MultiDaoRegister.java

/*
	Milyn - Copyright (C) 2006 - 2010

	This library is free software; you can redistribute it and/or
	modify it under the terms of the GNU Lesser General Public
	License (version 2.1) as published by the Free Software
	Foundation.

	This library is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

	See the GNU Lesser General Public License for more details:
	http://www.gnu.org/licenses/lgpl.txt
*/
package org.milyn.scribe.register;

import java.util.HashMap;
import java.util.Map;

import org.apache.commons.lang.builder.ToStringBuilder;
import org.milyn.assertion.AssertArgument;

/**
 * Enables multiple {@link DaoRegister} objects to be used as one DaoRegister.
 * Each DaoRegister gets a name. To get the correct DAO the following name notation
 * is used "{DaoRegister name}.{Dao name}".
 * <p>
 * A {@link MultiDaoRegister} can be created via the static {@link #newInstance(Map)} method
 * or via the {@link Builder} object. The Builder object can be created via it's constructor
 * or the static {@link #builder()} or {@link #builder(Map)} methods.
 *
 * @author <a href="mailto:maurice.zeijen@smies.com">maurice.zeijen@smies.com</a>
 *
 */
public class MultiDaoRegister<T> extends AbstractDaoRegister<T> {

	/**
	 * Creates a new {@link MultiDaoRegister} and fills it with the provided map.
	 *
	 * @param <T> the type of the DAO
	 * @param map the map that fills the new {@link MultiDaoRegister}
	 * @return the new {@link MultiDaoRegister}
	 */
	public static <T> MultiDaoRegister<T> newInstance(Map<String, ? extends DaoRegister<T>> map) {
		AssertArgument.isNotNull(map, "map");

		return new MultiDaoRegister<T>(new HashMap<String, DaoRegister<T>>(map));
	}

	/**
	 * Creates a Builder object that can build a {@link MultiDaoRegister}
	 *
	 * @param <T> The type of the DAO
	 * @return The builder
	 */
	public static <T> Builder<T> builder() {
		return new Builder<T>();
	}


	/**
	 * Creates a Builder object that can build a {@link MultiDaoRegister}.
	 * The builder will be instantiated with the provided map.
	 *
	 * @param <T> The type of the DAO
	 * @param map The map that is added to the builder
	 * @return The builder
	 */
	public static <T> Builder<T> builder(Map<String, ? extends DaoRegister<T>> map) {
		return new Builder<T>(map);
	}

	private Map<String, DaoRegister<T>> daoRegisterMap = new HashMap<String, DaoRegister<T>>();

	/**
	 * @param hashMap
	 */
	private MultiDaoRegister(Map<String, DaoRegister<T>> daoRegisterMap) {
		this.daoRegisterMap = daoRegisterMap;
	}

	/* (non-Javadoc)
	 * @see org.milyn.scribe.register.AbstractDaoRegister#getDao(java.lang.String)
	 */
	@Override
	public T getDao(String name) {

		int sepIndex = name.indexOf(".");
		String key = name;
		String subName = null;
		if(sepIndex >= 0) {
			key = name.substring(0, sepIndex);
			subName = name.substring(sepIndex+1);
		}

		DaoRegister<T> subDaoRegister = daoRegisterMap.get(key);

		if(subDaoRegister == null) {
			return null;
		}
		if(subName == null) {
			return subDaoRegister.getDefaultDao();
		} else {
			return subDaoRegister.getDao(subName);
		}
	}

	public int size() {
		return daoRegisterMap.size();
	}

	public Map<String, DaoRegister<T>> getDaoRegisterMap() {
		return new HashMap<String, DaoRegister<T>>(daoRegisterMap);
	}

	/* (non-Javadoc)
	 * @see java.lang.Object#hashCode()
	 */
	@Override
	public int hashCode() {
		return daoRegisterMap.hashCode();
	}

	@Override
	public String toString() {
		return new ToStringBuilder(this)
				.append("daoRegisterMap", daoRegisterMap, true)
				.toString();
	}

	/* (non-Javadoc)
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
	public boolean equals(final Object obj) {

		if(obj == null) {
			return false;
		}
		if(obj instanceof MultiDaoRegister == false) {
			return false;
		}

		@SuppressWarnings("unchecked")
		final MultiDaoRegister<T> other = (MultiDaoRegister<T>) obj;

		return daoRegisterMap.equals(other.daoRegisterMap);
	}

	/**
	 * Builds a MapDaoRegister object.
	 *
	 * @author <a href="mailto:maurice.zeijen@smies.com">maurice.zeijen@smies.com</a>
	 *
	 * @param <T> The DAO type
	 */
	static class Builder<T> {

		private final Map<String, DaoRegister<T>> map;

		/**
		 * creates an empty Builder
		 */
		public Builder() {
			map = new HashMap<String, DaoRegister<T>>();
		}

		/**
		 * Creates an Builder and copies all of the mappings for the
		 * specified map to this builder
		 */
		public Builder(Map<String, ? extends DaoRegister<T>> map) {
			AssertArgument.isNotNull(map, "map");

			this.map = new HashMap<String, DaoRegister<T>>(map);
		}

		/**
		 * Adds a DAO register under a specified name
		 *
		 * @param name the name of the DAO
		 * @param dao the DAO
		 * @return the builder
		 */
		public Builder<T> put(String name, DaoRegister<T> daoRegister) {
			AssertArgument.isNotNull(name, "name");
			AssertArgument.isNotNull(daoRegister, "daoRegister");

			map.put(name, daoRegister);

			return this;
		}

		/**
		 * Copies all of the mappings for the specified map to this builder
		 *
		 * @param map mapping to be stored in this builder
		 * @return the builder
		 */
		public Builder<T> putAll(Map<String, ? extends DaoRegister<T>> map) {
			AssertArgument.isNotNull(map, "map");

			this.map.putAll(map);

			return this;
		}

		/**
		 * Creates the {@link MultiDaoRegister} and provides it with the
		 * DAO register mapping
		 *
		 * @return the created {@link MultiDaoRegister}
		 */
		public MultiDaoRegister<T> build() {
			return new MultiDaoRegister<T>(map);
		}

	}


}