Package com.luciad.lucy.model

Class TLcyCompositeModelDecoder

java.lang.Object
com.luciad.lucy.util.TLcyGenericComposite<TLcyModelDecoderHolder>
com.luciad.lucy.model.TLcyCompositeModelDecoder
All Implemented Interfaces:
ILcyModelDecoderContainer, ILcdDataSourceModelDecoder, ILcdModelDecoder, Iterable<TLcyModelDecoderHolder>
public class TLcyCompositeModelDecoder extends TLcyGenericComposite<TLcyModelDecoderHolder> implements ILcdDataSourceModelDecoder, ILcyModelDecoderContainer

Composite implementation (see composite design pattern) of ILcdModelDecoder. It keeps a list of associated ILcdModelDecoders. When it is asked to decode a model, it loops over its associated ILcdModelDecoders to find a suitable ILcdModelDecoder. That ILcdModelDecoder is asked to decode a model.

When creating a new TLcyCompositeModelDecoder using the default constructor (see TLcyCompositeModelDecoder(), the created instance will only work on/with the ILcdModelDecoders registered on this composite instance (see addModelDecoder(com.luciad.model.ILcdModelDecoder, ALcyFileTypeDescriptor) and removeModelDecoder(com.luciad.model.ILcdModelDecoder).

When creating a new TLcyCompositeModelDecoder using the constructor specifying an ILcyLucyEnv instance (see TLcyCompositeModelDecoder(com.luciad.lucy.ILcyLucyEnv), the created instance will work on the Lucy back-end services. It will use all registered ILcdModelDecoder instances of the Lucy back-end, adding and/or removing an ILcdModelDecoder will add/remove the ILcdModelDecoder as service from Lucy, ... .

Decoding a source into an ILcdModel using the back-end based implementation can be done by creating a new instance of this class:


 //Create a new instance whenever you need it
 TLcyCompositeModelDecoder decoder = new TLcyCompositeModelDecoder( aLucyEnv );
 try{
   ILcdModel model = decoder.decode( String aSourceName );
 } catch( IOException aException ){
   //an IOException occurred during the decoding of aSourceName
 }
 //There is no need to keep a reference to the composite instance, you can create a new one
 //the next time you would need it
 decoder = null;

Note: the ILcdModelDecoders are not directly registered as service to Lucy, but wrapped with a holder object. This holder object allows to register the ILcdModelDecoder with some extra information like e.g. an ALcyFileTypeDescriptor. Using a back-end based TLcyCompositeModelDecoder will only use the registered TLcyModelDecoderHolder objects, and not for example an ILcdModelDecoder which was directly (=not wrapped) registered as a service .

See Also:

  • Constructor Details

  • Method Details

    • addModelDecoder

      public void addModelDecoder(ILcdModelDecoder aModelDecoder, ALcyFileTypeDescriptor aFileTypeDescriptor)
      Adds the given model decoder to this container.

      If the constructor specifying an ILcyLucyEnv is used, the ALcyFileTypeDescriptor and its associated ILcdModelDecoder will be registered on the Lucy back-end (see ILcyLucyEnv.addService(Object, int) by using an TLcyModelDecoderHolder. When calling ILcyLucyEnv.getServices(Class) afterwards, the holder objects will only be returned when the requested class was TLcyModelDecoderHolder.class
      Note: if you want to remove the registered ALcyFileTypeDescriptor and its associated ILcdModelDecoder, use removeModelDecoder(com.luciad.model.ILcdModelDecoder) and not ILcyLucyEnv.removeService(Object).

      Specified by:
      addModelDecoder in interface ILcyModelDecoderContainer
      Parameters:
      aModelDecoder - The model decoder to add
      aFileTypeDescriptor - The file type descriptor that provides more information on the file types this decoder can handle, or null if this decoder does not work with files.
      See Also:

    • removeModelDecoder

      public void removeModelDecoder(ILcdModelDecoder aModelDecoder)
      Removes the given model decoder from this container. Does nothing if the given decoder was not in this container. The corresponding ALcyFileTypeDescriptor is also removed.

      If the constructor specifying an ILcyLucyEnv is used, the TLcyModelDecoderHolder object containing the ILcdModelDecoder aModelDecoder will be removed as service from the Lucy back-end (see ILcyLucyEnv.removeService(Object)).
      Note: it is only possible to remove TLcyModelDecoderHolder instances which were registered using the addModelDecoder(com.luciad.model.ILcdModelDecoder, ALcyFileTypeDescriptor) method.

      Specified by:
      removeModelDecoder in interface ILcyModelDecoderContainer
      Parameters:
      aModelDecoder - The model decoder to remove.
      See Also:

    • getModelDecoderCount

      public int getModelDecoderCount()
      Description copied from interface: ILcyModelDecoderContainer
      Returns the number of model decoders currently in this container.
      Specified by:
      getModelDecoderCount in interface ILcyModelDecoderContainer
      Returns:
      the number of model decoders currently in this container.

    • getModelDecoder

      public ILcdModelDecoder getModelDecoder(int aIndex)
      Description copied from interface: ILcyModelDecoderContainer
      Returns the model decoder at the given index.
      Specified by:
      getModelDecoder in interface ILcyModelDecoderContainer
      Parameters:
      aIndex - The index of the asked model decoder. Make sure 0 <= aIndex < ILcyModelDecoderContainer.getModelDecoderCount()
      Returns:
      The model decoder at the given index.

    • getDecoderFileTypeDescriptor

      public ALcyFileTypeDescriptor getDecoderFileTypeDescriptor(int aIndex)
      Description copied from interface: ILcyModelDecoderContainer
      Retrieves the file type descriptor at the given index, or null if the decoder was added with null as a descriptor.
      Specified by:
      getDecoderFileTypeDescriptor in interface ILcyModelDecoderContainer
      Parameters:
      aIndex - The index to retrieve the file type descriptor for.
      Returns:
      the file type descriptor at the given index.

    • getDisplayName

      public String getDisplayName()
      Description copied from interface: ILcdModelDecoder
      Returns a short, displayable name for the format that is decoded by this ILcdModelDecoder.
      Specified by:
      getDisplayName in interface ILcdModelDecoder
      Returns:
      the displayable name of this ILcdModelDecoder.

    • canDecodeSource

      public boolean canDecodeSource(String aSourceName)
      Loops over its associated list of ILcdModelDecoders to find a suitable ILcdModelDecoder. Suitable means that canDecodeSource returns true. If it can find such a suitable ILcdModelDecoder it returns true, false otherwise.
      Specified by:
      canDecodeSource in interface ILcdModelDecoder
      Parameters:
      aSourceName - The name of the source to decode.
      Returns:
      True if a suitable ILcdModelDecoder could be found, false otherwise.
      See Also:

    • canDecodeSource

      public boolean canDecodeSource(ILcdDataSource aDataSource)
      Loops over its associated list of ILcdModelDecoders to find a suitable ILcdModelDecoder. Suitable means that canDecodeSource returns true. If it can find such a suitable ILcdModelDecoder it returns true, false otherwise.
      Specified by:
      canDecodeSource in interface ILcdModelDecoder
      Parameters:
      aDataSource - The object identifying the data source(s) to decode.
      Returns:
      True if a suitable ILcdModelDecoder could be found, false otherwise.
      See Also:

    • decode

      public ILcdModel decode(String aSourceName) throws IOException

      Loops over its associated list of ILcdModelDecoders to find a suitable ILcdModelDecoder. Suitable means that canDecodeSource returns true.

      It will first loop over all model decoders for which the associated ALcyFileTypeDescriptor accepts aSourceName. The decode will be delegated to the first of those decoders for which the canDecode returns true.

      When none of those model decoders is suitable, it will loop over all available model decoders, and delegate the decode to the first suitable one.

      Specified by:
      decode in interface ILcdModelDecoder
      Parameters:
      aSourceName - The name of the source to decode.
      Returns:
      The model decoded by the first suitable ILcdModelDecoder
      Throws:
      IOException - for any exceptions caused by IO problems or invalid data. Since decoding invalid data almost always results in RunTimeExceptions (NullPointerException, IndexOutOfBoundsException, IllegalArgumentException, ...) on unexpected places, implementations are advised to catch RuntimeExceptions in their decode() method, and wrap them into an IOException, as illustrated in the code snippet below. 
      
   public ILcdModel decode( String aSourceName ) throws IOException {
      try (InputStream input = fInputStreamFactory.createInputStream(aSourceName)) {
         // Perform decoding ...
      } catch (RuntimeException e) {
         throw new IOException(e);
      }
   }
      See Also:

    • decodeSource

      public ILcdModel decodeSource(ILcdDataSource aDataSource) throws IOException
      Loops over its associated list of ILcdModelDecoders to find a suitable ILcdModelDecoder. Suitable means that canDecodeSource returns true.

      The first suitable ILcdModelDecoder is used to decode the given source.

      Specified by:
      decodeSource in interface ILcdModelDecoder
      Parameters:
      aDataSource - The object identifying the data source(s) to decode.
      Returns:
      The model decoded by the first suitable ILcdModelDecoder
      Throws:
      IOException - for any exceptions caused by IO problems or invalid data. Since decoding invalid data almost always results in RunTimeExceptions (NullPointerException, IndexOutOfBoundsException, IllegalArgumentException, ...) on unexpected places, implementations are advised to catch RuntimeExceptions in their decode() method, and wrap them into an IOException, as illustrated in the code snippet below. 
      
 public ILcdModel decodeSource(ILcdDataSource aDataSource) throws IOException {
   try {
     // Perform decoding ...
   } catch (RuntimeException e) {
     throw new IOException(e);
   }
 }
      See Also: