lang.Float, java.lang.Double, java.lang.String</CODE>).

 * </DL>

 *

 * When an m-let text file is loaded, an

 * instance of each MBean specified in the file is created and registered.

 * <P>

 * The m-let service extends the <CODE>java.net.URLClassLoader</CODE> and can be used to load remote classes

 * and jar files in the VM of the agent.

 * <p><STRONG>Note - </STRONG> The <CODE>MLet</CODE> class loader uses the {@link javax.management.MBeanServerFactory#getClassLoaderRepository(javax.management.MBeanServer)}

 * to load classes that could not be found in the loaded jar files.

 *

 * @since 1.5

 */

public class MLet extends java.net.URLClassLoader

     implements MLetMBean, MBeanRegistration, Externalizable {

     private static final long serialVersionUID = 3636148327800330130L;

     /*

     * ------------------------------------------

     *   PRIVATE VARIABLES

     * ------------------------------------------

     */

     /**

      * The reference to the MBean server.

      * @serial

      */

     private MBeanServer server = null;

     /**

      * The list of instances of the <CODE>MLetContent</CODE>

      * class found at the specified URL.

      * @serial

      */

     private List<MLetContent> mletList = new ArrayList<MLetContent>();

     /**

      * The directory used for storing libraries locally before they are loaded.

      */

     private String libraryDirectory;

     /**

      * The object name of the MLet Service.

      * @serial

      */

     private ObjectName mletObjectName = null;

     /**

      * The URLs of the MLet Service.

      * @serial

      */

     private URL[] myUrls = null;

     /**

      * What ClassLoaderRepository, if any, to use if this MLet

      * doesn't find an asked-for class.

      */

     private transient ClassLoaderRepository currentClr;

     /**

      * True if we should consult the {@link ClassLoaderRepository}

      * when we do not find a class ourselves.

      */

     private transient boolean delegateToCLR;

     /**

      * objects maps from primitive classes to primitive object classes.

      */

     private Map<String,Class<?>> primitiveClasses =

         new HashMap<String,Class<?>>(8) ;

     {

         primitiveClasses.put(Boolean.TYPE.toString(), Boolean.class);

         primitiveClasses.put(Character.TYPE.toString(), Character.class);

         primitiveClasses.put(Byte.TYPE.toString(), Byte.class);

         primitiveClasses.put(Short.TYPE.toString(), Short.class);

         primitiveClasses.put(Integer.TYPE.toString(), Integer.class);

         primitiveClasses.put(Long.TYPE.toString(), Long.class);

         primitiveClasses.put(Float.TYPE.toString(), Float.class);

         primitiveClasses.put(Double.TYPE.toString(), Double.class);

     }

     /*

      * ------------------------------------------

      *  CONSTRUCTORS

      * ------------------------------------------

      */

     /*

      * The constructor stuff would be considerably simplified if our

      * parent, URLClassLoader, specified that its one- and

      * two-argument constructors were equivalent to its

      * three-argument constructor with trailing null arguments.  But

      * it doesn't, which prevents us from having all the constructors

      * but one call this(...args...).

      */

     /**

      * Constructs a new MLet using the default delegation parent ClassLoader.

      */

     public MLet() {

         this(new URL[0]);

     }

     /**

      * Constructs a new MLet for the specified URLs using the default

      * delegation parent ClassLoader.  The URLs will be searched in

      * the order specified for classes and resources after first

      * searching in the parent class loader.

      *

      * @param  urls  The URLs from which to load classes and resources.

      *

      */

     public MLet(URL[] urls) {

         this(urls, true);

     }

     /**

      * Constructs a new MLet for the given URLs. The URLs will be

      * searched in the order specified for classes and resources

      * after first searching in the specified parent class loader.

      * The parent argument will be used as the parent class loader

      * for delegation.

      *

      * @param  urls  The URLs from which to load classes and resources.

      * @param  parent The parent class loader for delegation.

      *

      */

     public MLet(URL[] urls, ClassLoader parent) {

         this(urls, parent, true);

     }

     /**

      * Constructs a new MLet for the specified URLs, parent class

      * loader, and URLStreamHandlerFactory. The parent argument will

      * be used as the parent class loader for delegation. The factory

      * argument will be used as the stream handler factory to obtain

      * protocol handlers when creating new URLs.

      *

      * @param  urls  The URLs from which to load classes and resources.

      * @param  parent The parent class loader for delegation.

      * @param  factory  The URLStreamHandlerFactory to use when creating URLs.

      *

      */

     public MLet(URL[] urls,

                 ClassLoader parent,

                 URLStreamHandlerFactory factory) {

         this(urls, parent, factory, true);

     }

     /**

      * Constructs a new MLet for the specified URLs using the default

      * delegation parent ClassLoader.  The URLs will be searched in

      * the order specified for classes and resources after first

      * searching in the parent class loader.

      *

      * @param  urls  The URLs from which to load classes and resources.

      * @param  delegateToCLR  True if, when a class is not found in

      * either the parent ClassLoader or the URLs, the MLet should delegate

      * to its containing MBeanServer's {@link ClassLoaderRepository}.

      *

      */

     public MLet(URL[] urls, boolean delegateToCLR) {

         super(urls);

         init(delegateToCLR);

     }

     /**

      * Constructs a new MLet for the given URLs. The URLs will be

      * searched in the order specified for classes and resources

      * after first searching in the specified parent class loader.

      * The parent argument will be used as the parent class loader

      * for delegation.

      *

      * @param  urls  The URLs from which to load classes and resources.

      * @param  parent The parent class loader for delegation.

      * @param  delegateToCLR  True if, when a class is not found in

      * either the parent ClassLoader or the URLs, the MLet should delegate

      * to its containing MBeanServer's {@link ClassLoaderRepository}.

      *

      */

     public MLet(URL[] urls, ClassLoader parent, boolean delegateToCLR) {

         super(urls, parent);

         init(delegateToCLR);

     }

     /**

      * Constructs a new MLet for the specified URLs, parent class

      * loader, and URLStreamHandlerFactory. The parent argument will

      * be used as the parent class loader for delegation. The factory

      * argument will be used as the stream handler factory to obtain

      * protocol handlers when creating new URLs.

      *

      * @param  urls  The URLs from which to load classes and resources.

      * @param  parent The parent class loader for delegation.

      * @param  factory  The URLStreamHandlerFactory to use when creating URLs.

      * @param  delegateToCLR  True if, when a class is not found in

      * either the parent ClassLoader or the URLs, the MLet should delegate

      * to its containing MBeanServer's {@link ClassLoaderRepository}.

      *

      */

     public MLet(URL[] urls,

                 ClassLoader parent,

                 URLStreamHandlerFactory factory,

                 boolean delegateToCLR) {

         super(urls, parent, factory);

         init(delegateToCLR);

     }

     private void init(boolean delegateToCLR) {

         this.delegateToCLR = delegateToCLR;

         try {

             libraryDirectory = System.getProperty(MLET_LIB_DIR);

             if (libraryDirectory == null)

                 libraryDirectory = getTmpDir();

         } catch (SecurityException e) {

             // OK : We don't do AccessController.doPrivileged, but we don't

             //      stop the user from creating an MLet just because they

             //      can't read the MLET_LIB_DIR or java.io.tmpdir properties

             //      either.

         }

     }

     /*

      * ------------------------------------------

      *  PUBLIC METHODS

      * ------------------------------------------

      */

     /**

      * Appends the specified URL to the list of URLs to search for classes and

      * resources.

      */

     public void addURL(URL url) {

         if (!Arrays.asList(getURLs()).contains(url))

             super.addURL(url);

     }

     /**

      * Appends the specified URL to the list of URLs to search for classes and

      * resources.

      * @exception ServiceNotFoundException The specified URL is malformed.

      */

     public void addURL(String url) throws ServiceNotFoundException {

         try {

             URL ur = new URL(url);

             if (!Arrays.asList(getURLs()).contains(ur))

                 super.addURL(ur);

         } catch (MalformedURLException e) {

             if (MLET_LOGGER.isLoggable(Level.FINEST)) {

                 MLET_LOGGER.logp(Level.FINEST, MLet.class.getName(),

                         "addUrl", "Malformed URL: " + url, e);

             }

             throw new

                 ServiceNotFoundException("The specified URL is malformed");

         }

     }

     /** Returns the search path of URLs for loading classes and resources.

