contentdisposition.java

一个用java写的mail.里面的代码值得我们去研究！学习。

/*
** $Id: ContentDisposition.java,v 1.3 2001/05/07 12:37:21 kunugi Exp $
**
** Copyright (c) 2000-2001 Jeff Gay
** on behalf of ICEMail.org <http://www.icemail.org>
** Copyright (c) 1999 by Jeff Gay
** 
** This program is free software.
** 
** You may redistribute it and/or modify it under the terms of the GNU
** General Public License as published by the Free Software Foundation.
** Version 2 of the license should be included with this distribution in
** the file LICENSE, as well as License.html. If the license is not
** included with this distribution, you may find a copy at the FSF web
** site at 'www.gnu.org' or 'www.fsf.org', or you may write to the
** Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139 USA.
**
** THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY OF ANY KIND,
** NOT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY. THE AUTHOR
** OF THIS SOFTWARE, ASSUMES _NO_ RESPONSIBILITY FOR ANY
** CONSEQUENCE RESULTING FROM THE USE, MODIFICATION, OR
** REDISTRIBUTION OF THIS SOFTWARE. 
** 
*/

package org.icemail.mail;

import java.util.Enumeration;
import java.util.Hashtable;

import javax.mail.Part;

import javax.mail.internet.HeaderTokenizer;
import javax.mail.internet.HeaderTokenizer.Token;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.ParseException;


/**
 * This class represents a MIME ContentDisposition value.
 * It provides methods to parse a MIME formatted string into the individual
 * disposition components, access the components, and to generate a MIME
 * style ContentType string. 
 */
public class ContentDisposition
{
  String    type_;
  Hashtable params_;

  /**
   * Construct a ContentDisposition by parsing the MIME formatted string.
   *
   * @param header the MIME formated string
   */
  public
  ContentDisposition( String header ) throws ParseException {
    type_ = null;
    params_ = new Hashtable( 5 ); // max number of MIME parameters

  // parse the header line looking for the MIME specifics
    if ( header == null ) {
      type_ = new String( "default" );
    }

    String xname = null;
    String xvalue = null;
    HeaderTokenizer.Token xtoken;

    HeaderTokenizer xtkr = new HeaderTokenizer( header, HeaderTokenizer.MIME );

    do {
      xtoken = xtkr.next();
      switch ( xtoken.getType() ) {
      case ';':
      // end of a parameter
        if ( type_ == null ) {
          if ( xname == null || xvalue != null ) {
            throw new ParseException( "Missing disposition type" );
          }
          type_ = xname;
        } else if ( xname == null || xvalue == null ) {
          throw new ParseException( "Invalid disposition parameter" );
        } else {
          params_.put( xname, xvalue );
        }

      // reset for next parameter
        xname = null;
        xvalue = null;
        break;

      case '=':
        if ( xname == null || xvalue != null ) {
          throw new ParseException( "Invalid disposition parameter" );
        }
        break;

      case HeaderTokenizer.Token.QUOTEDSTRING:
        xtoken = new HeaderTokenizer.Token( HeaderTokenizer.Token.ATOM,
                                            '"' + xtoken.getValue() + '"' );

      case HeaderTokenizer.Token.ATOM:
        if ( xname == null ) {
          xname = xtoken.getValue();
        } else if ( xvalue == null ) {
          xvalue = xtoken.getValue();
        } else {
          xvalue = xvalue + xtoken.getValue();
        }
        break;

      case HeaderTokenizer.Token.COMMENT:
        break;

      case HeaderTokenizer.Token.EOF:
        if ( xname != null ) {
          if ( xvalue != null ) {
          // parameter name and value pair
            params_.put( xname, xvalue );
          } else {
          // type
            if ( type_ != null ) {
                throw new ParseException( "Duplicate disposition type" );
            }
            type_ = xname;
          }
        }
        break;
      }
    } while ( xtoken.getType() != HeaderTokenizer.Token.EOF );

  // last check to make sure that at lease type was specific
    if ( type_ == null ) {
      throw new ParseException( "Missing disposition type" );
    }
  }

  /**
   * Get the disposition type.
   *
   * @return the disposition type
   */
  public String
  getType() {
    return type_;
  }

  /**
   * Match with the given disposition type.
   *
   * @param type the disposition type to match
   */
  public boolean
  match( String type ) {
    return type_.equals( type );
  }

  /**
   * Get a parameter by name.
   *
   * @return the parameter value or null
   */
  public String
  getParameter( String name ) {
    return (String)params_.get( name );
  }

  /**
   * Get the parameters formatted as a MIME string.
   *
   * @return the parameters formatted as a MIME string
   */
  public String
  getValues() {
    String x822 = type_ + ';';
    for ( Enumeration xe = params_.keys() ; xe.hasMoreElements() ; ) {
      String xname = (String)xe.nextElement();
      String xvalue = (String)params_.get( xname );
      x822 = x822 + xname + '=' + xvalue + ';';
    }

    return x822;
  }

  /**
   * Format this ContentDisposition as a MIME string.
   */
  public String
  toString() {
    return "Content-Disposition: " + getValues();
  }
}