cursor.java

derby database source code.good for you.

        return org.apache.derby.client.am.SignedBinary.getLong(dataBuffer_,
                columnDataPosition_[column - 1]);
    }

    // Build a Java float from a 4-byte floating point representation.
    private final float get_FLOAT(int column) {
        return org.apache.derby.client.am.FloatingPoint.getFloat(dataBuffer_,
                columnDataPosition_[column - 1]);
    }

    // Build a Java double from an 8-byte floating point representation.
    private final double get_DOUBLE(int column) {
        return org.apache.derby.client.am.FloatingPoint.getDouble(dataBuffer_,
                columnDataPosition_[column - 1]);
    }

    // Build a java.math.BigDecimal from a fixed point decimal byte representation.
    private final java.math.BigDecimal get_DECIMAL(int column) throws SqlException {
        try {
            return org.apache.derby.client.am.Decimal.getBigDecimal(dataBuffer_,
                    columnDataPosition_[column - 1],
                    getColumnPrecision(column - 1),
                    getColumnScale(column - 1));
        } catch (java.io.UnsupportedEncodingException e) {
            throw new SqlException(agent_.logWriter_, e, "Encoding is unsupported for conversion to BigDecimal");
        }
    }


    // Build a Java double from a fixed point decimal byte representation.
    private final double getDoubleFromDECIMAL(int column) throws SqlException {
        try {
            return org.apache.derby.client.am.Decimal.getDouble(dataBuffer_,
                    columnDataPosition_[column - 1],
                    getColumnPrecision(column - 1),
                    getColumnScale(column - 1));
        } catch (java.lang.IllegalArgumentException e) {
            throw new SqlException(agent_.logWriter_, e, "Decimal value is out of range for conversion to double");
        } catch (java.io.UnsupportedEncodingException e) {
            throw new SqlException(agent_.logWriter_, e, "Encoding is unsupported for conversion to BigDecimal");
        }
    }

    // Build a Java long from a fixed point decimal byte representation.
    private final long getLongFromDECIMAL(int column) throws SqlException {
        try {
            return org.apache.derby.client.am.Decimal.getLong(dataBuffer_,
                    columnDataPosition_[column - 1],
                    getColumnPrecision(column - 1),
                    getColumnScale(column - 1));
        } catch (java.lang.IllegalArgumentException e) {
            throw new SqlException(agent_.logWriter_, e, "Decimal value is out of range for conversion to long");
        } catch (java.io.UnsupportedEncodingException e) {
            throw new SqlException(agent_.logWriter_, e, "Encoding is unsupported for conversion to BigDecimal");
        }
    }

    // Build a Java String from a database VARCHAR or LONGVARCHAR field.
    //
    // Depending on the ccsid, length is the number of chars or number of bytes.
    // For 2-byte character ccsids, length is the number of characters,
    // for all other cases length is the number of bytes.
    // The length does not include the null terminator.
    private final String getVARCHAR(int column) throws SqlException {
        String tempString = null;
        try {
            if (ccsid_[column - 1] == 1200) {
                return getStringWithoutConvert(columnDataPosition_[column - 1] + 2, columnDataComputedLength_[column - 1] - 2);
            }

            // check for null encoding is needed because the net layer
            // will no longer throw an exception if the server didn't specify
            // a mixed or double byte ccsid (ccsid = 0).  this check for null in the
            // cursor is only required for types which can have mixed or double
            // byte ccsids.
            if (charsetName_[column - 1] == null) {
                throw new SqlException(agent_.logWriter_,
                        "Required character converter not available for data type.");
            }

            tempString = new String(dataBuffer_,
                    columnDataPosition_[column - 1] + 2,
                    columnDataComputedLength_[column - 1] - 2,
                    charsetName_[column - 1]);
            return (maxFieldSize_ == 0) ? tempString :
                    tempString.substring(0, java.lang.Math.min(maxFieldSize_, tempString.length()));
        } catch (java.io.UnsupportedEncodingException e) {
            throw new SqlException(agent_.logWriter_, e, "unsupported encoding for result set column " + column);
        }
    }

