JDBCBlob.java
/* Copyright (c) 2001-2024, 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.
*
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* contributors may be used to endorse or promote products derived from this
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*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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package org.hsqldb.jdbc;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Blob;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
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 JAVA 1.6 (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 JAVA 1.6 (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} value. An SQL {@code BLOB} 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} using
* an SQL {@code locator(BLOB)}, which means that a
* {@code Blob} object contains a logical pointer to the
* SQL {@code BLOB} data rather than the data itself.
* A {@code Blob} object is valid for the duration of the
* transaction in which it was created.
*
* <P>Methods in the interfaces {@link java.sql.ResultSet},
* {@link java.sql.CallableStatement}, and {@link java.sql.PreparedStatement}, such as
* {@code getBlob} and {@code setBlob} allow a programmer to
* access an SQL {@code BLOB} value.
* The {@code Blob} interface provides methods for getting the
* length of an SQL {@code BLOB} (Binary Large Object) value,
* for materializing a {@code BLOB} value on the client, and for
* determining the position of a pattern of bytes within a
* {@code BLOB} value. In addition, this interface has methods for updating
* a {@code BLOB} value.
* <p>
* All methods on the {@code Blob} interface must be fully implemented if the
* JDBC driver supports the data type.
*
* <!-- start Release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <p class="rshead">HSQLDB-Specific Information:</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.
*
* </div>
* <!-- end Release-specific documentation -->
*
* @author james house (jhouse@part.net)
* @author Campbell Burnet (campbell-burnet@users dot sourceforge.net)
* @version 2.7.3
* @since JDK 1.2, HSQLDB 1.7.2
*/
public class JDBCBlob implements Blob {
/**
* Returns the number of bytes in the {@code BLOB} value
* designated by this {@code Blob} object.
*
* @return length of the {@code BLOB} in bytes
* @throws SQLException if there is an error accessing the
* length of the {@code BLOB}
* @throws 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}
* value that this {@code Blob} object represents, as an array of
* bytes. This {@code byte} array contains up to {@code length}
* consecutive bytes starting at position {@code pos}.
*
* <!-- start release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <p class="rshead">HSQLDB-Specific Information:</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} value to be extracted; the first byte is at
* position 1
* @param length the number of consecutive bytes to be copied; the value
* for length must be 0 or greater
* @return a byte array containing up to {@code length}
* consecutive bytes from the {@code BLOB} value designated
* by this {@code Blob} object, starting with the
* byte at position {@code pos}
* @throws SQLException if there is an error accessing the
* {@code BLOB} value; if pos is less than 1 or length is
* less than 0
* @throws 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} value designated by this
* {@code Blob} instance as a stream.
*
* @return a stream containing the {@code BLOB} data
* @throws SQLException if there is an error accessing the
* {@code BLOB} value
* @throws 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} begins within the {@code BLOB}
* value that this {@code Blob} object represents.
* The search for {@code pattern} begins at position
* {@code 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
* {@code BLOB} or if start is less than 1
* @throws 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} value
* designated by this {@code Blob} object at which
* {@code pattern} begins. The search begins at position
* {@code start}.
*
* @param pattern the {@code Blob} object designating
* the {@code BLOB} value for which to search
* @param start the position in the {@code 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
* {@code BLOB} value or if start is less than 1
* @throws 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} value that
* this {@code Blob} object represents, starting at position
* {@code pos}, and returns the number of bytes written.
* The array of bytes will overwrite the existing bytes
* in the {@code Blob} object starting at the position
* {@code pos}. If the end of the {@code Blob} value is reached
* while writing the array of bytes, then the length of the {@code Blob}
* value will be increased to accommodate the extra bytes.
* <p>
* <b>Note:</b> If the value specified for {@code pos}
* is greater than the length+1 of the {@code BLOB} value then the
* behavior is undefined. Some JDBC drivers may throw an
* {@code SQLException} while other drivers may support this
* operation.
*
* <!-- start release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <p class="rshead">HSQLDB-Specific Information:</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.
*
* </div>
* <!-- end release-specific documentation -->
*
* @param pos the position in the {@code BLOB} object at which
* to start writing; the first position is 1
* @param bytes the array of bytes to be written to the {@code BLOB}
* value that this {@code Blob} object represents
* @return the number of bytes written
* @throws SQLException if there is an error accessing the
* {@code BLOB} value or if pos is less than 1
* @throws 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} array to the
* {@code BLOB} value that this {@code Blob} object represents
* and returns the number of bytes written.
