/*
 * @(#)BinaryRefAddr.java	1.6 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package javax.naming;

/**
  * This class represents the binary form of the address of 
  * a communications end-point.
  *<p>
  * A BinaryRefAddr consists of a type that describes the communication mechanism
  * and an opaque buffer containing the address description
  * specific to that communication mechanism. The format and interpretation of
  * the address type and the contents of the opaque buffer are based on 
  * the agreement of three parties: the client that uses the address,
  * the object/server that can be reached using the address,
  * and the administrator or program that creates the address.
  *<p>
  * An example of a binary reference address is an BER X.500 presentation address.
  * Another example of a binary reference address is a serialized form of
  * a service's object handle.
  *<p>
  * A binary reference address is immutable in the sense that its fields
  * once created, cannot be replaced. However, it is possible to access
  * the byte array used to hold the opaque buffer. Programs are strongly
  * recommended against changing this byte array. Changes to this
  * byte array need to be explicitly synchronized.
  *
  * @author Rosanna Lee
  * @author Scott Seligman
  * @version 1.6 03/01/23
  *
  * @see RefAddr
  * @see StringRefAddr
  * @since 1.3
  */

  /*
  * The serialized form of a BinaryRefAddr object consists of its type
  * name String and a byte array containing its "contents".
  */

public class BinaryRefAddr extends RefAddr {
    /**
     * Contains the bytes of the address.
     * This field is initialized by the constructor and returned
     * using getAddressBytes() and getAddressContents().
     * @serial 
     */
    private byte[] buf = null;

    /**
      * Constructs a new instance of BinaryRefAddr using its address type and a byte
      * array for contents.
      *
      * @param addrType A non-null string describing the type of the address.
      * @param src	The non-null contents of the address as a byte array.
      *			The contents of src is copied into the new BinaryRefAddr.
      */
    public BinaryRefAddr(String addrType, byte[] src) {
	this(addrType, src, 0, src.length);
    }

    /**
      * Constructs a new instance of BinaryRefAddr using its address type and
      * a region of a byte array for contents.
      *
      * @param addrType A non-null string describing the type of the address.
      * @param src	The non-null contents of the address as a byte array.
      *			The contents of src is copied into the new BinaryRefAddr.
      * @param offset	The starting index in src to get the bytes.
      *			0 <= offset <= src.length.
      * @param count	The number of bytes to extract from src.
      *                 0 <= count <= src.length-offset.
      */
    public BinaryRefAddr(String addrType, byte[] src, int offset, int count) {
	super(addrType);
	buf = new byte[count];
	System.arraycopy(src, offset, buf, 0, count);
    }

    /**
      * Retrieves the contents of this address as an Object.
      * The result is a byte array.
      * Changes to this array will affect this BinaryRefAddr's contents.
      * Programs are recommended against changing this array's contents
      * and to lock the buffer if they need to change it.
      *
      * @return The non-null buffer containing this address's contents.
      */
    public Object getContent() {
	return buf;
    }

    
    /**
      * Determines whether obj is equal to this address.  It is equal if
      * it contains the same address type and their contents are byte-wise
      * equivalent.
      * @param obj	The possibly null object to check.
      * @return true if the object is equal; false otherwise.
      */
    public boolean equals(Object obj) {
	if ((obj != null) && (obj instanceof BinaryRefAddr)) {
	    BinaryRefAddr target = (BinaryRefAddr)obj;
	    if (addrType.compareTo(target.addrType) == 0) {
		if (buf == null && target.buf == null)
		    return true;
		if (buf == null || target.buf == null ||
		    buf.length != target.buf.length)
		    return false;
		for (int i = 0; i < buf.length; i++)
		    if (buf[i] != target.buf[i])
			return false;
		return true;
	    }
	}
	return false;
    }
    
    /**
      * Computes the hash code of this address using its address type and contents.
      * Two BinaryRefAddrs have the same hash code if they have
      * the same address type and the same contents.
      * It is also possible for different BinaryRefAddrs to have
      * the same hash code.
      *
      * @return The hash code of this address as an int.
      */
    public int hashCode() {
	int hash = addrType.hashCode();
	for (int i = 0; i < buf.length; i++) {
	    hash += buf[i];	// %%% improve later
	}
	return hash;
    }

    /**
      * Generates the string representation of this address.
      * The string consists of the address's type and contents with labels.
      * The first 32 bytes of contents are displayed (in hexadecimal).
      * If there are more than 32 bytes, "..." is used to indicate more.
      * This string is meant to used for debugging purposes and not
      * meant to be interpreted programmatically.
      * @return The non-null string representation of this address.
      */
    public String toString(){
	StringBuffer str = new StringBuffer("Address Type: " + addrType + "\n");

	str.append("AddressContents: ");
	for (int i = 0; i<buf.length && i < 32; i++) {
	    str.append(Integer.toHexString(buf[i]) +" ");
	}
	if (buf.length >= 32)
	    str.append(" ...\n");
	return (str.toString());
    }

    /**
     * Use serialVersionUID from JNDI 1.1.1 for interoperability
     */
    private static final long serialVersionUID = -3415254970957330361L;
}