+
−/*
+
− * This Source Code Form is subject to the terms of the Mozilla Public
+
− * License, v. 2.0.  If a copy of the MPL was not distributed with this
+
− * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
− *
+
− * Copyright 1997 - July 2008 CWI, August 2008 - 2016 MonetDB B.V.
+
− */
+
−
+
−package nl.cwi.monetdb.jdbc;
+
−
+
−import java.sql.*;
+
−import java.util.Arrays;
+
−import java.io.*;
+
−
+
−/**
+
− * The MonetBlob class implements the {@link java.sql.Blob} interface.  Because
+
− * MonetDB/SQL currently has no support for streams, this class is a
+
− * shallow wrapper of a byte[].  It is more or less supplied to
+
− * enable an application that depends on it to run.  It may be obvious
+
− * that it is a real resource expensive workaround that contradicts the
+
− * benefits for a Blob: avoidance of huge resource consumption.
+
− *
+
− * @author Fabian Groffen
+
− */
+
−public class MonetBlob implements Blob, Serializable, Comparable<MonetBlob> {
+
−
+
−	private byte[] buffer;
+
−
+
−	public MonetBlob(byte[] buf) {
+
−		this.buffer = buf;
+
−	}
+
−
+
−	public byte[] getBuffer() {
+
−		return buffer;
+
−	}
+
−
+
−	//== begin interface Blob
+
−
+
−	/**
+
−	 * This method frees the Blob object and releases the resources that it holds. The object is invalid once the
+
−	 * free method is called.
+
−	 *
+
−	 * After free has been called, any attempt to invoke a method other than free will result in a SQLException being
+
−	 * thrown. If free is called multiple times, the subsequent calls to free are treated as a no-op.
+
−	 */
+
−	@Override
+
−	public void free() throws SQLException {
+
−		buffer = null;
+
−	}
+
−
+
−	/**
+
−	 * Retrieves the BLOB value designated by this Blob instance as a stream.
+
−	 *
+
−	 * @return a stream containing the BLOB data
+
−	 * @throws SQLException if there is an error accessing the BLOB value
+
−	 */
+
−	@Override
+
−	public InputStream getBinaryStream() throws SQLException {
+
−		if (buffer == null)
+
−			throw new SQLException("This Blob object has been freed", "M1M20");
+
−		return new ByteArrayInputStream(buffer);
+
−	}
+
−
+
−	/**
+
−	 * Returns an InputStream object that contains a partial Blob value, starting with the byte specified by pos,
+
−	 * which is length bytes in length.
+
−	 *
+
−	 * @param pos the offset to the first byte of the partial value to be retrieved. The first byte in the Blob is at
+
−	 * position 1
+
−	 * @param length the length in bytes of the partial value to be retrieved
+
−	 * @return InputStream through which the partial Blob value can be read.
+
−	 * @throws SQLException if pos is less than 1 or if pos is greater than the number of bytes in the Blob or if pos +
+
−	 * length is greater than the number of bytes in the Blob
+
−	 */
+
−	@Override
+
−	public InputStream getBinaryStream(long pos, long length) throws SQLException {
+
−		if (buffer == null)
+
−			throw new SQLException("This Blob object has been freed", "M1M20");
+
−		if (pos < 1)
+
−			throw new SQLException("pos is less than 1", "M1M05");
+
−		if (pos - 1 > buffer.length)
+
−			throw new SQLException("pos is greater than the number of bytes in the Blob", "M1M05");
+
−		if (pos - 1 + length > buffer.length)
+
−			throw new SQLException("pos + length is greater than the number of bytes in the Blob", "M1M05");
+
−		return new ByteArrayInputStream(buffer, (int)(pos - 1), (int)length);
+
−	}
+
−
+
−	/**
+
−	 * Retrieves all or part of the BLOB value that this Blob object represents, as an array of bytes. This byte array
+
−	 * contains up to length consecutive bytes starting at position pos.
+
−	 *
+
−	 * @param pos the ordinal position of the first byte in the BLOB value to be extracted; the first byte is at
+
−	 * position 1.
