tdsdata.java

第三方的SQL Server and Sybase的jdbc dirver,速度更快

// 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.io.*;
import java.math.BigInteger;
import java.math.BigDecimal;
import java.sql.SQLException;

import net.sourceforge.jtds.util.BlobBuffer;

/**
 * Implement TDS data types and related I/O logic.
 * <p>
 * Implementation notes:
 * <bl>
 * <li>This class encapsulates all the knowledge about reading and writing
 *     TDS data descriptors and related application data.
 * <li>There are four key methods supplied here:
 * <ol>
 * <li>readType() - Reads the column and parameter meta data.
 * <li>readData() - Reads actual data values.
 * <li>writeParam() - Write parameter descriptors and data.
 * <li>getNativeType() - knows how to map JDBC data types to the equivalent TDS type.
 * </ol>
 * </bl>
 *
 * @author Mike Hutchinson
 * @author Alin Sinpalean
 * @author freeTDS project
 * @version $Id: TdsData.java,v 1.51 2005/06/03 12:29:09 alin_sinpalean Exp $
 */
public class TdsData {
    /**
     * This class implements a descriptor for TDS data types;
     *
     * @author Mike Hutchinson.
     */
    private static class TypeInfo {
        /** The SQL type name. */
        public final String sqlType;
        /**
         * The size of this type or &lt; 0 for variable sizes.
         * <p> Special values as follows:
         * <ol>
         * <li> -5 sql_variant type.
         * <li> -4 text, image or ntext types.
         * <li> -2 SQL Server 7+ long char and var binary types.
         * <li> -1 varchar, varbinary, null types.
         * </ol>
         */
        public final int size;
        /**
         * The precision of the type.
         * <p>If this is -1 precision must be calculated from buffer size
         * eg for varchar fields.
         */
        public final int precision;
        /**
         * The display size of the type.
         * <p>-1 If the display size must be calculated from the buffer size.
         */
        public final int displaySize;
        /** true if type is a signed numeric. */
        public final boolean isSigned;
        /** true if type requires TDS80 collation. */
        public final boolean isCollation;
        /** The java.sql.Types constant for this data type. */
        public final int jdbcType;

        /**
         * Construct a new TDS data type descriptor.
         *
         * @param sqlType   SQL type name.
         * @param size Byte size for this type or &lt; 0 for variable length types.
         * @param precision Decimal precision or -1
         * @param displaySize Printout size for this type or special values -1,-2.
         * @param isSigned True if signed numeric type.
         * @param isCollation True if type has TDS 8 collation information.
         * @param jdbcType The java.sql.Type constant for this type.
         */
        TypeInfo(String sqlType, int size, int precision, int displaySize,
                 boolean isSigned, boolean isCollation, int jdbcType) {
            this.sqlType = sqlType;
            this.size = size;
            this.precision = precision;
            this.displaySize = displaySize;
            this.isSigned = isSigned;
            this.isCollation = isCollation;
            this.jdbcType = jdbcType;
        }