    // Build a Java String from a database CHAR field.
    private final String getCHAR(int column) throws SqlException {
        String tempString = null;
        if (ccsid_[column - 1] == 1200) {
            return getStringWithoutConvert(columnDataPosition_[column - 1], columnDataComputedLength_[column - 1]);
        }

        try {
            // check for null encoding is needed because the net layer
            // will no longer throw an exception if the server didn't specify
            // a mixed or double byte ccsid (ccsid = 0).  this check for null in the
            // cursor is only required for types which can have mixed or double
            // byte ccsids.
            if (charsetName_[column - 1] == null) {
                throw new SqlException(agent_.logWriter_,
                        "Required character converter not available for data type.");
            }

            tempString = new String(dataBuffer_,
                    columnDataPosition_[column - 1],
                    columnDataComputedLength_[column - 1],
                    charsetName_[column - 1]);
            return (maxFieldSize_ == 0) ? tempString :
                    tempString.substring(0, java.lang.Math.min(maxFieldSize_, tempString.length()));
        } catch (java.io.UnsupportedEncodingException e) {
            throw new SqlException(agent_.logWriter_, e, "unsupported encoding for result set column " + column);
        }
    }

    // Build a JDBC Date object from the DERBY ISO DATE field.
    private final java.sql.Date getDATE(int column) throws SqlException {
        try {
            return org.apache.derby.client.am.DateTime.dateBytesToDate(dataBuffer_,
                columnDataPosition_[column - 1],
                recyclableDate_, 
                charsetName_[column - 1]);
        }catch (UnsupportedEncodingException e) {
             throw new SqlException(agent_.logWriter_, e, 
                    "Encoding is unsupported for conversion to DATE");
        }

        
    }

    // Build a JDBC Time object from the DERBY ISO TIME field.
    private final java.sql.Time getTIME(int column) throws SqlException {
        try {
            return org.apache.derby.client.am.DateTime.timeBytesToTime(dataBuffer_,
                    columnDataPosition_[column - 1],
                    recyclableTime_,
                    charsetName_[column - 1]);
        } catch (UnsupportedEncodingException e) {
            throw new SqlException(agent_.logWriter_, e, 
                    "Encoding is unsupported for conversion to TIME");
        }
    }

    // Build a JDBC Timestamp object from the DERBY ISO TIMESTAMP field.
    private final java.sql.Timestamp getTIMESTAMP(int column) throws SqlException {

        try {
        return org.apache.derby.client.am.DateTime.timestampBytesToTimestamp(
                dataBuffer_,
                columnDataPosition_[column - 1],
                recyclableTimestamp_, 
                charsetName_[column - 1]);
    } catch (java.io.UnsupportedEncodingException e) {
        throw new SqlException(agent_.logWriter_, e, 
                "Encoding is unsupported for conversion to TIMESTAMP");
    }
    }

    // Build a JDBC Timestamp object from the DERBY ISO DATE field.
    private final java.sql.Timestamp getTimestampFromDATE(int column) throws SqlException {
        try {
            return org.apache.derby.client.am.DateTime.dateBytesToTimestamp(dataBuffer_,
                    columnDataPosition_[column - 1],
                    recyclableTimestamp_, 
                    charsetName_[column -1]);
        } catch (UnsupportedEncodingException e) {
              throw new SqlException(agent_.logWriter_, e, 
                      "Encoding is unsupported for conversion to TIMESTAMP");            
        }
    }

    // Build a JDBC Timestamp object from the DERBY ISO TIME field.
    private final java.sql.Timestamp getTimestampFromTIME(int column) throws SqlException {
        try {
            return org.apache.derby.client.am.DateTime.timeBytesToTimestamp(dataBuffer_,
                    columnDataPosition_[column - 1],
                    recyclableTimestamp_,
                    charsetName_[column -1]);
        } catch (UnsupportedEncodingException e) {
            throw new SqlException(agent_.logWriter_, e, 
                    "Encoding is unsupported for conversion to TIMESTAMP");
        }
    }

    // Build a JDBC Date object from the DERBY ISO TIMESTAMP field.
    private final java.sql.Date getDateFromTIMESTAMP(int column) throws SqlException {
        try {
            return org.apache.derby.client.am.DateTime.timestampBytesToDate(dataBuffer_,
                    columnDataPosition_[column - 1],
                    recyclableDate_,
                    charsetName_[column -1]);
        } catch (UnsupportedEncodingException e) {
             throw new SqlException(agent_.logWriter_, e, 
                     "Encoding is unsupported for conversion to DATE");
        }
    }

    // Build a JDBC Time object from the DERBY ISO TIMESTAMP field.
    private final java.sql.Time getTimeFromTIMESTAMP(int column) throws SqlException {
        try {
            return org.apache.derby.client.am.DateTime.timestampBytesToTime(dataBuffer_,
                    columnDataPosition_[column - 1],
                    recyclableTime_,
                    charsetName_[column -1]);
        } catch (UnsupportedEncodingException e) {
             throw new SqlException(agent_.logWriter_, e, 
                     "Encoding is unsupported for conversion to TIME");
        }
    }

    private final String getStringFromDATE(int column) throws SqlException {
        return getDATE(column).toString();
    }

    // Build a string object from the DERBY byte TIME representation.
    private final String getStringFromTIME(int column) throws SqlException {
        return getTIME(column).toString();
    }

    // Build a string object from the DERBY byte TIMESTAMP representation.
    private final String getStringFromTIMESTAMP(int column) throws SqlException {
        return getTIMESTAMP(column).toString();
    }

    // Extract bytes from a database java.sql.Types.BINARY field.
    // This is the DERBY type CHAR(n) FOR BIT DATA.
    private final byte[] get_CHAR_FOR_BIT_DATA(int column) throws SqlException {
        // There is no limit to the size of a column if maxFieldSize is zero.
        // Otherwise, use the smaller of maxFieldSize and the actual column length.
        int columnLength = (maxFieldSize_ == 0) ? columnDataComputedLength_[column - 1] :
                java.lang.Math.min(maxFieldSize_, columnDataComputedLength_[column - 1]);

        byte[] bytes = new byte[columnLength];
        System.arraycopy(dataBuffer_, columnDataPosition_[column - 1], bytes, 0, columnLength);
        return bytes;
    }

    // Extract bytes from a database java.sql.Types.VARBINARY or LONGVARBINARY field.
    // This includes the DERBY types:
    //   VARCHAR(n) FOR BIT DATA
    //   LONG VARCHAR(n) FOR BIT DATA
    private final byte[] get_VARCHAR_FOR_BIT_DATA(int column) throws SqlException {
        byte[] bytes;
        int columnLength = 0;
        columnLength = (maxFieldSize_ == 0) ? columnDataComputedLength_[column - 1] - 2 :
                java.lang.Math.min(maxFieldSize_, columnDataComputedLength_[column - 1] - 2);
        bytes = new byte[columnLength];
        System.arraycopy(dataBuffer_, columnDataPosition_[column - 1] + 2, bytes, 0, bytes.length);
        return bytes;
    }

    abstract public Blob getBlobColumn_(int column, Agent agent) throws SqlException;

    abstract public Clob getClobColumn_(int column, Agent agent) throws SqlException;

    // get the raw clob bytes, without translation.  dataOffset must be int[1]
    abstract public byte[] getClobBytes_(int column, int[] dataOffset /*output*/) throws SqlException;

    //------- the following getters perform any necessary cross-conversion _------

    final boolean getBoolean(int column) throws SqlException {
        switch (jdbcTypes_[column - 1]) {
        case java.sql.Types.SMALLINT:
            return agent_.crossConverters_.getBooleanFromShort(get_SMALLINT(column));
        case java.sql.Types.INTEGER:
            return agent_.crossConverters_.getBooleanFromInt(get_INTEGER(column));
        case java.sql.Types.BIGINT:
            return agent_.crossConverters_.getBooleanFromLong(get_BIGINT(column));
        case java.sql.Types.REAL:
            return agent_.crossConverters_.getBooleanFromFloat(get_FLOAT(column));
        case java.sql.Types.DOUBLE:
            return agent_.crossConverters_.getBooleanFromDouble(get_DOUBLE(column));
        case java.sql.Types.DECIMAL:
            // For performance we don't materialize the BigDecimal, but convert directly from decimal bytes to a long.
            return agent_.crossConverters_.getBooleanFromLong(getLongFromDECIMAL(column));