de.uni_hildesheim.sse.monitoring.runtime.wrap

Class DelegatingReader

java.lang.Object

java.io.Reader

de.uni_hildesheim.sse.monitoring.runtime.wrap.DelegatingReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.lang.Readable

public class DelegatingReader
extends java.io.Reader

A reader delegating its operation to an arbitrary reader 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.io.Reader	reader Stores the reader to delegate to.
private java.lang.String	recId Stores the recorder id to aggregate the notifications for.
private StreamType	type Stores the stream type.

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Constructor and Description
DelegatingReader(java.io.Reader reader, StreamType type) Creates a new delegating reader.
DelegatingReader(java.io.Reader reader, StreamType type, java.lang.String recId) Creates a new delegating reader.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the reader.
void	mark(int readAheadLimit) Marks the present position in the stream.
boolean	markSupported() Tells whether this stream supports the mark() operation.
int	read() Reads a char from a stream.
int	read(char[] buffer) Reads chars into buffer, at maximum up to the length of the buffer.
int	read(char[] buffer, int off, int len) Reads at maximum len chars into buffer starting at off.
boolean	ready() Tells whether this stream is ready to be read.
void	reset() Resets the stream.
long	skip(long number) Skips characters.

Methods inherited from class java.io.Reader

read

Methods inherited from class java.lang.Object

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

Field Detail

reader

private java.io.Reader reader

Stores the reader 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

DelegatingReader

public DelegatingReader(java.io.Reader reader,
                        StreamType type)

Creates a new delegating reader.

Parameters:

reader - the reader to delegate the operations to

type - the type of the stream

Since:

1.00

DelegatingReader

public DelegatingReader(java.io.Reader reader,
                        StreamType type,
                        java.lang.String recId)

Creates a new delegating reader.

Parameters:

reader - the reader 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

read

public int read()
         throws java.io.IOException

Reads a char from a stream.

Overrides:

read in class java.io.Reader

Returns:

the char 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(char[] buffer)
         throws java.io.IOException

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

Overrides:

read in class java.io.Reader

Parameters:

buffer - the char 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(char[] buffer,
                int off,
                int len)
         throws java.io.IOException

Reads at maximum len chars into buffer starting at off.

Specified by:

read in class java.io.Reader

Parameters:

buffer - the char 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 reader.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in class java.io.Reader

Throws:

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

skip

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

Skips characters. This method will block until some characters are available, an I/O error occurs, or the end of the stream is reached.

Overrides:

skip in class java.io.Reader

Parameters:

number - The number of characters to skip

Returns:

The number of characters actually skipped

Throws:

java.lang.IllegalArgumentException - If n is negative.

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

ready

public boolean ready()
              throws java.io.IOException

Tells whether this stream is ready to be read.

Overrides:

ready in class java.io.Reader

Returns:

True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.

Throws:

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

markSupported

public boolean markSupported()

Tells whether this stream supports the mark() operation. The default implementation always returns false. Subclasses should override this method.

Overrides:

markSupported in class java.io.Reader

Returns:

true if and only if this stream supports the mark operation.

mark

public void mark(int readAheadLimit)
          throws java.io.IOException

Marks the present position in the stream. Subsequent calls to reset() will attempt to reposition the stream to this point. Not all character-input streams support the mark() operation.

Overrides:

mark in class java.io.Reader

Parameters:

readAheadLimit - Limit on the number of characters that may be read while still preserving the mark. After reading this many characters, attempting to reset the stream may fail.

Throws:

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

reset

public void reset()
           throws java.io.IOException

Resets the stream. If the stream has been marked, then attempt to reposition it at the mark. If the stream has not been marked, then attempt to reset it in some way appropriate to the particular stream, for example by repositioning it to its starting point. Not all character-input streams support the reset() operation, and some support reset() without supporting mark().

Overrides:

reset in class java.io.Reader

Throws:

java.io.IOException - If the stream has not been marked, or if the mark has been invalidated, or if the stream does not support reset(), or if some other I/O error occurs