- java.lang.Object
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- javax.imageio.spi.IIOServiceProvider
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- javax.imageio.spi.ImageOutputStreamSpi
 
 
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- All Implemented Interfaces:
- RegisterableService
 
 public abstract class ImageOutputStreamSpi extends IIOServiceProvider The service provider interface (SPI) forImageOutputStreams. For more information on service provider interfaces, see the class comment for theIIORegistryclass.This interface allows arbitrary objects to be "wrapped" by instances of ImageOutputStream. For example, a particularImageOutputStreamSpimight allow a genericOutputStreamto be used as a destination; another might output to aFileor 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 ofImageOutputStream(for example, native implementations for a particular platform) can be installed and used transparently by applications.- See Also:
- IIORegistry,- ImageOutputStream
 
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Field SummaryFields Modifier and Type Field Description protected Class<?>outputClassAClassobject indicating the legal object type for use by thecreateInputStreamInstancemethod.- 
Fields declared in class javax.imageio.spi.IIOServiceProvidervendorName, version
 
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Constructor SummaryConstructors Modifier Constructor Description protectedImageOutputStreamSpi()Constructs a blankImageOutputStreamSpi.ImageOutputStreamSpi(String vendorName, String version, Class<?> outputClass)Constructs anImageOutputStreamSpiwith a given set of values.
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Method SummaryAll Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description booleancanUseCacheFile()Returnstrueif theImageOutputStreamimplementation associated with this service provider can optionally make use of a cacheFilefor improved performance and/or memory footrprint.ImageOutputStreamcreateOutputStreamInstance(Object output)Returns an instance of theImageOutputStreamimplementation associated with this service provider.abstract ImageOutputStreamcreateOutputStreamInstance(Object output, boolean useCache, File cacheDir)Returns an instance of theImageOutputStreamimplementation associated with this service provider.Class<?>getOutputClass()Returns aClassobject representing the class or interface type that must be implemented by an output destination in order to be "wrapped" in anImageOutputStreamvia thecreateOutputStreamInstancemethod.booleanneedsCacheFile()Returnstrueif theImageOutputStreamimplementation associated with this service provider requires the use of a cacheFile.- 
Methods declared in class javax.imageio.spi.IIOServiceProvidergetDescription, getVendorName, getVersion, onDeregistration, onRegistration
 
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Field Detail- 
outputClassprotected Class<?> outputClass AClassobject indicating the legal object type for use by thecreateInputStreamInstancemethod.
 
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Constructor Detail- 
ImageOutputStreamSpiprotected ImageOutputStreamSpi() Constructs a blankImageOutputStreamSpi. 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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ImageOutputStreamSpipublic ImageOutputStreamSpi(String vendorName, String version, Class<?> outputClass) Constructs anImageOutputStreamSpiwith a given set of values.- Parameters:
- vendorName- the vendor name.
- version- a version identifier.
- outputClass- a- Classobject indicating the legal object type for use by the- createOutputStreamInstancemethod.
- Throws:
- IllegalArgumentException- if- vendorNameis- null.
- IllegalArgumentException- if- versionis- null.
 
 
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Method Detail- 
getOutputClasspublic Class<?> getOutputClass() Returns aClassobject representing the class or interface type that must be implemented by an output destination in order to be "wrapped" in anImageOutputStreamvia thecreateOutputStreamInstancemethod.Typical return values might include OutputStream.classorFile.class, but any class may be used.- Returns:
- a Classvariable.
- See Also:
- createOutputStreamInstance(Object, boolean, File)
 
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canUseCacheFilepublic boolean canUseCacheFile() Returnstrueif theImageOutputStreamimplementation associated with this service provider can optionally make use of a cacheFilefor improved performance and/or memory footrprint. Iffalse, the value of thecacheFileargument tocreateOutputStreamInstancewill be ignored.The default implementation returns false.- Returns:
- trueif a cache file can be used by the output streams created by this service provider.
 
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needsCacheFilepublic boolean needsCacheFile() Returnstrueif theImageOutputStreamimplementation associated with this service provider requires the use of a cacheFile.The default implementation returns false.- Returns:
- trueif a cache file is needed by the output streams created by this service provider.
 
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createOutputStreamInstancepublic abstract ImageOutputStream createOutputStreamInstance(Object output, boolean useCache, File cacheDir) throws IOException Returns an instance of theImageOutputStreamimplementation associated with this service provider. If the use of a cache file is optional, theuseCacheparameter will be consulted. Where a cache is required, or not applicable, the value ofuseCachewill be ignored.- Parameters:
- output- an object of the class type returned by- getOutputClass.
- useCache- a- booleanindicating whether a cache file should be used, in cases where it is optional.
- cacheDir- a- Fileindicating where the cache file should be created, or- nullto use the system directory.
- Returns:
- an ImageOutputStreaminstance.
- Throws:
- IllegalArgumentException- if- outputis not an instance of the correct class or is- null.
- IllegalArgumentException- if a cache file is needed, but- cacheDiris non-- nulland is not a directory.
- IOException- if a cache file is needed but cannot be created.
- See Also:
- getOutputClass()
 
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createOutputStreamInstancepublic ImageOutputStream createOutputStreamInstance(Object output) throws IOException Returns an instance of theImageOutputStreamimplementation associated with this service provider. A cache file will be created in the system-dependent default temporary-file directory, if needed.- Parameters:
- output- an object of the class type returned by- getOutputClass.
- Returns:
- an ImageOutputStreaminstance.
- Throws:
- IllegalArgumentException- if- outputis not an instance of the correct class or is- null.
- IOException- if a cache file is needed but cannot be created.
- See Also:
- getOutputClass()
 
 
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