/* Copyright (c) 2001-2018, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.hsqldb.jdbc;
import java.io.
ByteArrayInputStream;
import java.io.
InputStream;
import java.io.
OutputStream;
import java.sql.
Blob;
import java.sql.
SQLException;
//#ifdef JAVA6
import java.sql.
SQLFeatureNotSupportedException;
//#endif JAVA6
import org.hsqldb.error.
ErrorCode;
import org.hsqldb.lib.
KMPSearchAlgorithm;
import org.hsqldb.lib.java.
JavaSystem;
// campbell-burnet@users 2004-04-xx - patch 1.7.2 - position and truncate methods
// implemented; minor changes for moderate thread
// safety and optimal performance
// campbell-burnet@users 2004-04-xx - doc 1.7.2 - javadocs updated; methods put in
// correct (historical, interface declared) order
// campbell-burnet@users 2005-12-07 - patch 1.8.0.x - initial JDBC 4.0 support work
// campbell-burnet@users 2006-05-22 - doc 1.9.0 - full synch up to Mustang Build 84
// - patch 1.9.0 - setBinaryStream improvement
// patch 1.9.0
// - fixed invalid reference to new BinaryStream(...) in getBinaryStream
//
// patch 1.9.0 - full synch up to Mustang b90
// - better bounds checking
// - added support for clients to decide whether getBinaryStream
// uses copy of internal byte buffer
/**
* The representation (mapping) in
* the Java™ programming language of an SQL
* <code>BLOB</code> value. An SQL <code>BLOB</code> is a built-in type
* that stores a Binary Large Object as a column value in a row of
* a database table. By default drivers implement <code>Blob</code> using
* an SQL <code>locator(BLOB)</code>, which means that a
* <code>Blob</code> object contains a logical pointer to the
* SQL <code>BLOB</code> data rather than the data itself.
* A <code>Blob</code> object is valid for the duration of the
* transaction in which is was created.
*
* <P>Methods in the interfaces {@link java.sql.ResultSet},
* {@link java.sql.CallableStatement}, and {@link java.sql.PreparedStatement}, such as
* <code>getBlob</code> and <code>setBlob</code> allow a programmer to
* access an SQL <code>BLOB</code> value.
* The <code>Blob</code> interface provides methods for getting the
* length of an SQL <code>BLOB</code> (Binary Large Object) value,
* for materializing a <code>BLOB</code> value on the client, and for
* determining the position of a pattern of bytes within a
* <code>BLOB</code> value. In addition, this interface has methods for updating
* a <code>BLOB</code> value.
* <p>
* All methods on the <code>Blob</code> interface must be fully implemented if the
* JDBC driver supports the data type.
*
* <!-- start Release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <h3>HSQLDB-Specific Information:</h3> <p>
*
* Previous to 2.0, the HSQLDB driver did not implement Blob using an SQL
* locator(BLOB). That is, an HSQLDB Blob object did not contain a logical
* pointer to SQL BLOB data; rather it directly contained a representation of
* the data (a byte array). As a result, an HSQLDB Blob object was itself
* valid beyond the duration of the transaction in which is was created,
* although it did not necessarily represent a corresponding value
* on the database. Also, the interface methods for updating a BLOB value
* were unsupported, with the exception of the truncate method,
* in that it could be used to truncate the local value. <p>
*
* Starting with 2.0, the HSQLDB driver fully supports both local and remote
* SQL BLOB data implementations, meaning that an HSQLDB Blob object <em>may</em>
* contain a logical pointer to remote SQL BLOB data (see {@link JDBCBlobClient
* JDBCBlobClient}) or it may directly contain a local representation of the
* data (as implemented in this class). In particular, when the product is built
* under JDK 1.6+ and the Blob instance is constructed as a result of calling
* JDBCConnection.createBlob(), then the resulting Blob instance is initially
* disconnected (is not bound to the transaction scope of the vending Connection
* object), the data is contained directly and all interface methods for
* updating the BLOB value are supported for local use until the first
* invocation of free(); otherwise, an HSQLDB Blob's implementation is
* determined at runtime by the driver, it is typically not valid beyond the
* duration of the transaction in which is was created, and there no
* standard way to query whether it represents a local or remote
* value.<p>
*
* </div>
* <!-- end Release-specific documentation -->
*
* @author james house (jhouse@part.net)
* @author Campbell Burnet (campbell-burnet@users dot sourceforge.net)
* @version 2.4.0
* @since JDK 1.2, HSQLDB 1.7.2
*/
public class
JDBCBlob implements
Blob {
/**
* Returns the number of bytes in the <code>BLOB</code> value
* designated by this <code>Blob</code> object.
* @return length of the <code>BLOB</code> in bytes
* @exception SQLException if there is an error accessing the
* length of the <code>BLOB</code>
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since JDK 1.2, HSQLDB 1.7.2
*/
public long
length() throws
SQLException {
return
getData().length;
}
/**
* Retrieves all or part of the <code>BLOB</code>
* value that this <code>Blob</code> object represents, as an array of
* bytes. This <code>byte</code> array contains up to <code>length</code>
* consecutive bytes starting at position <code>pos</code>.
*
* <!-- start release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <h3>HSQLDB-Specific Information:</h3> <p>
*
* The official specification above is ambiguous in that it does not
* precisely indicate the policy to be observed when
* {@code pos > this.length() - length}. One policy would be to retrieve the
* octets from pos to this.length(). Another would be to throw an
* exception. HSQLDB observes the second policy.
* </div>
* <!-- end release-specific documentation -->
*
* @param pos the ordinal position of the first byte in the
* <code>BLOB</code> value to be extracted; the first byte is at
* position 1
* @param length the number of consecutive bytes to be copied; JDBC 4.1[the value
* for length must be 0 or greater]
* @return a byte array containing up to <code>length</code>
* consecutive bytes from the <code>BLOB</code> value designated
* by this <code>Blob</code> object, starting with the
* byte at position <code>pos</code>
* @exception SQLException if there is an error accessing the
* <code>BLOB</code> value; if pos is less than 1 or length is
* less than 0
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @see #setBytes
* @since JDK 1.2, HSQLDB 1.7.2
*/
public byte[]
getBytes(long
pos, final int
length) throws
SQLException {
final byte[]
data =
getData();
final int
dlen =
data.length;
if (
pos <
MIN_POS ||
pos -
MIN_POS >
dlen) {
throw
JDBCUtil.
outOfRangeArgument("pos: " +
pos);
}
final int
index = (int)
pos - 1;
if (
length < 0 ||
length >
dlen -
index) {
throw
JDBCUtil.
outOfRangeArgument("length: " +
length);
}
final byte[]
result = new byte[
length];
System.
arraycopy(
data,
index,
result, 0,
length);
return
result;
}
/**
* Retrieves the <code>BLOB</code> value designated by this
* <code>Blob</code> instance as a stream.
*
* @return a stream containing the <code>BLOB</code> data
* @exception SQLException if there is an error accessing the
* <code>BLOB</code> value
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @see #setBinaryStream
* @since JDK 1.2, HSQLDB 1.7.2
*/
public
InputStream getBinaryStream() throws
SQLException {
return new
ByteArrayInputStream(
getData());
}
/**
* Retrieves the byte position at which the specified byte array
* <code>pattern</code> begins within the <code>BLOB</code>
* value that this <code>Blob</code> object represents. The
* search for <code>pattern</code> begins at position
* <code>start</code>.
*
* @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
* @exception SQLException if there is an error accessing the
* <code>BLOB</code> or if start is less than 1
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since JDK 1.2, HSQLDB 1.7.2
*/
public long
position(final byte[]
pattern,
final long
start) throws
SQLException {
final byte[]
data =
getData();
final int
dlen =
data.length;
if (
start <
MIN_POS) {
throw
JDBCUtil.
outOfRangeArgument("start: " +
start);
} else if (
start >
dlen ||
pattern == null) {
return -1L;
}
// by now, we know start <= Integer.MAX_VALUE;
final int
startIndex = (int)
start - 1;
final int
plen =
pattern.length;
if (
plen == 0 ||
startIndex >
dlen -
plen) {
return -1L;
}
final int
result =
KMPSearchAlgorithm.
search(
data,
pattern,
KMPSearchAlgorithm.
computeTable(
pattern),
startIndex);
return (
result == -1) ? -1
:
result + 1;
}
/**
* Retrieves the byte position in the <code>BLOB</code> value
* designated by this <code>Blob</code> object at which
* <code>pattern</code> begins. The search begins at position
* <code>start</code>.
