org.apache.myfaces.trinidad.webapp.ChainedUploadedFileProcessor Maven / Gradle / Ivy

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 *   http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.myfaces.trinidad.webapp;

import java.io.IOException;
import org.apache.myfaces.trinidad.model.UploadedFile;

 /**
  * Marker Interface responsible for processing file uploads by multiple processors 
  * one after another in a chained fashion.  An Apache Trinidad application could have
  * multiple ChainedUploadedFileProcessor instances. A composite UploadedFileProcessor 
  * is accessible from the {@link org.apache.myfaces.trinidad.context.RequestContext},
  * but will be invoked automatically by the framework as needed. Developers
  * can implement this interface and chain many of them up together using space
  * separated class names in trinidad-config.xml file under
  * uploaded-file-processor element. The order in which the processors
  * will be instantated and called will be the same as how it appears inside the element.
  * As such, it is expected that the input of the ChainedUploadedFileProcessor will be
  * the output of the last ChainedUploadedFileProcessor.
  * 
  * UploadedFileProcessors which implement this interface are subject to the following
  * limitations/abilities:
  * 

  * 
  *   Unlike in the UploadedFileProcessor the {@link UploadedFile} objects given
  *   to a chained UploadedFileProcessor should allow for multiple reads such that
  *   {@link UploadedFile#getInputStream()} may be called multiple times and must return a 
  *   new InputStream every time it is called.
  * 
  * 
  *   Chained processors need not return new UploadedFile instances.  They may,
  *   instead, return the same instance as its predecessor, thus saving the need to move
  *   content around with each call into the chain.  If a ChainedUploadedFileProcessor
  *   DOES return a new instance of UploadedFile, it must be allowed to be read multiple times.
  * 
  * 
  *   Chained processors may extend the {@link ExtendedUploadedFileProcessor} abstract
  *   class.  Any additional methods will be handled in accordance to the modifications listed above.
  * 
  * 
  * 
  * @see org.apache.myfaces.trinidad.model.UploadedFile
  */
public interface ChainedUploadedFileProcessor extends UploadedFileProcessor {}