javax.imageio.spi: abstract public class: ImageOutputStreamSpi

javax.imageio.spi
abstract public class: ImageOutputStreamSpi [javadoc | source]

java.lang.Object
   javax.imageio.spi.IIOServiceProvider
      javax.imageio.spi.ImageOutputStreamSpi

All Implemented Interfaces:
RegisterableService

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.

Also see:

IIORegistry

javax.imageio.stream.ImageOutputStream

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

Fields inherited from javax.imageio.spi.IIOServiceProvider:
vendorName, version

Constructor:

Constructor:
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.
public ImageOutputStreamSpi(String vendorName, String version, Class<?> outputClass) { super(vendorName, version); this.outputClass = outputClass; } Constructs an `ImageOutputStreamSpi` with a given set of values. Parameters: `vendorName` - the vendor name. `version` - a version identifier. `outputClass` - a `Class` object indicating the legal object type for use by the `createOutputStreamInstance` method. Throws: `IllegalArgumentException` - if `vendorName` is `null`. `IllegalArgumentException` - if `version` is `null`. exception: `IllegalArgumentException` - if `vendorName` is `null`. exception: `IllegalArgumentException` - if `version` is `null`.

 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.

 public ImageOutputStreamSpi(String vendorName,
    String version,
    Class<?> outputClass) {
        super(vendorName, version);
        this.outputClass = outputClass;
}

ImageOutputStreamSpi

Parameters:

vendorName - the vendor name.

version - a version identifier.

outputClass - a Class object indicating the legal object type for use by the createOutputStreamInstance method.

Throws:

IllegalArgumentException - if vendorName is null.

IllegalArgumentException - if version is null.

exception: IllegalArgumentException - if vendorName is null.

exception: IllegalArgumentException - if version is null.

Method from javax.imageio.spi.ImageOutputStreamSpi Summary:
canUseCacheFile, createOutputStreamInstance, createOutputStreamInstance, getOutputClass, needsCacheFile

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

Methods from java.lang.Object:
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from javax.imageio.spi.ImageOutputStreamSpi Detail:
public boolean canUseCacheFile() { return false; } 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`.
public ImageOutputStream createOutputStreamInstance(Object output) throws IOException { return createOutputStreamInstance(output, true, null); } 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.
abstract public 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.
public Class<?> getOutputClass() { return outputClass; } 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.
public boolean needsCacheFile() { return false; } Returns `true` if the `ImageOutputStream` implementation associated with this service provider requires the use of a cache `File`. The default implementation returns `false`.

Method from javax.imageio.spi.ImageOutputStreamSpi Detail:

 public boolean canUseCacheFile() {
        return false;
}

true

ImageOutputStream

File

false

cacheFile

createOutputStreamInstance

The default implementation returns false.

 public ImageOutputStream createOutputStreamInstance(Object output) throws IOException {
        return createOutputStreamInstance(output, true, null);
}

ImageOutputStream

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

 public Class<?> getOutputClass() {
        return outputClass;
}

Class

ImageOutputStream

createOutputStreamInstance

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

 public boolean needsCacheFile() {
        return false;
}

true

ImageOutputStream

File

The default implementation returns false.