*
* @param pattern the <code>Blob</code> object designating
* the <code>BLOB</code> value for which to search
* @param start the position in the <code>BLOB</code> value
* at which to begin searching; the first position is 1
* @return the position at which the pattern begins, else -1
* @exception SQLException if there is an error accessing the
* <code>BLOB</code> value or if start is less than 1
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since JDK 1.2, HSQLDB 1.7.2
*/
public long
position(final
Blob pattern, long
start) throws
SQLException {
final byte[]
data =
getData();
final int
dlen =
data.length;
if (
start <
MIN_POS) {
throw
JDBCUtil.
outOfRangeArgument("start: " +
start);
} else if (
start >
dlen ||
pattern == null) {
return -1L;
}
// by now, we know start <= Integer.MAX_VALUE;
final int
startIndex = (int) (
start -
MIN_POS);
final long
plen =
pattern.
length();
if (
plen == 0 ||
startIndex > ((long)
dlen) -
plen) {
return -1L;
}
// by now, we know plen <= Integer.MAX_VALUE
final int
iplen = (int)
plen;
byte[]
bytePattern;
if (
pattern instanceof
JDBCBlob) {
bytePattern = ((
JDBCBlob)
pattern).
data();
} else {
bytePattern =
pattern.
getBytes(1L,
iplen);
}
final int
result =
KMPSearchAlgorithm.
search(
data,
bytePattern,
KMPSearchAlgorithm.
computeTable(
bytePattern),
startIndex);
return (
result == -1) ? -1
:
result + 1;
}
// -------------------------- JDBC 3.0 -----------------------------------
/**
* Writes the given array of bytes to the <code>BLOB</code> value that
* this <code>Blob</code> object represents, starting at position
* <code>pos</code>, and returns the number of bytes written.
* The array of bytes will overwrite the existing bytes
* in the <code>Blob</code> object starting at the position
* <code>pos</code>. If the end of the <code>Blob</code> value is reached
* while writing the array of bytes, then the length of the <code>Blob</code>
* value will be increased to accommodate the extra bytes.
* <p>
* <b>Note:</b> If the value specified for <code>pos</code>
* is greater then the length+1 of the <code>BLOB</code> value then the
* behavior is undefined. Some JDBC drivers may throw a
* <code>SQLException</code> while other drivers may support this
* operation.
*
* <!-- start release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <h3>HSQLDB-Specific Information:</h3> <p>
*
* Starting with HSQLDB 2.0 this feature is supported. <p>
*
* When built under JDK 1.6+ and the Blob instance is constructed as a
* result of calling JDBCConnection.createBlob(), this operation affects
* only the client-side value; it has no effect upon a value stored in a
* database because JDBCConnection.createBlob() constructs disconnected,
* initially empty Blob instances. To propagate the Blob value to a database
* in this case, it is required to supply the Blob instance to an updating
* or inserting setXXX method of a Prepared or Callable Statement, or to
* supply the Blob instance to an updateXXX method of an updatable
* ResultSet. <p>
*
* <b>Implementation Notes:</b><p>
*
* Starting with HSQLDB 2.1, JDBCBlob no longer utilizes volatile fields
* and is effectively thread safe, but still uses local variable
* snapshot isolation. <p>
*
* As such, the synchronization policy still does not strictly enforce
* serialized read/write access to the underlying data <p>
*
* So, if an application may perform concurrent JDBCBlob modifications and
* the integrity of the application depends on total order Blob modification
* semantics, then such operations should be synchronized on an appropriate
* monitor. <p>
*
* </div>
* <!-- end release-specific documentation -->
*
* @param pos the position in the <code>BLOB</code> object at which
* to start writing; the first position is 1
* @param bytes the array of bytes to be written to the <code>BLOB</code>
* value that this <code>Blob</code> object represents
* @return the number of bytes written
* @exception SQLException if there is an error accessing the
* <code>BLOB</code> value or if pos is less than 1
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @see #getBytes
* @since JDK 1.4, HSQLDB 1.7.2
*/
public int
setBytes(long
pos, byte[]
bytes) throws
SQLException {
return
setBytes(
pos,
bytes, 0,
bytes == null ? 0 :
bytes.length);
}
/**
* Writes all or part of the given <code>byte</code> array to the
* <code>BLOB</code> value that this <code>Blob</code> object represents
* and returns the number of bytes written.
* Writing starts at position <code>pos</code> in the <code>BLOB</code>
* value; <code>len</code> bytes from the given byte array are written.
