1 | /* |
2 | Copyright (C) 2002-2004 MySQL AB |
3 | |
4 | This program is free software; you can redistribute it and/or modify |
5 | it under the terms of version 2 of the GNU General Public License as |
6 | published by the Free Software Foundation. |
7 | |
8 | There are special exceptions to the terms and conditions of the GPL |
9 | as it is applied to this software. View the full text of the |
10 | exception in file EXCEPTIONS-CONNECTOR-J in the directory of this |
11 | software distribution. |
12 | |
13 | This program is distributed in the hope that it will be useful, |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
16 | GNU General Public License for more details. |
17 | |
18 | You should have received a copy of the GNU General Public License |
19 | along with this program; if not, write to the Free Software |
20 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
21 | |
22 | |
23 | |
24 | */ |
25 | package com.mysql.jdbc; |
26 | |
27 | import java.io.ByteArrayInputStream; |
28 | import java.io.IOException; |
29 | import java.io.OutputStream; |
30 | |
31 | import java.sql.SQLException; |
32 | |
33 | /** |
34 | * The representation (mapping) in the JavaTM programming language of an SQL |
35 | * BLOB value. An SQL BLOB is a built-in type that stores a Binary Large Object |
36 | * as a column value in a row of a database table. The driver implements Blob |
37 | * using an SQL locator(BLOB), which means that a Blob object contains a logical |
38 | * pointer to the SQL BLOB data rather than the data itself. A Blob object is |
39 | * valid for the duration of the transaction in which is was created. Methods in |
40 | * the interfaces ResultSet, CallableStatement, and PreparedStatement, such as |
41 | * getBlob and setBlob allow a programmer to access an SQL BLOB value. The Blob |
42 | * interface provides methods for getting the length of an SQL BLOB (Binary |
43 | * Large Object) value, for materializing a BLOB value on the client, and for |
44 | * determining the position of a pattern of bytes within a BLOB value. This |
45 | * class is new in the JDBC 2.0 API. |
46 | * |
47 | * @author Mark Matthews |
48 | * @version $Id: Blob.java 3726 2005-05-19 15:52:24Z mmatthews $ |
49 | */ |
50 | public class Blob implements java.sql.Blob, OutputStreamWatcher { |
51 | |
52 | // |
53 | // This is a real brain-dead implementation of BLOB. Once I add |
54 | // streamability to the I/O for MySQL this will be more efficiently |
55 | // implemented (except for the position() method, ugh). |
56 | // |
57 | |
58 | /** The binary data that makes up this BLOB */ |
59 | private byte[] binaryData = null; |
60 | |
61 | /** |
62 | * Creates a BLOB encapsulating the given binary data |
63 | * |
64 | * @param data |
65 | * DOCUMENT ME! |
66 | */ |
67 | Blob(byte[] data) { |
68 | setBinaryData(data); |
69 | } |
70 | |
71 | /** |
72 | * Creates an updatable BLOB that can update in-place (not implemented yet). |
73 | * |
74 | * @param data |
75 | * DOCUMENT ME! |
76 | * @param creatorResultSetToSet |
77 | * DOCUMENT ME! |
78 | * @param columnIndexToSet |
79 | * DOCUMENT ME! |
80 | */ |
81 | Blob(byte[] data, ResultSet creatorResultSetToSet, int columnIndexToSet) { |
82 | setBinaryData(data); |
83 | } |
84 | |
85 | private byte[] getBinaryData() { |
86 | return this.binaryData; |
87 | } |
88 | |
89 | /** |
90 | * Retrieves the BLOB designated by this Blob instance as a stream. |
91 | * |
92 | * @return this BLOB represented as a binary stream of bytes. |
93 | * |
94 | * @throws SQLException |
95 | * if a database error occurs |
96 | */ |
97 | public java.io.InputStream getBinaryStream() throws SQLException { |
98 | return new ByteArrayInputStream(getBinaryData()); |
99 | } |
100 | |
101 | /** |
102 | * Returns as an array of bytes, part or all of the BLOB value that this |
103 | * Blob object designates. |
104 | * |
105 | * @param pos |
106 | * where to start the part of the BLOB |
107 | * @param length |
108 | * the length of the part of the BLOB you want returned. |
109 | * |
110 | * @return the bytes stored in the blob starting at position |
