gov.nasa.pds.label.object

Class DataObject

java.lang.Object

gov.nasa.pds.label.object.DataObject

Direct Known Subclasses:

ArrayObject, GenericObject, TableObject

public abstract class DataObject
extends Object

Defines a base type for objects within a label.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	DataObject(File parentDir, File fileObject, long offset, long size)
protected	DataObject(URL parentDir, File fileObject, long offset, long size)

Method Summary

Methods

Modifier and Type	Method and Description
ByteBuffer	getBuffer() Gets a ByteBuffer for accessing the data object.
URL	getDataFile() Gets a url that refers to the data file for this object.
InputStream	getInputStream() Gets an input stream to the data object.
long	getOffset() Gets the offset within the data file where the object data begins.
long	getSize() Gets the size of the data object within the data file.
protected void	setSize(long newSize)

Methods inherited from class java.lang.Object

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

Constructor Detail

DataObject

protected DataObject(File parentDir,
          File fileObject,
          long offset,
          long size)
              throws IOException

Throws:

IOException

DataObject

protected DataObject(URL parentDir,
          File fileObject,
          long offset,
          long size)
              throws IOException

Throws:

IOException

Method Detail

getDataFile

public URL getDataFile()
                throws MalformedURLException

Gets a url that refers to the data file for this object.

Returns:

a URL for the file containing the data object

Throws:

MalformedURLException

getOffset

public long getOffset()

Gets the offset within the data file where the object data begins.

Returns:

the offset to the data

getSize

public long getSize()

Gets the size of the data object within the data file.

Returns:

the size of the data object, in bytes

setSize

protected void setSize(long newSize)

getInputStream

public InputStream getInputStream()
                           throws FileNotFoundException,
                                  IOException

Gets an input stream to the data object. This input stream will read from the first byte in the data object to the last byte within that object. Other bytes outside of the range for the data object will not be accessed.

Returns:

an input stream to the data object

Throws:

FileNotFoundException - if the data file cannot be found

IOException - if there is an error reading the data file

getBuffer

public ByteBuffer getBuffer()
                     throws FileNotFoundException,
                            IOException

Gets a ByteBuffer for accessing the data object. The buffer is read-only, and represents only the portion of the data file containing the data object.

Returns:

a ByteBuffer for reading bytes from the data object

Throws:

FileNotFoundException - if the data file cannot be found

IOException - if there is an error reading the data file