* The array of bytes will overwrite the existing bytes
* in the <code>Blob</code> object starting at the position
* <code>pos</code>. If the end of the <code>Blob</code> value is reached
* while writing the array of bytes, then the length of the <code>Blob</code>
* value will be increased to accommodate the extra bytes.
* <p>
* <b>Note:</b> If the value specified for <code>pos</code>
* is greater then the length+1 of the <code>BLOB</code> value then the
* behavior is undefined. Some JDBC drivers may throw a
* <code>SQLException</code> while other drivers may support this
* operation.
*
* <!-- start release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <h3>HSQLDB-Specific Information:</h3> <p>
*
* Starting with HSQLDB 2.0 this feature is supported. <p>
*
* When built under JDK 1.6+ and the Blob instance is constructed as a
* result of calling JDBCConnection.createBlob(), this operation affects
* only the client-side value; it has no effect upon a value stored in a
* database because JDBCConnection.createBlob() constructs disconnected,
* initially empty Blob instances. To propagate the Blob value to a database
* in this case, it is required to supply the Blob instance to an updating
* or inserting setXXX method of a Prepared or Callable Statement, or to
* supply the Blob instance to an updateXXX method of an updatable
* ResultSet. <p>
*
* <b>Implementation Notes:</b><p>
*
* If the value specified for <code>pos</code>
* is greater than the length of the <code>BLOB</code> value, then
* the <code>BLOB</code> value is extended in length to accept the
* written octets and the undefined region up to <code>pos</code> is
* filled with (byte)0. <p>
*
* Starting with HSQLDB 2.1, JDBCBlob no longer utilizes volatile fields
* and is effectively thread safe, but still uses local variable
* snapshot isolation. <p>
*
* As such, the synchronization policy still does not strictly enforce
* serialized read/write access to the underlying data <p>
*
* So, if an application may perform concurrent JDBCBlob modifications and
* the integrity of the application depends on total order Blob modification
* semantics, then such operations should be synchronized on an appropriate
* monitor. <p>
*
* </div>
* <!-- end release-specific documentation -->
*
* @param pos the position in the <code>BLOB</code> object at which
* to start writing; the first position is 1
* @param bytes the array of bytes to be written to this <code>BLOB</code>
* object
* @param offset the offset into the array <code>bytes</code> at which
* to start reading the bytes to be set
* @param len the number of bytes to be written to the <code>BLOB</code>
* value from the array of bytes <code>bytes</code>
* @return the number of bytes written
* @exception SQLException if there is an error accessing the
* <code>BLOB</code> value or if pos is less than 1
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @see #getBytes
* @since JDK 1.4, HSQLDB 1.7.2
*/
public int
setBytes(long
pos, byte[]
bytes, int
offset,
int
len) throws
SQLException {
checkReadonly();
if (
bytes == null) {
throw
JDBCUtil.
nullArgument("bytes");
}
if (
offset < 0 ||
offset >
bytes.length) {
throw
JDBCUtil.
outOfRangeArgument("offset: " +
offset);
}
if (
len >
bytes.length -
offset) {
throw
JDBCUtil.
outOfRangeArgument("len: " +
len);
}
if (
pos <
MIN_POS || (
pos -
MIN_POS) > (
Integer.
MAX_VALUE -
len)) {
throw
JDBCUtil.
outOfRangeArgument("pos: " +
pos);
}
final int
index = (int) (
pos -
MIN_POS);
byte[]
data =
getData();
final int
dlen =
data.length;
if (
index >
dlen -
len) {
byte[]
temp = new byte[
index +
len];
System.
arraycopy(
data, 0,
temp, 0,
dlen);
data =
temp;
temp = null;
}
System.
arraycopy(
bytes,
offset,
data,
index,
len);
setData(
data);
return
len;
}
/**
* Retrieves a stream that can be used to write to the <code>BLOB</code>
* value that this <code>Blob</code> object represents. The stream begins
* at position <code>pos</code>.
* The bytes written to the stream will overwrite the existing bytes
* in the <code>Blob</code> object starting at the position
* <code>pos</code>. If the end of the <code>Blob</code> value is reached
* while writing to the stream, then the length of the <code>Blob</code>
* value will be increased to accommodate the extra bytes.
