org.hsqldb.jdbc.JDBCClobClient Maven / Gradle / Ivy
/* Copyright (c) 2001-2022, The HSQL Development Group
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*
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*
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*
* Redistributions in binary form must reproduce the above copyright notice,
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package org.hsqldb.jdbc;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
import java.sql.Clob;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import org.hsqldb.HsqlException;
import org.hsqldb.SessionInterface;
import org.hsqldb.error.ErrorCode;
import org.hsqldb.types.ClobDataID;
import org.hsqldb.types.ClobInputStream;
/**
* A wrapper for HSQLDB ClobData objects.
*
* Instances of this class are returned by calls to ResultSet methods.
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 2.7.0
* @since HSQLDB 1.9.0
*/
public class JDBCClobClient implements Clob {
/**
* Retrieves the CLOB value designated by this
* Clob object as an ascii stream.
*
* The ascii stream consists of the low ordre bytes of UTF-16 characters
* in the clob. The question mark character is returnd for UTF-16 characters
* beyond the range of 8-bit ASCII.
*
* @return a java.io.InputStream object containing the
* CLOB data
* @throws SQLException if there is an error accessing the
* CLOB value
*/
public synchronized InputStream getAsciiStream() throws SQLException {
checkClosed();
return new InputStream() {
private Reader reader = clob.getCharacterStream(session);
public int read() throws IOException {
int c = reader.read();
if (c < 0) {
return -1;
}
return c < 256 ? c & 0xff
: '?';
}
public int read(byte[] b, int off, int len) throws IOException {
if (b == null) {
throw new NullPointerException();
}
if (off < 0 || len < 0 || len > b.length - off) {
throw new IndexOutOfBoundsException();
}
if (len == 0) {
return 0;
}
int bytesRead = 0;
for (int i = 0; i < len; i++) {
int c = reader.read();
if (c < 0) {
break;
}
b[off + i] = (byte) c;
bytesRead++;
}
return bytesRead == 0 ? -1 : bytesRead;
}
public void close() throws IOException {
try {
reader.close();
} catch (Exception ex) {}
}
};
}
/**
* Retrieves the CLOB value designated by this
* Clob object as a java.io.Reader object (or
* as a stream of characters).
*
* @return a java.io.Reader object containing the
* CLOB data
* @throws SQLException if there is an error accessing the
* CLOB value
*/
public synchronized Reader getCharacterStream() throws SQLException {
checkClosed();
return new ClobInputStream(session, clob, 0, length());
}
/**
* Retrieves a copy of the specified substring in the CLOB
* value designated by this Clob object.
*
* @param pos the first character of the substring to be extracted. The
* first character is at position 1.
* @param length the number of consecutive characters to be copied
* @return a String that is the specified substring in the
* CLOB value designated by this Clob object
* @throws SQLException if there is an error accessing the
* CLOB value
*/
public synchronized String getSubString(long pos,
int length) throws SQLException {
checkClosed();
if (!isInLimits(Long.MAX_VALUE, pos - 1, length)) {
throw JDBCUtil.outOfRangeArgument();
}
try {
return clob.getSubString(session, pos - 1, length);
} catch (HsqlException e) {
throw JDBCUtil.sqlException(e);
}
}
/**
* Retrieves the number of characters in the CLOB value
* designated by this Clob object.
*
* @return length of the CLOB in characters
* @throws SQLException if there is an error accessing the length of the
* CLOB value
*/
public synchronized long length() throws SQLException {
checkClosed();
try {
return clob.length(session);
} catch (HsqlException e) {
throw JDBCUtil.sqlException(e);
}
}
/**
* Retrieves the character position at which the specified substring
* searchstr appears in the SQL CLOB value
* represented by this Clob object.
*
* @param searchstr the substring for which to search
* @param start the position at which to begin searching; the first
* position is 1
* @return the position at which the substring appears or -1 if it is
* not present; the first position is 1
* @throws SQLException if there is an error accessing the
* CLOB value
*/
public synchronized long position(String searchstr,
long start) throws SQLException {
checkClosed();
if (!isInLimits(Long.MAX_VALUE, start - 1, 0)) {
throw JDBCUtil.outOfRangeArgument();
}
try {
return clob.position(session, searchstr, start - 1);
} catch (HsqlException e) {
throw JDBCUtil.sqlException(e);
}
}
/**
* Retrieves the character position at which the specified
* Clob object searchstr appears in this
* Clob object.
