com.sun.dtv.broadcast
Class BroadcastStream

java.lang.Object
  java.io.File
      com.sun.dtv.broadcast.BroadcastStream

All Implemented Interfaces:

Serializable, Comparable

public class BroadcastStream
extends File

The BroadcastStream class represents stream obtained from broadcast file systems. An instance of BroadcastStream may be constructed from a Locator instance or via constructors similar to those of java.io.File. This also means that all these constructors use the same characters for name and path separation as other files. On the other hand the locator based constructor uses locators possibly created from URLs following the usual URL based schema where path names are separated by '/'.

Successful instantiation of a BroadcastStream object causes its broadcast stream to be dynamically "mounted" in the local filesystem. The precise mount point can be determined by calling getBroadcastFilesystem(). It should be noted that a broadcast filesystem can also be explicitly mounted using instances of BroadcastFilesystem.

Construction of a BroadcastStream object does not cause its contents to be loaded automatically from the broadcast stream. Content will be only be loaded when a FileInputStream will be created from this BroadcastStream. Subsequent attempts to read the data of a BroadcastStream object will then block until its contents are loaded.

All constructors and subsequent input or output operations must use BroadcastException to throw broadcast specific exceptions.

Broadcast file systems for which there are no remaining BroadcastStream instances or open file descriptors are eligible for unmounting from the local filesystem.

Java DTV API implementations that do not support broadcast filesystem access will throw UnsupportedOperationException upon any attempt to construct a BroadcastStream object.

See Also:

Serialized Form

Field Summary

Fields inherited from class java.io.File

pathSeparator, pathSeparatorChar, separator, separatorChar

Constructor Summary

BroadcastStream(File dir, String name)
Creates a BroadcastStream instance that represents the stream with the specified name in the specified broadcast directory.

BroadcastStream(Locator locator)
Creates a BroadcastStream instance that represents the file referenced by the given Locator.

BroadcastStream(String path)
Creates a BroadcastStream instance that represents the stream whose path name in the broadcast is the given path argument.

BroadcastStream(String path, String name)
Creates a BroadcastStream instance that represents the stream with the specified name in the specified broadcast directory.

Method Summary

BroadcastFilesystem	getBroadcastFilesystem() Returns the BroadcastFileSystem this BroadcastStream belongs to.
long	getCurrentTime() Returns the time of the next chunk in BroadcastStream.
long	getDuration() Returns the duration of this BroadcastStream.
Locator	getLocator() Returns a Locator identifying this BroadcastStream.
String	getType() Retrieve the mime type of a BroadcastStream.

Methods inherited from class java.io.File

canRead, canWrite, compareTo, compareTo, createNewFile, createTempFile, createTempFile, delete, deleteOnExit, equals, exists, getAbsoluteFile, getAbsolutePath, getCanonicalFile, getCanonicalPath, getName, getParent, getParentFile, getPath, hashCode, isAbsolute, isDirectory, isFile, isHidden, lastModified, length, list, list, listFiles, listFiles, listFiles, listRoots, mkdir, mkdirs, renameTo, setLastModified, setReadOnly, toString, toURI, toURL

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BroadcastStream

public BroadcastStream(Locator locator)
                throws InvalidLocatorException,
                       IOException

Creates a BroadcastStream instance that represents the file referenced by the given Locator.

This constructor throws java.io.IOException if it determines immediately that the requested broadcast stream cannot be accessed. Since this constructor may complete its work asynchronously, absence of an IOException is not a guarantee that the requested broadcast stream is accessible.

Parameters:

locator - A Locator referencing the source of the BroadcastStream.

Throws:

InvalidLocatorException - If locator does not refer to a broadcast stream.

IOException - If the requested broadcast stream cannot be accessed or the received data is invalid.

UnsupportedOperationException - If broadcast filesystem is not supported.

BroadcastStream

public BroadcastStream(String path)
                throws IOException

Creates a BroadcastStream instance that represents the stream whose path name in the broadcast is the given path argument.

This constructor throws java.io.IOException if it determines immediately that the requested broadcast stream cannot be accessed. Since this constructor may complete its work asynchronously, absence of an IOException is not a guarantee that the requested broadcast stream is accessible.

Parameters:

path - The stream path name.

Throws:

IOException - If the requested broadcast stream cannot be accessed or the received data is invalid.

UnsupportedOperationException - If broadcast filesystem is not supported.

BroadcastStream

public BroadcastStream(File dir,
                       String name)
                throws IOException

Creates a BroadcastStream instance that represents the stream with the specified name in the specified broadcast directory.

This constructor throws java.io.IOException if it determines immediately that the requested broadcast stream cannot be accessed. Since this constructor may complete its work asynchronously, absence of an IOException is not a guarantee that the requested broadcast stream is accessible.

Parameters:

dir - The directory.

name - The stream name.

Throws:

IOException - If the requested broadcast stream cannot be accessed or the received data is invalid.

UnsupportedOperationException - If broadcast filesystem is not supported.

BroadcastStream

public BroadcastStream(String path,
                       String name)
                throws IOException

Creates a BroadcastStream instance that represents the stream with the specified name in the specified broadcast directory.

This constructor throws java.io.IOException if it determines immediately that the requested broadcast stream cannot be accessed. Since this constructor may complete its work asynchronously, absence of an IOException is not a guarantee that the requested broadcast stream is accessible.

Parameters:

path - The directory path name.

name - The stream name.

Throws:

IOException - If the requested broadcast stream cannot be accessed or the received data is invalid.

UnsupportedOperationException - If broadcast filesystem is not supported.

Method Detail

getType

public String getType()

Retrieve the mime type of a BroadcastStream.

Returns:

the mime type of the BroadcastStream, null if not available.

getDuration

public long getDuration()

Returns the duration of this BroadcastStream.

Returns:

the duration of this broadcast stream in microseconds. Returns -1 if unknown.

getCurrentTime

public long getCurrentTime()

Returns the time of the next chunk in BroadcastStream.

Returns:

the time of the next chunk in microseconds. Returns -1 if unknown.

getBroadcastFilesystem

public BroadcastFilesystem getBroadcastFilesystem()

Returns the BroadcastFileSystem this BroadcastStream belongs to.

Returns:

A BroadcastFilesystem this BroadcastStream belongs to.

getLocator

public Locator getLocator()

Returns a Locator identifying this BroadcastStream.

Returns:

A Locator identifying this BroadcastStream.