KeyFactory.java :  » Google-tech » slim3 » com » google » appengine » api » datastore » Java Open Source

package com.google.appengine.api.datastore;

public class KeyFactory {
    public static final class Builder {

        public Builder addChild(String kind, String name) {
            current = KeyFactory.createKey(current, kind, name);
            return this;
        }

        public Builder addChild(String kind, long id) {
            current = KeyFactory.createKey(current, kind, id);
            return this;
        }

        public Key getKey() {
            return current;
        }

        public String getString() {
            return KeyFactory.keyToString(current);
        }

        private Key current;

        public Builder(String kind, String name) {
            current = KeyFactory.createKey(null, kind, name);
        }

        public Builder(String kind, long id) {
            current = KeyFactory.createKey(null, kind, id);
        }

        public Builder(Key key) {
            current = key;
        }
    }

    public static Key createKey(String kind, long id) {
        return createKey(null, kind, id);
    }

    public static Key createKey(Key parent, String kind, long id) {
        if (id == 0L)
            throw new IllegalArgumentException("id cannot be zero");
        else
            return new Key(kind, parent, id);
    }

    public static Key createKey(String kind, String name) {
        return createKey(null, kind, name);
    }

    public static Key createKey(Key parent, String kind, String name) {
        if (name == null || name.length() == 0)
            throw new IllegalArgumentException("name cannot be null or empty");
        else
            return new Key(kind, parent, name);
    }

    /**
     * Non-supported. 
     */
    public static String createKeyString(String kind, long id) {
        return keyToString(createKey(kind, id));
    }

    /**
     * Non-supported. 
     */
    public static String createKeyString(Key parent, String kind, long id) {
        return keyToString(createKey(parent, kind, id));
    }

    /**
     * Non-supported. 
     */
    public static String createKeyString(String kind, String name) {
        return keyToString(createKey(kind, name));
    }

    /**
     * Non-supported. 
     */
    public static String createKeyString(Key parent, String kind, String name) {
        return keyToString(createKey(parent, kind, name));
    }

    /**
     * Non-supported. 
     */
    public static String keyToString(Key key) {
        throw new IllegalStateException("This method isn't supported on gwt.");
    }

    /**
     * Non-supported. 
     */
    public static Key stringToKey(String encoded) {
        throw new IllegalStateException("This method isn't supported on gwt.");
    }

    private KeyFactory() {
    }
}