server.java

hsqldb是100％java实现的数据库,是一个开放源代码的JAVA数据库 l 具有标准的SQL语法和JAVA接口 l HSQLDB可以自由使用和分发 l 非常简洁和快速的

/* Copyright (c) 2001-2005, The HSQL Development Group
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the HSQL Development Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


package org.hsqldb;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Enumeration;
import java.util.StringTokenizer;

import org.hsqldb.lib.ArrayUtil;
import org.hsqldb.lib.FileUtil;
import org.hsqldb.lib.HashSet;
import org.hsqldb.lib.Iterator;
import org.hsqldb.lib.StopWatch;
import org.hsqldb.lib.StringUtil;
import org.hsqldb.lib.WrapperIterator;
import org.hsqldb.lib.java.JavaSystem;
import org.hsqldb.persist.HsqlDatabaseProperties;
import org.hsqldb.persist.HsqlProperties;
import org.hsqldb.resources.BundleHandler;

// fredt@users 20020215 - patch 1.7.0
// methods reorganised to use new HsqlProperties class
// fredt@users 20020424 - patch 1.7.0 - shutdown without exit
// see the comments in ServerConnection.java
// unsaved@users 20021113 - patch 1.7.2 - SSL support
// boucherb@users 20030510-14 - 1.7.2 - SSL support moved to factory interface
// boucherb@users 20030510-14 - 1.7.2 - service control, JavaBean API
// fredt@users 20030916 - 1.7.2 - review, simplification and multiple DB's
// fredt@users 20040320 - 1.7.2 - review and correction
// fredt@users 20050225 - 1.8.0 - minor corrections
// fredt@users 20051231 - 1.8.1 - support for remote opening of databases

