Module java.desktop
Package javax.imageio.spi

## Class IIOServiceProvider

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

- All Implemented Interfaces:
    `RegisterableService`
  Direct Known Subclasses:
    `ImageInputStreamSpi`, `ImageOutputStreamSpi`, `ImageReaderWriterSpi`, `ImageTranscoderSpi`

      public abstract class IIOServiceProvider
      extends Object
      implements RegisterableService

  A superinterface for functionality common to all Image I/O service provider interfaces (SPIs). For more information on service provider classes, see the class comment for the `IIORegistry` class.
  See Also:
    `IIORegistry`, `ImageReaderSpi`, `ImageWriterSpi`, `ImageTranscoderSpi`, `ImageInputStreamSpi`, `ImageOutputStreamSpi`

- - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `protected String` | `vendorName` | A `String` to be returned from `getVendorName`, initially `null`.
    `protected String` | `version` | A `String` to be returned from `getVersion`, initially null.

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `IIOServiceProvider​()` | Constructs a blank `IIOServiceProvider`.
    `IIOServiceProvider​(String vendorName, String version)` | Constructs an `IIOServiceProvider` with a given vendor name and version identifier.

  - ### Method Summary

    All Methods Instance Methods Abstract Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `abstract String` | `getDescription​(Locale locale)` | Returns a brief, human-readable description of this service provider and its associated implementation.
    `String` | `getVendorName​()` | Returns the name of the vendor responsible for creating this service provider and its associated implementation.
    `String` | `getVersion​()` | Returns a string describing the version number of this service provider and its associated implementation.
    `void` | `onDeregistration​(ServiceRegistry registry, Class<?> category)` | A callback that will be whenever the Spi class has been deregistered from a `ServiceRegistry`.
    `void` | `onRegistration​(ServiceRegistry registry, Class<?> category)` | A callback that will be called exactly once after the Spi class has been instantiated and registered in a `ServiceRegistry`.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Field Detail

    - #### vendorName

          protected String vendorName

      A `String` to be returned from `getVendorName`, initially `null`. Constructors should set this to a non-`null` value.

    - #### version

          protected String version

      A `String` to be returned from `getVersion`, initially null. Constructors should set this to a non-`null` value.

  - ### Constructor Detail

    - #### IIOServiceProvider

          public IIOServiceProvider​(String vendorName,
                                    String version)

      Constructs an `IIOServiceProvider` with a given vendor name and version identifier.
      Parameters:
        `vendorName` - the vendor name.
        `version` - a version identifier.
      Throws:
        `IllegalArgumentException` - if `vendorName` is `null`.
        `IllegalArgumentException` - if `version` is `null`.

    - #### IIOServiceProvider

          public IIOServiceProvider​()

      Constructs a blank `IIOServiceProvider`. It is up to the subclass to initialize instance variables and/or override method implementations in order to ensure that the `getVendorName` and `getVersion` methods will return non-`null` values.

  - ### Method Detail

    - #### onRegistration

          public void onRegistration​(ServiceRegistry registry,
                                     Class<?> category)

      A callback that will be called exactly once after the Spi class has been instantiated and registered in a `ServiceRegistry`. This may be used to verify that the environment is suitable for this service, for example that native libraries can be loaded. If the service cannot function in the environment where it finds itself, it should deregister itself from the registry.

      Only the registry should call this method.

      The default implementation does nothing.

      Specified by:
        `onRegistration` in interface `RegisterableService`
      Parameters:
        `registry` - a `ServiceRegistry` where this object has been registered.
        `category` - a `Class` object indicating the registry category under which this object has been registered.
      See Also:
        `ServiceRegistry.registerServiceProvider(Object provider)`

    - #### onDeregistration

          public void onDeregistration​(ServiceRegistry registry,
                                       Class<?> category)

      A callback that will be whenever the Spi class has been deregistered from a `ServiceRegistry`.

      Only the registry should call this method.

      The default implementation does nothing.

      Specified by:
        `onDeregistration` in interface `RegisterableService`
      Parameters:
        `registry` - a `ServiceRegistry` from which this object is being (wholly or partially) deregistered.
        `category` - a `Class` object indicating the registry category from which this object is being deregistered.
      See Also:
        `ServiceRegistry.deregisterServiceProvider(Object provider)`

    - #### getVendorName

          public String getVendorName​()

      Returns the name of the vendor responsible for creating this service provider and its associated implementation. Because the vendor name may be used to select a service provider, it is not localized.

      The default implementation returns the value of the `vendorName` instance variable.

      Returns:
        a non-`null String` containing the name of the vendor.

    - #### getVersion

          public String getVersion​()

      Returns a string describing the version number of this service provider and its associated implementation. Because the version may be used by transcoders to identify the service providers they understand, this method is not localized.

      The default implementation returns the value of the `version` instance variable.

      Returns:
        a non-`null String` containing the version of this service provider.

    - #### getDescription

          public abstract String getDescription​(Locale locale)

      Returns a brief, human-readable description of this service provider and its associated implementation. The resulting string should be localized for the supplied `Locale`, if possible.
      Parameters:
        `locale` - a `Locale` for which the return value should be localized.
      Returns:
        a `String` containing a description of this service provider.