GlobalItemIDImpl.java

package org.buddycloud.channelserver.pubsub.model.impl;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.buddycloud.channelserver.pubsub.model.GlobalItemID;
import org.xmpp.packet.JID;

/**
 * Basic implementation of {@link GlobalItemID}
 */
public class GlobalItemIDImpl implements GlobalItemID {

    private static final Pattern STRING_PATTERN = Pattern.compile("^tag:([^,]+),([^,]+),([^,]+)$");

    /**
     * Creates a new global item ID
     * 
     * @param service the JID of the pubsub service hosting the node
     * @param nodeID the id of the node containing the item
     * @param itemID the id of the item
     */
    public GlobalItemIDImpl(JID service, String nodeID, String itemID) {
        this.service = service;
        this.nodeID = nodeID;
        this.itemID = itemID;
    }

    private JID service;
    private String nodeID;
    private String itemID;

    @Override
    public JID getService() {
        return service;
    }

    @Override
    public String getNodeID() {
        return nodeID;
    }

    @Override
    public String getItemID() {
        return itemID;
    }

    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();

        if (service != null) {
            builder.append("tag:");
            builder.append(service.toString());
            builder.append(",");
        }
        builder.append(nodeID);
        builder.append(",");
        builder.append(itemID);

        return builder.toString();
    }

    /**
     * Creates a new {@link GlobalItemID} from a tag string which looks a bit like: <blockquote>
     * <code>tag:pubsub.server.com,a/node/id,an/item/id</code> </blockquote>
     * 
     * @param str The tag string
     * @return the {@link GlobalItemID}
     */
    public static GlobalItemID fromString(final String str) {
        Matcher matcher = STRING_PATTERN.matcher(str);

        if (!matcher.matches()) {
            throw new IllegalArgumentException(str + " is not a valid GlobalItemID String. Expected something like 'tag:example.com,node,item'.");
        }

        JID service = new JID(matcher.group(1));

        // Handle an issue with certain clients
        if ((service.getNode() != null) && service.getNode().equals("null")) {
            service = new JID(null, service.getDomain(), service.getResource());
        }

        return new GlobalItemIDImpl(service, matcher.group(2), matcher.group(3));
    }

    public static GlobalItemID fromBuddycloudString(String itemId) {
        String[] splittedItemId = itemId.split(",");
        if (splittedItemId.length < 2) {
            throw new IllegalArgumentException("Illegal format for buddycloud global id");
        }
        if (splittedItemId.length == 3) {
            return fromString(itemId);
        }
        return new GlobalItemIDImpl(null, splittedItemId[0], splittedItemId[1]);
    }

    public static String toLocalId(String itemId) {
        if (itemId == null) {
            return null;
        }
        String[] splittedItemId = itemId.split(",");
        if (splittedItemId.length == 1) {
            // Already a local id
            return itemId;
        }
        return fromBuddycloudString(itemId).getItemID();
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((itemID == null) ? 0 : itemID.hashCode());
        result = prime * result + ((nodeID == null) ? 0 : nodeID.hashCode());
        result = prime * result + ((service == null) ? 0 : service.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (!(obj instanceof GlobalItemID)) {
            return false;
        }
        GlobalItemID other = (GlobalItemID) obj;
        if (itemID == null) {
            if (other.getItemID() != null) {
                return false;
            }
        } else if (!itemID.equals(other.getItemID())) {
            return false;
        }
        if (nodeID == null) {
            if (other.getNodeID() != null) {
                return false;
            }
        } else if (!nodeID.equals(other.getNodeID())) {
            return false;
        }
        if (service == null) {
            if (other.getService() != null) {
                return false;
            }
        } else if (!service.equals(other.getService())) {
            return false;
        }
        return true;
    }

    public static boolean isGlobalId(String id) {
        Matcher matcher = STRING_PATTERN.matcher(id);

        if (!matcher.matches()) {
            return false;
        }
        return true;
    }
}