DirectoryProductHandler.java

/*
 * DirectoryProductHandler
 */
package gov.usgs.earthquake.product.io;

import gov.usgs.earthquake.product.Content;
import gov.usgs.earthquake.product.FileContent;
import gov.usgs.earthquake.product.ProductId;
import gov.usgs.earthquake.product.URLContent;
import gov.usgs.util.StreamUtils;

import java.io.File;
import java.io.OutputStream;

/**
 * Store a product to a Directory.
 *
 * Product attributes are stored to a file named "product.xml". All
 * ProductOutput methods are passed to an ObjectProductOutput object, except
 * files with non-empty paths. Files are stored in the directory, and all other
 * product attributes are stored using the product xml format to a file name
 * "product.xml".
 */
public class DirectoryProductHandler extends ObjectProductHandler {

  /** The file where product attributes are stored. */
  public static final String PRODUCT_XML_FILENAME = "product.xml";

  /** Directory where product contents are stored. */
  private File directory;

  /**
   * Construct a new DirectoryProductHandler object.
   *
   * @param directory where product contents will be stored.
   */
  public DirectoryProductHandler(final File directory) {
    this.directory = directory;
  }

  /**
   * Extract content when path isn't empty.
   */
  public void onContent(ProductId id, String path, Content content) throws Exception {
    if ("".equals(path)) {
      super.onContent(id, path, content);
    } else {
      // FileContent copy constructor extracts content
      FileContent fc = new FileContent(content, new File(directory, path));
      super.onContent(id, path, new URLContent(fc));
      fc = null;
    }
  }

  /**
   * Store all except product contents to product.xml.
   */
  public void onEndProduct(ProductId id) throws Exception {
    super.onEndProduct(id);

    // save reference to stream, so it can be forced close.
    OutputStream out = null;
    ProductSource source = null;
    ProductHandler handler = null;
    try {
      out = StreamUtils.getOutputStream(new File(directory, PRODUCT_XML_FILENAME));

      // save product attributes as xml
      source = new ObjectProductSource(getProduct());
      handler = new XmlProductHandler(out);
      source.streamTo(handler);
    } finally {
      // close stream
      StreamUtils.closeStream(out);
      if (source != null) {
        source.close();
      }
      if (handler != null) {
        handler.close();
      }
    }
  }

}