ObjectProductSource.java

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

import gov.usgs.earthquake.product.Content;
import gov.usgs.earthquake.product.Product;
import gov.usgs.earthquake.product.ProductId;

import java.net.URI;

import java.util.Iterator;
import java.util.Map;
import java.util.List;
import java.util.TreeSet;

/**
 * Convert a java Product object into events for a ProductHandler.
 *
 * ObjectProductSource turns a product object into a stream of events for
 * ProductOutputs.
 *
 * ObjectProductSources are reuseable for a given product.
 */
public class ObjectProductSource implements ProductSource {

    /** The product being sent. */
    private Product product;

    /**
     * Construct a new ObjectProductSource.
     *
     * @param product
     *            the product used for input.
     */
    public ObjectProductSource(final Product product) {
        this.product = product;
    }

    /**
     * Send a product object to a ProductOutput.
     *
     * Calls these methods in the following order:
     * <ol>
     * <li>sendBeginProduct
     * <li>sendProperties
     * <li>sendLinks
     * <li>sendContents
     * <li>sendSignature
     * <li>sendEndProducct
     * </ol>
     *
     * @param out
     *            the ProductOutput that will receive the Product.
     */
    public void streamTo(final ProductHandler out) throws Exception {
        sendBeginProduct(out);
        sendProperties(out);
        sendLinks(out);
        sendContents(out);
        sendSignatureVersion(out);
        sendSignature(out);
        sendEndProduct(out);
    }

    /**
     * Call out's onBeginProduct method for this product.
     *
     * @param out
     *            the receiving ProductOutput.
     * @throws Exception
     *             if out.onBeginProduct throws an Exception.
     */
    public void sendBeginProduct(final ProductHandler out) throws Exception {
        out.onBeginProduct(product.getId(), product.getStatus(), product
                .getTrackerURL());
    }

    /**
     * Call out's onProperty method for each product property. Calls in
     * alphabetical order by property name.
     *
     * @param out
     *            the receiving ProductOutput.
     * @throws Exception
     *             if out.onProperty throws an Exception.
     */
    public void sendProperties(final ProductHandler out) throws Exception {
        ProductId id = product.getId();
        Map<String, String> props = product.getProperties();
        // in alphabetical order by property name
        Iterator<String> keys = new TreeSet<String>(props.keySet()).iterator();
        while (keys.hasNext()) {
            String key = keys.next().toString();
            String value = props.get(key);
            out.onProperty(id, key, value);
        }
    }

    /**
     * Call out's onLink method for each product link. Calls in alphabetical
     * order by relation name, by URI.
     *
     * @param out
     *            the receiving ProductOutput.
     * @throws Exception
     *             if out.onProperty throws an Exception.
     */
    public void sendLinks(final ProductHandler out) throws Exception {
        ProductId id = product.getId();
        Map<String, List<URI>> links = product.getLinks();
        // in alphabetical order by relation name
        Iterator<String> linkRelations = new TreeSet<String>(links.keySet())
                .iterator();
        while (linkRelations.hasNext()) {
            String relation = linkRelations.next();
            // in alphabetical order by URI
            Iterator<URI> linkURIs = new TreeSet<URI>(links.get(relation))
                    .iterator();
            while (linkURIs.hasNext()) {
                URI uri = linkURIs.next();
                out.onLink(id, relation, uri);
            }
        }
    }

    /**
     * Call out's onContent method for each product content. Calls
     * alphabetically by content path.
     *
     * @param out
     *            the receiving ProductOutput.
     * @throws Exception
     *             if out.onContent throws an Exception.
     */
    public void sendContents(final ProductHandler out) throws Exception {
        ProductId id = product.getId();
        Map<String, Content> contents = product.getContents();
        // in alphabetical order by content path
        Iterator<String> paths = new TreeSet<String>(contents.keySet())
                .iterator();
        while (paths.hasNext()) {
            String path = paths.next();
            out.onContent(id, path, contents.get(path));
        }
    }


    /**
     * Call out's onSignature method with product signature.
     *
     * @param out
     *            the receiving ProductOutput.
     * @throws Exception
     *             if out.onSignature throws an Exception.
     */
    public void sendSignatureVersion(final ProductHandler out) throws Exception {
        out.onSignatureVersion(product.getId(), product.getSignatureVersion());
    }

    /**
     * Call out's onSignature method with product signature.
     *
     * @param out
     *            the receiving ProductOutput.
     * @throws Exception
     *             if out.onSignature throws an Exception.
     */
    public void sendSignature(final ProductHandler out) throws Exception {
        out.onSignature(product.getId(), product.getSignature());
    }

    /**
     * Call out's onEndProduct method for product.
     *
     * @param out
     *            the receiving ProductOutput.
     * @throws Exception
     *             if out.onEndProduct throws an Exception.
     */
    public void sendEndProduct(final ProductHandler out) throws Exception {
        out.onEndProduct(product.getId());
    }


    /**
     * Free any resources associated with this source.
     */
    @Override
    public void close() {
        this.product = null;
    }

}