connectionjdbc2.java

jtds的源码 是你学习java的好东西

        appName = info.getProperty(Messages.get(Driver.APPNAME));
        progName = info.getProperty(Messages.get(Driver.PROGNAME));
        wsid = info.getProperty(Messages.get(Driver.WSID));
        serverCharset = info.getProperty(Messages.get(Driver.CHARSET));
        language = info.getProperty(Messages.get(Driver.LANGUAGE));
        bindAddress = info.getProperty(Messages.get(Driver.BINDADDRESS));
        lastUpdateCount = "true".equalsIgnoreCase(
                info.getProperty(Messages.get(Driver.LASTUPDATECOUNT)));
        useUnicode = "true".equalsIgnoreCase(
                info.getProperty(Messages.get(Driver.SENDSTRINGPARAMETERSASUNICODE)));
        namedPipe = "true".equalsIgnoreCase(
                info.getProperty(Messages.get(Driver.NAMEDPIPE)));
        tcpNoDelay = "true".equalsIgnoreCase(
                info.getProperty(Messages.get(Driver.TCPNODELAY)));
        useCursors = (serverType == Driver.SQLSERVER)
                && "true".equalsIgnoreCase(
                        info.getProperty(Messages.get(Driver.USECURSORS)));
        useLOBs = "true".equalsIgnoreCase(
                info.getProperty(Messages.get(Driver.USELOBS)));
        useMetadataCache = "true".equalsIgnoreCase(
                info.getProperty(Messages.get(Driver.CACHEMETA)));
        xaEmulation = "true".equalsIgnoreCase(
                info.getProperty(Messages.get(Driver.XAEMULATION)));
        useJCIFS = "true".equalsIgnoreCase(
                info.getProperty(Messages.get(Driver.USEJCIFS)));
        charsetSpecified = serverCharset.length() > 0;
        useNTLMv2 = "true".equalsIgnoreCase(
                info.getProperty(Messages.get(Driver.USENTLMV2)));

        //note:mdb in certain cases (e.g. NTLMv2) the domain name must be
        //  all upper case for things to work.
        if( domainName != null )
            domainName = domainName.toUpperCase();

        Integer parsedTdsVersion =
                DefaultProperties.getTdsVersion(info.getProperty(Messages.get(Driver.TDS)));
        if (parsedTdsVersion == null) {
            throw new SQLException(Messages.get("error.connection.badprop",
                    Messages.get(Driver.TDS)), "08001");
        }
        tdsVersion = parsedTdsVersion.intValue();

        packetSize = parseIntegerProperty(info, Driver.PACKETSIZE);
        if (packetSize < TdsCore.MIN_PKT_SIZE) {
            if (tdsVersion >= Driver.TDS70) {
                // Default of 0 means let the server specify packet size
                packetSize = (packetSize == 0) ? 0 : TdsCore.DEFAULT_MIN_PKT_SIZE_TDS70;
            } else if (tdsVersion == Driver.TDS42) {
                // Sensible minimum for older versions of TDS
                packetSize = TdsCore.MIN_PKT_SIZE;
            } // else for TDS 5 can auto negotiate
        }
        if (packetSize > TdsCore.MAX_PKT_SIZE) {
            packetSize = TdsCore.MAX_PKT_SIZE;
        }
        packetSize = (packetSize / 512) * 512;

        loginTimeout = parseIntegerProperty(info, Driver.LOGINTIMEOUT);
        socketTimeout = parseIntegerProperty(info, Driver.SOTIMEOUT);
        lobBuffer = parseLongProperty(info, Driver.LOBBUFFER);

        maxStatements = parseIntegerProperty(info, Driver.MAXSTATEMENTS);

        statementCache = new ProcedureCache(maxStatements);
        prepareSql = parseIntegerProperty(info, Driver.PREPARESQL);
        if (prepareSql < 0) {
            prepareSql = 0;
        } else if (prepareSql > 3) {
            prepareSql = 3;
        }
        // For Sybase use equivalent of sp_executesql.
        if (tdsVersion < Driver.TDS70 && prepareSql == TdsCore.PREPARE) {
            prepareSql = TdsCore.EXECUTE_SQL;
        }
        // For SQL 6.5 sp_executesql not available so use stored procedures.
        if (tdsVersion < Driver.TDS50 && prepareSql == TdsCore.EXECUTE_SQL) {
            prepareSql = TdsCore.TEMPORARY_STORED_PROCEDURES;
        }