+
−	 * @param length the number of consecutive bytes to be copied
+
−	 * @return a byte array containing up to length consecutive bytes from the BLOB value designated by this Blob
+
−	 * object, starting with the byte at position pos.
+
−	 * @throws SQLException if there is an error accessing the BLOB value
+
−	 */
+
−	@Override
+
−	public byte[] getBytes(long pos, int length) throws SQLException {
+
−		if (buffer == null)
+
−			throw new SQLException("This Blob object has been freed", "M1M20");
+
−		try {
+
−			return Arrays.copyOfRange(buffer, (int) pos - 1, (int) pos - 1 + length);
+
−		} catch (IndexOutOfBoundsException e) {
+
−			throw new SQLException(e.getMessage(), "M0M10");
+
−		}
+
−	}
+
−
+
−	/**
+
−	 * Returns the number of bytes in the BLOB value designated by this Blob object.
+
−	 *
+
−	 * @return length of the BLOB in bytes
+
−	 * @throws SQLException if there is an error accessing the length of the BLOB value
+
−	 */
+
−	@Override
+
−	public long length() throws SQLException {
+
−		if (buffer == null)
+
−			throw new SQLException("This Blob object has been freed", "M1M20");
+
−		return (long) buffer.length;
+
−	}
+
−
+
−	/**
+
−	 * Retrieves the byte position in the BLOB value designated by this Blob object at which pattern begins. The search
+
−	 * begins at position start.
+
−	 *
+
−	 * @param pattern the Blob object designating the BLOB value for which to search
+
−	 * @param start the position in the BLOB value at which to begin searching; the first position is 1
+
−	 * @return the position at which the pattern begins, else -1
+
−	 * @throws SQLException if there is an error accessing the BLOB value
+
−	 */
+
−	@Override
+
−	public long position(Blob pattern, long start) throws SQLException {
+
−		return position(pattern.getBytes(1L, (int)pattern.length()), start);
+
−	}
+
−
+
−	/**
+
−	 * Retrieves the byte position at which the specified byte array pattern begins within the BLOB value that this
+
−	 * Blob object represents. The search for pattern begins at position start.
+
−	 *
+
−	 * @param pattern the byte array for which to search
+
−	 * @param start the position at which to begin searching; the first position is 1
+
−	 * @return the position at which the pattern appears, else -1
+
−	 * @throws SQLException if there is an error accessing the BLOB value
+
−	 */
+
−	@Override
+
−	public long position(byte[] pattern, long start) throws SQLException {
+
−		if (buffer == null)
+
−			throw new SQLException("This Blob object has been freed", "M1M20");
+
−		try {
+
−			for (int i = (int)(start - 1); i < buffer.length - pattern.length; i++) {
+
−				int j;
+
−				for (j = 0; j < pattern.length; j++) {
+
−					if (buffer[i + j] != pattern[j])
+
−						break;
+
−				}
+
−				if (j == pattern.length)
+
−					return i;
+
−			}
+
−		} catch (IndexOutOfBoundsException e) {
+
−			throw new SQLException(e.getMessage(), "M0M10");
+
−		}
+
−		return -1;
+
−	}
+
−
+
−	/**
+
−	 * Retrieves a stream that can be used to write to the BLOB value
+
−	 * that this Blob object represents. The stream begins at position
+
−	 * pos. The bytes written to the stream will overwrite the existing
+
−	 * bytes in the Blob object starting at the position pos. If the end
+
−	 * of the Blob value is reached while writing to the stream, then
+
−	 * the length of the Blob value will be increased to accomodate the
+
−	 * extra bytes.
+
−	 *
+
−	 * @param pos the position in the BLOB value at which to start writing; the first position is 1
+
−	 * @return a java.io.OutputStream object to which data can be written
+
−	 * @throws SQLException if there is an error accessing the BLOB value or if pos is less than 1
+
−	 * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
+
−	 */
+
−	@Override
+
−	public OutputStream setBinaryStream(long pos) throws SQLException {
+
−		if (buffer == null)
+
−			throw new SQLException("This Blob object has been freed", "M1M20");
+
−		if (pos < 1)
+
−			throw new SQLException("pos is less than 1", "M1M05");
+
−		throw new SQLFeatureNotSupportedException("Operation setBinaryStream(long pos) currently not supported",
+
−				"0A000");
+
−	}
+
−
+
−	/**
+
−	 * Writes the given array of bytes to the BLOB value that this Blob
+
−	 * object represents, starting at position pos, and returns the
+
−	 * number of bytes written.
