java.io

Class SequenceInputStream

Implemented Interfaces:
Closeable

public class SequenceInputStream
extends InputStream

This class merges a sequence of multiple InputStream's in order to form a single logical stream that can be read by applications that expect only one stream.

The streams passed to the constructor method are read in order until they return -1 to indicate they are at end of stream. When a stream reports end of stream, it is closed, then the next stream is read. When the last stream is closed, the next attempt to read from this stream will return a -1 to indicate it is at end of stream.

If this stream is closed prior to all subordinate streams being read to completion, all subordinate streams are closed.

Constructor Summary

SequenceInputStream(InputStream> e)
This method creates a new SequenceInputStream that obtains its list of subordinate InputStreams from the specified Enumeration
SequenceInputStream(InputStream s1, InputStream s2)
This method creates a new SequenceInputStream that will read the two specified subordinate InputStreams in sequence.

Method Summary

int
available()
This method returns the number of bytes than can be read from the currently being read subordinate stream before that stream could block.
void
close()
Closes this stream.
int
read()
This method reads an unsigned byte from the input stream and returns it as an int in the range of 0-255.
int
read(byte[] b, int off, int len)
This method reads bytes from a stream and stores them into a caller supplied buffer.

Methods inherited from class java.io.InputStream

available, close, mark, markSupported, read, read, read, reset, skip

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

SequenceInputStream

public SequenceInputStream(InputStream> e)
This method creates a new SequenceInputStream that obtains its list of subordinate InputStreams from the specified Enumeration
Parameters:
e - An Enumeration that will return a list of InputStreams to read in sequence

SequenceInputStream

public SequenceInputStream(InputStream s1,
                           InputStream s2)
This method creates a new SequenceInputStream that will read the two specified subordinate InputStreams in sequence.
Parameters:
s1 - The first InputStream to read
s2 - The second InputStream to read

Method Details

available

public int available()
            throws IOException
This method returns the number of bytes than can be read from the currently being read subordinate stream before that stream could block. Note that it is possible more bytes than this can actually be read without the stream blocking. If a 0 is returned, then the stream could block on the very next read.
Overrides:
available in interface InputStream
Returns:
The number of bytes that can be read before blocking could occur
Throws:
IOException - If an error occurs

close

public void close()
            throws IOException
Closes this stream. This will cause any remaining unclosed subordinate InputStream's to be closed as well. Subsequent attempts to read from this stream may cause an exception.
Specified by:
close in interface Closeable
Overrides:
close in interface InputStream
Throws:
IOException - If an error occurs

read

public int read()
            throws IOException
This method reads an unsigned byte from the input stream and returns it as an int in the range of 0-255. This method also will return -1 if the end of the stream has been reached. This will only happen when all of the subordinate streams have been read.

This method will block until the byte can be read.

Overrides:
read in interface InputStream
Returns:
The byte read, or -1 if end of stream
Throws:
IOException - If an error occurs

read

public int read(byte[] b,
                int off,
                int len)
            throws IOException
This method reads bytes from a stream and stores them into a caller supplied buffer. It starts storing the data at index offset into the buffer and attempts to read len bytes. This method can return before reading the number of bytes requested. The actual number of bytes read is returned as an int. A -1 is returend to indicate the end of the stream. This will only happen when all of the subordinate streams have been read.

This method will block until at least one byte can be read.

Overrides:
read in interface InputStream
Parameters:
b - The array into which bytes read should be stored
off - The offset into the array to start storing bytes
len - The requested number of bytes to read
Returns:
The actual number of bytes read, or -1 if end of stream
Throws:
IOException - If an error occurs

SequenceInputStream.java -- Reads multiple input streams in sequence Copyright (C) 1998, 1999, 2001, 2004, 2005 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.