org.omnifaces.io.ResettableBufferedOutputStream Maven / Gradle / Ivy
/*
* Copyright 2012 OmniFaces.
*
* 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 org.omnifaces.io;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
* This resettable buffered output stream will buffer everything until the given buffer size, regardless of flush calls.
* Only when the buffer size is exceeded, or when close is called, then the buffer will be actually flushed.
*
* There is a {@link #reset()} method which enables the developer to reset the buffer, as long as it's not flushed yet,
* which can be determined by {@link #isResettable()}.
*
* @author Bauke Scholtz
* @see ResettableBufferedWriter
*/
public class ResettableBufferedOutputStream extends OutputStream implements ResettableBuffer {
// Variables ------------------------------------------------------------------------------------------------------
private OutputStream output;
private ByteArrayOutputStream buffer;
private int bufferSize;
private int writtenBytes;
// Constructors ---------------------------------------------------------------------------------------------------
/**
* Construct a new resettable buffered output stream which wraps the given output stream and forcibly buffers
* everything until the given buffer size, regardless of flush calls.
* @param output The wrapped output stream .
* @param bufferSize The buffer size.
*/
public ResettableBufferedOutputStream(OutputStream output, int bufferSize) {
this.output = output;
this.bufferSize = bufferSize;
buffer = new ByteArrayOutputStream(bufferSize);
}
// Actions --------------------------------------------------------------------------------------------------------
@Override
public void write(int b) throws IOException {
write(new byte[] { (byte) b }, 0, 1);
}
@Override
public void write(byte[] bytes) throws IOException {
write(bytes, 0, bytes.length);
}
@Override
public void write(byte[] bytes, int offset, int length) throws IOException {
if (buffer != null) {
writtenBytes += (length - offset);
if (writtenBytes > bufferSize) {
output.write(buffer.toByteArray());
output.write(bytes, offset, length);
buffer = null;
}
else {
buffer.write(bytes, offset, length);
}
}
else {
output.write(bytes, offset, length);
}
}
@Override
public void reset() {
buffer = new ByteArrayOutputStream(bufferSize);
writtenBytes = 0;
}
@Override
public void flush() throws IOException {
if (buffer == null) {
output.flush();
}
}
@Override
public void close() throws IOException {
if (buffer != null) {
output.write(buffer.toByteArray());
buffer = null;
}
output.close();
}
@Override
public boolean isResettable() {
return buffer != null;
}
}