/**
 * The HSQLDB HSQL protocol network database server. <p>
 *
 * A Server object acts as a network database server and is one way of using
 * the client-server mode of HSQLDB Database Engine. Instances of this
 * class handle native HSQL protocol connections exclusively, allowing database
 * queries to be performed efficienly across the network.  Server's direct
 * descendent, WebServer, handles HTTP protocol connections exclusively,
 * allowing HSQL protocol to be tunneled over HTTP to avoid sandbox and
 * firewall issues, albeit less efficiently. <p>
 *
 * There are a number of ways to configure and start a Server instance. <p>
 *
 * When started from the command line or programatically via the main(String[])
 * method, configuration occurs in three phases, with later phases overriding
 * properties set by previous phases:
 *
 * <ol>
 *   <li>Upon construction, a Server object is assigned a set of default
 *       properties. <p>
 *
 *   <li>If it exists, properties are loaded from a file named
 *       'server.properties' in the present working directory. <p>
 *
 *   <li>The command line arguments (alternatively, the String[] passed to
 *       main()) are parsed and used to further configure the Server's
 *       properties. <p>
 *
 * </ol> <p>
 *
 * From the command line, the options are as follows: <p>
 * <pre>
 * +----------------+-------------+----------+------------------------------+
 * |    OPTION      |    TYPE     | DEFAULT  |         DESCRIPTION          |
 * +----------------+-------------+----------+------------------------------|
 * | -?             | --          | --       | prints this message          |
 * | -address       | name|number | any      | server inet address          |
 * | -port          | number      | 9001/544 | port at which server listens |
 * | -database.i    | [type]spec  | 0=test   | path of database i           |
 * | -dbname.i      | alias       | --       | url alias for database i     |
 * | -silent        | true|false  | true     | false => display all queries |
 * | -trace         | true|false  | false    | display JDBC trace messages  |
 * | -tls           | true|false  | false    | TLS/SSL (secure) sockets     |
 * | -no_system_exit| true|false  | false    | do not issue System.exit()   |
 * | -remote_open   | true|false  | false    | can open databases remotely  |
 * +----------------+-------------+----------+------------------------------+
 * </pre>
 *
 * The <em>database.i</em> and <em>dbname.i</em> options need further
 * explanation:
 *
 * <ul>
 *   <li>Multiple databases can be served by each instance of the Server.
 *       The value of <em>i</em> is currently limited to the range 0..9,
 *       allowing up to 10 different databases. Any number is this range
 *       can be used.<p>
 *
 *   <li>The value assigned to <em>database.i</em> is interpreted using the
 *       format <b>'[type]spec'</b>, where the optional <em>type</em> component
 *       is one of <b>'file:'</b>, <b>'res:'</b> or <b>'mem:'</b> and the
 *       <em>spec</em> component is interpreted in the context of the
 *       <em>type</em> component.  <p>
 *
 *       If omitted, the <em>type</em> component is taken to be
 *       <b>'file:'</b>.  <p>
 *
 *        A full description of how
 *       <b>'[type]spec'</b> values are interpreted appears in the overview for
 *       {@link org.hsqldb.jdbc.jdbcConnection jdbcConnection}. <p>
 *
 *   <li>The value assigned to <em>dbname.i</em> is taken to be the key used to
 *       look up the desired database instance and thus corresponds to the
 *       <b>&lt;alias&gt;</b> component of the HSQLDB HSQL protocol database
 *       connection url:
 *       'jdbc:hsqldb:hsql[s]://host[port][/<b>&lt;alias&gt;</b>]'. <p>
 *
 *   <li>The value of <em>database.0</em> is special. If  <em>dbname.0</em>
 *       is not specified, then this defaults to an empty string and
 *       a connection is made to <em>database.0</em> path when
 *       the <b>&lt;alias&gt;</b> component of an HSQLDB HSQL protocol database
 *       connection url is omitted. If a <em>database</em> key/value pair is
 *       found in the properties when the main method is called, this
 *       pair is supersedes the <em>database.0</em> setting<p>
 *
 *       This behaviour allows the previous
 *       database connection url format to work with essentially unchanged
 *       semantics.<p>
 * </ul>
 *
 * From the 'server.properties' file, options can be set similarly, using a
 * slightly different format. <p>
 *
 * Here is an example 'server.properties' file:
 *
 * <pre>
 * server.port=9001
 * server.database.0=test
 * server.dbname.0=...
 * ...
 * server.database.n=...
 * server.dbname.n=...
 * server.silent=true
 * </pre>
 *
 * Starting with 1.7.2, Server has been refactored to become a simple JavaBean
 * with non-blocking start() and stop() service methods.  It is possible to
 * configure a Server instance through the JavaBean API as well, but this
 * part of the public interface is still under review and will not be finalized
 * or documented fully until the final 1.7.2 release. <p>
 *
 * <b>Note:</b> <p>
 *
 * The 'no_system_exit' property is of particular interest. <p>
 *
 * If a Server instance is to run embedded in, say, an application server,
 * such as when the jdbcDataSource or HsqlServerFactory classes are used, it
 * is typically necessary to avoid calling System.exit() when the Server
 * instance shuts down. <p>
 *
 * By default, 'no_system_exit' is set: <p>
 *
 * <ol>
 *    <li><b>true</b> when a Server is started directly from the start()
 *        method. <p>
 *
 *    <li><b>false</b> when a Server is started from the main(String[])
 *         method.
 * </ol> <p>
 *
 * These values are natural to their context because the first case allows
 * the JVM to exit by default on Server shutdown when a Server instance is
 * started from a command line environment, whereas the second case prevents
 * a typically unwanted JVM exit on Server shutdown when a Server intance
 * is started as part of a larger framework. <p>
 *
 * Replaces original Hypersonic source of the same name.
 *
 * @author fredt@users
 * @version 1.8.0
 * @since 1.7.2
 *
 * @jmx.mbean
 *    description="HSQLDB Server"
 *    extends="org.hsqldb.mx.mbean.RegistrationSupportBaseMBean"
 *
 * @jboss.xmbean
 */
public class Server implements HsqlSocketRequestHandler {

//
    protected static final int serverBundleHandle =
        BundleHandler.getBundleHandle("org_hsqldb_Server_messages", null);

//
    HsqlProperties serverProperties;

//
    HashSet serverConnSet;

//
    private String[]         dbAlias;
    private String[]         dbType;
    private String[]         dbPath;
    private HsqlProperties[] dbProps;
    private int[]            dbID;

//  Currently unused
    private int maxConnections;

//
    protected String            serverId;
    protected int               serverProtocol;
    protected ThreadGroup       serverConnectionThreadGroup;
    protected HsqlSocketFactory socketFactory;
    protected ServerSocket      socket;

//
    private Thread           serverThread;
    private Throwable        serverError;
    private volatile int     serverState;
    private volatile boolean isSilent;
    private volatile boolean isRemoteOpen;
    private PrintWriter      logWriter;
    private PrintWriter      errWriter;

//

    /**
     * A specialized Thread inner class in which the run() method of this
     * server executes.
     */
    private class ServerThread extends Thread {

        /**
         * Constructs a new thread in which to execute the run method
         * of this server.
         *
         * @param name The thread name
         */
        ServerThread(String name) {

            super(name);

            setName(name + '@'
                    + Integer.toString(Server.this.hashCode(), 16));
        }

        /**
         * Executes the run() method of this server
         */
        public void run() {
            Server.this.run();
            printWithThread("ServerThread.run() exited");
        }
    }

    /**
     * Creates a new Server instance handling HSQL protocol connections.
     */
    public Server() {
        this(ServerConstants.SC_PROTOCOL_HSQL);
    }

    /**
     * Creates a new Server instance handling the specified connection
     * protocol. <p>
     *
     * For example, the no-args WebServer constructor invokes this constructor
     * with ServerConstants.SC_PROTOCOL_HTTP, while the Server() no args
     * contructor invokes this constructor with
     * ServerConstants.SC_PROTOCOL_HSQL. <p>
     *
     * @param protocol the ServerConstants code indicating which
     *      connection protocol to handle
     */
    protected Server(int protocol) {
        init(protocol);
    }

    /**
     * Creates and starts a new Server.  <p>
     *
     * Allows starting a Server via the command line interface. <p>
     *
     * @param args the command line arguments for the Server instance
     */
    public static void main(String[] args) {

        String propsPath = FileUtil.canonicalOrAbsolutePath("server");
        HsqlProperties fileProps =
            ServerConfiguration.getPropertiesFromFile(propsPath);
        HsqlProperties props = fileProps == null ? new HsqlProperties()
                                                 : fileProps;
        HsqlProperties stringProps = HsqlProperties.argArrayToProps(args,
            ServerConstants.SC_KEY_PREFIX);

        if (stringProps != null) {
            if (stringProps.getErrorKeys().length != 0) {
                printHelp("server.help");

                return;
            }

            props.addProperties(stringProps);
        }

        ServerConfiguration.translateDefaultDatabaseProperty(props);

        // Standard behaviour when started from the command line
        // is to halt the VM when the server shuts down.  This may, of
        // course, be overridden by whatever, if any, security policy
        // is in place.
        ServerConfiguration.translateDefaultNoSystemExitProperty(props);

        // finished setting up properties;
        Server server = new Server();

        server.setProperties(props);

        // now messages go to the channel specified in properties
        server.print("Startup sequence initiated from main() method");

        if (fileProps != null) {
            server.print("Loaded properties from [" + propsPath
                         + ".properties]");
        } else {
            server.print("Could not load properties from file");
            server.print("Using cli/default properties only");
        }

        server.start();
    }

    /**
     * Checks if this Server object is or is not running and throws if the
     * current state does not match the specified value.
     *
     * @param running if true, ensure the server is running, else ensure the
     *      server is not running
     * @throws RuntimeException if the supplied value does not match the
     *      current running status
     */
    public void checkRunning(boolean running) throws RuntimeException {

        int     state;
        boolean error;

        printWithThread("checkRunning(" + running + ") entered");

        state = getState();
        error = (running && state != ServerConstants.SERVER_STATE_ONLINE)
                || (!running
                    && state != ServerConstants.SERVER_STATE_SHUTDOWN);

        if (error) {
            String msg = "server is " + (running ? "not "
                                                 : "") + "running";

            throw new RuntimeException(msg);
        }

        printWithThread("checkRunning(" + running + ") exited");
    }

    /**
     * Closes all connections to this Server.
     *
     * @jmx.managed-operation
     *  impact="ACTION"
     *  description="Closes all open connections"
     */
    public synchronized void signalCloseAllServerConnections() {

        Iterator it;

        printWithThread("signalCloseAllServerConnections() entered");

        synchronized (serverConnSet) {

            // snapshot
            it = new WrapperIterator(serverConnSet.toArray(null));
        }

        for (; it.hasNext(); ) {
            ServerConnection sc = (ServerConnection) it.next();

            printWithThread("Closing " + sc);

            // also removes all but one connection from serverConnSet
            sc.signalClose();
        }