* <p>
* <b>Note:</b> If the value specified for <code>pos</code>
* is greater then the length+1 of the <code>BLOB</code> value then the
* behavior is undefined. Some JDBC drivers may throw a
* <code>SQLException</code> while other drivers may support this
* operation.
*
* <!-- start release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <h3>HSQLDB-Specific Information:</h3> <p>
*
* Starting with HSQLDB 2.0 this feature is supported. <p>
*
* When built under JDK 1.6+ and the Blob instance is constructed as a
* result of calling JDBCConnection.createBlob(), this operation affects
* only the client-side value; it has no effect upon a value stored in a
* database because JDBCConnection.createBlob() constructs disconnected,
* initially empty Blob instances. To propagate the Blob value to a database
* in this case, it is required to supply the Blob instance to an updating
* or inserting setXXX method of a Prepared or Callable Statement, or to
* supply the Blob instance to an updateXXX method of an updatable
* ResultSet. <p>
*
* <b>Implementation Notes:</b><p>
*
* The data written to the stream does not appear in this
* Blob until the stream is closed <p>
*
* When the stream is closed, if the value specified for <code>pos</code>
* is greater than the length of the <code>BLOB</code> value, then
* the <code>BLOB</code> value is extended in length to accept the
* written octets and the undefined region up to <code>pos</code> is
* filled with (byte)0. <p>
*
* Starting with HSQLDB 2.1, JDBCBlob no longer utilizes volatile fields
* and is effectively thread safe, but still uses local variable
* snapshot isolation. <p>
*
* As such, the synchronization policy still does not strictly enforce
* serialized read/write access to the underlying data <p>
*
* So, if an application may perform concurrent JDBCBlob modifications and
* the integrity of the application depends on total order Blob modification
* semantics, then such operations should be synchronized on an appropriate
* monitor. <p>
*
* </div>
* <!-- end release-specific documentation -->
*
* @param pos the position in the <code>BLOB</code> value at which
* to start writing; the first position is 1
* @return a <code>java.io.OutputStream</code> object to which data can
* be written
* @exception SQLException if there is an error accessing the
* <code>BLOB</code> value or if pos is less than 1
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @see #getBinaryStream
* @since JDK 1.4, HSQLDB 1.7.2
*/
public
OutputStream setBinaryStream(final long
pos) throws
SQLException {
checkReadonly();
if (
pos <
MIN_POS ||
pos >
MAX_POS) {
throw
JDBCUtil.
outOfRangeArgument("pos: " +
pos);
}
checkClosed();
return new java.io.
ByteArrayOutputStream() {
private boolean
closed;
public synchronized void
close() throws java.io.
IOException {
if (
closed) {
return;
}
closed = true;
byte[]
bytes = super.
buf;
int
length = super.
count;
super.
buf =
NO_BYTES;
super.
count = 0;
try {
JDBCBlob.this.
setBytes(
pos,
bytes, 0,
length);
} catch (
SQLException se) {
throw
JavaSystem.
toIOException(
se);
} finally {
super.close();
}
}
};
}
/**
* Truncates the <code>BLOB</code> value that this <code>Blob</code>
* object represents to be <code>len</code> bytes in length.
* <p>
* <b>Note:</b> If the value specified for <code>pos</code>
* is greater then the length+1 of the <code>BLOB</code> value then the
* behavior is undefined. Some JDBC drivers may throw a
* <code>SQLException</code> while other drivers may support this
* operation.
*
* <!-- start release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <h3>HSQLDB-Specific Information:</h3> <p>
*
* Starting with HSQLDB 2.0 this feature is fully supported. <p>
*
* When built under JDK 1.6+ and the Blob instance is constructed as a
* result of calling JDBCConnection.createBlob(), this operation affects
* only the client-side value; it has no effect upon a value stored in a
* database because JDBCConnection.createBlob() constructs disconnected,
* initially empty Blob instances. To propagate the truncated Blob value to
* a database in this case, it is required to supply the Blob instance to
* an updating or inserting setXXX method of a Prepared or Callable
* Statement, or to supply the Blob instance to an updateXXX method of an
* updateable ResultSet. <p>
*
* </div>
* <!-- end release-specific documentation -->
*
* @param len the length, in bytes, to which the <code>BLOB</code> value
* that this <code>Blob</code> object represents should be truncated
* @exception SQLException if there is an error accessing the
* <code>BLOB</code> value or if len is less than 0
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since JDK 1.4, HSQLDB 1.7.2
*/
public void
truncate(final long
len) throws
SQLException {
checkReadonly();
final byte[]
data =
getData();
if (
len < 0 ||
len >
data.length) {
throw
JDBCUtil.
outOfRangeArgument("len: " +
len);
} else if (
len ==
data.length) {
return;
}
byte[]
newData = new byte[(int)
len];
System.
arraycopy(
data, 0,
newData, 0, (int)
len);
setData(
newData);
}
//------------------------- JDBC 4.0 -----------------------------------
/**
* This method frees the <code>Blob</code> object and releases the resources that
* it holds. The object is invalid once the <code>free</code>
* method is called.
