ObjectProductHandler.java

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

import gov.usgs.earthquake.product.Content;
import gov.usgs.earthquake.product.ByteContent;
import gov.usgs.earthquake.product.FileContent;
import gov.usgs.earthquake.product.URLContent;
import gov.usgs.util.CryptoUtils.Version;
import gov.usgs.earthquake.product.Product;
import gov.usgs.earthquake.product.ProductId;

import java.net.URI;
import java.net.URL;

import java.util.List;
import java.util.LinkedList;

/**
 * Convert ProductSource events into a java Product object.
 *
 * ObjectProductHandlers are not designed to handle multiple products
 * simultaneously and separate objects must be created for each unique product
 * id.
 *
 * The static method ObjectProductHandler.getProduct(ProductInput) should
 * usually be used instead of constructing objects manually.
 */
public class ObjectProductHandler implements ProductHandler {

    /** The Product being created. */
    private Product product = null;

    /** Whether onEndProduct has been called yet. */
    private boolean complete = false;

    /** Empty constructor */
    public ObjectProductHandler() {
    }

    /**
     * @return the product object that was created.
     * @throws Exception if error occurs
     */
    public Product getProduct() throws Exception {
        if (product == null) {
            throw new IllegalArgumentException(
                    "Called getProduct before onBeginProduct");
        } else if (!complete) {
            throw new IllegalArgumentException(
                    "Called getProduct before onEndProduct");
        }

        return product;
    }

    public void onBeginProduct(final ProductId id, final String status,
            final URL trackerURL) throws Exception {
        if (product != null) {
            throw new IllegalArgumentException(
                    "Called onBeginProduct after onBeginProduct");
        } else if (complete) {
            throw new IllegalArgumentException(
                    "Called onBeginProduct after onEndProduct");
        }

        // System.err.println("onBeginProduct(" + id.toString() + ", " + status
        // + ", " + trackerURL + ")");

        product = new Product(id, status);
        product.setTrackerURL(trackerURL);
    }

    public void onContent(final ProductId id, final String path,
            final Content content) throws Exception {
        if (product == null) {
            throw new IllegalArgumentException(
                    "Called onContent before onBeginProduct");
        } else if (complete) {
            throw new IllegalArgumentException(
                    "Called onContent after onEndProduct");
        } else if (!product.getId().equals(id)) {
            throw new IllegalArgumentException("ProductIds do not match");
        }

        // System.err.println("onContent(" + id.toString() + ", " + path + ", "
        // + content.toString() + ")");

        if (content instanceof FileContent || content instanceof ByteContent
                || content instanceof URLContent) {
            // these types of content do not need to be read immediately
            product.getContents().put(path, content);
        } else {
            // new ByteContent reads stream into byte array
            product.getContents().put(path, new ByteContent(content));
        }

    }

    public void onEndProduct(final ProductId id) throws Exception {
        // System.err.println("onEndProduct(" + id.toString() + ")");

        complete = true;
    }

    public void onLink(final ProductId id, final String relation, final URI href)
            throws Exception {
        if (product == null) {
            throw new IllegalArgumentException(
                    "Called onLink before onBeginProduct");
        } else if (complete) {
            throw new IllegalArgumentException(
                    "Called onLink after onEndProduct");
        } else if (!product.getId().equals(id)) {
            throw new IllegalArgumentException("ProductIds do not match");
        }

        // get list of links for relation
        List<URI> links = product.getLinks().get(relation);
        if (links == null) {
            // create if doesn't already exist
            links = new LinkedList<URI>();
            product.getLinks().put(relation, links);
        }

        // add if doesn't already contain
        if (!links.contains(href)) {
            links.add(href);
        }
    }

    public void onProperty(final ProductId id, final String name,
            final String value) throws Exception {
        if (product == null) {
            throw new IllegalArgumentException(
                    "Called onProperty before onBeginProduct");
        } else if (complete) {
            throw new IllegalArgumentException(
                    "Called onProperty after onEndProduct");
        } else if (!product.getId().equals(id)) {
            throw new IllegalArgumentException("ProductIds do not match");
        }

        // System.err.println("onProperty(" + id.toString() + ", " + name + ", "
        // + value + ")");
        product.getProperties().put(name, value);
    }

    public void onSignatureVersion(final ProductId id, final Version version)
            throws Exception {
        if (product == null) {
            throw new IllegalArgumentException(
                    "Called onSignature before onBeginProduct");
        } else if (complete) {
            throw new IllegalArgumentException(
                    "Called onSignature after onEndProduct");
        } else if (!product.getId().equals(id)) {
            throw new IllegalArgumentException("ProductIds do not match");
        }

        product.setSignatureVersion(version);
    }

    public void onSignature(final ProductId id, final String signature)
            throws Exception {
        if (product == null) {
            throw new IllegalArgumentException(
                    "Called onSignature before onBeginProduct");
        } else if (complete) {
            throw new IllegalArgumentException(
                    "Called onSignature after onEndProduct");
        } else if (!product.getId().equals(id)) {
            throw new IllegalArgumentException("ProductIds do not match");
        }

        product.setSignature(signature);
    }

    /**
     * Convenience method to get a Product object from a ProductInput.
     *
     * @param in
     *            the ProductInput to read.
     * @return the Product read, or null if errors occur.
     * @throws Exception if error occurs
     */
    public static Product getProduct(final ProductSource in) throws Exception {
        ObjectProductHandler out = new ObjectProductHandler();
        try {
            in.streamTo(out);
        } finally {
            in.close();
        }
        return out.getProduct();
    }


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

}