com.tangosol.io
Class WrapperInputStream

java.lang.Object
  java.io.InputStream
      com.tangosol.io.WrapperInputStream

All Implemented Interfaces:

InputStreaming, java.io.Closeable

Direct Known Subclasses:

AsymmetricEncryptionFilter.IdentityInputStream, ClusterEncryptionFilter.DemultiplexingInputStream, PackedDataInputStream

public class WrapperInputStream
extends java.io.InputStream
implements InputStreaming

This is an InputStream class that delegates to another InputStream. Primarily, this is intended as a base class for building specific-purpose InputStream wrappers.

Author:

cp 2004.09.09

Constructor Summary

WrapperInputStream()
Construct an uninitialized WrapperInputStream.

WrapperInputStream(java.io.InputStream in)
Construct a WrapperInputStream that will input from the specified InputStream object.

Method Summary

int	available() Returns the number of bytes that can be read (or skipped over) from this input stream without causing a blocking I/O condition to occur.
void	close() Close the InputStream and release any system resources associated with it.
protected java.io.InputStream	ensureInputStream() Return the underlying InputStream.
java.io.InputStream	getInputStream() Obtain the underlying InputStream.
void	mark(int cbReadLimit) Marks the current read position in the InputStream in order to support the stream to be later "rewound" (using the reset() method) to the current position.
boolean	markSupported() Determine if this InputStream supports the mark(int) and reset() methods.
int	read() Read the next byte of data from the InputStream.
int	read(byte[] ab) Read some number of bytes from the input stream and store them into the passed array ab.
int	read(byte[] ab, int of, int cb) Read up to cb bytes from the input stream and store them into the passed array ab starting at offset of.
void	reset() Rewind this stream to the position at the time the mark(int) method was last called on this InputStream.
protected void	setInputStream(java.io.InputStream in) Specify the underlying InputSream.
long	skip(long cb) Skips over up to the specified number of bytes of data from this InputStream.

Constructor Detail

WrapperInputStream

public WrapperInputStream()

Construct an uninitialized WrapperInputStream.

WrapperInputStream

public WrapperInputStream(java.io.InputStream in)

Construct a WrapperInputStream that will input from the specified InputStream object.

Parameters:

in - an InputStream object to read from

Method Detail

getInputStream

public java.io.InputStream getInputStream()

Obtain the underlying InputStream.

Returns:

the underlying InputStream

ensureInputStream

protected java.io.InputStream ensureInputStream()

Return the underlying InputStream.

Returns:

the underlying InputStream

Throws:

java.lang.IllegalStateException - if the underlying stream has not been specified.

setInputStream

protected void setInputStream(java.io.InputStream in)

Specify the underlying InputSream. This method may only be called once with a non-null value.

Parameters:

in - the stream to be wrapped

Throws:

java.lang.IllegalStateException - if the underlying stream has already been specified.

read

public int read()
         throws java.io.IOException

Read the next byte of data from the InputStream. The value byte is returned as an int in the range 0 to 255. If 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.

Specified by:

read in interface InputStreaming

Specified by:

read in class java.io.InputStream

Returns:

the next byte of data, or -1 if the end of the stream has been reached

Throws:

java.io.IOException - if an I/O error occurs

read

public int read(byte[] ab)
         throws java.io.IOException

Read some number of bytes from the input stream and store them into the passed array ab. The number of bytes actually read is returned.

This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Specified by:

read in interface InputStreaming

Overrides:

read in class java.io.InputStream

Parameters:

ab - the array to store the bytes which are read from the stream

Returns:

the number of bytes read from the stream, or -1 if no bytes were read from the stream because the end of the stream had been reached

Throws:

java.lang.NullPointerException - if the passed array is null

java.io.IOException - if an I/O error occurs

read

public int read(byte[] ab,
                int of,
                int cb)
         throws java.io.IOException

Read up to cb bytes from the input stream and store them into the passed array ab starting at offset of. The number of bytes actually read is returned.

This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Specified by:

read in interface InputStreaming

Overrides:

read in class java.io.InputStream

Parameters:

ab - the array to store the bytes which are read from the stream

of - the offset into the array that the read bytes will be stored

cb - the maximum number of bytes to read

Returns:

the number of bytes read from the stream, or -1 if no bytes were read from the stream because the end of the stream had been reached

Throws:

java.lang.NullPointerException - if the passed array is null

java.lang.IndexOutOfBoundsException - if of or cb is negative, or of+cb is greater than the length of the ab

java.io.IOException - if an I/O error occurs

skip

public long skip(long cb)
          throws java.io.IOException

Skips over up to the specified number of bytes of data from this InputStream. The number of bytes actually skipped over may be fewer than the number specified to skip, and may even be zero; this can be caused by an end-of-file condition, but can also occur even when there is data remaining in the InputStream. As a result, the caller should check the return value from this method, which indicates the actual number of bytes skipped.

Specified by:

skip in interface InputStreaming

Overrides:

skip in class java.io.InputStream

Parameters:

cb - the maximum number of bytes to skip over

Returns:

the actual number of bytes that were skipped over

Throws:

java.io.IOException - if an I/O error occurs

available

public int available()
              throws java.io.IOException

Returns the number of bytes that can be read (or skipped over) from this input stream without causing a blocking I/O condition to occur. This method reflects the assumed implementation of various buffering InputStreams, which can guarantee non-blocking reads up to the extent of their buffers, but beyond that the read operations will have to read from some underlying (and potentially blocking) source.

Specified by:

available in interface InputStreaming

Overrides:

available in class java.io.InputStream

Returns:

the number of bytes that can be read from this InputStream without blocking

Throws:

java.io.IOException - if an I/O error occurs

close

public void close()
           throws java.io.IOException

Close the InputStream and release any system resources associated with it.

Specified by:

close in interface InputStreaming

Specified by:

close in interface java.io.Closeable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException - if an I/O error occurs

mark

public void mark(int cbReadLimit)

Marks the current read position in the InputStream in order to support the stream to be later "rewound" (using the reset() method) to the current position. The caller passes in the maximum number of bytes that it expects to read before calling the reset() method, thus indicating the upper bounds of the responsibility of the stream to be able to buffer what it has read in order to support this functionality.

Specified by:

mark in interface InputStreaming

Overrides:

mark in class java.io.InputStream

Parameters:

cbReadLimit - the maximum number of bytes that caller expects the InputStream to be able to read before the mark position becomes invalid

reset

public void reset()
           throws java.io.IOException

Rewind this stream to the position at the time the mark(int) method was last called on this InputStream. If the InputStream cannot fulfill this contract, it should throw an IOException.

Specified by:

reset in interface InputStreaming

Overrides:

reset in class java.io.InputStream

Throws:

java.io.IOException - if an I/O error occurs, for example if this has not been marked or if the mark has been invalidated

markSupported

public boolean markSupported()

Determine if this InputStream supports the mark(int) and reset() methods.

Specified by:

markSupported in interface InputStreaming

Overrides:

markSupported in class java.io.InputStream

Returns:

true if this InputStream supports the mark and reset method; false otherwise