/*
* Copyright (c) 2003, PostgreSQL Global Development Group
* See the LICENSE file in the project root for more information.
*/
package org.postgresql.largeobject;
import java.io.
IOException;
import java.io.
OutputStream;
import java.sql.
SQLException;
/**
* This implements a basic output stream that writes to a LargeObject.
*/
public class
BlobOutputStream extends
OutputStream {
/**
* The parent LargeObject.
*/
private
LargeObject lo;
/**
* Buffer.
*/
private byte[]
buf;
/**
* Size of the buffer (default 1K).
*/
private int
bsize;
/**
* Position within the buffer.
*/
private int
bpos;
/**
* Create an OutputStream to a large object.
*
* @param lo LargeObject
*/
public
BlobOutputStream(
LargeObject lo) {
this(
lo, 1024);
}
/**
* Create an OutputStream to a large object.
*
* @param lo LargeObject
* @param bsize The size of the buffer used to improve performance
*/
public
BlobOutputStream(
LargeObject lo, int
bsize) {
this.
lo =
lo;
this.
bsize =
bsize;
buf = new byte[
bsize];
bpos = 0;
}
public void
write(int
b) throws java.io.
IOException {
checkClosed();
try {
if (
bpos >=
bsize) {
lo.
write(
buf);
bpos = 0;
}
buf[
bpos++] = (byte)
b;
} catch (
SQLException se) {
throw new
IOException(
se.
toString());
}
}
public void
write(byte[]
buf, int
off, int
len) throws java.io.
IOException {
checkClosed();
try {
// If we have any internally buffered data, send it first
if (
bpos > 0) {
flush();
}
if (
off == 0 &&
len ==
buf.length) {
lo.
write(
buf); // save a buffer creation and copy since full buffer written
} else {
lo.
write(
buf,
off,
len);
}
} catch (
SQLException se) {
throw new
IOException(
se.
toString());
}
}
/**
* Flushes this output stream and forces any buffered output bytes to be written out. The general
* contract of <code>flush</code> is that calling it is an indication that, if any bytes
* previously written have been buffered by the implementation of the output stream, such bytes
* should immediately be written to their intended destination.
*
* @throws IOException if an I/O error occurs.
*/
public void
flush() throws
IOException {
checkClosed();
try {
if (
bpos > 0) {
lo.
write(
buf, 0,
bpos);
}
bpos = 0;
} catch (
SQLException se) {
throw new
IOException(
se.
toString());
}
}
public void
close() throws
IOException {
if (
lo != null) {
try {
flush();
lo.
close();
lo = null;
} catch (
SQLException se) {
throw new
IOException(
se.
toString());
}
}
}
private void
checkClosed() throws
IOException {
if (
lo == null) {
throw new
IOException("BlobOutputStream is closed");
}
}
}