jdbcresultset.java

纯Java的数据库

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>short</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>0</code>
     * @exception SQLException if a database access error occurs
     */
    public short getShort(int columnIndex) throws SQLException {

        Object o = getColumnInType(columnIndex, Types.SMALLINT);

        return o == null ? 0
                         : ((Number) o).shortValue();
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * an <code>int</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>0</code>
     * @exception SQLException if a database access error occurs
     */
    public int getInt(int columnIndex) throws SQLException {

        Object o = getColumnInType(columnIndex, Types.INTEGER);

        return o == null ? 0
                         : ((Number) o).intValue();
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>long</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>0</code>
     * @exception SQLException if a database access error occurs
     */
    public long getLong(int columnIndex) throws SQLException {

        Object o = getColumnInType(columnIndex, Types.BIGINT);

        return o == null ? 0
                         : ((Number) o).longValue();
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>float</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>0</code>
     * @exception SQLException if a database access error occurs
     */
    public float getFloat(int columnIndex) throws SQLException {

        Object o = getColumnInType(columnIndex, Types.REAL);

        return o == null ? (float) 0.0
                         : ((Number) o).floatValue();
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>double</code> in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>0</code>
     * @exception SQLException if a database access error occurs
     */
    public double getDouble(int columnIndex) throws SQLException {

        Object o = getColumnInType(columnIndex, Types.DOUBLE);

        return o == null ? 0.0
                         : ((Number) o).doubleValue();
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>java.sql.BigDecimal</code> in the Java programming language.<p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * Beginning with 1.7.0, HSQLDB converts the result and sets the scale
     * with BigDecimal.ROUND_HALF_DOWN.
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @param scale the number of digits to the right of the decimal point
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>null</code>
     * @exception SQLException if a database access error occurs
     * @deprecated by java.sun.com as of JDK 1.2
     */

//#ifdef DEPRECATEDJDBC
    public BigDecimal getBigDecimal(int columnIndex,
                                    int scale) throws SQLException {

        // boucherb@users 20020502 - added conversion
        BigDecimal bd = (BigDecimal) getColumnInType(columnIndex,
            Types.DECIMAL);

        if (scale < 0) {
            throw Util.sqlException(Trace.INVALID_JDBC_ARGUMENT);
        }

        if (bd != null) {
            bd = bd.setScale(scale, BigDecimal.ROUND_HALF_DOWN);
        }

        return bd;
    }

//#endif

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>byte</code> array in the Java programming language.
     * The bytes represent the raw values returned by the driver. <p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * HSQLDB returns correct values for columns of type <code>BINARY</code>,
     * <code>CHAR</code> and their variations. For other types, it returns
     * the <code>byte[]</code> for the <code>String</code> representation
     * of the value.
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>null</code>
     * @exception SQLException if a database access error occurs
     */
    public byte[] getBytes(int columnIndex) throws SQLException {

        Object x = getObject(columnIndex);

        if (x == null) {
            return null;
        }

        if (x instanceof byte[]) {
            return (byte[]) x;
        }

        if (x instanceof java.lang.String) {
            return ((String) x).getBytes();
        }

        x = getColumnInType(columnIndex, Types.BINARY);

        return (byte[]) x;
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as a
     * <code>java.sql.Date</code> object in the Java programming language.<p>
     * <!-- end generic documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>null</code>
     * @exception SQLException if a database access error occurs
     */
    public Date getDate(int columnIndex) throws SQLException {
        return (Date) getColumnInType(columnIndex, Types.DATE);
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as a <code>java.sql.Time</code>
     * object in the Java programming language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>null</code>
     * @exception SQLException if a database access error occurs
     */
    public Time getTime(int columnIndex) throws SQLException {
        return (Time) getColumnInType(columnIndex, Types.TIME);
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a <code>java.sql.Timestamp</code> object in the Java programming
     * language. <p>
     * <!-- end generic documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return the column value; if the value is SQL <code>NULL</code>, the
     * value returned is <code>null</code>
     * @exception SQLException if a database access error occurs
     */
    public Timestamp getTimestamp(int columnIndex) throws SQLException {
        return (Timestamp) getColumnInType(columnIndex, Types.TIMESTAMP);
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * a stream of ASCII characters. The value can then be read in chunks
     * from the stream. This method is particularly
     * suitable for retrieving large <char>LONGVARCHAR</char> values.
     * The JDBC driver will
     * do any necessary conversion from the database format into ASCII.
     *
     * <P><B>Note:</B> All the data in the returned stream must be
     * read prior to getting the value of any other column. The next
     * call to a getter method implicitly closes the stream.  Also, a
     * stream may return <code>0</code> when the method
     * <code>InputStream.available</code>
     * is called whether there is data available or not. <p>
     * <!-- end generic documentation -->
     *
     * <!-- start release-specific documentation -->
     * <div class="ReleaseSpecificDocumentation">
     * <h3>HSQLDB-Specific Information:</h3> <p>
     *
     * The limitation noted above does not apply to HSQLDB.<p>
     *
     * In 1.6.1 and previous, getAsciiStream was identical to
     * getUnicodeStream and both simply returned a byte stream
     * constructed from the raw {@link #getBytes(int) getBytes}
     * representation.
     *
     * Starting with 1.7.0, this has been updated to comply with the
     * java.sql specification.
     *
     * When the column is of type CHAR and its variations, it requires no
     * conversion since it is represented internally already as a
     * Java String object. When the column is not of type CHAR and its
     * variations, the returned stream is based on a conversion to the
     * Java <code>String</code> representation of the value. In either case,
     * the obtained stream is always equivalent to a stream of the low order
     * bytes from the value's String representation. <p>
     *
     * HSQLDB SQL <code>CHAR</code> and its variations are all Unicode strings
     * internally, so the recommended alternatives to this method are
     * {@link #getString(int) getString},
     * {@link #getUnicodeStream(int) getUnicodeStream} (<b>deprecated</b>)
     * and new to 1.7.0: {@link #getCharacterStream(int) getCharacterStream}
     * (now prefered over the deprecated getUnicodeStream alternative).
     * </div>
     * <!-- end release-specific documentation -->
     *
     * @param columnIndex the first column is 1, the second is 2, ...
     * @return a Java input stream that delivers the database column value
     * as a stream of one-byte ASCII characters;
     * if the value is SQL <code>NULL</code>, the
     * value returned is <code>null</code>
     * @exception SQLException if a database access error occurs
     */
    public java.io.InputStream getAsciiStream(int columnIndex)
    throws SQLException {

        String s = getString(columnIndex);

        if (s == null) {
            return null;
        }

        return new AsciiStringInputStream(s);
    }

    /**
     * <!-- start generic documentation -->
     * Retrieves the value of the designated column in the current row
     * of this <code>ResultSet</code> object as
     * as a stream of two-byte Unicode characters. The first byte is
     * the high byte; the second byte is the low byte.
     *