de.uni_hildesheim.sse.monitoring.runtime.wrap

Class DelegatingInputStream

java.lang.Object

java.io.InputStream

de.uni_hildesheim.sse.monitoring.runtime.wrap.DelegatingInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class DelegatingInputStream
extends java.io.InputStream

A stream class delegating its operation to an arbitrary input stream while notifying the recorder about performed operations.

Since:

1.00

Version:

1.00

Author:

Holger Eichelberger

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	inRead1 Stores if we are in a read method with 1 parameter (avoid double recording).
private boolean	inRead3 Stores if we are in a read method with 3 parameters (avoid double recording).
private java.lang.String	recId Stores the recorder id to aggregate the notifications for.
private java.io.InputStream	stream Stores the stream to delegate to.
private StreamType	type Stores the stream type.

Constructor Summary

Constructors

Constructor and Description
DelegatingInputStream(java.io.InputStream stream, StreamType type) Creates a new delegating stream.
DelegatingInputStream(java.io.InputStream stream, StreamType type, java.lang.String recId) Creates a new delegating stream.

Method Summary

Modifier and Type	Method and Description
int	available() Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream.
void	close() Closes the stream.
static java.io.InputStream	createFrom(java.io.InputStream is, java.net.URL url, java.lang.String recId) Creates a delegating input stream (if possible) from the given parameters.
void	mark(int readlimit) Marks the current position in this input stream.
boolean	markSupported() Tests if this input stream supports the mark and reset methods.
int	read() Reads a byte from a stream.
int	read(byte[] buffer) Reads bytes into buffer, at maximum up to the length of the buffer.
int	read(byte[] buffer, int off, int len) Reads at maximum len bytes into buffer starting at off.
void	reset() Repositions this stream to the position at the time the mark method was last called on this input stream.
long	skip(long number) Skips over and discards n bytes of data from this input stream.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

stream

private java.io.InputStream stream

Stores the stream to delegate to.

inRead3

private boolean inRead3

Stores if we are in a read method with 3 parameters (avoid double recording).

inRead1

private boolean inRead1

Stores if we are in a read method with 1 parameter (avoid double recording).

type

private StreamType type

Stores the stream type.

recId

private java.lang.String recId

Stores the recorder id to aggregate the notifications for.

Constructor Detail

DelegatingInputStream

public DelegatingInputStream(java.io.InputStream stream,
                             StreamType type)

Creates a new delegating stream.

Parameters:

stream - the stream to delegate the operations to

type - the type of the stream

Since:

1.00

DelegatingInputStream

public DelegatingInputStream(java.io.InputStream stream,
                             StreamType type,
                             java.lang.String recId)

Creates a new delegating stream.

Parameters:

stream - the stream to delegate the operations to

type - the type of the stream

recId - the recorder id to aggregate the notifications for

Since:

1.00

Method Detail

createFrom

public static final java.io.InputStream createFrom(java.io.InputStream is,
                                                   java.net.URL url,
                                                   java.lang.String recId)

Creates a delegating input stream (if possible) from the given parameters.

Parameters:

is - the input stream to create the delegating input stream for

url - an URL to take the stream type from

recId - the recorder id to aggregate the notifications for

Returns:

the delegating input stream or is

Since:

1.00

available

public int available()
              throws java.io.IOException

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.

Overrides:

available in class java.io.InputStream

Returns:

an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking or 0 when it reaches the end of the input stream.

Throws:

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

mark

public void mark(int readlimit)

Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

Overrides:

mark in class java.io.InputStream

Parameters:

readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.

markSupported

public boolean markSupported()

Tests if this input stream supports the mark and reset methods. Whether or not mark and reset are supported is an invariant property of a particular input stream instance. The markSupported method of InputStream returns false.

Overrides:

markSupported in class java.io.InputStream

Returns:

true if this stream instance supports the mark and reset methods; false otherwise.

See Also:

InputStream.mark(int), InputStream.reset()

reset

public void reset()
           throws java.io.IOException

Repositions this stream to the position at the time the mark method was last called on this input stream.

Overrides:

reset in class java.io.InputStream

Throws:

java.io.IOException - if this stream has not been marked or if the mark has been invalidated.

skip

public long skip(long number)
          throws java.io.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.

The skip method of this class creates a byte array and then repeatedly reads into it until n bytes have been read or the end of the stream has been reached. Subclasses are encouraged to provide a more efficient implementation of this method. For instance, the implementation may depend on the ability to seek.

Overrides:

skip in class java.io.InputStream

Parameters:

number - the number of bytes to be skipped.

Returns:

the actual number of bytes skipped.

Throws:

java.io.IOException - if the stream does not support seek, or if some other I/O error occurs.

read

public int read()
         throws java.io.IOException

Reads a byte from a stream.

Specified by:

read in class java.io.InputStream

Returns:

the byte or -1 at the end of the stream

Throws:

java.io.IOException - in case of any I/O error or problem

read

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

Reads bytes into buffer, at maximum up to the length of the buffer.

Overrides:

read in class java.io.InputStream

Parameters:

buffer - the byte buffer to be modified

Returns:

the number of bytes read, negative at stream end

Throws:

java.io.IOException - in case of I/O reading errors

read

public int read(byte[] buffer,
                int off,
                int len)
         throws java.io.IOException

Reads at maximum len bytes into buffer starting at off.

Overrides:

read in class java.io.InputStream

Parameters:

buffer - the byte buffer to be modified

off - the offset where to start storing bytes

len - the maximum number of bytes to be read (less than length of b)

Returns:

the number of bytes read, negative at stream end

Throws:

java.io.IOException - in case of I/O reading errors

close

public void close()
           throws java.io.IOException

Closes the stream.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException - in case of I/O errors