* Writing starts at position {@code pos} in the {@code BLOB}
* value; {@code len} bytes from the given byte array are written.
* The array of bytes will overwrite the existing bytes
* in the {@code Blob} object starting at the position
* {@code pos}. If the end of the {@code Blob} value is reached
* while writing the array of bytes, then the length of the {@code Blob}
* value will be increased to accommodate the extra bytes.
* <p>
* <b>Note:</b> If the value specified for {@code pos}
* is greater than the length+1 of the {@code BLOB} value then the
* behavior is undefined. Some JDBC drivers may throw an
* {@code SQLException} while other drivers may support this
* operation.
*
* <!-- start release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <p class="rshead">HSQLDB-Specific Information:</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}
* is greater than the length of the {@code BLOB} value, then
* the {@code BLOB} value is extended in length to accept the
* written octets and the undefined region up to {@code pos} 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.
*
* </div>
* <!-- end release-specific documentation -->
*
* @param pos the position in the {@code BLOB} object at which
* to start writing; the first position is 1
* @param bytes the array of bytes to be written to this {@code BLOB}
* object
* @param offset the offset into the array {@code bytes} at which
* to start reading the bytes to be set
* @param len the number of bytes to be written to the {@code BLOB}
* value from the array of bytes {@code bytes}
* @return the number of bytes written
* @throws SQLException if there is an error accessing the
* {@code BLOB} value or if pos is less than 1
* @throws 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}
* value that this {@code Blob} object represents. The stream begins
* at position {@code pos}.
* The bytes written to the stream will overwrite the existing bytes
* in the {@code Blob} object starting at the position
* {@code pos}. If the end of the {@code Blob} value is reached
* while writing to the stream, then the length of the {@code Blob}
* value will be increased to accommodate the extra bytes.
* <p>
* <b>Note:</b> If the value specified for {@code pos}
* is greater than the length+1 of the {@code BLOB} value then the
* behavior is undefined. Some JDBC drivers may throw an
* {@code SQLException} while other drivers may support this
* operation.
*
* <!-- start release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <p class="rshead">HSQLDB-Specific Information:</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}
* is greater than the length of the {@code BLOB} value, then
* the {@code BLOB} value is extended in length to accept the
* written octets and the undefined region up to {@code pos} 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.
*
* </div>
* <!-- end release-specific documentation -->
*
* @param pos the position in the {@code BLOB} value at which
* to start writing; the first position is 1
* @return a {@code java.io.OutputStream} object to which data can
* be written
* @throws SQLException if there is an error accessing the
* {@code BLOB} value or if pos is less than 1
* @throws 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} value that this {@code Blob}
* object represents to be {@code len} bytes in length.
* <p>
* <b>Note:</b> If the value specified for {@code pos}
* is greater than the length+1 of the {@code BLOB} value then the
* behavior is undefined. Some JDBC drivers may throw an
* {@code SQLException} while other drivers may support this
* operation.
*
* <!-- start release-specific documentation -->
* <div class="ReleaseSpecificDocumentation">
* <p class="rshead">HSQLDB-Specific Information:</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.
*
* </div>
* <!-- end release-specific documentation -->
*
* @param len the length, in bytes, to which the {@code BLOB} value
* that this {@code Blob} object represents should be truncated
* @throws SQLException if there is an error accessing the
* {@code BLOB} value or if len is less than 0
* @throws 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} object and releases the resources that
* it holds. The object is invalid once the {@code free}
* method is called.
* <p>
* After {@code free} has been called, any attempt to invoke a
* method other than {@code free} will result in an {@code SQLException}
* being thrown. If {@code free} is called multiple times, the subsequent
* calls to {@code free} are treated as a no-op.
*
* @throws SQLException if an error occurs releasing
* the Blob's resources
* @throws 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} object that contains
* a partial {@code 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 {@code Blob} is at position 1.
* @param length the length in bytes of the partial value to be retrieved
* @return {@code InputStream} through which
* the partial {@code 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 {@code Blob} or if
* pos + length is greater than the number of bytes
* in the {@code Blob}
*
* @throws 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 --------------------------
private static final long MIN_POS = 1L;
private 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;
}
}