+
−	 *
+
−	 * @param pos the position in the BLOB object at which to start writing
+
−	 * @param bytes the array of bytes to be written to the BLOB value that this Blob object represents
+
−	 * @return the number of bytes written
+
−	 * @throws SQLException if there is an error accessing the BLOB value
+
−	 */
+
−	@Override
+
−	public int setBytes(long pos, byte[] bytes) throws SQLException {
+
−		return setBytes(pos, bytes, 1, bytes.length);
+
−	}
+
−
+
−	/**
+
−	 * Writes all or part of the given byte array to the BLOB value that
+
−	 * this Blob object represents and returns the number of bytes
+
−	 * written.  Writing starts at position pos in the BLOB  value; len
+
−	 * bytes from the given byte array are written.
+
−	 *
+
−	 * @param pos the position in the BLOB object at which to start writing
+
−	 * @param bytes the array of bytes to be written to this BLOB object
+
−	 * @param offset the offset into the array bytes at which to start reading the bytes to be set
+
−	 * @param len the number of bytes to be written to the BLOB value from the array of bytes bytes
+
−	 * @return the number of bytes written
+
−	 * @throws SQLException if there is an error accessing the BLOB value
+
−	 */
+
−	@Override
+
−	public int setBytes(long pos, byte[] bytes, int offset, int len) throws SQLException {
+
−		if (buffer == null)
+
−			throw new SQLException("This Blob object has been freed", "M1M20");
+
−		try {
+
−			/* transactions? what are you talking about? */
+
−			System.arraycopy(bytes, offset - 1 + (int) pos, buffer, (int) pos, len - (int) pos);
+
−		} catch (IndexOutOfBoundsException e) {
+
−			throw new SQLException(e.getMessage(), "M0M10");
+
−		}
+
−		return len;
+
−	}
+
−
+
−	/**
+
−	 * Truncates the BLOB value that this Blob  object represents to be len bytes in length.
+
−	 *
+
−	 * @param len the length, in bytes, to which the BLOB value should be truncated
+
−	 * @throws SQLException if there is an error accessing the BLOB value
+
−	 */
+
−	@Override
+
−	public void truncate(long len) throws SQLException {
+
−		if (buffer == null)
+
−			throw new SQLException("This Blob object has been freed", "M1M20");
+
−		if (buffer.length > len) {
+
−			byte[] newbuf = new byte[(int)len];
+
−			System.arraycopy(buffer, 0, newbuf, 0, (int) len);
+
−			buffer = newbuf;
+
−		}
+
−	}
+
−
+
−	/**
+
−	 * Overriding the equals method for the byte array.
+
−	 */
+
−	@Override
+
−	public boolean equals(Object obj) {
+
−		return obj instanceof MonetBlob && Arrays.equals(this.buffer, ((MonetBlob) obj).buffer);
+
−	}
+
−
+
−	/**
+
−	 * Overriding the hashCode method for the byte array.
+
−	 */
+
−	@Override
+
−	public int hashCode() { return Arrays.hashCode(this.buffer); }
+
−
+
−	/**
+
−	 * Overriding the toString method for the byte array.
+
−	 */
+
−	@Override
+
−	public String toString() { return Arrays.toString(this.buffer); }
+
−
+
−	@Override
+
−	public int compareTo(MonetBlob o) {
+
−		byte[] first = this.buffer, second = o.buffer;
+
−		int len = Math.min(first.length, second.length), res = 0;
+
−		for(int i = 0; i < len ; i++) {
+
−			res = res + first[i] - second[i];
+
−		}
+
−		return res;
+
−	}
+
−}