* <p>
* After <code>free</code> has been called, any attempt to invoke a
* method other than <code>free</code> will result in a <code>SQLException</code>
* being thrown. If <code>free</code> is called multiple times, the subsequent
* calls to <code>free</code> are treated as a no-op.
* <p>
*
* @throws SQLException if an error occurs releasing
* the Blob's resources
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since JDK 1.6, HSQLDB 2.0
*/
public synchronized void
free() throws
SQLException {
m_closed = true;
m_data = null;
}
/**
* Returns an <code>InputStream</code> object that contains a partial <code>Blob</code> 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 <code>Blob</code> is at position 1
* @param length the length in bytes of the partial value to be retrieved
* @return <code>InputStream</code> through which the partial <code>Blob</code> value can be read.
* @throws SQLException if pos is less than 1 or if pos is greater than the number of bytes
* in the <code>Blob</code> or if pos + length is greater than the number of bytes
* in the <code>Blob</code>
*
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since JDK 1.6, HSQLDB 2.0
*/
public
InputStream getBinaryStream(long
pos,
long
length) throws
SQLException {
final byte[]
data =
getData();
final int
dlen =
data.length;
if (
pos <
MIN_POS ||
pos >
dlen) {
throw
JDBCUtil.
outOfRangeArgument("pos: " +
pos);
}
int
index = (int) (
pos -
MIN_POS);
if (
length < 0 ||
length >
dlen -
index) {
throw
JDBCUtil.
outOfRangeArgument("length: " +
length);
}
if (
index == 0 &&
length ==
dlen) {
return new
ByteArrayInputStream(
data);
}
final int
ilength = (int)
length;
final byte[]
result = new byte[
ilength];
System.
arraycopy(
data,
index,
result, 0,
ilength);
return new
ByteArrayInputStream(
result);
}
// ---------------------- internal implementation --------------------------
public static final long
MIN_POS = 1L;
public static final long
MAX_POS =
MIN_POS + (long)
Integer.
MAX_VALUE;
private static final byte[]
NO_BYTES = new byte[0];
private boolean
m_closed;
private byte[]
m_data;
private final boolean
m_createdByConnection;
/**
* Constructs a new JDBCBlob instance wrapping the given octet sequence. <p>
*
* This constructor is used internally to retrieve result set values as
* Blob objects, yet it must be public to allow access from other packages.
* As such (in the interest of efficiency) this object maintains a reference
* to the given octet sequence rather than making a copy; special care
* should be taken by external clients never to use this constructor with a
* byte array object that may later be modified externally.
*
* @param data the octet sequence representing the Blob value
* @throws SQLException if the argument is null
*/
public
JDBCBlob(final byte[]
data) throws
SQLException {
if (
data == null) {
throw
JDBCUtil.
nullArgument("data");
}
m_data =
data;
m_createdByConnection = false;
}
protected
JDBCBlob() {
m_data = new byte[0];
m_createdByConnection = true;
}
protected void
checkReadonly() throws
SQLException {
if (!
m_createdByConnection) {
throw
JDBCUtil.
sqlException(
ErrorCode.
X_25006, "Blob is read-only");
}
}
protected synchronized void
checkClosed() throws
SQLException {
if (
m_closed) {
throw
JDBCUtil.
sqlException(
ErrorCode.
X_07501);
}
}
protected byte[]
data() throws
SQLException {
return
getData();
}
//@SuppressWarnings("ReturnOfCollectionOrArrayField")
private synchronized byte[]
getData() throws
SQLException {
checkClosed();
return
m_data;
}
//@SuppressWarnings("AssignmentToCollectionOrArrayFieldFromParameter")
private synchronized void
setData(byte[]
data) throws
SQLException {
checkClosed();
m_data =
data;
}
}