Memory Byte Array OutputStream
/**
*
* JFreeReport : a free Java reporting library
*
*
* Project Info: http://reporting.pentaho.org/
*
* (C) Copyright 2001-2007, by Object Refinery Ltd, Pentaho Corporation and Contributors.
*
* 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., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ------------
* MemoryByteArrayOutputStream.java
* ------------
* (C) Copyright 2001-2007, by Object Refinery Ltd, Pentaho Corporation and Contributors.
*/
import java.io.IOException;
import java.io.OutputStream;
/**
* A string writer that is able to write large amounts of data. The original
* StringWriter contained in Java doubles its buffersize everytime the buffer
* overflows. This is nice with small amounts of data, but awfull for huge
* buffers.
*
* @author Thomas Morgner
*/
public class MemoryByteArrayOutputStream extends OutputStream {
private int maximumBufferIncrement;
private int cursor;
private byte[] buffer;
private byte[] singleIntArray;
/**
* Create a new character-stream writer whose critical sections will
* synchronize on the writer itself.
*/
public MemoryByteArrayOutputStream() {
this(4096, 65536);
}
/**
* Create a new character-stream writer whose critical sections will
* synchronize on the writer itself.
*/
public MemoryByteArrayOutputStream(final int bufferSize, final int maximumBufferIncrement) {
this.maximumBufferIncrement = maximumBufferIncrement;
this.buffer = new byte[bufferSize];
this.singleIntArray = new byte[1];
}
/**
* Write a portion of an array of characters.
*
* @param cbuf
* Array of characters
* @param off
* Offset from which to start writing characters
* @param len
* Number of characters to write
* @throws java.io.IOException
* If an I/O error occurs
*/
public synchronized void write(final byte[] cbuf, final int off, final int len)
throws IOException {
if (len < 0) {
throw new IllegalArgumentException();
}
if (off < 0) {
throw new IndexOutOfBoundsException();
}
if (cbuf == null) {
throw new NullPointerException();
}
if ((len + off) > cbuf.length) {
throw new IndexOutOfBoundsException();
}
ensureSize(cursor + len);
System.arraycopy(cbuf, off, this.buffer, cursor, len);
cursor += len;
}
/**
* Writes <code>b.length</code> bytes from the specified byte array to this
* output stream. The general contract for <code>write(b)</code> is that it
* should have exactly the same effect as the call <code>write(b, 0,
* b.length)</code>.
*
* @param b
* the data.
* @throws java.io.IOException
* if an I/O error occurs.
* @see java.io.OutputStream#write(byte[], int, int)
*/
public void write(final byte[] b) throws IOException {
write(b, 0, b.length);
}
/**
* Writes the specified byte to this output stream. The general contract for
* <code>write</code> is that one byte is written to the output stream. The
* byte to be written is the eight low-order bits of the argument
* <code>b</code>. The 24 high-order bits of <code>b</code> are ignored.
* <p/> Subclasses of <code>OutputStream</code> must provide an
* implementation for this method.
*
* @param b
* the <code>byte</code>.
* @throws java.io.IOException
* if an I/O error occurs. In particular, an
* <code>IOException</code> may be thrown if the output stream has
* been closed.
*/
public synchronized void write(final int b) throws IOException {
this.singleIntArray[0] = (byte) (0xFF & b);
write(singleIntArray, 0, 1);
}
private void ensureSize(final int size) {
if (this.buffer.length >= size) {
return;
}
final int computedSize = (int) Math.min((this.buffer.length + 1) * 1.5, this.buffer.length
+ maximumBufferIncrement);
final int newSize = Math.max(size, computedSize);
final byte[] newBuffer = new byte[newSize];
System.arraycopy(this.buffer, 0, newBuffer, 0, cursor);
this.buffer = newBuffer;
}
/**
* Flush the stream. If the stream has saved any characters from the various
* write() methods in a buffer, write them immediately to their intended
* destination. Then, if that destination is another character or byte stream,
* flush it. Thus one flush() invocation will flush all the buffers in a chain
* of Writers and OutputStreams. <p/> If the intended destination of this
* stream is an abstraction provided by the underlying operating system, for
* example a file, then flushing the stream guarantees only that bytes
* previously written to the stream are passed to the operating system for
* writing; it does not guarantee that they are actually written to a physical
* device such as a disk drive.
*
* @throws java.io.IOException
* If an I/O error occurs
*/
public void flush() throws IOException {
if ((buffer.length - cursor) > 50000) {
System.out.println("WASTED: " + (buffer.length - cursor));
}
}
/**
* Close the stream, flushing it first. Once a stream has been closed, further
* write() or flush() invocations will cause an IOException to be thrown.
* Closing a previously-closed stream, however, has no effect.
*
* @throws java.io.IOException
* If an I/O error occurs
*/
public void close() throws IOException {
}
public synchronized byte[] toByteArray() {
final byte[] retval = new byte[cursor];
System.arraycopy(buffer, 0, retval, 0, cursor);
return retval;
}
public int getLength() {
return cursor;
}
public byte[] getRaw() {
if ((buffer.length - cursor) > 50000) {
System.out.println("WASTED: " + (buffer.length - cursor) + " Length: " + buffer.length);
}
return buffer;
}
}
Related examples in the same category