    }

    /*
     * Constants for TDS data types
     */
    private static final int SYBCHAR               = 47; // 0x2F
    private static final int SYBVARCHAR            = 39; // 0x27
    private static final int SYBINTN               = 38; // 0x26
    private static final int SYBINT1               = 48; // 0x30
    private static final int SYBDATE               = 49; // 0x31 Sybase 12
    private static final int SYBTIME               = 51; // 0x33 Sybase 12
    private static final int SYBINT2               = 52; // 0x34
    private static final int SYBINT4               = 56; // 0x38
    private static final int SYBINT8               = 127;// 0x7F
    private static final int SYBFLT8               = 62; // 0x3E
    private static final int SYBDATETIME           = 61; // 0x3D
    private static final int SYBBIT                = 50; // 0x32
    private static final int SYBTEXT               = 35; // 0x23
    private static final int SYBNTEXT              = 99; // 0x63
    private static final int SYBIMAGE              = 34; // 0x22
    private static final int SYBMONEY4             = 122;// 0x7A
    private static final int SYBMONEY              = 60; // 0x3C
    private static final int SYBDATETIME4          = 58; // 0x3A
    private static final int SYBREAL               = 59; // 0x3B
    private static final int SYBBINARY             = 45; // 0x2D
    private static final int SYBVOID               = 31; // 0x1F
    private static final int SYBVARBINARY          = 37; // 0x25
    private static final int SYBNVARCHAR           = 103;// 0x67
    private static final int SYBBITN               = 104;// 0x68
    private static final int SYBNUMERIC            = 108;// 0x6C
    private static final int SYBDECIMAL            = 106;// 0x6A
    private static final int SYBFLTN               = 109;// 0x6D
    private static final int SYBMONEYN             = 110;// 0x6E
    private static final int SYBDATETIMN           = 111;// 0x6F
    private static final int SYBDATEN              = 123;// 0x7B SYBASE 12
    private static final int SYBTIMEN              = 147;// 0x93 SYBASE 12
    private static final int XSYBCHAR              = 175;// 0xAF
    private static final int XSYBVARCHAR           = 167;// 0xA7
    private static final int XSYBNVARCHAR          = 231;// 0xE7
    private static final int XSYBNCHAR             = 239;// 0xEF
    private static final int XSYBVARBINARY         = 165;// 0xA5
    private static final int XSYBBINARY            = 173;// 0xAD
    private static final int SYBLONGBINARY         = 225;// 0xE1 SYBASE 12
    private static final int SYBSINT1              = 64; // 0x40
    private static final int SYBUINT2              = 65; // 0x41
    private static final int SYBUINT4              = 66; // 0x42
    private static final int SYBUINT8              = 67; // 0x43
    private static final int SYBUNIQUE             = 36; // 0x24
    private static final int SYBVARIANT            = 98; // 0x62
    /*
     * Special case for Sybase 12.5+
     * This long data type is used to send text and image
     * data as statement parameters as a replacement for
     * writetext.
     * As far as I can tell this data type is only sent not
     * received.
     */
    static final int SYBLONGDATA                   = 36; // 0x24 SYBASE 12

    /*
     * Constants for Sybase User Defined data types used to
     * qualify the new longchar and longbinary types.
     */
    private static final int UDT_CHAR              =  1; // 0x01
    private static final int UDT_VARCHAR           =  2; // 0x02
    private static final int UDT_BINARY            =  3; // 0x03
    private static final int UDT_VARBINARY         =  4; // 0x04
    private static final int UDT_NCHAR             = 18; // 0x03
    private static final int UDT_NVARCHAR          = 19; // 0x03
    private static final int UDT_UNICHAR           = 34; // 0x22
    private static final int UDT_UNIVARCHAR        = 35; // 0x23
    // Common to Sybase and SQL Server
    private static final int UDT_TIMESTAMP         = 80; // 0x50
    private static final int UDT_SYSNAME           = 18; // 0x12
    // SQL Server 7+
    private static final int UDT_NEWSYSNAME        =256; // 0x100

    /*
     * Constants for variable length data types
     */
    private static final int VAR_MAX               = 255;
    private static final int SYB_LONGVAR_MAX       = 16384;
    private static final int MS_LONGVAR_MAX        = 8000;
    private static final int SYB_CHUNK_SIZE        = 8192;

    /**
     * Array of TDS data type descriptors.
     */
    private final static TypeInfo types[] = new TypeInfo[256];

