OpenJDK 27 · javax.imageio.spi.ImageOutputStreamSpi · APIdia, the JavaDoc alternative

The service provider interface (SPI) for 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.

Modifier and Type	Field and Description
protected Class<?>	outputClass A `Class` object indicating the legal object type for use by the `createInputStreamInstance` method.

Constructor Summary

Access	Constructor and Description
protected	ImageOutputStreamSpi() Constructs a blank `ImageOutputStreamSpi`.
public	ImageOutputStreamSpi(String the vendor name. vendorName, String a version identifier. version, Class<?> a `Class` object indicating the legal object type for use by the `createOutputStreamInstance` method. outputClass) Constructs an `ImageOutputStreamSpi` with a given set of values.

Method Summary

Modifier and Type	Method and Description
public boolean	Returns: `true` if a cache file can be used by the output streams created by this service provider. 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.
public abstract ImageOutputStream	Returns: an `ImageOutputStream` instance. createOutputStreamInstance(Object an object of the class type returned by `getOutputClass`. output, boolean a `boolean` indicating whether a cache file should be used, in cases where it is optional. useCache, File a `File` indicating where the cache file should be created, or `null` to use the system directory. cacheDir) Returns an instance of the `ImageOutputStream` implementation associated with this service provider.
public ImageOutputStream	Returns: an `ImageOutputStream` instance. createOutputStreamInstance(Object an object of the class type returned by `getOutputClass`. output) Returns an instance of the `ImageOutputStream` implementation associated with this service provider.
public Class<?>	Returns: a `Class` variable. 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.
public boolean	Returns: `true` if a cache file is needed by the output streams created by this service provider. needsCacheFile() Returns `true` if the `ImageOutputStream` implementation associated with this service provider requires the use of a cache `File`.

Inherited from javax.imageio.spi.IIOServiceProvider:: getDescription getVendorName getVersion onDeregistration onRegistration

Field Detail

outputClass	back to summary
protected Class<?> outputClass A `Class` object indicating the legal object type for use by the `createInputStreamInstance` method.

Constructor Detail

ImageOutputStreamSpi	back to summary
protected ImageOutputStreamSpi() Constructs a blank `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.

ImageOutputStreamSpi back to summary

ImageOutputStreamSpi	back to summary
public ImageOutputStreamSpi(String vendorName, String version, Class<?> outputClass) Constructs an `ImageOutputStreamSpi` with a given set of values. Parameters vendorName:String the vendor name. version:String a version identifier. outputClass:Class<?> a `Class` object indicating the legal object type for use by the `createOutputStreamInstance` method. Exceptions IllegalArgumentException: if `vendorName` is `null`. if `version` is `null`.

public ImageOutputStreamSpi(String vendorName, String version, Class<?> outputClass)

Constructs an ImageOutputStreamSpi with a given set of values.

Parameters

vendorName:String: the vendor name.
version:String: a version identifier.
outputClass:Class<?>: a Class object indicating the legal object type for use by the createOutputStreamInstance method.

Exceptions

IllegalArgumentException:

if vendorName is null.
if version is null.

Method Detail

canUseCacheFile back to summary

canUseCacheFile	back to summary
public 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. If `false`, the value of the `cacheFile` argument to `createOutputStreamInstance` will be ignored. The default implementation returns `false`. Returns:boolean `true` if a cache file can be used by the output streams created by this service provider.

public 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. If false, the value of the cacheFile argument to createOutputStreamInstance will be ignored.

The default implementation returns false.

Returns:boolean: true if a cache file can be used by the output streams created by this service provider.

createOutputStreamInstance back to summary

createOutputStreamInstance	back to summary
public abstract ImageOutputStream createOutputStreamInstance(Object output, boolean useCache, File cacheDir) throws IOException Returns an instance of the `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. Parameters output:Object an object of the class type returned by `getOutputClass`. useCache:boolean a `boolean` indicating whether a cache file should be used, in cases where it is optional. cacheDir:File a `File` indicating where the cache file should be created, or `null` to use the system directory. Returns:ImageOutputStream an `ImageOutputStream` instance. Exceptions IOException: if a cache file is needed but cannot be created. IllegalArgumentException: if `output` is not an instance of the correct class or is `null`. if a cache file is needed, but `cacheDir` is non-`null` and is not a directory. See Also `getOutputClass`

public abstract ImageOutputStream createOutputStreamInstance(Object output, boolean useCache, File cacheDir) throws IOException

Returns an instance of the 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.

Parameters

output:Object: an object of the class type returned by getOutputClass.
useCache:boolean: a boolean indicating whether a cache file should be used, in cases where it is optional.
cacheDir:File: a File indicating where the cache file should be created, or null to use the system directory.

Returns:ImageOutputStream

an ImageOutputStream instance.

Exceptions

IOException:

if a cache file is needed but cannot be created.

IllegalArgumentException:

if output is not an instance of the correct class or is null.
if a cache file is needed, but cacheDir is non-null and is not a directory.

See Also

getOutputClass

createOutputStreamInstance back to summary

createOutputStreamInstance	back to summary
public ImageOutputStream createOutputStreamInstance(Object output) throws IOException Returns an instance of the `ImageOutputStream` implementation associated with this service provider. A cache file will be created in the system-dependent default temporary-file directory, if needed. Parameters output:Object an object of the class type returned by `getOutputClass`. Returns:ImageOutputStream an `ImageOutputStream` instance. Exceptions IOException: if a cache file is needed but cannot be created. IllegalArgumentException: if `output` is not an instance of the correct class or is `null`. See Also `getOutputClass()`

public ImageOutputStream createOutputStreamInstance(Object output) throws IOException

Returns an instance of the ImageOutputStream implementation associated with this service provider. A cache file will be created in the system-dependent default temporary-file directory, if needed.

Parameters

output:Object: an object of the class type returned by getOutputClass.

Returns:ImageOutputStream

an ImageOutputStream instance.

Exceptions

IOException:: if a cache file is needed but cannot be created.
IllegalArgumentException:: if output is not an instance of the correct class or is null.

See Also

getOutputClass()

getOutputClass back to summary

getOutputClass	back to summary
public 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. Typical return values might include `OutputStream.class` or `File.class`, but any class may be used. Returns:Class<?> a `Class` variable. See Also `createOutputStreamInstance(Object, boolean, File)`

public 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.

Typical return values might include OutputStream.class or File.class, but any class may be used.

Returns:Class<?>: a Class variable.
See Also: createOutputStreamInstance(Object, boolean, File)

needsCacheFile back to summary

needsCacheFile	back to summary
public boolean needsCacheFile() Returns `true` if the `ImageOutputStream` implementation associated with this service provider requires the use of a cache `File`. The default implementation returns `false`. Returns:boolean `true` if a cache file is needed by the output streams created by this service provider.

public boolean needsCacheFile()

Returns true if the ImageOutputStream implementation associated with this service provider requires the use of a cache File.

The default implementation returns false.

Returns:boolean: true if a cache file is needed by the output streams created by this service provider.

public abstract Class ImageOutputStreamSpi

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail