public abstract class ImageOutputStreamSpi extends IIOServiceProvider
ImageOutputStreams. For more information on service
provider interfaces, see the class comment for the
IIORegistry class.
This interface allows arbitrary objects to be "wrapped" by
instances of ImageOutputStream. For example, a
particular ImageOutputStreamSpi might allow a generic
OutputStream to be used as a destination; another
might output to a File or to a device such as a serial
port.
By treating the creation of ImageOutputStreams as
a pluggable service, it becomes possible to handle future output
destinations without changing the API. Also, high-performance
implementations of ImageOutputStream (for example,
native implementations for a particular platform) can be installed
and used transparently by applications.
IIORegistry,
ImageOutputStream| Modifier and Type | Field and Description |
|---|---|
protected Class<?> |
outputClass
A
Class object indicating the legal object type
for use by the createInputStreamInstance method. |
vendorName, version| Modifier | Constructor and Description |
|---|---|
protected |
ImageOutputStreamSpi()
Constructs a blank
ImageOutputStreamSpi. |
|
ImageOutputStreamSpi(String vendorName,
String version,
Class<?> outputClass)
Constructs an
ImageOutputStreamSpi with a given
set of values. |
| Modifier and Type | Method and Description |
|---|---|
boolean |
canUseCacheFile()
Returns
true if the ImageOutputStream
implementation associated with this service provider can
optionally make use of a cache File for improved
performance and/or memory footrprint. |
ImageOutputStream |
createOutputStreamInstance(Object output)
Returns an instance of the
ImageOutputStream
implementation associated with this service provider. |
abstract ImageOutputStream |
createOutputStreamInstance(Object output,
boolean useCache,
File cacheDir)
Returns an instance of the
ImageOutputStream
implementation associated with this service provider. |
Class<?> |
getOutputClass()
Returns a
Class object representing the class or
interface type that must be implemented by an output
destination in order to be "wrapped" in an
ImageOutputStream via the
createOutputStreamInstance method. |
boolean |
needsCacheFile()
Returns
true if the ImageOutputStream
implementation associated with this service provider requires
the use of a cache File. |
getDescription, getVendorName, getVersion, onDeregistration, onRegistrationprotected Class<?> outputClass
Class object indicating the legal object type
for use by the createInputStreamInstance method.protected ImageOutputStreamSpi()
ImageOutputStreamSpi. It is up
to the subclass to initialize instance variables and/or
override method implementations in order to provide working
versions of all methods.public ImageOutputStreamSpi(String vendorName, String version, Class<?> outputClass)
ImageOutputStreamSpi with a given
set of values.vendorName - the vendor name.version - a version identifier.outputClass - a Class object indicating the
legal object type for use by the
createOutputStreamInstance method.IllegalArgumentException - if vendorName
is null.IllegalArgumentException - if version
is null.public Class<?> getOutputClass()
Class object representing the class or
interface type that must be implemented by an output
destination in order to be "wrapped" in an
ImageOutputStream via the
createOutputStreamInstance method.
Typical return values might include
OutputStream.class or File.class, but
any class may be used.
Class variable.createOutputStreamInstance(Object, boolean, File)public boolean canUseCacheFile()
true if the ImageOutputStream
implementation associated with this service provider can
optionally make use of a cache File for improved
performance and/or memory footrprint. If false,
the value of the cacheFile argument to
createOutputStreamInstance will be ignored.
The default implementation returns false.
true if a cache file can be used by the
output streams created by this service provider.public boolean needsCacheFile()
true if the ImageOutputStream
implementation associated with this service provider requires
the use of a cache File.
The default implementation returns false.
true if a cache file is needed by the
output streams created by this service provider.public abstract ImageOutputStream createOutputStreamInstance(Object output, boolean useCache, File cacheDir) throws IOException
ImageOutputStream
implementation associated with this service provider. If the
use of a cache file is optional, the useCache
parameter will be consulted. Where a cache is required, or
not applicable, the value of useCache will be ignored.output - an object of the class type returned by
getOutputClass.useCache - a boolean indicating whether a
cache file should be used, in cases where it is optional.cacheDir - a File indicating where the
cache file should be created, or null to use the
system directory.ImageOutputStream instance.IllegalArgumentException - if output is
not an instance of the correct class or is null.IllegalArgumentException - if a cache file is needed,
but cacheDir is non-null and is not a
directory.IOException - if a cache file is needed but cannot be
created.getOutputClass()public ImageOutputStream createOutputStreamInstance(Object output) throws IOException
ImageOutputStream
implementation associated with this service provider. A cache
file will be created in the system-dependent default
temporary-file directory, if needed.output - an object of the class type returned by
getOutputClass.ImageOutputStream instance.IllegalArgumentException - if output is
not an instance of the correct class or is null.IOException - if a cache file is needed but cannot be
created.getOutputClass() Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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