    /**
     * Static block to initialise TDS data type descriptors.
     */
    static {//                             SQL Type       Size Prec  DS signed TDS8 Col java Type
        types[SYBCHAR]      = new TypeInfo("char",          -1, -1,  1, false, false, java.sql.Types.CHAR);
        types[SYBVARCHAR]   = new TypeInfo("varchar",       -1, -1,  1, false, false, java.sql.Types.VARCHAR);
        types[SYBINTN]      = new TypeInfo("int",           -1, 10, 11, true,  false, java.sql.Types.INTEGER);
        types[SYBINT1]      = new TypeInfo("tinyint",        1,  3,  4, false, false, java.sql.Types.TINYINT);
        types[SYBINT2]      = new TypeInfo("smallint",       2,  5,  6, true,  false, java.sql.Types.SMALLINT);
        types[SYBINT4]      = new TypeInfo("int",            4, 10, 11, true,  false, java.sql.Types.INTEGER);
        types[SYBINT8]      = new TypeInfo("bigint",         8, 19, 20, true,  false, java.sql.Types.BIGINT);
        types[SYBFLT8]      = new TypeInfo("float",          8, 15, 24, true,  false, java.sql.Types.DOUBLE);
        types[SYBDATETIME]  = new TypeInfo("datetime",       8, 23, 23, false, false, java.sql.Types.TIMESTAMP);
        types[SYBBIT]       = new TypeInfo("bit",            1,  1,  1, false, false, java.sql.Types.BIT);
        types[SYBTEXT]      = new TypeInfo("text",          -4, -1, -1, false, true,  java.sql.Types.CLOB);
        types[SYBNTEXT]     = new TypeInfo("ntext",         -4, -1, -1, false, true,  java.sql.Types.CLOB);
        types[SYBIMAGE]     = new TypeInfo("image",         -4, -1, -1, false, false, java.sql.Types.BLOB);
        types[SYBMONEY4]    = new TypeInfo("smallmoney",     4, 10, 12, true,  false, java.sql.Types.DECIMAL);
        types[SYBMONEY]     = new TypeInfo("money",          8, 19, 21, true,  false, java.sql.Types.DECIMAL);
        types[SYBDATETIME4] = new TypeInfo("smalldatetime",  4, 16, 19, false, false, java.sql.Types.TIMESTAMP);
        types[SYBREAL]      = new TypeInfo("real",           4,  7, 14, true,  false, java.sql.Types.REAL);
        types[SYBBINARY]    = new TypeInfo("binary",        -1, -1,  2, false, false, java.sql.Types.BINARY);
        types[SYBVOID]      = new TypeInfo("void",          -1,  1,  1, false, false, 0);
        types[SYBVARBINARY] = new TypeInfo("varbinary",     -1, -1, -1, false, false, java.sql.Types.VARBINARY);
        types[SYBNVARCHAR]  = new TypeInfo("nvarchar",      -1, -1, -1, false, false, java.sql.Types.VARCHAR);
        types[SYBBITN]      = new TypeInfo("bit",           -1,  1,  1, false, false, java.sql.Types.BIT);
        types[SYBNUMERIC]   = new TypeInfo("numeric",       -1, -1, -1, true,  false, java.sql.Types.NUMERIC);
        types[SYBDECIMAL]   = new TypeInfo("decimal",       -1, -1, -1, true,  false, java.sql.Types.DECIMAL);
        types[SYBFLTN]      = new TypeInfo("float",         -1, 15, 24, true,  false, java.sql.Types.DOUBLE);
        types[SYBMONEYN]    = new TypeInfo("money",         -1, 19, 21, true,  false, java.sql.Types.DECIMAL);
        types[SYBDATETIMN]  = new TypeInfo("datetime",      -1, 23, 23, false, false, java.sql.Types.TIMESTAMP);
        types[SYBDATE]      = new TypeInfo("date",           4, 10, 10, false, false, java.sql.Types.DATE);
        types[SYBTIME]      = new TypeInfo("time",           4,  8,  8, false, false, java.sql.Types.TIME);
        types[SYBDATEN]     = new TypeInfo("date",          -1, 10, 10, false, false, java.sql.Types.DATE);
        types[SYBTIMEN]     = new TypeInfo("time",          -1,  8,  8, false, false, java.sql.Types.TIME);
        types[XSYBCHAR]     = new TypeInfo("char",          -2, -1, -1, false, true,  java.sql.Types.CHAR);
        types[XSYBVARCHAR]  = new TypeInfo("varchar",       -2, -1, -1, false, true,  java.sql.Types.VARCHAR);
        types[XSYBNVARCHAR] = new TypeInfo("nvarchar",      -2, -1, -1, false, true,  java.sql.Types.VARCHAR);
        types[XSYBNCHAR]    = new TypeInfo("nchar",         -2, -1, -1, false, true,  java.sql.Types.CHAR);
        types[XSYBVARBINARY]= new TypeInfo("varbinary",     -2, -1, -1, false, false, java.sql.Types.VARBINARY);
        types[XSYBBINARY]   = new TypeInfo("binary",        -2, -1, -1, false, false, java.sql.Types.BINARY);
        types[SYBLONGBINARY]= new TypeInfo("varbinary",     -5, -1,  2, false, false, java.sql.Types.BINARY);
        types[SYBSINT1]     = new TypeInfo("tinyint",        1,  2,  3, false, false, java.sql.Types.TINYINT);
        types[SYBUINT2]     = new TypeInfo("smallint",       2,  5,  6, false, false, java.sql.Types.SMALLINT);
        types[SYBUINT4]     = new TypeInfo("int",            4, 10, 11, false, false, java.sql.Types.INTEGER);
        types[SYBUINT8]     = new TypeInfo("bigint",         8, 20, 20, false, false, java.sql.Types.BIGINT);
        types[SYBUNIQUE]    = new TypeInfo("uniqueidentifier",-1,36,36, false, false, java.sql.Types.CHAR);
        types[SYBVARIANT]   = new TypeInfo("sql_variant",   -5,  0, 8000, false, false, java.sql.Types.VARCHAR);
    }

