connectionjdbc2.java

jtds的源码 是你学习java的好东西

// jTDS JDBC Driver for Microsoft SQL Server and Sybase
// Copyright (C) 2004 The jTDS Project
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
package net.sourceforge.jtds.jdbc;

import java.lang.ref.WeakReference;
import java.sql.CallableStatement;
import java.sql.DatabaseMetaData;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.SQLWarning;
import java.sql.Savepoint;
import java.sql.Statement;
import java.sql.Types;
import java.sql.ResultSet;
import java.net.UnknownHostException;
import java.io.*;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;
import java.util.HashSet;
import java.util.Random;

import net.sourceforge.jtds.jdbc.cache.*;
import net.sourceforge.jtds.util.*;

/**
 * jTDS implementation of the java.sql.Connection interface.
 * <p>
 * Implementation notes:
 * <ol>
 * <li>Environment setting code carried over from old jTDS otherwise
 *     generally a new implementation of Connection.
 * <li>Connection properties and SQLException text messages are loaded from
 *     a properties file.
 * <li>Character set choices are also loaded from a resource file and the original
 *     Encoder class has gone.
 * <li>Prepared SQL statements are converted to procedures in the prepareSQL method.
 * <li>Use of Stored procedures is optional and controlled via connection property.
 * <li>This Connection object maintains a table of weak references to associated
 *     statements. This allows the connection object to control the statements (for
 *     example to close them) but without preventing them being garbage collected in
 *     a pooled environment.
 * </ol>
 *
 * @author Mike Hutchinson
 * @author Alin Sinpalean
 * @version $Id: ConnectionJDBC2.java,v 1.119 2007/07/08 21:43:02 bheineman Exp $
 */
public class ConnectionJDBC2 implements java.sql.Connection {
    /**
     * SQL query to determine the server charset on Sybase.
     */
    private static final String SYBASE_SERVER_CHARSET_QUERY
            = "select name from master.dbo.syscharsets where id ="
            + " (select value from master.dbo.sysconfigures where config=131)";

    /**
     * SQL query to determine the server charset on MS SQL Server 6.5.
     */
    private static final String SQL_SERVER_65_CHARSET_QUERY
            = "select name from master.dbo.syscharsets where id ="
            + " (select csid from master.dbo.syscharsets, master.dbo.sysconfigures"
            + " where config=1123 and id = value)";

    /** Sybase initial connection string. */
    private static final String SYBASE_INITIAL_SQL =     "SET TRANSACTION ISOLATION LEVEL 1\r\n" +
                                                         "SET CHAINED OFF\r\n" +
                                                         "SET QUOTED_IDENTIFIER ON\r\n"+
                                                         "SET TEXTSIZE 2147483647";
    /**
     * SQL Server initial connection string. Also contains a
     * <code>SELECT @@MAX_PRECISION</code> query to retrieve
     * the maximum precision for DECIMAL/NUMERIC data. */
    private static final String SQL_SERVER_INITIAL_SQL = "SELECT @@MAX_PRECISION\r\n" +
                                                         "SET TRANSACTION ISOLATION LEVEL READ COMMITTED\r\n" +
                                                         "SET IMPLICIT_TRANSACTIONS OFF\r\n" +
                                                         "SET QUOTED_IDENTIFIER ON\r\n"+
                                                         "SET TEXTSIZE 2147483647";
    /**
     * SQL Server custom transaction isolation level.
     */
    public static final int TRANSACTION_SNAPSHOT = 4096;

