IOutputStream.java

package co.codewizards.cloudstore.core.io;

import java.io.IOException;
import java.lang.reflect.Proxy;

/**
 * {@link OutputStream}-representing interface to be used in API contracts.
 * <p>
 * Interfaces modelling API should always use {@link IOutputStream} instead
 * of {@link OutputStream}, because this facilitates the usage of
 * {@linkplain Proxy proxies}. Proxies are needed to use APIs accross
 * local-server/-client boundaries.
 * <p>
 * To convert between {@link OutputStream} and {@link IOutputStream}, use
 * {@link StreamUtil#castStream(IOutputStream)} or {@link StreamUtil#castStream(OutputStream)}.
 * <p>
 * It is recommended that you statically import {@code StreamUtil.*} whenever
 * you need a {@code castStream(...)}. Also, you should register this in your IDE
 * as a favorite for static method imports.
 * <p>
 * <b>Important note about the naming:</b> We usually <i>never</i> use the "I-for-interface"
 * naming scheme! It sucks! But due to the fact that we already have "OutputStream" rather than
 * "OutputStreamImpl", we exceptionally use the "I"-prefix here.
 *
 * @author Marco หงุ่ยตระกูล-Schulze - marco at codewizards dot co
 * @see StreamUtil
 */
public interface IOutputStream extends AutoCloseable {

    /**
     * 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>IOutputStream</code> must provide an
     * implementation for this method.
     *
     * @param      b   the <code>byte</code>.
     * @exception  IOException  if an I/O error occurs. In particular,
     *             an <code>IOException</code> may be thrown if the
     *             output stream has been closed.
     */
    void write(int b) throws IOException;

    /**
     * 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.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.OutputStream#write(byte[], int, int)
     */
    void write(byte b[]) throws IOException;

    /**
     * Writes <code>len</code> bytes from the specified byte array
     * starting at offset <code>off</code> to this output stream.
     * The general contract for <code>write(b, off, len)</code> is that
     * some of the bytes in the array <code>b</code> are written to the
     * output stream in order; element <code>b[off]</code> is the first
     * byte written and <code>b[off+len-1]</code> is the last byte written
     * by this operation.
     * <p>
     * The <code>write</code> method of <code>IOutputStream</code> calls
     * the write method of one argument on each of the bytes to be
     * written out. Subclasses are encouraged to override this method and
     * provide a more efficient implementation.
     * <p>
     * If <code>b</code> is <code>null</code>, a
     * <code>NullPointerException</code> is thrown.
     * <p>
     * If <code>off</code> is negative, or <code>len</code> is negative, or
     * <code>off+len</code> is greater than the length of the array
     * <code>b</code>, then an <tt>IndexOutOfBoundsException</tt> is thrown.
     *
     * @param      b     the data.
     * @param      off   the start offset in the data.
     * @param      len   the number of bytes to write.
     * @exception  IOException  if an I/O error occurs. In particular,
     *             an <code>IOException</code> is thrown if the output
     *             stream is closed.
     */
    void write(byte b[], int off, int len) throws IOException;

    /**
     * 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.
     * <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.
     * <p>
     * The <code>flush</code> method of <code>IOutputStream</code> does nothing.
     *
     * @exception  IOException  if an I/O error occurs.
     */
    void flush() throws IOException;

    /**
     * Closes this output stream and releases any system resources
     * associated with this stream. The general contract of <code>close</code>
     * is that it closes the output stream. A closed stream cannot perform
     * output operations and cannot be reopened.
     * <p>
     * The <code>close</code> method of <code>IOutputStream</code> does nothing.
     *
     * @exception  IOException  if an I/O error occurs.
     */
    @Override
	void close() throws IOException;
}