        ssl = info.getProperty(Messages.get(Driver.SSL));

        batchSize = parseIntegerProperty(info, Driver.BATCHSIZE);
        if (batchSize < 0) {
            throw new SQLException(Messages.get("error.connection.badprop",
                    Messages.get(Driver.BATCHSIZE)), "08001");
        }
        
        bufferDir = new File(info.getProperty(Messages.get(Driver.BUFFERDIR)));
        if (!bufferDir.isDirectory()) {
        	if (!bufferDir.mkdirs()) {
                throw new SQLException(Messages.get("error.connection.badprop",
                        Messages.get(Driver.BUFFERDIR)), "08001");
        	}
        }

        bufferMaxMemory = parseIntegerProperty(info, Driver.BUFFERMAXMEMORY);
        if (bufferMaxMemory < 0) {
            throw new SQLException(Messages.get("error.connection.badprop",
                    Messages.get(Driver.BUFFERMAXMEMORY)), "08001");
        }

        bufferMinPackets = parseIntegerProperty(info, Driver.BUFFERMINPACKETS);
        if (bufferMinPackets < 1) {
            throw new SQLException(Messages.get("error.connection.badprop",
                    Messages.get(Driver.BUFFERMINPACKETS)), "08001");
        }
    }

    /**
     * Parse a string property value into an integer value.
     *
     * @param info The connection properties object.
     * @param key The message key used to retrieve the property name.
     * @return The integer value of the string property value.
     * @throws SQLException If the property value can't be parsed.
     */
    private static int parseIntegerProperty(final Properties info, final String key)
            throws SQLException {

        final String propertyName = Messages.get(key);
        try {
            return Integer.parseInt(info.getProperty(propertyName));
        } catch (NumberFormatException e) {
            throw new SQLException(
                    Messages.get("error.connection.badprop", propertyName), "08001");
        }
    }

    /**
     * Parse a string property value into a long value.
     *
     * @param info The connection properties object.
     * @param key The message key used to retrieve the property name.
     * @return The long value of the string property value.
     * @throws SQLException If the property value can't be parsed.
     */
    private static long parseLongProperty(final Properties info, final String key)
            throws SQLException {

        final String propertyName = Messages.get(key);
        try {
            return Long.parseLong(info.getProperty(propertyName));
        } catch (NumberFormatException e) {
            throw new SQLException(
                    Messages.get("error.connection.badprop", propertyName), "08001");
        }
    }

    /**
     * Retrieve the Java charset to use for encoding.
     *
     * @return the Charset name as a <code>String</code>
     */
    protected String getCharset() {
        return charsetInfo.getCharset();
    }

    /**
     * Retrieve the multibyte status of the current character set.
     *
     * @return <code>boolean</code> true if a multi byte character set
     */
    protected boolean isWideChar() {
        return charsetInfo.isWideChars();
    }

    /**
     * Retrieve the <code>CharsetInfo</code> instance used by this connection.
     *
     * @return the default <code>CharsetInfo</code> for this connection
     */
    protected CharsetInfo getCharsetInfo() {
        return charsetInfo;
    }

    /**
     * Retrieve the sendParametersAsUnicode flag.
     *
     * @return <code>boolean</code> true if parameters should be sent as unicode.
     */
    protected boolean getUseUnicode() {
        return this.useUnicode;
    }

    /**
     * Retrieve the Sybase capability data.
     *
     * @return Capability bit mask as an <code>int</code>.
     */
    protected boolean getSybaseInfo(int flag) {
        return (this.sybaseInfo & flag) != 0;
    }

    /**
     * Set the Sybase capability data.
     *
     * @param mask The capability bit mask.
     */
    protected void setSybaseInfo(int mask) {
        this.sybaseInfo = mask;
    }

    /**
     * Called by the protocol to change the current character set.
     *
     * @param charset the server character set name
     */
    protected void setServerCharset(final String charset) throws SQLException {
        // If the user specified a charset, ignore environment changes
        if (charsetSpecified) {
            Logger.println("Server charset " + charset +
                    ". Ignoring as user requested " + serverCharset + '.');
            return;
        }

        if (!charset.equals(serverCharset)) {
            loadCharset(charset);

            if (Logger.isActive()) {
                Logger.println("Set charset to " + serverCharset + '/'
                        + charsetInfo);
            }
        }
    }

    /**
     * Load the Java charset to match the server character set.
     *
     * @param charset the server character set
     */
    private void loadCharset(String charset) throws SQLException {
        // MS SQL Server's iso_1 is Cp1252 not ISO-8859-1!
        if (getServerType() == Driver.SQLSERVER
                && charset.equalsIgnoreCase("iso_1")) {
            charset = "Cp1252";
        }

        // Do not default to any charset; if the charset is not found we want
        // to know about it
        CharsetInfo tmp = CharsetInfo.getCharset(charset);

        if (tmp == null) {
            throw new SQLException(
                    Messages.get("error.charset.nomapping", charset), "2C000");
        }

        loadCharset(tmp, charset);
        serverCharset = charset;
    }

    /**
     * Load the Java charset to match the server character set.
     *
     * @param ci the <code>CharsetInfo</code> to load
     */
    private void loadCharset(CharsetInfo ci, String ref) throws SQLException {
        try {
            "This is a test".getBytes(ci.getCharset());

            charsetInfo = ci;
        } catch (UnsupportedEncodingException ex) {
            throw new SQLException(
                    Messages.get("error.charset.invalid", ref,
                            ci.getCharset()),
                    "2C000");
        }

        socket.setCharsetInfo(charsetInfo);
    }

    /**
     * Discovers the server charset for server versions that do not send
     * <code>ENVCHANGE</code> packets on login ack, by executing a DB
     * vendor/version specific query.
     * <p>
     * Will throw an <code>SQLException</code> if used on SQL Server 7.0 or
     * 2000; the idea is that the charset should already be determined from
     * <code>ENVCHANGE</code> packets for these DB servers.
     * <p>
     * Should only be called from the constructor.
     *
     * @return the default server charset
     * @throws SQLException if an error condition occurs
     */
    private String determineServerCharset() throws SQLException {
        String queryStr = null;

        switch (serverType) {
            case Driver.SQLSERVER:
                if (databaseProductVersion.indexOf("6.5") >= 0) {
                    queryStr = SQL_SERVER_65_CHARSET_QUERY;
                } else {
                    // This will never happen. Versions 7.0 and 2000 of SQL
                    // Server always send ENVCHANGE packets, even over TDS 4.2.
                    throw new SQLException(
                            "Please use TDS protocol version 7.0 or higher");
                }
                break;
            case Driver.SYBASE:
                // There's no need to check for versions here
                queryStr = SYBASE_SERVER_CHARSET_QUERY;
                break;
        }

        Statement stmt = this.createStatement();
        ResultSet rs = stmt.executeQuery(queryStr);
        rs.next();
        String charset = rs.getString(1);
        rs.close();
        stmt.close();

        return charset;
    }

    /**
     * Set the default collation for this connection.
     * <p>
     * Set by a SQL Server 2000 environment change packet. The collation
     * consists of the following fields:
     * <ul>
     * <li>bits 0-19  - The locale eg 0x0409 for US English which maps to code
     *                  page 1252 (Latin1_General).
     * <li>bits 20-31 - Reserved.
     * <li>bits 32-39 - Sort order (csid from syscharsets)
     * </ul>
     * If the sort order is non-zero it determines the character set, otherwise
     * the character set is determined by the locale id.
     *
     * @param collation The new collation.
     */
    void setCollation(byte[] collation) throws SQLException {
        String strCollation = "0x" + Support.toHex(collation);
        // If the user specified a charset, ignore environment changes
        if (charsetSpecified) {
            Logger.println("Server collation " + strCollation +
                    ". Ignoring as user requested " + serverCharset + '.');
            return;
        }

        CharsetInfo tmp = CharsetInfo.getCharset(collation);

        loadCharset(tmp, strCollation);
        this.collation = collation;

        if (Logger.isActive()) {
            Logger.println("Set collation to " + strCollation + '/'
                    + charsetInfo);
        }
    }

    /**
     * Retrieve the SQL Server 2000 default collation.
     *
     * @return The collation as a <code>byte[5]</code>.
     */
    byte[] getCollation() {
        return this.collation;
    }

    /**
     * Retrieves whether a specific charset was requested on creation. If this
     * is the case, all character data should be encoded/decoded using that
     * charset.
     */
    boolean isCharsetSpecified() {
        return charsetSpecified;
    }

    /**