/* Copyright (C) 2002-2004 MySQL AB This program is free software; you can redistribute it and/or modify it under the terms of version 2 of the GNU General Public License as published by the Free Software Foundation.  There are special exceptions to the terms and conditions of the GPL  as it is applied to this software. View the full text of the  exception exception in file EXCEPTIONS-CONNECTOR-J in the directory of this  software distribution. This program 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 for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */package com.mysql.jdbc;import java.io.IOException;import java.io.InputStream;import java.io.Reader;import java.io.UnsupportedEncodingException;import java.math.BigDecimal;import java.net.URL;import java.sql.CallableStatement;import java.sql.Clob;import java.sql.Date;import java.sql.ParameterMetaData;import java.sql.Ref;import java.sql.SQLException;import java.sql.Savepoint;import java.sql.Time;import java.sql.Timestamp;import java.util.ArrayList;import java.util.Calendar;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Properties;import java.util.TimeZone;import java.util.TreeMap;/** * A Connection represents a 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, etc.  This information is obtained with the getMetaData * method. * </p> * * @author Mark Matthews * @version $Id: Connection.java,v 1.31.2.85 2004/11/15 00:23:07 mmatthew Exp $ * * @see java.sql.Connection */public class Connection implements java.sql.Connection {    // The command used to "ping" the database.    // Newer versions of MySQL server have a ping() command,    // but this works for everything    private static final String PING_COMMAND = "SELECT 1";    /**     * Map mysql transaction isolation level name to     * java.sql.Connection.TRANSACTION_XXX     */    private static Map mapTransIsolationName2Value = null;    /**     * The mapping between MySQL charset names and Java charset names.     * Initialized by loadCharacterSetMapping()     */    private static Map charsetMap;    /** Table of multi-byte charsets. Initialized by loadCharacterSetMapping() */    private static Map multibyteCharsetsMap;    /** Default socket factory classname */    private static final String DEFAULT_SOCKET_FACTORY = StandardSocketFactory.class        .getName();    static {        loadCharacterSetMapping();        mapTransIsolationName2Value = new HashMap(8);        mapTransIsolationName2Value.put("READ-UNCOMMITED",            new Integer(TRANSACTION_READ_UNCOMMITTED));        mapTransIsolationName2Value.put("READ-UNCOMMITTED",            new Integer(TRANSACTION_READ_UNCOMMITTED));        mapTransIsolationName2Value.put("READ-COMMITTED",            new Integer(TRANSACTION_READ_COMMITTED));        mapTransIsolationName2Value.put("REPEATABLE-READ",            new Integer(TRANSACTION_REPEATABLE_READ));        mapTransIsolationName2Value.put("SERIALIZABLE",            new Integer(TRANSACTION_SERIALIZABLE));    }    /**     * Marker for character set converter not being available (not written,     * multibyte, etc)  Used to prevent multiple instantiation requests.     */    private final static Object CHARSET_CONVERTER_NOT_AVAILABLE_MARKER = new Object();    boolean parserKnowsUnicode = false;    /** Internal DBMD to use for various database-version specific features */    private DatabaseMetaData dbmd = null;    /** The list of host(s) to try and connect to */    private List hostList = null;    /** A map of SQL to parsed prepared statement parameters. */    private Map cachedPreparedStatementParams;    /**     * Holds cached mappings to charset converters to avoid static     * synchronization and at the same time save memory (each charset     * converter takes approx 65K of static data).     */    private Map charsetConverterMap = new HashMap(CharsetMapping.JAVA_TO_MYSQL_CHARSET_MAP            .size());    /** A map of statements that have had setMaxRows() called on them */    private Map statementsUsingMaxRows;    /**     * The type map for UDTs (not implemented, but used by some third-party     * vendors, most notably IBM WebSphere)     */    private Map typeMap;    /** The I/O abstraction interface (network conn to MySQL server */    private MysqlIO io = null;    /** Mutex */    private final Object mutex = new Object();    /** The map of server variables that we retrieve at connection init. */    private Map serverVariables = null;    /** The driver instance that created us */    private NonRegisteringDriver myDriver;    /** Properties for this connection specified by user */    private Properties props = null;    /** The database we're currently using (called Catalog in JDBC terms). */    private String database = null;    /** If we're doing unicode character conversions, what encoding do we use? */    private String encoding = null;    /** The hostname we're connected to */    private String host = null;    /** The JDBC URL we're using */    private String myURL = null;    /** What does MySQL call this encoding? */    private String mysqlEncodingName = null;    private String negativeInfinityRep = MysqlDefs.MIN_DOUBLE_VAL_STRING;    private String notANumberRep = MysqlDefs.NAN_VAL_STRING;    /** The password we used */    private String password = null;    private String positiveInfinityRep = MysqlDefs.MAX_DOUBLE_VAL_STRING;    /** Classname for socket factory */    private String socketFactoryClassName = null;    /** The user we're connected as */    private String user = null;    /** Where was the connection _explicitly_ closed by the application? */    private Throwable explicitCloseLocation;    /** If the connection was forced closed, why was it  forced closed? */    private Throwable forcedCloseReason;    private TimeZone defaultTimeZone;    /** The timezone of the server */    private TimeZone serverTimezone = null;    /**     * We need this 'bootstrapped', because 4.1 and newer will send fields back     * with this even before we fill this dynamically from the server.     */    private String[] indexToCharsetMapping = CharsetMapping.INDEX_TO_CHARSET;    /** Allow LOAD LOCAL INFILE (defaults to true) */    private boolean allowLoadLocalInfile = true;    /** Should we clear the input stream each query? */    private boolean alwaysClearStream = false;    /** Are we in autoCommit mode? */    private boolean autoCommit = true;    /** SHould we cache the parsing of prepared statements? */    private boolean cachePreparedStatements = false;    /** Should we capitalize mysql types */    private boolean capitalizeDBMDTypes = false;    /** Should we clobber streaming results on new queries, or issue an error? */    private boolean clobberStreamingResults = false;    /**     * Should we continue processing batch commands if one fails. The JDBC spec     * allows either way, so we let the user choose     */    private boolean continueBatchOnError = true;    /** Should we do unicode character conversions? */    private boolean doUnicode = false;    /** When failed-over, set connection to read-only? */    private boolean failOverReadOnly = true;    /** Are we failed-over to a non-master host */    private boolean failedOver = false;    /** Does the server suuport isolation levels? */    private boolean hasIsolationLevels = false;    /** Does this version of MySQL support quoted identifiers? */    private boolean hasQuotedIdentifiers = false;    //    // This is for the high availability :) routines    //    private boolean highAvailability = false;    /** Ignore non-transactional table warning for rollback? */    private boolean ignoreNonTxTables = false;    /** Has this connection been closed? */    private boolean isClosed = true;    /** Should we tell MySQL that we're an interactive client? */    private boolean isInteractiveClient = false;    /** Is the server configured to use lower-case table names only? */    private boolean lowerCaseTableNames = false;    /** Has the max-rows setting been changed from the default? */    private boolean maxRowsChanged = false;    private boolean needsPing = false;    private boolean negativeInfinityRepIsClipped = true;    private boolean notANumberRepIsClipped = true;    /** Do we expose sensitive information in exception and error messages? */    private boolean paranoid = false;    /** Should we do 'extra' sanity checks? */    private boolean pedantic = false;    private boolean positiveInfinityRepIsClipped = true;    /** Should we retrieve 'info' messages from the server? */    private boolean readInfoMsg = false;    /** Are we in read-only mode? */    private boolean readOnly = false;    /**     * If autoReconnect == true, should we attempt to reconnect at transaction     * boundaries?     */    private boolean reconnectAtTxEnd = false;    /** Do we relax the autoCommit semantics? (For enhydra, for example) */    private boolean relaxAutoCommit = false;    /** Do we need to correct endpoint rounding errors */    private boolean strictFloatingPoint = false;    /** Do we check all keys for updatable result sets? */    private boolean strictUpdates = true;    /** Are transactions supported by the MySQL server we are connected to? */    private boolean transactionsSupported = false;    /** Has ANSI_QUOTES been enabled on the server? */    private boolean useAnsiQuotes = false;    /** Should we use compression? */    private boolean useCompression = false;    /** Can we use the "ping" command rather than a query? */    private boolean useFastPing = false;    /** Should we tack on hostname in DBMD.getTable/ColumnPrivileges()? */    private boolean useHostsInPrivileges = true;        /** Should we only use the error message from the server when reporting     * errors?     */    private boolean useOnlyServerErrorMessages = true;    /** Should we use SSL? */    private boolean useSSL = false;    /**     * Should we use stream lengths in prepared statements? (true by default ==     * JDBC compliant)     */    private boolean useStreamLengthsInPrepStmts = true;    /** Should we use timezone information? */    private boolean useTimezone = false;    /** Should we return PreparedStatements for UltraDev's stupid bug? */    private boolean useUltraDevWorkAround = false;    private boolean useUnbufferedInput = true;    private double initialTimeout = 2.0D;    /** How many hosts are in the host list? */    private int hostListSize = 0;    /** isolation level */    private int isolationLevel = java.sql.Connection.TRANSACTION_READ_COMMITTED;    /**     * The largest packet we can send (changed once we know what the server     * supports, we get this at connection init).     */    private int maxAllowedPacket = 65536;    private int maxReconnects = 3;    /**     * The max rows that a result set can contain. Defaults to -1, which     * according to the JDBC spec means "all".     */    private int maxRows = -1;    private int netBufferLength = 16384;    /** The port number we're connected to (defaults to 3306) */    private int port = 3306;    /**     * If prepared statement caching is enabled, what should the threshold     * length of the SQL to prepare should be in order to _not_ cache?     */    private int preparedStatementCacheMaxSqlSize = 256;    /** If prepared statement caching is enabled, how many should we cache? */    private int preparedStatementCacheSize = 25;    /**     * How many queries should we wait before we try to re-connect to the     * master, when we are failing over to replicated hosts Defaults to 50     */    private int queriesBeforeRetryMaster = 50;    /** What should we set the socket timeout to? */    private int socketTimeout = 0; // infinite    /** When did the last query finish? */    private long lastQueryFinishedTime = 0;    /** When did the master fail? */    private long masterFailTimeMillis = 0L;    /** Number of queries we've issued since the master failed */    private long queriesIssuedFailedOver = 0;    /**     * How many seconds should we wait before retrying to connect to the master     * if failed over? We fall back when either queriesBeforeRetryMaster or     * secondsBeforeRetryMaster is reached.     */    private long secondsBeforeRetryMaster = 30L;    /**     * Creates a connection to a MySQL Server.     *     * @param host the hostname of the database server     * @param port the port number the server is listening on     * @param info a Properties[] list holding the user and password     * @param database the database to connect to     * @param url the URL of the connection     * @param d the Driver instantation of the connection     *     * @exception java.sql.SQLException if a database access error occurs