www.pudn.com > j2me_cldc-1_1-fcs-src-winunix.rar > OutputStream.java, change:2003-02-05,size:5034b

/*
 * Copyright © 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 */

package java.io;

/**
 * This abstract class is the superclass of all classes representing
 * an output stream of bytes. An output stream accepts output bytes
 * and sends them to some sink.
 * 

 * Applications that need to define a subclass of
 * OutputStream must always provide at least a method
 * that writes one byte of output.
 *
 * @author  Arthur van Hoff
 * @version 12/17/01 (CLDC 1.1)
 * @see     java.io.ByteArrayOutputStream
 * @see     java.io.DataOutputStream
 * @see     java.io.InputStream
 * @see     java.io.OutputStream#write(int)
 * @since   JDK1.0, CLDC 1.0
 */
public abstract class OutputStream {

    /**
     * Writes the specified byte to this output stream. The general
     * contract for write is that one byte is written
     * to the output stream. The byte to be written is the eight
     * low-order bits of the argument b. The 24
     * high-order bits of b are ignored.
     * 

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

    /**
     * Writes b.length bytes from the specified byte array
     * to this output stream. The general contract for write(b)
     * is that it should have exactly the same effect as the call
     * write(b, 0, b.length).
     *
     * @param      b   the data.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.OutputStream#write(byte[], int, int)
     */
    public void write(byte b[]) throws IOException {
        write(b, 0, b.length);
    }

    /**
     * Writes len bytes from the specified byte array
     * starting at offset off to this output stream.
     * The general contract for write(b, off, len) is that
     * some of the bytes in the array b are written to the
     * output stream in order; element b[off] is the first
     * byte written and b[off+len-1] is the last byte written
     * by this operation.
     * 

     * The write method of OutputStream 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.
     * 

     * If b is null, a
     * NullPointerException is thrown.
     * 

     * If off is negative, or len is negative, or
     * off+len is greater than the length of the array
     * b, then an IndexOutOfBoundsException 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 IOException is thrown if the output
     *             stream is closed.
     */
    public void write(byte b[], int off, int len) throws IOException {
        if (b == null) {
            throw new NullPointerException();
        } else if ((off < 0) || (off > b.length) || (len < 0) ||
                   ((off + len) > b.length) || ((off + len) < 0)) {
            throw new IndexOutOfBoundsException();
        } else if (len == 0) {
            return;
        }
        for (int i = 0 ; i < len ; i++) {
            write(b[off + i]);
        }
    }

    /**
     * Flushes this output stream and forces any buffered output bytes
     * to be written out. 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.
     * 

     * The flush method of OutputStream does nothing.
     *
     * @exception  IOException  if an I/O error occurs.
     */
    public void flush() throws IOException {
    }

    /**
     * Closes this output stream and releases any system resources
     * associated with this stream. The general contract of close
     * is that it closes the output stream. A closed stream cannot perform
     * output operations and cannot be reopened.
     * 

     * The close method of OutputStream does nothing.
     *
     * @exception  IOException  if an I/O error occurs.
     */
    public void close() throws IOException {
    }

}