public Class LOBInputStream

Implements org.apache.derby.iapi.types.PositionedStream.asInputStream.

Doc from org.apache.derby.iapi.types.PositionedStream.asInputStream.

Returns a reference to self as an InputStream.

This method is not allowed to return null.

Returns:InputStream

An InputStream reference to self.

Overrides java.io.InputStream.close.

Implements java.io.Closeable.close.

Closes this input stream and releases any system resources associated with the stream.

The close method of InputStream does nothing.

Exceptions

IOException:

if an I/O error occurs.

Implements org.apache.derby.iapi.types.PositionedStream.getPosition.

Returns the current byte position.

Returns:long

The current byte position.

Overrides java.io.InputStream.read.

Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read. 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 b is null, a NullPointerException is thrown.

If off is negative, or len is negative, or off+len is greater than the length of the array b, then an IndexOutOfBoundsException is thrown.

If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k] through b[off+len-1] unaffected.

In every case, elements b[0] through b[off] and elements b[off+len] through b[b.length-1] are unaffected.

If the first byte cannot be read for any reason other than end of file, then an IOException is thrown. In particular, an IOException is thrown if the input stream has been closed.

The read(b, off, len) method for class InputStream simply calls the method read() repeatedly. If the first such call results in an IOException, that exception is returned from the call to the read(b, off, len) method. If any subsequent call to read() results in a IOException, the exception is caught and treated as if it were end of file; the bytes read up to that point are stored into b and the number of bytes read before the exception occurred is returned. Subclasses are encouraged to provide a more efficient implementation of this method.

Parameters

b:byte[]

the buffer into which the data is read.

off:int

the start offset in array b at which the data is written.

len:int

the maximum number of bytes to read.

Returns:int

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Exceptions

IOException:

if an I/O error occurs.

NullPointerException:

if b is null.

See Also

java.io.InputStream#read()

Implements abstract java.io.InputStream.read.

Reads the next byte of data from the input stream. 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.

A subclass must provide an implementation of this method.

Returns:int

the next byte of data, or -1 if the end of the stream is reached.

Exceptions

IOException:

if an I/O error occurs.

Implements org.apache.derby.iapi.types.PositionedStream.reposition.

Repositions the stream to the requested byte position.

Parameters

requestedPos:long

the requested position, starting at 0

Exceptions

IOException:

if obtaining the stream length fails

EOFException:

if the requested position is larger than the length