/*
* 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 java.io;
import org.apache.harmony.luni.util.Msg;
/**
* The base class for all output streams. An output stream is a means of writing
* data to a target in a byte-wise manner. Most output streams expect the
* {@link #flush()} method to be called before closing the stream, to ensure all
* data is actually written through.
* <p>
* This abstract class does not provide a fully working implementation, so it
* needs to be subclassed, and at least the {@link #write(int)} method needs to
* be overridden. Overriding some of the non-abstract methods is also often
* advised, since it might result in higher efficiency.
* <p>
* Many specialized output streams for purposes like writing to a file already
* exist in this package.
*
* @see InputStream
*/
public abstract class OutputStream implements Closeable, Flushable {
/**
* Default constructor.
*/
public OutputStream() {
super();
}
/**
* Closes this stream. Implementations of this method should free any
* resources used by the stream. This implementation does nothing.
*
* @throws IOException
* if an error occurs while closing this stream.
*/
public void close() throws IOException {
/* empty */
}
/**
* Flushes this stream. Implementations of this method should ensure that
* any buffered data is written out. This implementation does nothing.
*
* @throws IOException
* if an error occurs while flushing this stream.
*/
public void flush() throws IOException {
/* empty */
}
/**
* Writes the entire contents of the byte array {@code buffer} to this
* stream.
*
* @param buffer
* the buffer to be written.
* @throws IOException
* if an error occurs while writing to this stream.
*/
public void write(byte[] buffer) throws IOException {
// BEGIN android-note
// changed array notation to be consistent with the rest of harmony
// END android-note
write(buffer, 0, buffer.length);
}
/**
* Writes {@code count} bytes from the byte array {@code buffer} starting at
* position {@code offset} to this stream.
*
* @param buffer
* the buffer to be written.
* @param offset
* the start position in {@code buffer} from where to get bytes.
* @param count
* the number of bytes from {@code buffer} to write to this
* stream.
* @throws IOException
* if an error occurs while writing to this stream.
* @throws IndexOutOfBoundsException
* if {@code offset < 0} or {@code count < 0}, or if
* {@code offset + count} is bigger than the length of
* {@code buffer}.
*/
public void write(byte[] buffer, int offset, int count) throws IOException {
// BEGIN android-note
// changed array notation to be consistent with the rest of harmony
// END android-note
// avoid int overflow, check null buffer
// BEGIN android-changed
// Exception priorities (in case of multiple errors) differ from
// RI, but are spec-compliant.
// removed redundant check, made implicit null check explicit,
// used (offset | count) < 0 instead of (offset < 0) || (count < 0)
// to safe one operation
if (buffer == null) {
throw new NullPointerException(Msg.getString("K0047")); //$NON-NLS-1$
}
if ((offset | count) < 0 || count > buffer.length - offset) {
throw new IndexOutOfBoundsException(Msg.getString("K002f")); //$NON-NLS-1$
}
// END android-changed
for (int i = offset; i < offset + count; i++) {
write(buffer[i]);
}
}
/**
* Writes a single byte to this stream. Only the least significant byte of
* the integer {@code oneByte} is written to the stream.
*
* @param oneByte
* the byte to be written.
* @throws IOException
* if an error occurs while writing to this stream.
*/
public abstract void write(int oneByte) throws IOException;
/**
* Returns true if this writer has encountered and suppressed an error. Used
* by PrintStreams as an alternative to checked exceptions.
*/
boolean checkError() {
return false;
}
}