Package dap4.dap4lib

Class ChunkInputStream

java.lang.Object

java.io.InputStream

dap4.dap4lib.ChunkInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class ChunkInputStream
extends InputStream

This class wraps a chunked source of databuffer as an InputStream. It is mostly pass-thru in the sense that reads on this class are turned into a series of reads of the underlying stream.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	avail
protected int	chunksize
protected int	flags
protected InputStream	input
protected ByteOrder	localorder
protected boolean	nochecksum
protected ByteOrder	remoteorder
protected RequestMode	requestmode
protected dap4.dap4lib.ChunkInputStream.State	state

Constructor Summary

Constructors

Constructor	Description
ChunkInputStream(InputStream input, RequestMode requestmode)
ChunkInputStream(InputStream input, RequestMode requestmode, ByteOrder order)

Method Summary

Modifier and Type	Method	Description
int	available()	Returns an estimate of the number of databuffer 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 this output stream and releases any system resources associated with this stream.
ByteOrder	getHostByteOrder()
boolean	getNoChecksum()
ByteOrder	getRemoteByteOrder()
int	read()	Reads the next byte of databuffer from the input stream.
int	read(byte[] buf, int off, int len)	Reads up to len databuffer of databuffer from the input stream into an array of databuffer.
String	readDMR()	Read the DMR, trimmed.
String	readError()	Read an error chunk
void	throwError(String document)	Convert an error chunk to an exception

Methods inherited from class java.io.InputStream

mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, skip, transferTo

Methods inherited from class java.lang.Object

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

Field Detail

input

protected InputStream input

state

protected dap4.dap4lib.ChunkInputStream.State state

requestmode

protected RequestMode requestmode

localorder

protected ByteOrder localorder

remoteorder

protected ByteOrder remoteorder

nochecksum

protected boolean nochecksum

flags

protected int flags

chunksize

protected int chunksize

avail

protected int avail

Constructor Detail

ChunkInputStream

public ChunkInputStream(InputStream input,
                        RequestMode requestmode)

ChunkInputStream

public ChunkInputStream(InputStream input,
                        RequestMode requestmode,
                        ByteOrder order)

Method Detail

getHostByteOrder

public ByteOrder getHostByteOrder()

getRemoteByteOrder

public ByteOrder getRemoteByteOrder()

getNoChecksum

public boolean getNoChecksum()

readDMR

public String readDMR()
               throws dap4.core.util.DapException

Read the DMR, trimmed.

Returns:

the DMR as a Java String

Throws:

dap4.core.util.DapException

throwError

public void throwError(String document)
                throws ErrorException

Convert an error chunk to an exception

Parameters:

document - XML representation of the error

Throws:

dap4.core.util.DapException - containing the contents of the error chunk

ErrorException

readError

public String readError()
                 throws IOException

Read an error chunk

Returns:

the error document as a string

Throws:

IOException

read

public int read()
         throws IOException

Reads the next byte of databuffer 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 databuffer is available, the end of the stream is detected, or an exception is thrown.

Operates by loading chunk by chunk. If an error chunk is detected, then return ErrorException (which is a subclass of IOException).

Specified by:

read in class InputStream

Returns:

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

Throws:

IOException - if an I/O error occurs.

read

public int read(byte[] buf,
                int off,
                int len)
         throws IOException

Reads up to len databuffer of databuffer from the input stream into an array of databuffer. An attempt is made to read as many as len databuffer, but a smaller number may be read. The number of databuffer actually read is returned as an integer.

Overrides:

read in class InputStream

Parameters:

buf - the byte array into which databuffer is read

off - the offset in the byte array at which to write

len - the amount to read

Returns:

the actual number of databuffer read

Throws:

IOException

available

public int available()

Returns an estimate of the number of databuffer that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream.

Repurposed here to do equivalent of peek().

Overrides:

available in class InputStream

Returns:

0 if at eof, some number > 0 otherwise.

close

public void close()
           throws IOException

Closes this output stream and releases any system resources associated with this stream. The underlying servlet stream is not closed; that is left to the level above.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException