/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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 GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.core.types;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.StringReader;
import java.io.Writer;
import java.nio.charset.Charset;
import java.sql.Clob;
import java.sql.SQLException;
import org.teiid.core.util.ObjectConverterUtil;
import org.teiid.core.util.ReaderInputStream;
import org.teiid.runtime.client.Messages;
/**
* This object holds a chunk of char data and implements the JDBC Clob interface.
* This object presents a streaming interface and provides a way to access partial
* of the Clob data. Connectors can use this object when dealing with large
* objects.
*/
public class ClobImpl extends BaseLob implements Clob {
private static final class StringInputStreamFactory extends
InputStreamFactory {
String str;
private StringInputStreamFactory(String str) {
this.str = str;
}
@Override
public InputStream getInputStream() throws IOException {
return new ByteArrayInputStream(str.getBytes(Streamable.CHARSET));
}
@Override
public Reader getCharacterStream() throws IOException {
return new StringReader(str);
}
@Override
public StorageMode getStorageMode() {
return StorageMode.MEMORY;
}
}
private final static class ClobStreamProvider implements
LobSearchUtil.StreamProvider {
private final Clob searchstr;
private ClobStreamProvider(Clob searchstr) {
this.searchstr = searchstr;
}
public InputStream getBinaryStream() throws SQLException {
ReaderInputStream ris = new ReaderInputStream(searchstr.getCharacterStream(), Charset.forName("UTF-16")); //$NON-NLS-1$
try {
ris.skip(2);
return ris;
} catch (IOException e) {
throw new SQLException(e);
}
}
}
private long len = -1;
public ClobImpl() {
}
/**
* Creates a new ClobImpl. Note that the length is not taken from the {@link InputStreamFactory} since
* it refers to bytes and not chars.
* @param streamFactory
* @param length
*/
public ClobImpl(InputStreamFactory streamFactory, long length) {
super(streamFactory);
this.len = length;
}
public ClobImpl(final char[] chars) {
this(new StringInputStreamFactory(new String(chars)), chars.length);
}
public ClobImpl(String str) {
this(new StringInputStreamFactory(str), str.length());
}
/**
* Gets the <code>CLOB</code> value designated by this <code>Clob</code>
* object as a stream of Ascii bytes.
* @return an ascii stream containing the <code>CLOB</code> data
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value
*/
public InputStream getAsciiStream() throws SQLException {
return new ReaderInputStream(getCharacterStream(), Charset.forName("US-ASCII")); //$NON-NLS-1$
}
/**
* Returns a copy of the specified substring
* in the <code>CLOB</code> value
* designated by this <code>Clob</code> object.
* The substring begins at position
* <code>pos</code> and has up to <code>length</code> consecutive
* characters.
* @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 <code>String</code> that is the specified substring in
* the <code>CLOB</code> value designated by this <code>Clob</code> object
* @exception SQLException if there is an error accessing the <code>CLOB</code>
*/
public String getSubString(long pos, int length) throws SQLException {
if (pos < 1) {
Object[] params = new Object[] {new Long(pos)};
throw new SQLException(Messages.getString(Messages.MMClob.MMBlob_0, params));
} else if (pos > length()) {
return null;
}
pos = pos - 1;
if (length < 0) {
Object[] params = new Object[] {new Integer( length)};
throw new SQLException(Messages.getString(Messages.MMClob.MMBlob_1, params));
} else if ((pos+length) > length()) {
length = (int)(length()-pos);
}
Reader in = getCharacterStream();
try {
try {
long skipped = 0;
while (pos > 0) {
skipped = in.skip(pos);
pos -= skipped;
}
return new String(ObjectConverterUtil.convertToCharArray(in, length));
} finally {
in.close();
}
} catch (IOException e) {
throw new SQLException(e);
}
}
/**
* Returns the number of characters in the <code>CLOB</code> value
* designated by this <code>Clob</code> object.
* @return length of the <code>CLOB</code> in characters
*/
public long length() throws SQLException {
if (len == -1) {
long length = 0;
Reader r = new BufferedReader(getCharacterStream());
try {
while (r.read() != -1) {
length++;
}
} catch (IOException e) {
throw new SQLException(e);
} finally {
try {
r.close();
} catch (IOException e) {
}
}
this.len = length;
}
return len;
}
/**
* Determines the character position at which the specified
* <code>Clob</code> object <code>searchstr</code> appears in this
* <code>Clob</code> object. The search begins at position
* <code>start</code>.
* @param searchstr the <code>Clob</code> 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 <code>Clob</code> object appears,
* else -1; the first position is 1
*/
public long position(final Clob searchstr, long start) throws SQLException {
if (searchstr == null) {
return -1;
}
return LobSearchUtil.position(new ClobStreamProvider(searchstr), searchstr.length(), new ClobStreamProvider(this), this.length(), start, 2);
}
/**
* Determines the character position at which the specified substring
* <code>searchstr</code> appears in the SQL <code>CLOB</code> value
* represented by this <code>Clob</code> object. The search
* begins at position <code>start</code>.
* @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, else -1; the first
* position is 1
* @exception SQLException if there is an error accessing the
* <code>CLOB</code> value
*/
public long position(String searchstr, long start) throws SQLException {
if (searchstr == null) {
return -1;
}
return position(new ClobImpl(searchstr), start);
}
public Reader getCharacterStream(long arg0, long arg1) throws SQLException {
throw new UnsupportedOperationException();
}
public OutputStream setAsciiStream(long arg0) throws SQLException {
throw new UnsupportedOperationException();
}
public Writer setCharacterStream(long arg0) throws SQLException {
throw new UnsupportedOperationException();
}
public int setString(long arg0, String arg1) throws SQLException {
throw new UnsupportedOperationException();
}
public int setString(long arg0, String arg1, int arg2, int arg3)
throws SQLException {
throw new UnsupportedOperationException();
}
public void truncate(long arg0) throws SQLException {
throw new UnsupportedOperationException();
}
public static Clob createClob(char[] chars) {
return new ClobImpl(chars);
}
}