A format for String objects that is easier to persist
/***
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Project: www.simpledbm.org
* Author : Dibyendu Majumdar
* Email : dibyendu@mazumdar.demon.co.uk
*/
import java.nio.ByteBuffer;
/**
* A format for String objects that is easier to persist.
*
* @author Dibyendu Majumdar
* @since 26-Jun-2005
*/
public final class ByteString implements Comparable<ByteString> {
private byte[] bytes;
public ByteString() {
}
public ByteString(String s) {
bytes = s.getBytes();
}
public ByteString(byte[] bytes) {
this.bytes = bytes.clone();
}
@Override
public String toString() {
if (bytes == null)
return "";
return new String(bytes);
}
public int getStoredLength() {
return bytes.length + (Short.SIZE / Byte.SIZE);
}
public void store(ByteBuffer bb) {
short n = 0;
if (bytes != null) {
n = (short) bytes.length;
}
bb.putShort(n);
if (n > 0) {
bb.put(bytes, 0, n);
}
}
public void retrieve(ByteBuffer bb) {
short n = bb.getShort();
if (n > 0) {
bytes = new byte[n];
bb.get(bytes);
}
else {
bytes = null;
}
}
public int compareTo(ByteString o) {
/*
* FIXME: This is inefficient
*/
String s1 = new String(bytes);
String s2 = new String(o.bytes);
return s1.compareTo(s2);
}
public int length() {
return bytes.length;
}
public byte get(int offset) {
return bytes[offset];
}
}
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