*
* @param searchstr the Clob object for which to search
* @param start the position at which to begin searching; the first
* position is 1
* @return the position at which the Clob object appears or
* -1 if it is not present; the first position is 1
* @throws SQLException if there is an error accessing the
* CLOB value
*/
public synchronized long position(Clob searchstr,
long start) throws SQLException {
checkClosed();
if (!isInLimits(Long.MAX_VALUE, start - 1, 0)) {
throw JDBCUtil.outOfRangeArgument();
}
if (searchstr instanceof JDBCClobClient) {
ClobDataID searchClob = ((JDBCClobClient) searchstr).clob;
try {
return clob.position(session, searchClob, start - 1);
} catch (HsqlException e) {
throw JDBCUtil.sqlException(e);
}
}
if (!isInLimits(Integer.MAX_VALUE, 0, searchstr.length())) {
throw JDBCUtil.outOfRangeArgument();
}
return position(searchstr.getSubString(1, (int) searchstr.length()),
start);
}
/**
* Retrieves a stream to be used to write Ascii characters to the
* CLOB value that this Clob object represents,
* starting at position pos.
*
* The bytes written to the OutputStream are stored verbatim in the clob as
* the low order bytes of UTF-16 characters.
*
* @param pos the position at which to start writing to this
* CLOB object
* @return the stream to which ASCII encoded characters can be written
* @throws SQLException if there is an error accessing the
* CLOB value
*/
public synchronized OutputStream setAsciiStream(final long pos)
throws SQLException {
return new OutputStream() {
Writer writer = setCharacterStream(pos);
public void write(int b) throws IOException {
writer.write(b & 0xff);
}
public void write(byte[] b, int off, int len) throws IOException {
if (b == null) {
throw new NullPointerException();
}
if (off < 0 || len < 0 || len > b.length - off) {
throw new IndexOutOfBoundsException();
}
if (len == 0) {
return;
}
char[] charArray = new char[len];
for (int i = 0; i < len; i++) {
charArray[i] = (char) b[off + i];
}
writer.write(charArray, 0, len);
}
public void close() throws IOException {
writer.close();
}
};
}
/**
* Retrieves a stream to be used to write a stream of Unicode characters
* to the CLOB value that this Clob object
* represents, at position pos.
*
* @param pos the position at which to start writing to the
* CLOB value
* @return a stream to which Unicode encoded characters can be written
* @throws SQLException if there is an error accessing the
* CLOB value
*/
public synchronized Writer setCharacterStream(final long pos)
throws SQLException {
checkClosed();
if (pos < 1) {
throw JDBCUtil.outOfRangeArgument("pos: " + pos);
}
if (!isWritable) {
throw JDBCUtil.notUpdatableColumn();
}
startUpdate();
return new Writer() {
private long m_clobPosition = pos - 1;
private boolean m_closed;
public void write(char[] cbuf, int off,
int len) throws IOException {
checkClosed();
clob.setChars(session, m_clobPosition, cbuf, off, len);
m_clobPosition += len;
}
public void flush() throws IOException {
// no-op
}
@Override
public void close() throws IOException {
m_closed = true;
}
private void checkClosed() throws IOException {
if (m_closed || JDBCClobClient.this.isClosed()) {
throw new IOException("The stream is closed");
}
}
};
}
/**
* Writes the given Java String to the CLOB
* value that this Clob object designates at the position
* pos.
*
* @param pos the position at which to start writing to the
* CLOB value that this Clob object
* represents
* @param str the string to be written to the CLOB value
* that this Clob designates
* @return the number of characters written
* @throws SQLException if there is an error accessing the
* CLOB value
*/
public synchronized int setString(long pos,
String str) throws SQLException {
return setString(pos, str, 0, str.length());
}
/**
* Writes len characters of str, starting at
* character offset, to the CLOB value that
* this Clob represents.
