com.github.fge.msgsimple.source.MapMessageSource Maven / Gradle / Ivy

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/*
 * Copyright (c) 2013, Francis Galiegue 
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the Lesser GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program 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
 * Lesser GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */

package com.github.fge.msgsimple.source;

import com.github.fge.msgsimple.InternalBundle;

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

/**
 * A {@link Map}-based message source
 *
 * This is a simple message source using a {@link Map} as a key/value pair to
 * look up messages.
 *
 * In order to build such a source, use {@link #newBuilder()}. Sample:
 *
 *  *     final MessageSource source = MapMessageSource.newBuilder()
 *         .put("key1", "message1").put("key2", "message2")
 *         .putAll(existingMap).build();
 * 
 *
 * Note that null keys or values are not allowed.
 *
 * @see Builder
 */
public final class MapMessageSource
    implements MessageSource
{
    private static final InternalBundle BUNDLE
        = InternalBundle.getInstance();

    private final Map messages;

    private MapMessageSource(final Builder builder)
    {
        messages = new HashMap(builder.messages);
    }

    /**
     * Create a new builder for a map message source
     *
     * @return a {@link Builder}
     */
    public static Builder newBuilder()
    {
        return new Builder();
    }

    @Override
    public String getKey(final String key)
    {
        return messages.get(key);
    }

    /**
     * Builder class for a {@link MapMessageSource}
     */
    public static final class Builder
    {
        private final Map messages
            = new HashMap();

        private Builder()
        {
        }

        /**
         * Add one key/message pair
         *
         * This overrides the value if the key already existed.
         *
         * @param key the key
         * @param message the message
         * @return this
         * @throws NullPointerException either the key or the value is null
         */
        public Builder put(final String key, final String message)
        {
            BUNDLE.checkNotNull(key, "cfg.map.nullKey");
            BUNDLE.checkNotNull(message, "cfg.map.nullValue");
            messages.put(key, message);
            return this;
        }

        /**
         * Add a map of key/message pairs
         *
         * This overrides all values of already existing keys.
         *
         * @param map the map
         * @return this
         * @throws NullPointerException the map is null; or a key, or value, is
         * null
         */
        public Builder putAll(final Map map)
        {
            BUNDLE.checkNotNull(map, "cfg.nullMap");
            for (final Map.Entry entry: map.entrySet())
                put(entry.getKey(), entry.getValue());
            return this;
        }

        /**
         * Build a new message source from the contents of this builder
         *
         * @return a {@link MapMessageSource}
         */
        public MessageSource build()
        {
            return new MapMessageSource(this);
        }
    }
}