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JDBC Driver for the Firebird RDBMS
/*
* Firebird Open Source JavaEE Connector - JDBC Driver
*
* Distributable under LGPL license.
* You may obtain a copy of the License at http://www.gnu.org/copyleft/lgpl.html
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* LGPL License for more details.
*
* This file was created by members of the firebird development team.
* All individual contributions remain the Copyright (C) of those
* individuals. Contributors to this file are either listed here or
* can be obtained from a source control history command.
*
* All rights reserved.
*/
package org.firebirdsql.jdbc.field;
import org.firebirdsql.gds.ng.FbBlob;
import org.firebirdsql.gds.ng.FbTransaction;
import org.firebirdsql.gds.ng.fields.FieldDescriptor;
import org.firebirdsql.gds.ng.listeners.TransactionListener;
import org.firebirdsql.jdbc.FBBlob;
import org.firebirdsql.jdbc.FBClob;
import org.firebirdsql.jdbc.FirebirdBlob;
import java.io.InputStream;
import java.io.Reader;
import java.sql.Blob;
import java.sql.Clob;
import java.sql.SQLException;
/**
* Describe class FBBlobField here.
*
* @author Roman Rokytskyy
* @author Mark Rotteveel
*/
class FBBlobField extends FBField implements FBFlushableField {
protected FirebirdBlob blob;
private boolean blobExplicitNull;
private long length;
private InputStream binaryStream;
private Reader characterStream;
private byte[] bytes;
FBBlobField(FieldDescriptor fieldDescriptor, FieldDataProvider dataProvider, int requiredType) throws SQLException {
super(fieldDescriptor, dataProvider, requiredType);
}
@Override
public void close() throws SQLException {
try {
if (blob != null) blob.free();
} finally {
// forget this blob instance, resource waste but simplifies our life. BLOB handle will be
// released by a server automatically later
blob = null;
blobExplicitNull = false;
bytes = null;
binaryStream = null;
characterStream = null;
length = 0;
}
}
protected FirebirdBlob getBlobInternal() {
if (blob != null) return blob;
final byte[] bytes = getFieldData();
if (bytes == null) return null;
/*@todo convert this into a method of FirebirdConnection */
blob = new FBBlob(gdsHelper, getDatatypeCoder().decodeLong(bytes));
return blob;
}
@Override
public Blob getBlob() throws SQLException {
FirebirdBlob blob = getBlobInternal();
// Need to use detached blob to ensure the blob is usable after resultSet.next()
return blob != null ? registerWithTransaction(blob.detach()) : null;
}
@Override
public Clob getClob() throws SQLException {
FBBlob blob = (FBBlob) getBlob();
if (blob == null) return null;
return new FBClob(blob);
}
@Override
public InputStream getBinaryStream() throws SQLException {
Blob blob = getBlobInternal();
if (blob == null) return null;
return blob.getBinaryStream();
}
@Override
public byte[] getBytes() throws SQLException {
return getBytesInternal();
}
public byte[] getBytesInternal() throws SQLException {
final byte[] blobIdBuffer = getFieldData();
if (blobIdBuffer == null) return null;
final long blobId = getDatatypeCoder().decodeLong(blobIdBuffer);
synchronized (gdsHelper.getSynchronizationObject()) {
try (FbBlob blobHandle = gdsHelper.openBlob(blobId, FBBlob.SEGMENTED)) {
final int blobLength = (int) blobHandle.length();
final int bufferLength = gdsHelper.getBlobBufferLength();
final byte[] resultBuffer = new byte[blobLength];
int offset = 0;
while (offset < blobLength) {
final byte[] segmentBuffer = blobHandle.getSegment(bufferLength);
if (segmentBuffer.length == 0) {
// unexpected EOF
throw new TypeConversionException(BYTES_CONVERSION_ERROR);
}
System.arraycopy(segmentBuffer, 0, resultBuffer, offset, segmentBuffer.length);
offset += segmentBuffer.length;
}
return resultBuffer;
}
}
}
@Override
public byte[] getCachedData() throws SQLException {
if (isNull()) {
return bytes;
}
return getBytesInternal();
}
@Override
public FBFlushableField.CachedObject getCachedObject() throws SQLException {
if (isNull())
return new FBFlushableField.CachedObject(bytes, binaryStream, characterStream, length);
final byte[] bytes = getBytesInternal();
return new CachedObject(bytes, null, null, bytes.length);
}
@Override
public void setCachedObject(FBFlushableField.CachedObject cachedObject) throws SQLException {
// setNull() to reset field to empty state
setNull();
bytes = cachedObject.bytes;
binaryStream = cachedObject.binaryStream;
characterStream = cachedObject.characterStream;
length = cachedObject.length;
blobExplicitNull = bytes == null && binaryStream == null && characterStream == null;
}
@Override
public String getString() throws SQLException {
// getString() is not defined for BLOB fields, only for BINARY
if (fieldDescriptor.getSubType() < 0)
throw new TypeConversionException(STRING_CONVERSION_ERROR);
Blob blob = getBlobInternal();
if (blob == null) return null;
return getDatatypeCoder().decodeString(getBytes(), getDatatypeCoder().getEncodingFactory().getDefaultEncoding(),
mappingPath);
}
//--- setXXX methods
@Override
protected void setCharacterStreamInternal(Reader in, long length) throws SQLException {
// setNull() to reset field to empty state
setNull();
if (in != null) {
characterStream = in;
this.length = length;
blobExplicitNull = false;
}
}
@Override
protected void setBinaryStreamInternal(InputStream in, long length) throws SQLException {
// setNull() to reset field to empty state
setNull();
if (in != null) {
binaryStream = in;
this.length = length;
blobExplicitNull = false;
}
}
@Override
public void flushCachedData() throws SQLException {
if (binaryStream != null) {
copyBinaryStream(binaryStream, length);
} else if (characterStream != null) {
copyCharacterStream(characterStream, length,
getDatatypeCoder().getEncodingFactory().getDefaultEncoding().getCharsetName());
} else if (bytes != null) {
copyBytes(bytes, (int) length);
} else if (blob == null && blobExplicitNull) {
setNull();
}
this.characterStream = null;
this.binaryStream = null;
this.bytes = null;
this.length = 0;
}
private void copyBinaryStream(InputStream in, long length) throws SQLException {
FBBlob blob = new FBBlob(gdsHelper);
blob.copyStream(in, length);
setFieldData(getDatatypeCoder().encodeLong(blob.getBlobId()));
blobExplicitNull = false;
}
private void copyCharacterStream(Reader in, long length, String encoding) throws SQLException {
FBBlob blob = new FBBlob(gdsHelper);
blob.copyCharacterStream(in, length, encoding);
setFieldData(getDatatypeCoder().encodeLong(blob.getBlobId()));
blobExplicitNull = false;
}
private void copyBytes(byte[] bytes, int length) throws SQLException {
FBBlob blob = new FBBlob(gdsHelper);
blob.copyBytes(bytes, 0, length);
setFieldData(getDatatypeCoder().encodeLong(blob.getBlobId()));
blobExplicitNull = false;
}
@Override
public void setBytes(byte[] value) throws SQLException {
// setNull() to reset field to empty state
setNull();
if (value != null) {
bytes = value;
length = value.length;
blobExplicitNull = false;
}
}
@Override
public void setString(String value) throws SQLException {
if (value == null) {
setNull();
return;
}
setBytes(getDatatypeCoder().encodeString(value, getDatatypeCoder().getEncodingFactory().getDefaultEncoding(),
mappingPath));
}
@Override
public void setBlob(FBBlob blob) throws SQLException {
// setNull() to reset field to empty state
setNull();
setFieldData(getDatatypeCoder().encodeLong(blob.getBlobId()));
this.blob = blob;
blobExplicitNull = false;
}
@Override
public void setClob(FBClob clob) throws SQLException {
FBBlob blob = clob.getWrappedBlob();
setBlob(blob);
}
@Override
public void setNull() {
super.setNull();
try {
if (blob != null) blob.free();
} catch (SQLException e) {
//ignore
} finally {
blob = null;
blobExplicitNull = true;
binaryStream = null;
characterStream = null;
bytes = null;
length = 0;
}
}
private T registerWithTransaction(T blob) {
if (blob instanceof TransactionListener) {
FbTransaction currentTransaction = gdsHelper.getCurrentTransaction();
if (currentTransaction != null) {
currentTransaction.addWeakTransactionListener((TransactionListener) blob);
}
}
return blob;
}
}
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