com.Ostermiller.util Java Utilities


com.Ostermiller.util
Class ConcatInputStream

java.lang.Object
  extended by java.io.InputStream
      extended by com.Ostermiller.util.ConcatInputStream
All Implemented Interfaces:
Closeable

public class ConcatInputStream
extends InputStream

An input stream which reads sequentially from multiple sources. More information about this class is available from ostermiller.org.

Since:
ostermillerutils 1.04.00
Author:
Stephen Ostermiller http://ostermiller.org/contact.pl?regarding=Java+Utilities

Constructor Summary
ConcatInputStream()
          Create a new input stream that can dynamically accept new sources.
ConcatInputStream(InputStream in)
          Create a new InputStream with one source.
ConcatInputStream(InputStream[] in)
          Create a new InputStream with an arbitrary number of sources.
ConcatInputStream(InputStream in1, InputStream in2)
          Create a new InputStream with two sources.
 
Method Summary
 void addInputStream(InputStream in)
          Add the given inputStream to the queue of inputStreams from which to concatenate data.
 void addInputStreams(InputStream[] in)
          Add the given inputStream to the queue of inputStreams from which to concatenate data.
 int available()
          Returns the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream.
 void close()
          Closes this input stream and releases any system resources associated with the stream.
 void lastInputStreamAdded()
          Causes the addInputStream method to throw IllegalStateException and read() methods to return -1 (end of stream) when there is no more available data.
 void mark(int readlimit)
          Mark not supported
 boolean markSupported()
          Does not support mark.
 int read()
          Reads the next byte of data from the underlying streams.
 int read(byte[] b)
          Reads some number of bytes from the underlying streams and stores them into the buffer array b.
 int read(byte[] b, int off, int len)
          Reads up to length bytes of data from the underlying streams into an array of bytes.
 void reset()
          Reset not supported.
 long skip(long n)
          Skips over and discards n bytes of data from this input stream.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ConcatInputStream

public ConcatInputStream()
Create a new input stream that can dynamically accept new sources.

New sources should be added using the addInputStream() method. When all sources have been added the lastInputStreamAdded() should be called so that read methods can return -1 (end of stream).

Adding new sources may by interleaved with read calls.

Since:
ostermillerutils 1.04.01

ConcatInputStream

public ConcatInputStream(InputStream in)
Create a new InputStream with one source.

Parameters:
in - InputStream to use as a source.
Throws:
NullPointerException - if in is null
Since:
ostermillerutils 1.04.00

ConcatInputStream

public ConcatInputStream(InputStream in1,
                         InputStream in2)
Create a new InputStream with two sources.

Parameters:
in1 - first InputStream to use as a source.
in2 - second InputStream to use as a source.
Throws:
NullPointerException - if either source is null.
Since:
ostermillerutils 1.04.00

ConcatInputStream

public ConcatInputStream(InputStream[] in)
Create a new InputStream with an arbitrary number of sources.

Parameters:
in - InputStreams to use as a sources.
Throws:
NullPointerException - if the input array on any element is null.
Since:
ostermillerutils 1.04.00
Method Detail

lastInputStreamAdded

public void lastInputStreamAdded()
Causes the addInputStream method to throw IllegalStateException and read() methods to return -1 (end of stream) when there is no more available data.

Calling this method when this class is no longer accepting more inputStreams has no effect.

Since:
ostermillerutils 1.04.01

addInputStream

public void addInputStream(InputStream in)
Add the given inputStream to the queue of inputStreams from which to concatenate data.

Parameters:
in - InputStream to add to the concatenation.
Throws:
IllegalStateException - if more inputStreams can't be added because lastInputStreamAdded() has been called, close() has been called, or a constructor with inputStream parameters was used.
Since:
ostermillerutils 1.04.01

addInputStreams

public void addInputStreams(InputStream[] in)
Add the given inputStream to the queue of inputStreams from which to concatenate data.

Parameters:
in - InputStream to add to the concatenation.
Throws:
IllegalStateException - if more inputStreams can't be added because lastInputStreamAdded() has been called, close() has been called, or a constructor with inputStream parameters was used.
NullPointerException - the array of inputStreams, or any of the contents is null.
Since:
ostermillerutils 1.04.01

read

public int read()
         throws IOException
Reads the next byte of data from the underlying streams. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

If this class in not done accepting input streams and the end of the last known stream is reached, this method will block forever unless another thread adds an input stream or interrupts.

Specified by:
read in class InputStream
Returns:
the next byte of data, or -1 if the end of the stream is reached.
Throws:
IOException - if an I/O error occurs.

read

public int read(byte[] b)
         throws IOException
Reads some number of bytes from the underlying streams and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown.

If the length of b is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte.

The read(b) method for class InputStream has the same effect as:
read(b, 0, b.length)

If this class in not done accepting input streams and the end of the last known stream is reached, this method will block forever unless another thread adds an input stream or interrupts.

Overrides:
read in class InputStream
Parameters:
b - - Destination buffer
Returns:
The number of bytes read, or -1 if the end of the stream has been reached
Throws:
IOException - - If an I/O error occurs
NullPointerException - - If b is null.
Since:
ostermillerutils 1.04.00

read

public int read(byte[] b,
                int off,
                int len)
         throws IOException
Reads up to length bytes of data from the underlying streams into an array of bytes. An attempt is made to read as many as length bytes, but a smaller number may be read, possibly zero. The number of bytes actually read is returned as an integer.

If length is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte.

This method blocks until input data is available

If this class in not done accepting input streams and the end of the last known stream is reached, this method will block forever unless another thread adds an input stream or interrupts.

Overrides:
read in class InputStream
Parameters:
b - Destination buffer
off - Offset at which to start storing bytes
len - Maximum number of bytes to read
Returns:
The number of bytes read, or -1 if the end of the stream has been reached
Throws:
IOException - - If an I/O error occurs
NullPointerException - - If b is null.
IndexOutOfBoundsException - - if length or offset are not possible.

skip

public long skip(long n)
          throws IOException
Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If n is negative, no bytes are skipped.

If this class in not done accepting input streams and the end of the last known stream is reached, this method will block forever unless another thread adds an input stream or interrupts.

Overrides:
skip in class InputStream
Parameters:
n - he number of characters to skip
Returns:
The number of characters actually skipped
Throws:
IOException - If an I/O error occurs
Since:
ostermillerutils 1.04.00

available

public int available()
              throws IOException
Returns the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream. The next caller might be the same thread or or another thread.

Overrides:
available in class InputStream
Throws:
IOException - If an I/O error occurs
Since:
ostermillerutils 1.04.00

close

public void close()
           throws IOException
Closes this input stream and releases any system resources associated with the stream.

Specified by:
close in interface Closeable
Overrides:
close in class InputStream
Throws:
IOException
Since:
ostermillerutils 1.04.00

mark

public void mark(int readlimit)
Mark not supported

Overrides:
mark in class InputStream
Since:
ostermillerutils 1.04.00

reset

public void reset()
           throws IOException
Reset not supported.

Overrides:
reset in class InputStream
Throws:
IOException - because reset is not supported.
Since:
ostermillerutils 1.04.00

markSupported

public boolean markSupported()
Does not support mark.

Overrides:
markSupported in class InputStream
Returns:
false
Since:
ostermillerutils 1.04.00

com.Ostermiller.util Java Utilities


Copyright © 2001-2012 by Stephen Ostermiller