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regarding copyright ownership.  The ASF licenses this file
to you 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.
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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.commons.crypto.stream.output;

import java.io.IOException;
import java.nio.ByteBuffer;

The Output interface abstract the output target of
CryptoOutputStream so that different implementation of output
can be used. The implementation Output interface will usually wraps an output
mechanism such as OutputStream or
WritableByteChannel.
/**
 * The Output interface abstract the output target of
 * <code>CryptoOutputStream</code> so that different implementation of output
 * can be used. The implementation Output interface will usually wraps an output
 * mechanism such as <code>OutputStream</code> or
 * <code>WritableByteChannel</code>.
 */
public interface Output {

    
Writes a sequence of bytes to this output from the given buffer.

An attempt is made to write up to r bytes to the channel, where
r is the number of bytes remaining in the buffer, that is,
src.remaining(), at the moment this method is invoked.

Suppose that a byte sequence of length n is written, where
0 <= n <=
 r. This byte sequence will be transferred from the buffer
starting at index p, where p is the buffer's position at
the moment this method is invoked; the index of the last byte written
will be p + n - 
1. Upon return the buffer's position will be equal to
p + n; its limit will not have changed.
Params:
src – The buffer from which bytes are to be retrieved.
Throws:
IOException – If some other I/O error occurs.
Returns:
The number of bytes written, possibly zero./**
     * Writes a sequence of bytes to this output from the given buffer.
     *
     * <p>
     * An attempt is made to write up to <i>r</i> bytes to the channel, where
     * <i>r</i> is the number of bytes remaining in the buffer, that is,
     * <tt>src.remaining()</tt>, at the moment this method is invoked.
     *
     * <p>
     * Suppose that a byte sequence of length <i>n</i> is written, where
     * <tt>0</tt>&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>
     * &nbsp;<i>r</i>. This byte sequence will be transferred from the buffer
     * starting at index <i>p</i>, where <i>p</i> is the buffer's position at
     * the moment this method is invoked; the index of the last byte written
     * will be <i>p</i>&nbsp;<tt>+</tt>&nbsp;<i>n</i>&nbsp;<tt>-</tt>&nbsp;
     * <tt>1</tt>. Upon return the buffer's position will be equal to
     * <i>p</i>&nbsp;<tt>+</tt>&nbsp;<i>n</i>; its limit will not have changed.
     *
     * @param src The buffer from which bytes are to be retrieved.
     *
     * @return The number of bytes written, possibly zero.
     *
     * @throws IOException If some other I/O error occurs.
     */
    int write(ByteBuffer src) throws IOException;

    
Flushes this output and forces any buffered output bytes to be written
out if the under layer output method support. The general contract of
flush 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./**
     * Flushes this output and forces any buffered output bytes to be written
     * out if the under layer output method support. 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.
     */
    void flush() throws IOException;

    
Closes this output and releases any system resources associated with the
under layer output.
Throws:
IOException – if an I/O error occurs./**
     * Closes this output and releases any system resources associated with the
     * under layer output.
     *
     * @throws IOException if an I/O error occurs.
     */
    void close() throws IOException;
}