/*
* Copyright 2014-2015 the original author or authors
*
* Licensed under the Apache License, Version 2.0 (the “License”);
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an “AS IS” BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.wplatform.ddal.jdbc;
import java.io.*;
import java.sql.Clob;
import java.sql.NClob;
import java.sql.SQLException;
import com.wplatform.ddal.engine.Constants;
import com.wplatform.ddal.message.DbException;
import com.wplatform.ddal.message.ErrorCode;
import com.wplatform.ddal.message.TraceObject;
import com.wplatform.ddal.util.IOUtils;
import com.wplatform.ddal.util.Task;
import com.wplatform.ddal.value.Value;
/**
* Represents a CLOB value.
*/
public class JdbcClob extends TraceObject implements NClob {
private final JdbcConnection conn;
Value value;
/**
* INTERNAL
*/
public JdbcClob(JdbcConnection conn, Value value, int id) {
setTrace(conn.getSession().getTrace(), TraceObject.CLOB, id);
this.conn = conn;
this.value = value;
}
/**
* Returns the length.
*
* @return the length
*/
@Override
public long length() throws SQLException {
try {
debugCodeCall("length");
checkClosed();
if (value.getType() == Value.CLOB) {
long precision = value.getPrecision();
if (precision > 0) {
return precision;
}
}
return IOUtils.copyAndCloseInput(value.getReader(), null, Long.MAX_VALUE);
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* [Not supported] Truncates the object.
*/
@Override
public void truncate(long len) throws SQLException {
throw unsupported("LOB update");
}
/**
* Returns the input stream.
*
* @return the input stream
*/
@Override
public InputStream getAsciiStream() throws SQLException {
try {
debugCodeCall("getAsciiStream");
checkClosed();
String s = value.getString();
return IOUtils.getInputStreamFromString(s);
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* [Not supported] Returns an output stream.
*/
@Override
public OutputStream setAsciiStream(long pos) throws SQLException {
throw unsupported("LOB update");
}
/**
* Returns the reader.
*
* @return the reader
*/
@Override
public Reader getCharacterStream() throws SQLException {
try {
debugCodeCall("getCharacterStream");
checkClosed();
return value.getReader();
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Get a writer to update the Clob. This is only supported for new, empty
* Clob objects that were created with Connection.createClob() or
* createNClob(). The Clob is created in a separate thread, and the object
* is only updated when Writer.close() is called. The position must be 1,
* meaning the whole Clob data is set.
*
* @param pos where to start writing (the first character is at position 1)
* @return a writer
*/
@Override
public Writer setCharacterStream(long pos) throws SQLException {
try {
if (isDebugEnabled()) {
debugCodeCall("setCharacterStream(" + pos + ");");
}
checkClosed();
if (pos != 1) {
throw DbException.getInvalidValueException("pos", pos);
}
if (value.getPrecision() != 0) {
throw DbException.getInvalidValueException("length", value.getPrecision());
}
final JdbcConnection c = conn;
// PipedReader / PipedWriter are a lot slower
// than PipedInputStream / PipedOutputStream
// (Sun/Oracle Java 1.6.0_20)
final PipedInputStream in = new PipedInputStream();
final Task task = new Task() {
@Override
public void call() {
value = c.createClob(IOUtils.getReader(in), -1);
}
};
PipedOutputStream out = new PipedOutputStream(in) {
@Override
public void close() throws IOException {
super.close();
try {
task.get();
} catch (Exception e) {
throw DbException.convertToIOException(e);
}
}
};
task.execute();
return IOUtils.getBufferedWriter(out);
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Returns a substring.
*
* @param pos the position (the first character is at position 1)
* @param length the number of characters
* @return the string
*/
@Override
public String getSubString(long pos, int length) throws SQLException {
try {
if (isDebugEnabled()) {
debugCode("getSubString(" + pos + ", " + length + ");");
}
checkClosed();
if (pos < 1) {
throw DbException.getInvalidValueException("pos", pos);
}
if (length < 0) {
throw DbException.getInvalidValueException("length", length);
}
StringWriter writer = new StringWriter(
Math.min(Constants.IO_BUFFER_SIZE, length));
Reader reader = value.getReader();
try {
IOUtils.skipFully(reader, pos - 1);
IOUtils.copyAndCloseInput(reader, writer, length);
} finally {
reader.close();
}
return writer.toString();
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Fills the Clob. This is only supported for new, empty Clob objects that
* were created with Connection.createClob() or createNClob(). The position
* must be 1, meaning the whole Clob data is set.
*
* @param pos where to start writing (the first character is at position 1)
* @param str the string to add
* @return the length of the added text
*/
@Override
public int setString(long pos, String str) throws SQLException {
try {
if (isDebugEnabled()) {
debugCode("setString(" + pos + ", " + quote(str) + ");");
}
checkClosed();
if (pos != 1) {
throw DbException.getInvalidValueException("pos", pos);
} else if (str == null) {
throw DbException.getInvalidValueException("str", str);
}
value = conn.createClob(new StringReader(str), -1);
return str.length();
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* [Not supported] Sets a substring.
*/
@Override
public int setString(long pos, String str, int offset, int len)
throws SQLException {
throw unsupported("LOB update");
}
/**
* [Not supported] Searches a pattern and return the position.
*/
@Override
public long position(String pattern, long start) throws SQLException {
throw unsupported("LOB search");
}
/**
* [Not supported] Searches a pattern and return the position.
*/
@Override
public long position(Clob clobPattern, long start) throws SQLException {
throw unsupported("LOB search");
}
/**
* Release all resources of this object.
*/
@Override
public void free() {
debugCodeCall("free");
value = null;
}
/**
* [Not supported] Returns the reader, starting from an offset.
*/
@Override
public Reader getCharacterStream(long pos, long length) throws SQLException {
throw unsupported("LOB subset");
}
private void checkClosed() {
conn.checkClosed();
if (value == null) {
throw DbException.get(ErrorCode.OBJECT_CLOSED);
}
}
/**
* INTERNAL
*/
@Override
public String toString() {
return getTraceObjectName() + ": " + (value == null ?
"null" : value.getTraceSQL());
}
}