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();
            }
        }
    }

}