    /** Default Decimal Scale. */
    static final int DEFAULT_SCALE = 10;

    /**
     * TDS 8 supplies collation information for character data types.
     *
     * @param in the server response stream
     * @param ci the column descriptor
     * @return the number of bytes read from the stream as an <code>int</code>
     */
    static int getCollation(ResponseStream in, ColInfo ci) throws IOException {
        if (TdsData.isCollation(ci)) {
            // Read TDS8 collation info
            ci.collation = new byte[5];
            in.read(ci.collation);

            return 5;
        }

        return 0;
    }

    /**
     * Set the <code>charsetInfo</code> field of <code>ci</code> according to
     * the value of its <code>collation</code> field.
     * <p>
     * The <code>Connection</code> is used to find out whether a specific
     * charset was requested. In this case, the column charset will be ignored.
     *
     * @param ci         the <code>ColInfo</code> instance to update
     * @param connection a <code>Connection</code> instance to check whether it
     *                   has a fixed charset or not
     * @throws SQLException if a <code>CharsetInfo</code> is not found for this
     *                      particular column collation
     */
    static void setColumnCharset(ColInfo ci, ConnectionJDBC2 connection)
            throws SQLException {
        if (connection.isCharsetSpecified()) {
            // If a charset was requested on connection creation, ignore the
            // column collation and use default
            ci.charsetInfo = connection.getCharsetInfo();
        } else if (ci.collation != null) {
            // TDS version will be 8.0 or higher in this case and connection
            // collation will be non-null
            byte[] collation = ci.collation;
            byte[] defaultCollation = connection.getCollation();
            int i;

            for (i = 0; i < 5; ++i) {
                if (collation[i] != defaultCollation[i]) {
                    break;
                }
            }

            if (i == 5) {
                ci.charsetInfo = connection.getCharsetInfo();
            } else {
                ci.charsetInfo = CharsetInfo.getCharset(collation);
            }
        }
    }

    /**
     * Read the TDS datastream and populate the ColInfo parameter with
     * data type and related information.
     * <p>The type infomation conforms to one of the following formats:
     * <ol>
     * <li> [int1 type]  - eg SYBINT4.
     * <li> [int1 type] [int1 buffersize]  - eg VARCHAR &lt; 256
     * <li> [int1 type] [int2 buffersize]  - eg VARCHAR &gt; 255.
     * <li> [int1 type] [int4 buffersize] [int1 tabnamelen] [int1*n tabname] - eg text.
     * <li> [int1 type] [int4 buffersize] - eg sql_variant.