    /*
     * Conection attributes
     */

    /** The orginal connection URL. */
    private final String url;
    /** The server host name. */
    private String serverName;
    /** The server port number. */
    private int portNumber;
    /** The make of SQL Server (sybase/microsoft). */
    private int serverType;
    /** The SQL Server instance. */
    private String instanceName;
    /** The requested database name. */
    private String databaseName;
    /** The current database name. */
    private String currentDatabase;
    /** The Windows Domain name. */
    private String domainName;
    /** The database user ID. */
    private String user;
    /** The user password. */
    private String password;
    /** The server character set. */
    private String serverCharset;
    /** The application name. */
    private String appName;
    /** The program name. */
    private String progName;
    /** Workstation ID. */
    private String wsid;
    /** The server message language. */
    private String language;
    /** The client MAC Address. */
    private String macAddress;
    /** The server protocol version. */
    private int tdsVersion;
    /** The network TCP/IP socket. */
    private final SharedSocket socket;
    /** The cored TDS protocol object. */
    private final TdsCore baseTds;
    /** The initial network packet size. */
    private int netPacketSize = TdsCore.MIN_PKT_SIZE;
    /** User requested packet size. */
    private int packetSize;
    /** SQL Server 2000 collation. */
    private byte collation[];
    /** True if user specifies an explicit charset. */
    private boolean charsetSpecified;
    /** The database product name eg SQL SERVER. */
    private String databaseProductName;
    /** The product version eg 11.92. */
    private String databaseProductVersion;
    /** The major version number eg 11. */
    private int databaseMajorVersion;
    /** The minor version number eg 92. */
    private int databaseMinorVersion;
    /** True if this connection is closed. */
    private boolean closed;
    /** True if this connection is read only. */
    private boolean readOnly;
    /** List of statements associated with this connection. */
    private final ArrayList statements = new ArrayList();
    /** Default transaction isolation level. */
    private int transactionIsolation = java.sql.Connection.TRANSACTION_READ_COMMITTED;
    /** Default auto commit state. */
    private boolean autoCommit = true;
    /** Diagnostc messages for this connection. */
    private final SQLDiagnostic messages;
    /** Connection's current rowcount limit. */
    private int rowCount;
    /** Connection's current maximum field size limit. */
    private int textSize;
    /** Maximum decimal precision. */
    private int maxPrecision = TdsData.DEFAULT_PRECISION_38; // Sybase default
    /** Stored procedure unique ID number. */
    private int spSequenceNo = 1;
    /** Cursor unique ID number. */
    private int cursorSequenceNo = 1;
    /** Procedures in this transaction. */
    private final ArrayList procInTran = new ArrayList();
    /** Java charset for encoding. */
    private CharsetInfo charsetInfo;
    /** Method for preparing SQL used in Prepared Statements. */
    private int prepareSql;
    /** The amount of LOB data to buffer in memory. */
    private long lobBuffer;
    /** The maximum number of statements to keep open. */
    private int maxStatements;
    /** Statement cache.*/
    private StatementCache statementCache;
    /** Send parameters as unicode. */
    private boolean useUnicode = true;
    /** Use named pipe IPC instead of TCP/IP sockets. */
    private boolean namedPipe;
    /** Only return the last update count. */
    private boolean lastUpdateCount;
    /** TCP_NODELAY */
    private boolean tcpNoDelay = true;
    /** Login timeout value in seconds or 0. */
    private int loginTimeout;
    /** Sybase capability mask.*/
    private int sybaseInfo;
    /** True if running distributed transaction. */
    private boolean xaTransaction;
    /** Current emulated XA State eg start/end/prepare etc. */
    private int xaState;
    /** Current XA Transaction ID. */
    private Object xid;
    /** True if driver should emulate distributed transactions. */
    private boolean xaEmulation = true;
    /** Mutual exclusion lock to control access to connection. */
    private final Semaphore mutex = new Semaphore(1);
    /** Socket timeout value in seconds or 0. */
    private int socketTimeout;
    /** SSL setting. */
    private String ssl;
    /** The maximum size of a batch. */
    private int batchSize;
    /** Use metadata cache for prepared statements. */
    private boolean useMetadataCache;
    /** Use fast forward cursors for forward only result sets. */
    private boolean useCursors;
    /** The directory to buffer data to */
    private File bufferDir;
    /** The global buffer memory limit for all connections (in kilobytes). */
    private int bufferMaxMemory;
    /** The minimum number of packets per statement to buffer to memory. */
    private int bufferMinPackets;
    /** Map large types (IMAGE and TEXT/NTEXT) to LOBs by default. */
    private boolean useLOBs;
    /** A cached <code>TdsCore</code> instance to reuse on new statements. */
    private TdsCore cachedTds;
    /** The local address to bind to when connecting to a database via TCP/IP. */
    private String bindAddress;
    /** Force use of jCIFS library on Windows when connecting via named pipes. */
    private boolean useJCIFS;
    /** When doing NTLM authentication, send NTLMv2 response rather than regular response */
    private boolean useNTLMv2 = false;


