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| java.lang.Object
 javax.imageio.spi.IIOServiceProvider
javax.imageio.spi.ImageInputStreamSpi
| ImageInputStreamSpi | | abstract public class ImageInputStreamSpi extends IIOServiceProvider (Code) | | The service provider interface (SPI) for
ImageInputStreams. 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 ImageInputStream. For example,
a particular ImageInputStreamSpi might allow
a generic InputStream to be used as an input source;
another might take input from a URL.
By treating the creation of ImageInputStreams as a
pluggable service, it becomes possible to handle future input
sources without changing the API. Also, high-performance
implementations of ImageInputStream (for example,
native implementations for a particular platform) can be installed
and used transparently by applications.
See Also: IIORegistry
See Also: javax.imageio.stream.ImageInputStream
version:
0.5 |
| Field Summary | |
| protected Class | inputClass
A Class object indicating the legal object type
for use by the createInputStreamInstance method. |
| Method Summary | |
| public boolean | canUseCacheFile()
Returns true if the ImageInputStream
implementation associated with this service provider can
optionally make use of a cache file for improved performance
and/or memory footrprint. | | abstract public ImageInputStream | createInputStreamInstance(Object input, boolean useCache, File cacheDir)
Returns an instance of the ImageInputStream
implementation associated with this service provider. | | public ImageInputStream | createInputStreamInstance(Object input)
Returns an instance of the ImageInputStream
implementation associated with this service provider. | | public Class | getInputClass()
Returns a Class object representing the class or
interface type that must be implemented by an input source in
order to be "wrapped" in an ImageInputStream via
the createInputStreamInstance method. | | public boolean | needsCacheFile()
Returns true if the ImageInputStream
implementation associated with this service provider requires
the use of a cache File. |
| inputClass | | protected Class inputClass(Code) | | A Class object indicating the legal object type
for use by the createInputStreamInstance method.
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| ImageInputStreamSpi | | protected ImageInputStreamSpi()(Code) | | Constructs a blank ImageInputStreamSpi. It is up
to the subclass to initialize instance variables and/or
override method implementations in order to provide working
versions of all methods.
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| ImageInputStreamSpi | | public ImageInputStreamSpi(String vendorName, String version, Class inputClass)(Code) | | Constructs an ImageInputStreamSpi with a given set
of values.
Parameters:
vendorName - the vendor name.
Parameters:
version - a version identifier.
Parameters:
inputClass - a Class object indicating thelegal object type for use by thecreateInputStreamInstance method.
exception:
IllegalArgumentException - if vendorNameis null.
exception:
IllegalArgumentException - if versionis null. |
| canUseCacheFile | | public boolean canUseCacheFile()(Code) | | Returns true if the ImageInputStream
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 useCache argument to
createInputStreamInstance will be ignored.
The default implementation returns false.
true if a cache file can be used by theinput streams created by this service provider. |
| createInputStreamInstance | | abstract public ImageInputStream createInputStreamInstance(Object input, boolean useCache, File cacheDir) throws IOException(Code) | | Returns an instance of the ImageInputStream
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.
Parameters:
input - an object of the class type returned bygetInputClass.
Parameters:
useCache - a boolean indicating whether acache file should be used, in cases where it is optional.
Parameters:
cacheDir - a File indicating where the cache file should be created, or null to use thesystem directory. an ImageInputStream instance.
exception:
IllegalArgumentException - if input isnot an instance of the correct class or is null.
exception:
IllegalArgumentException - if a cache file is neededbut cacheDir is non-null and is not adirectory.
exception:
IOException - if a cache file is needed but cannot becreated.
See Also: ImageInputStreamSpi.getInputClass
See Also: ImageInputStreamSpi.canUseCacheFile
See Also: ImageInputStreamSpi.needsCacheFile |
| createInputStreamInstance | | public ImageInputStream createInputStreamInstance(Object input) throws IOException(Code) | | Returns an instance of the ImageInputStream
implementation associated with this service provider. A cache
file will be created in the system-dependent default
temporary-file directory, if needed.
Parameters:
input - an object of the class type returned bygetInputClass. an ImageInputStream instance.
exception:
IllegalArgumentException - if input isnot an instance of the correct class or is null.
exception:
IOException - if a cache file is needed but cannot becreated.
See Also: ImageInputStreamSpi.getInputClass() |
| getInputClass | | public Class getInputClass()(Code) | | Returns a Class object representing the class or
interface type that must be implemented by an input source in
order to be "wrapped" in an ImageInputStream via
the createInputStreamInstance method.
Typical return values might include
InputStream.class or URL.class, but
any class may be used.
a Class variable.
See Also: ImageInputStreamSpi.createInputStreamInstance(Object,boolean,File) |
| needsCacheFile | | public boolean needsCacheFile()(Code) | | Returns true if the ImageInputStream
implementation associated with this service provider requires
the use of a cache File. If true,
the value of the useCache argument to
createInputStreamInstance will be ignored.
The default implementation returns false.
true if a cache file is needed by theinput streams created by this service provider. |
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