*
* @param pos the position at which to start writing to this
* CLOB object
* @param str the string to be written to the CLOB value
* that this Clob object represents
* @param offset the offset into str to start reading the
* characters to be written
* @param len the number of characters to be written
* @return the number of characters written
* @throws SQLException if there is an error accessing the
* CLOB value
*/
public synchronized int setString(long pos, String str, int offset,
int len) throws SQLException {
checkClosed();
if (!isInLimits(str.length(), offset, len)) {
throw JDBCUtil.outOfRangeArgument();
}
if (pos < 1) {
throw JDBCUtil.outOfRangeArgument("pos: " + pos);
}
if (!isWritable) {
throw JDBCUtil.notUpdatableColumn();
}
try {
startUpdate();
str = str.substring(offset, offset + len);
clob.setString(session, pos - 1, str);
return len;
} catch (HsqlException e) {
throw JDBCUtil.sqlException(e);
}
}
/**
* Truncates the CLOB value that this Clob
* designates to have a length of len characters.
*
* @param len the length, in bytes, to which the CLOB value
* should be truncated
* @throws SQLException if there is an error accessing the
* CLOB value
*/
public synchronized void truncate(long len) throws SQLException {
checkClosed();
if (len < 0) {
throw JDBCUtil.outOfRangeArgument("len: " + len);
}
try {
clob.truncate(session, len);
} catch (HsqlException e) {
throw JDBCUtil.sqlException(e);
}
}
//------------------------- JDBC 4.0 -----------------------------------
/**
* This method frees the Clob 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.
*
* @throws SQLException if an error occurs releasing
* the Clob'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 {
isClosed = true;
clob = null;
session = null;
}
/**
* Returns a Reader object that contains a partial Clob value, starting
* with the character specified by pos, which is length characters in length.
*
* @param pos the offset to the first character of the partial value to
* be retrieved. The first character in the Clob is at position 1.
* @param length the length in characters of the partial value to be retrieved.
* @return Reader through which the partial Clob value can be read.
* @throws SQLException if pos is less than 1 or if pos is greater than the number of
* characters in the Clob or if pos + length is greater than the number of
* characters in the Clob
*
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since JDK 1.6, HSQLDB 2.0
*/
public synchronized Reader getCharacterStream(long pos,
long length) throws SQLException {
checkClosed();
if (!isInLimits(this.length(), pos - 1, length)) {
throw JDBCUtil.outOfRangeArgument();
}
return new ClobInputStream(session, clob, pos - 1, length);
}
char[] getChars(long position, int length) throws SQLException {
try {
return clob.getChars(session, position - 1, length);
} catch (HsqlException e) {
throw JDBCUtil.sqlException(e);
}
}
//
ClobDataID originalClob;
ClobDataID clob;
SessionInterface session;
int colIndex;
private boolean isClosed;
private boolean isWritable;
JDBCResultSet resultSet;
public JDBCClobClient(SessionInterface session, ClobDataID clob) {
this.session = session;
this.clob = clob;
}
public ClobDataID getClob() {
return clob;
}
public synchronized boolean isClosed() {
return isClosed;
}
public synchronized void setWritable(JDBCResultSet result, int index) {
isWritable = true;
resultSet = result;
colIndex = index;
}
public synchronized void clearUpdates() {
if (originalClob != null) {
clob = originalClob;
originalClob = null;
}
}
private void startUpdate() throws SQLException {
if (originalClob != null) {
return;
}
originalClob = clob;
clob = (ClobDataID) clob.duplicate(session);
resultSet.startUpdate(colIndex + 1);
resultSet.preparedStatement.parameterValues[colIndex] = clob;
resultSet.preparedStatement.parameterSet[colIndex] = true;
}
private void checkClosed() throws SQLException {
if (isClosed) {
throw JDBCUtil.sqlException(ErrorCode.X_0F502);
}
}
static boolean isInLimits(long fullLength, long pos, long len) {
return fullLength >= 0 && pos >= 0 && len >= 0
&& pos <= fullLength - len;
}
}