    /**
     * Default constructor.
     * <p/>
     * Used for testing.
     */
    private ConnectionJDBC2() {
        url = null;
        socket = null;
        baseTds = null;
        messages = null;
    }

    /**
     * Create a new database connection.
     *
     * @param url The connection URL starting jdbc:jtds:.
     * @param info The additional connection properties.
     * @throws SQLException
     */
    ConnectionJDBC2(String url, Properties info)
            throws SQLException {
        this.url = url;
        //
        // Extract properties into instance variables
        //
        unpackProperties(info);
        this.messages = new SQLDiagnostic(serverType);
        //
        // Get the instance port, if it is specified.
        // Named pipes use instance names differently.
        //
        if (instanceName.length() > 0 && !namedPipe) {
            final MSSqlServerInfo msInfo = new MSSqlServerInfo(serverName);

            portNumber = msInfo.getPortForInstance(instanceName);

            if (portNumber == -1) {
                throw new SQLException(
                                      Messages.get("error.msinfo.badinst", serverName, instanceName),
                                      "08003");
            }
        }

        SharedSocket.setMemoryBudget(bufferMaxMemory * 1024);
        SharedSocket.setMinMemPkts(bufferMinPackets);
        SQLWarning warn;

        try {
            Object timer = null;
            if (loginTimeout > 0) {
                // Start a login timer
                timer = TimerThread.getInstance().setTimer(loginTimeout * 1000,
                        new TimerThread.TimerListener() {
                            public void timerExpired() {
                                if (socket != null) {
                                    socket.forceClose();
                                }
                            }
                        });
            }

            if (namedPipe) {
                // Use named pipe
                socket = createNamedPipe(this);
            } else {
                // Use plain TCP/IP socket
                socket = new SharedSocket(this);
            }

            if (timer != null && TimerThread.getInstance().hasExpired(timer)) {
                // If the timer has expired during the connection phase, close
                // the socket and throw an exception
                socket.forceClose();
                throw new IOException("Login timed out");
            }

            if ( charsetSpecified ) {
                loadCharset(serverCharset);
            } else {
                // Need a default charset to process login packets for TDS 4.2/5.0
                // Will discover the actual serverCharset later
                loadCharset("iso_1");
                serverCharset = ""; // But don't send charset name to server!
            }

            //
            // Create TDS protocol object
            //
            baseTds = new TdsCore(this, messages);

            //
            // Negotiate SSL connection if required
            //
            if (tdsVersion >= Driver.TDS80 && !namedPipe) {
                baseTds.negotiateSSL(instanceName, ssl);
            }

            //
            // Now try to login
            //
            baseTds.login(serverName,
                          databaseName,
                          user,
                          password,
                          domainName,
                          serverCharset,
                          appName,
                          progName,
                          wsid,
                          language,
                          macAddress,
                          packetSize);

            if (timer != null) {
                // Cancel loginTimer
                TimerThread.getInstance().cancelTimer(timer);
            }

            //
            // Save any login warnings so that they will not be overwritten by
            // the internal configuration SQL statements e.g. setCatalog() etc.
            //
            warn = messages.warnings;

            // Update the tdsVersion with the value in baseTds. baseTds sets
            // the TDS version for the socket and there are no other objects