/* 
 * 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 javax.naming;

import java.io.Serializable;

/**
 * This is an abstract class describing the address of an object which is
 * outside of a naming system. It contains an address type and the address
 * itself is dealt with by its subclasses, for example,
 * <code>BinaryRefAddr</code> and <code>StringRefAddr
 * </code>.
 * 
 * @see BinaryRefAddr
 * @see StringRefAddr
 */
public abstract class RefAddr implements Serializable {

    /*
     * This constant is used during deserialization to check the version which
     * created the serialized object.
     */
    private static final long serialVersionUID = -1468165120479154358L;

    /**
     * The type of the address.
     * 
     * @serial
     */
    protected String addrType;

    /**
     * Constructs a <code>RefAddr</code> instance using the supplied address
     * type.
     * 
     * @param type
     *            the address type which may be null
     */
    protected RefAddr(String type) {
        this.addrType = type;
    }

    /**
     * Returns true if this address is equal to the supplied object
     * <code>o</code>. They are considered equal if the address types are
     * equal and the address contents are equivalent. *
     * 
     * @param o
     *            the object to compare with
     * @return true if this address is equal to <code>o</code>, otherwise
     *         false
     */
    @Override
    public boolean equals(Object o) {
        if (o instanceof RefAddr) {
            RefAddr a = (RefAddr) o;
            return this.addrType.equals(a.addrType)
                    && (null == this.getContent() ? null == a.getContent()
                            : this.getContent().equals(a.getContent()));
        }
        return false;
    }

    /**
     * Gets the address itself which may be null. Each subclass of
     * <code>RefAddr</code> describes the format of the returned address.
     * 
     * @return the address itself
     */
    public abstract Object getContent();

    /**
     * Gets the type of this address.
     * 
     * @return the type of this address which cannot be null
     */
    public String getType() {
        return addrType;
    }

    /**
     * Returns the hashcode for this address. The result is the sum of the
     * hashcode of its address type and address.
     * 
     * @return the hashcode of this address
     */
    @Override
    public int hashCode() {
        return this.addrType.hashCode()
                + (null == this.getContent() ? 0 : this.getContent().hashCode());
    }

    /**
     * Returns the string representation of this address. This contains the
     * string representations of the address type and the address.
     * 
     * @return the string representation of this address
     */
    @SuppressWarnings("nls")
    @Override
    public String toString() {
        return "Type: " + addrType + "\nContent: " + getContent() + "\n";
    }

}