      * This includes the original list of URLs specified to the constructor,

      * along with any URLs subsequently appended by the addURL() method.

      */

     public URL[] getURLs() {

         return super.getURLs();

     }

     /**

      * Loads a text file containing MLET tags that define the MBeans to

      * be added to the MBean server. The location of the text file is specified by

      * a URL. The MBeans specified in the MLET file will be instantiated and

      * registered in the MBean server.

      *

      * @param url The URL of the text file to be loaded as URL object.

      *

      * @return  A set containing one entry per MLET tag in the m-let text file loaded.

      * Each entry specifies either the ObjectInstance for the created MBean, or a throwable object

      * (that is, an error or an exception) if the MBean could not be created.

      *

      * @exception ServiceNotFoundException One of the following errors has occurred: The m-let text file does

      * not contain an MLET tag, the m-let text file is not found, a mandatory

      * attribute of the MLET tag is not specified, the value of url is

      * null.

      * @exception IllegalStateException MLet MBean is not registered with an MBeanServer.

      */

     public Set<Object> getMBeansFromURL(URL url)

             throws ServiceNotFoundException  {

         if (url == null) {

             throw new ServiceNotFoundException("The specified URL is null");

         }

         return getMBeansFromURL(url.toString());

     }

     /**

      * Loads a text file containing MLET tags that define the MBeans to

      * be added to the MBean server. The location of the text file is specified by

      * a URL. The MBeans specified in the MLET file will be instantiated and

      * registered in the MBean server.

      *

      * @param url The URL of the text file to be loaded as String object.

      *

      * @return A set containing one entry per MLET tag in the m-let

      * text file loaded.  Each entry specifies either the

      * ObjectInstance for the created MBean, or a throwable object

      * (that is, an error or an exception) if the MBean could not be

      * created.

      *

      * @exception ServiceNotFoundException One of the following

      * errors has occurred: The m-let text file does not contain an

      * MLET tag, the m-let text file is not found, a mandatory

      * attribute of the MLET tag is not specified, the url is

      * malformed.

      * @exception IllegalStateException MLet MBean is not registered

      * with an MBeanServer.

      *

      */

     public Set<Object> getMBeansFromURL(String url)

             throws ServiceNotFoundException  {

         String mth = "getMBeansFromURL";

         if (server == null) {

             throw new IllegalStateException("This MLet MBean is not " +

                                             "registered with an MBeanServer.");

         }

         // Parse arguments

         if (url == null) {

             MLET_LOGGER.logp(Level.FINER, MLet.class.getName(),

                     mth, "URL is null");

             throw new ServiceNotFoundException("The specified URL is null");

         } else {

             url = url.replace(File.separatorChar,'/');

         }

         if (MLET_LOGGER.isLoggable(Level.FINER)) {

             MLET_LOGGER.logp(Level.FINER, MLet.class.getName(),

                     mth, "<URL = " + url + ">");

         }

         // Parse URL

         try {

             MLetParser parser = new MLetParser();

             mletList = parser.parseURL(url);

         } catch (Exception e) {

             final String msg =

                 "Problems while parsing URL [" + url +

                 "], got exception [" + e.toString() + "]";

             MLET_LOGGER.logp(Level.FINER, MLet.class.getName(), mth, msg);

             throw EnvHelp.initCause(new ServiceNotFoundException(msg), e);

         }

         // Check that the list of MLets is not empty

         if (mletList.size() == 0) {

             final String msg =

                 "File " + url + " not found or MLET tag not defined in file";

             MLET_LOGGER.logp(Level.FINER, MLet.class.getName(), mth, msg);

             throw new ServiceNotFoundException(msg);

         }

         // Walk through the list of MLets

         Set<Object> mbeans = new HashSet<Object>();

         for (MLetContent elmt : mletList) {

             // Initialize local variables

             String code = elmt.getCode();