messageelementimpl.java

jxme的一些相关程序,主要是手机上程序开发以及手机和计算机通信的一些程序资料,程序编译需要Ant支持

/*
 * Copyright (c) 2001 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *       Sun Microsystems, Inc. for Project JXTA."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact Project JXTA at http://www.jxta.org.
 *
 * 5. Products derived from this software may not be called "JXTA",
 *    nor may "JXTA" appear in their name, without prior written
 *    permission of Sun.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL SUN MICROSYSTEMS OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Project JXTA.  For more
 * information on Project JXTA, please see
 * <http://www.jxta.org/>.
 *
 * This license is based on the BSD license adopted by the Apache Foundation.
 *
 * $Id: MessageElementImpl.java,v 1.5 2002/05/02 05:19:15 bondolo Exp $
 */
package net.jxta.impl.endpoint;

import net.jxta.document.MimeMediaType;
import net.jxta.endpoint.Message;
import net.jxta.endpoint.MessageElement;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Vector;

/**
 *
 * @author  chgenly
 * @version
 */
public class MessageElementImpl extends MessageElement {
  private String name;
  private MimeMediaType type;
  private byte[] bytes;
  private int offset;
  private int len;
  
  /**
   * Create a new Element, but dont add it to the message. The contents
   * of the byte array are not copied.
   *
   * @param name Name of the Element. May be the empty string ("") if
   *   the Element is not named.
   * @param type Type of the Element. null is equivalent to specifying
   *   the type "Application/Octet-stream"
   * @param b A byte array containing the contents of this element.
   * @param offset all bytes before this location in <code>b</code>
   *   will be ignored.
   * @param len the number of bytes of the array starting from offset to
   *  use as the content of this element.
   *
   * @throws NullPointerException if name or b are null.
   * @throws IndexOutOfBoundsException if offset is negative or greater
   *  than or equal to the length of <code>b</code>
   *
   * @since JXTA 1.0
   */
  public MessageElementImpl(String name, MimeMediaType type, byte[] b,
  int offset, int len) {
    this.name = name;
    
    if( null != type )
      this.type = type;
    else
      this.type = new MimeMediaType( "application/octet-stream" );
    
    bytes = b;
    this.offset = offset;
    this.len = len;
  }
  
  
  /**
   *  Create a new Element, but don't add it to the message.
   *
   *  @param name Name of the Element. May be the empty string ("") if
   *   the Element is not named.
   *  @param type Type of the Element. null is equivalent to specifying
   *   the type "Application/Octet-stream"
   *  @param in the stream containing the body of the Element. If the
   *   stream does not support the "mark" operation then a copy of the
   *   stream contents is made immediately. The stream will <b>NOT</b> be
   *   closed by the Element.
   *  @param len The size of the Element will be limited to len bytes
   *   from the stream. If you are using the stream interface and know
   *   the size of the stream, specifying it here improves performance
   *   and space effciency a lot.  If the len is -1, then the input
   *   stream will be read until end of file, and then the stream will
   *   be closed.
   *
   *  @throws NullPointerException if name or InputStream are null.
   *
   * @since JXTA 1.0
   */
  public MessageElementImpl(String name, MimeMediaType type,
  InputStream in, int len) throws IOException {
    ByteArrayOutputStream baos = new ByteArrayOutputStream(len<0 ? 1024 : len);
    byte[] buff = new byte[1024];
    this.name = name;

    if( null != type )
      this.type = type;
    else
      this.type = new MimeMediaType( "application/octet-stream" );
    
    int tcnt = 0;
    while(len < 0 || tcnt < len) {
      int needed = len - tcnt;
      int thistime = len < 0 || needed > 1024 ? 1024 : needed;
      int cnt = in.read(buff, 0, thistime);
      if (cnt <= 0) break;
      baos.write(buff, 0, cnt);
      tcnt += cnt;
    }
    this.offset = 0;
    this.len = tcnt;
    bytes = baos.toByteArray();
    
    if (len < 0)
      in.close();
  }
  
  /**
   *  Create a new MessageElement
   *
   *  @param name Name of the Element. May be the empty string ("") if
   *   the Element is not named.
   *  @param type Type of the Element. null is equivalent to specifying
   *   the type "Application/Octet-stream"
   *  @param in the stream containing the body of the Element. The stream
   * will be closed by the Element.
   *
   *  @throws NullPointerException if name or InputStream are null.
   *
   */
  public MessageElementImpl(String name, MimeMediaType type,
  InputStream in) throws IOException {
    this(name, type, in, -1);
    in.close();
  }
  
  /**
   * Returns the offset into the array returned by getBytes()
   * of where data use by this element starts.
   */
  public int getOffset() {
    return offset;
  }
  
  /**
   *   Returns the number of bytes used in the array
   *   returned by getBytes().  This may or may not be the
   *   entire length of the array returned by getBytes().
   *   <P>
   *   post:<br>
   *   0 <= getLength() <= getBytes().length
   *
   *
   *   @return int the number of bytes of the element data.
   *
   *  @since JXTA 1.0
   **/
  public int getLength() {
    return len;
  }
  
  
  /**
   *   Returns the byte array which contains the element data.
   *   The portion of the array
   *   which is used as the element data starts at getOffset()
   *   and continues up to but not including the byte at
   *   getOffset()+getLength().
   *   <P>
   *   The byte array returned is not a copy of the element
   *   content.
   *
   *   @return byte[] Contents of message element.
   */
  public byte[] getBytesOffset() {
    return bytes;
  }
  
  /**
   *   Returns a stream containing the element data.
   *
   *   @return InputStream of the stream containing element data.
   *
   *  @since JXTA 1.0
   **/
  public InputStream getStream() {
    return new ByteArrayInputStream(bytes, offset, len);
  }
  
  /**
   *  Returns the name of the MessageElement.
   *
   *  @return String containing the name of the MessageElement.
   *
   *  @since JXTA 1.0
   **/
  public String getName() {
    return name;
  }
  
  /**
   *  Returns the type of the MessageElement.
   *
   *  @return MimeMediaType containing a copy of the type of the element.
   *   Will return "Application/Octet-Stream" if no type was originally
   *   specified.
   *
   *  @since JXTA 1.0
   **/
  public MimeMediaType getType() {
      return type;
  }
  
  /**
   *  make a clone of this element. Since element are immutable, this
   *  returns the same object.
   *
   *  @return Element a clone of this element.
   *
   *  @since JXTA 1.0
   **/
  public Object clone( ) {
    return this;
  }
  
  /**
   *  Compare this MessageElement against another
   *
   *  @param target The  to compare against.
   *  @return boolean true if the elements are identical.
   *
   *  @since JXTA 1.0
   **/
  public boolean equals( Object target ) {
    if (!(target instanceof MessageElement))
      return false;
    MessageElement other = (MessageElement)target;
    
    if (name == null ? other.getName() != null
    : !name.equals(other.getName()))
      return false;
    
    if (type == null ? other.getType() != null
    : !type.equals(other.getType()))
      return false;
    
    if (len != other.getLength())
      return false;
    
    byte[] otherBytes = other.getBytesOffset();
    int otherI = other.getOffset();
    for(int i=0; i<len; ++i)
      if (bytes[offset+i] != otherBytes[otherI++])
        return false;
    
    return true;
  }
}