111 | * <code>pos</code> and having a length of <code>length</code>. |
112 | * |
113 | * @throws SQLException |
114 | * if a database error occurs |
115 | */ |
116 | public byte[] getBytes(long pos, int length) throws SQLException { |
117 | if (pos < 1) { |
118 | throw new SQLException(Messages.getString("Blob.2"), //$NON-NLS-1$ |
119 | SQLError.SQL_STATE_ILLEGAL_ARGUMENT); |
120 | } |
121 | |
122 | byte[] newData = new byte[length]; |
123 | System.arraycopy(getBinaryData(), (int) (pos - 1), newData, 0, length); |
124 | |
125 | return newData; |
126 | } |
127 | |
128 | /** |
129 | * Returns the number of bytes in the BLOB value designated by this Blob |
130 | * object. |
131 | * |
132 | * @return the length of this blob |
133 | * |
134 | * @throws SQLException |
135 | * if a database error occurs |
136 | */ |
137 | public long length() throws SQLException { |
138 | return getBinaryData().length; |
139 | } |
140 | |
141 | /** |
142 | * @see java.sql.Blob#position(byte[], long) |
143 | */ |
144 | public long position(byte[] pattern, long start) throws SQLException { |
145 | throw new SQLException("Not implemented"); //$NON-NLS-1$ |
146 | } |
147 | |
148 | /** |
149 | * Finds the position of the given pattern in this BLOB. |
150 | * |
151 | * @param pattern |
152 | * the pattern to find |
153 | * @param start |
154 | * where to start finding the pattern |
155 | * |
156 | * @return the position where the pattern is found in the BLOB, -1 if not |
157 | * found |
158 | * |
159 | * @throws SQLException |
160 | * if a database error occurs |
161 | */ |
162 | public long position(java.sql.Blob pattern, long start) throws SQLException { |
163 | return position(pattern.getBytes(0, (int) pattern.length()), start); |
164 | } |
165 | |
166 | private void setBinaryData(byte[] newBinaryData) { |
167 | this.binaryData = newBinaryData; |
168 | } |
169 | |
170 | /** |
171 | * @see Blob#setBinaryStream(long) |
172 | */ |
173 | public OutputStream setBinaryStream(long indexToWriteAt) |
174 | throws SQLException { |
175 | if (indexToWriteAt < 1) { |
176 | throw new SQLException(Messages.getString("Blob.0"), //$NON-NLS-1$ |
177 | SQLError.SQL_STATE_ILLEGAL_ARGUMENT); |
178 | } |
179 | |
180 | WatchableOutputStream bytesOut = new WatchableOutputStream(); |
181 | bytesOut.setWatcher(this); |
182 | |
183 | if (indexToWriteAt > 0) { |
184 | bytesOut.write(this.binaryData, 0, (int) (indexToWriteAt - 1)); |
185 | } |
186 | |
187 | return bytesOut; |
188 | } |
189 | |
190 | /** |
191 | * @see Blob#setBytes(long, byte[]) |
192 | */ |
193 | public int setBytes(long writeAt, byte[] bytes) throws SQLException { |
194 | return setBytes(writeAt, bytes, 0, bytes.length); |
195 | } |
196 | |
197 | /** |
198 | * @see Blob#setBytes(long, byte[], int, int) |
199 | */ |
200 | public int setBytes(long writeAt, byte[] bytes, int offset, int length) |
201 | throws SQLException { |
202 | OutputStream bytesOut = setBinaryStream(writeAt); |
203 | |
204 | try { |
205 | bytesOut.write(bytes, offset, length); |
206 | } catch (IOException ioEx) { |
207 | throw new SQLException(Messages.getString("Blob.1"), //$NON-NLS-1$ |
208 | SQLError.SQL_STATE_GENERAL_ERROR); |
209 | } finally { |
210 | try { |
211 | bytesOut.close(); |
212 | } catch (IOException doNothing) { |
213 | ; // do nothing |
214 | } |
215 | } |
216 | |
217 | return length; |
218 | } |
219 | |
220 | /** |
221 | * @see com.mysql.jdbc.OutputStreamWatcher#streamClosed(byte[]) |
222 | */ |
223 | public void streamClosed(byte[] byteData) { |
224 | this.binaryData = byteData; |
225 | } |
226 | |
227 | /** |
228 | * @see com.mysql.jdbc.OutputStreamWatcher#streamClosed(byte[]) |
229 | */ |
230 | public void streamClosed(WatchableOutputStream out) { |
231 | int streamSize = out.size(); |
232 | |
233 | if (streamSize < this.binaryData.length) { |
234 | out.write(this.binaryData, streamSize, this.binaryData.length |
235 | - streamSize); |
236 | } |
237 | |
238 | this.binaryData = out.toByteArray(); |
239 | } |
240 | |
241 | /** |
242 | * @see Blob#truncate(long) |
243 | */ |
244 | public void truncate(long arg0) throws SQLException { |
245 | throw new NotImplemented(); |
246 | } |
247 | } |