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GATE - general achitecture for text engineering - is open source software capable of solving almost any text processing problem. This artifact enables you to embed the core GATE Embedded with its essential dependencies. You will able to use the GATE Embedded API and load and store GATE XML documents. This artifact is the perfect dependency for CREOLE plugins or for applications that need to customize the GATE dependencies due to confict with their own dependencies or for lower footprint.

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/*
 *  Copyright (c) 1995-2014, The University of Sheffield. See the file
 *  COPYRIGHT.txt in the software or at http://gate.ac.uk/gate/COPYRIGHT.txt
 *
 *  This file is part of GATE (see http://gate.ac.uk/), and is free
 *  software, licenced under the GNU Library General Public License,
 *  Version 2, June 1991 (in the distribution as file licence.html,
 *  and also available at http://gate.ac.uk/gate/licence.html).
 *
 *  Mark A. Greenwood 11/07/2014
 *
 */

package gate;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import javax.swing.filechooser.FileFilter;

import gate.creole.AbstractResource;
import gate.util.ExtensionFileFilter;

/**
 * Adds support for exporting documents from GATE. Subclasses of
 * DocumentExporter now how to export in a given format. These exporters
 * are loaded as Creole resources and made easily available within the
 * GUI, but can also be easily accessed from within the API.
 */
public abstract class DocumentExporter extends AbstractResource {

  private static final long serialVersionUID = -4810523902750051704L;

  protected String fileType, defaultExtension, mimeType;

  protected FileFilter filter;

  /**
   * Creates a new exporter instance for a given file type with default
   * extension.
   * 
   * @param fileType this is the human readable file type name that will
   *          appear on the menu
   * @param defaultExtension the default file extension for this type
   */
  public DocumentExporter(String fileType, String defaultExtension, String mimeType) {
    this.fileType = fileType;
    this.defaultExtension = defaultExtension;
    this.mimeType = mimeType;
  }

  /**
   * The name of the file type exported
   * 
   * @return the name of the file type exported
   */
  public String getFileType() {
    return fileType;
  }

  /**
   * The default extension added to files saved in this format
   * 
   * @return the default extension added to files saved in this format
   */
  public String getDefaultExtension() {
    return defaultExtension;
  }
  
  @Override
  public String getName() {
    return fileType;
  }
  
  public String getMimeType() {
    return mimeType;
  }

  /**
   * A filter used in the file chooser to restrict the view to files of
   * this type. The default implementation just uses the default
   * extension as the filter constraint
   */
  public FileFilter getFileFilter() {
    if(filter == null)
      filter =
              new ExtensionFileFilter(fileType + " Files (*."
                      + defaultExtension + ")", defaultExtension);
    return filter;
  }

  /**
   * Equivalent to {@link #export(Document,File,FeatureMap)} with an empty map
   * of options.
   */
  public void export(Document doc, File file) throws IOException {
    export(doc, file, Factory.newFeatureMap());
  }

  /**
   * Equivalent to {@link #export(Document,OutputStream,FeatureMap)} using a
   * FileOutputStream instance constructed from the File param.
   */
  public void export(Document doc, File file, FeatureMap options)
          throws IOException {
    try (FileOutputStream out = new FileOutputStream(file)){
      export(doc, out, options);
      out.flush();
    }
  }

  /**
   * Equivalent to {@link #export(Document,OutputStream)} with an empty
   * map of options.
   */
  public void export(Document doc, OutputStream out) throws IOException {
    export(doc, out, Factory.newFeatureMap());
  }

  /**
   * Exports the provided {@link Document} instance to the specified
   * {@link OutputStream} using the specified options.
   * 
   * @param doc the document to export
   * @param out the OutputStream to export the document to
   * @param options DocumentExporter specific options
   */
  public abstract void export(Document doc, OutputStream out, FeatureMap options)
          throws IOException;
  
  public static DocumentExporter getInstance(String className) {
    return (DocumentExporter)Gate.getCreoleRegister().get(className)
            .getInstantiations().iterator().next();
  }
}