jdbcconnection.java

一个用java写的开源的数据库系统

/* Copyrights and Licenses
 *
 * This product includes Hypersonic SQL.
 * Originally developed by Thomas Mueller and the Hypersonic SQL Group. 
 *
 * Copyright (c) 1995-2000 by the Hypersonic SQL 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. 
 *     -  All advertising materials mentioning features or use of this software must display the
 *        following acknowledgment: "This product includes Hypersonic SQL." 
 *     -  Products derived from this software may not be called "Hypersonic SQL" nor may
 *        "Hypersonic SQL" appear in their names without prior written permission of the
 *         Hypersonic SQL Group. 
 *     -  Redistributions of any form whatsoever must retain the following acknowledgment: "This
 *          product includes Hypersonic SQL." 
 * This software is provided "as is" and any expressed 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 the Hypersonic SQL Group or its 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 any 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. 
 * This software consists of voluntary contributions made by many individuals on behalf of the
 * Hypersonic SQL Group.
 *
 *
 * For work added by the HSQL Development Group:
 *
 * Copyright (c) 2001-2002, 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, including earlier
 * license statements (above) and comply with all above license conditions.
 *
 * 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, including earlier
 * license statements (above) and comply with all above license conditions.
 *
 * 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.
 *
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 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


package org.hsqldb;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.URL;
import java.net.URLConnection;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.SQLWarning;
import java.sql.Statement;
import java.util.*;    // for Map
import java.util.Hashtable;
import java.util.StringTokenizer;

// fredt@users 20020320 - patch 1.7.0 - JDBC 2 support and error trapping
// JDBC 2 methods can now be called from jdk 1.1.x - see javadoc comments
// boucherb@users 20020509 - added "throws SQLException" to all methods where
// it was missing here but specified in the java.sql.Connection interface,
// updated generic documentation to JDK 1.4, and added JDBC3 methods and docs
// boucherb@users and fredt@users 20020409/20020505 extensive review and update
// of docs and behaviour to comply with previous and latest java.sql specification
// fredt@users 20020830 - patch 487323 by xclayl@users - better synchronization

/**
 * <!-- start generic documentation -->
 * A connection (session) with a specific database. Within the context
 * of a Connection, SQL statements are executed and results
 * are returned. <p>
 *
 * A Connection's database is able to provide information describing
 * its tables, its supported SQL grammar, its stored procedures, the
 * capabilities of this connection, and so on. This information is
 * obtained with the <code>getMetaData</code> method. <p>
 *
 * <B>Note:</B> By default the Connection automatically commits
 * changes after executing each statement. If auto commit has been
 * disabled, an explicit commit must be done or database changes will
 * not be saved. <p>
 *
 * <!-- end generic documentation -->
 * <!-- start release-specific documentation -->
 * <span class="ReleaseSpecificDocumentation">
 * <b>HSQLDB-Specific Information:</b> <p>
 *
 * To get a <code>Connection</code> to an HSQLDB database, the
 * following code may be used: <p>
 *
 * <code class="JavaCodeExample">
 * Class.<b>forName</b> (<span class="JavaStringLiteral">
 * "org.hsqldb.jdbcDriver"</span> );<br>
 * Connection c = DriverManager.<b>getConnection</b>
 * (url,user,password); </code><p>
 *
 * For HSQLDB connections, the <B>url</B> must start with <B>
 * 'jdbc:hsqldb'</B> .<p>
 *
 * The {@link Server Server} database <B>url</B> is <B>
 * 'jdbc:hsqldb:hsql://host[:port]'</B> . <p>
 *
 * The {@link WebServer WebServer} database <B>url</B> is <B>
 * 'jdbc:hsqldb:http://host[:port]'</B> . <p>
 *
 * The In-Memory (diskless, in-process) database <B>url</B> is <B>
 * 'jdbc:hsqldb:.'</B> . <p>
 *
 * The Standalone (in-process) database connection <B>url</B> is <B>
 * 'jdbc:hsqldb:name'</B> . <p>
 *
 * <B>'name'</B> is the common prefix of the files that compose the
 * database, including the <B>path</B> .<p>
 *
 * For example: <B>'jdbc:hsqldb:test'</B> connects to a database
 * named <B>'test'</B> , which is composed of the files <B>
 * 'test.properties'</B> , <B>'test.data'</B> and <B>'test.script'
 * </B>, all located in the working directory fixed at the time the
 * JVM is started. <p>
 *
 * Under <em>Windows</em> <sup><font size="-2">TM</font> </sup> , <B>
 * 'jdbc:hsqldb:c:\databases\test'</B> connects to a database named
 * <B>'test'</B> , located on drive c: in the directory <B>
 * 'databases'</B> , composed of the files: <B>'test.properties'</B>
 * , <B>'test.data'</B> and <B>'test.script'</B> . <p>
 *
 * Under most variations of UNIX, <B>'jdbc:hsqldb:/databases/test'
 * </B> connects to a database named <B>'test'</B> located in the
 * directory <B>'databases'</B> directly under root, and composed of
 * the files: <B>'test.properties'</B> , <B>'test.data'</B> and <B>
 * 'test.script'</B> . <p>
 *
 * <B>Some Guidelines:</B>
 * <OL>
 * <LI> Both relative and absolute paths are supported.</LI>
 * <LI> Relative paths can be specified in a platform independent
 * manner as: <B>'[dir1/dir2/.../dirn/]name'.</B> </LI>
 * <LI> Specification of absolute paths is operating-system
 * specific.<br>
 * Please read your OS file system documentation.</LI>
 * <LI> Typically, special care must be taken w.r.t. path
 * specifications containing whitespace, and mixed-case may also be
 * a concern.<br>
 * Please read your OS file system documentation.</LI>
 * </OL>
 * <B>Note:</B> Previous versions of HSQLDB did not support creating
 * directories along the path specified in Standalone mode jdbc urls,
 * in the case that they did not already exist. As of HSQLDB 1.7.0,
 * directories <i>will</i> be created if they do not already exist
 * (but not if the HSQLDB Jar is built under JDK 1.1.x).
 * <p>
 *
 * For more information about HSQLDB file structure, please read the
 * {@link Files Files} section of the documentation. <p>
 *
 * <b>JRE 1.1.x Notes:</b> <p>
 *
 * In general, JDBC 2 support requires Java 1.2 and above, and JDBC3 requires
 * Java 1.4 and above. In HSQLDB, support for methods introduced in different
 * versions of JDBC depends on the JDK version used for compiling and building
 * HSQLDB.<p>
 *
 * Since 1.7.0, it is possible to build the product so that
 * all JDBC 2 methods can be called while executing under the version 1.1.x
 * <em>Java Runtime Environment</em><sup><font size="-2">TM</font></sup>.
 * However, some of these method calls require <code>int</code> values that
 * are defined only in the JDBC 2 or greater version of
 * <a href="http://java.sun.com/j2se/1.4/docs/api/java/sql/ResultSet.html">
 * <CODE>ResultSet</CODE></a> interface.  For this reason, when the
 * product is compiled under JDK 1.1.x, these values are defined here in
 * this class.<p>
 *
 * In a JRE 1.1.x environment, calling JDBC 2 methods that take or return the
 * JDBC2-only <CODE>ResultSet</CODE> values can be achieved by referring
 * to them in parameter specifications and return value comparisons,
 * respectively, as follows: <p>
 *
 * <CODE class="JavaCodeExample">
 * jdbcResultSet.FETCH_FORWARD<br>
 * jdbcResultSet.TYPE_FORWARD_ONLY<br>
 * jdbcResultSet.TYPE_SCROLL_INSENSITIVE<br>
 * jdbcResultSet.CONCUR_READ_ONLY<br>
 * </CODE> <p>
 *
 * However, please note that code written in such a manner will not be
 * compatible for use with other JDBC 2 drivers, since they expect and use
 * <code>ResultSet</code>, rather than <code>jdbcResultSet</code>.  Also
 * note, this feature is offered solely as a convenience to developers
 * who must work under JDK 1.1.x due to operating constraints, yet wish to
 * use some of the more advanced features available under the JDBC 2
 * specification.<p>
 *
 * (fredt@users)<br>
 * (boucherb@users)<p>
 *
 * </span> <!-- end release-specific documentation -->
 *
 * @see jdbcDriver
 * @see jdbcStatement
 * @see jdbcResultSet
 * @see jdbcDatabaseMetaData
 */
public class jdbcConnection implements Connection {

// ---------------------------- Common Attributes --------------------------

    /**
     *  Is this connection closed?<p>
     *
     *  This attribute is false until the first call to {@link
     *  #close()}. If the close is successful, then this
     *  attribute is set to true and stays true until this connection
     *  is eventually garbage collected.
     */
    private boolean bClosed;

    /**
     *  The name of this connection's {@link Database Database}, as
     *  known to this connection. <p>
     *
     *  <B>Note:</B> Network connections know their database name as
     *  the network url of that database, without the protocol
     *  specifier. Connections to in-process database instances know
     *  their database name as the local path specifier for the
     *  database. For in-memory databases, this is always <B>"."</B>
     */
    private String sDatabaseName;

    /**
     * Properties for the connection
     *
     */
    private HsqlProperties connProperties;

    /**
     * One of the possible values for this connection's type. <p>
     *
     * This value indicates a network <code>Connection</code> to a
     * {@link org.hsqldb.WebServer WebServer} mode <code>Database</code>,
     * using http protocol. <p>
     */
    final static int HTTP = 0;

    /**
     * One of the possible values for this connection's type. <p>
     *
     * This value indicates a <code>Connection</code> to an
     * in-process (Standalone mode) <code>Database</code>. <p>
     */
    final static int STANDALONE = 1;

    /**
     *  One of the possible values for this connection's type. <p>
     *
     *  This value indicates a <code>Connection</code> created inside
     *  the database on behalf of an existing {@link Session Session},
     *  to be used as the parameter to a SQL function or stored
     *  procedure that needs to execute in the context of the calling
     *  <code>Session</code>. <p>
     *
     *
     */
    final static int INTERNAL = 2;

    /**
     *  One of the possible values for this connection's type. <p>
     *
     *  This value indicates a network <code>Connection</code> to a
     *  {@link org.hsqldb.Server Server} mode <code>Database</code>,
     *  using native hsqldb protocol. <p>
     *
     *
     */
    final static int HSQLDB = 3;

    /**
     * The type of this connection: {@link #STANDALONE STANDALONE},
     * {@link #HSQLDB HSQLDB}, {@link #HTTP HTTP}, or {@link
     * #INTERNAL INTERNAL}. <p>
     */
    private int iType;

// ----------------- In-process Database Connection Attributes -------------

    /**
     *  This connection's in-process {@link Database Database}. <p>
     *
     *  This attribute is used only for {@link #STANDALONE STANDALONE}
     *  or {@link #INTERNAL INTERNAL} type connections. <p>
     *
     *
     */
    Database dDatabase;

    /**
     * This connection's corresponding in-process {@link
     * Session Session}.<p>
     *