JsonDirectoryProductHandler.java

/*
 * JsonDirectoryProductHandler
 */
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.json". 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 json format to a file name
 * "product.json".
 */
public class JsonDirectoryProductHandler extends DirectoryProductHandler {

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

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

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

  /**
   * Store all except product contents to product.json.
   */
  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_JSON_FILENAME));

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

}