api/src/main/java/org/apache/clerezza/Language.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor  license  agreements.  See the NOTICE file distributed
 * with this work  for  additional  information  regarding  copyright
 * ownership.  The ASF  licenses  this file to you under  the  Apache
 * License, Version 2.0 (the "License"); you may not  use  this  file
 * except in compliance with the License.  You may obtain  a copy  of
 * the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless  required  by  applicable law  or  agreed  to  in  writing,
 * software  distributed  under  the  License  is  distributed  on an
 * "AS IS"  BASIS,  WITHOUT  WARRANTIES  OR  CONDITIONS  OF ANY KIND,
 * either  express  or implied.  See  the License  for  the  specific
 * language governing permissions and limitations under  the License.
 */
package org.apache.clerezza;

/**
 * Represents a language as expressed by the RDF 4646 language tag
 *
 * @author reto
 */
public class Language {

    private String id;

    /**
     * Constructs the language tag defined by RDF 4646, normalized to lowercase.
     *
     * @param the id as defined by RDF 4646, normalized to lowercase.
     */
    public Language(String id) {
        if ((id == null) || (id.equals(""))) {
            throw new IllegalArgumentException("A language id may not be null or empty");
        }
        this.id = id.toLowerCase();
    }

    @Override
    public boolean equals(Object other) {
        if (other == null) {
            return false;
        }
        if (other instanceof Language) {
            return id.equals(((Language) other).id);
        } else {
            return false;
        }
    }

    @Override
    public int hashCode() {
        return id.hashCode();
    }

    @Override
    public String toString() {
        return id;
    }
}