/*

 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

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 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

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package javax.print;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.Serializable;

/**

 * Class <code>DocFlavor</code> encapsulates an object that specifies the

 * format in which print data is supplied to a {@link DocPrintJob}.

 * "Doc" is a short, easy-to-pronounce term that means "a piece of print data."

 * The print data format, or "doc flavor", consists of two things:

 * <UL>

 * <LI>

 * <B>MIME type.</B> This is a Multipurpose Internet Mail Extensions (MIME)

 * media type (as defined in <A HREF="http://www.ietf.org/rfc/rfc2045.txt">RFC

 * 2045</A> and <A HREF="http://www.ietf.org/rfc/rfc2046.txt">RFC 2046</A>)

 * that specifies how the print data is to be interpreted.

 * The charset of text data should be the IANA MIME-preferred name, or its

 * canonical name if no preferred name is specified. Additionally a few

 * historical names supported by earlier versions of the Java platform may

 * be recognized.

 * See <a href="../../java/lang/package-summary.html#charenc">

 * character encodings</a> for more information on the character encodings

 * supported on the Java platform.

 * <P>

 * <LI>

 * <B>Representation class name.</B> This specifies the fully-qualified name of

 * the class of the object from which the actual print data comes, as returned

 * by the {@link java.lang.Class#getName() Class.getName()} method.

 * (Thus the class name for <CODE>byte[]</CODE> is <CODE>"[B"</CODE>, for

 * <CODE>char[]</CODE> it is <CODE>"[C"</CODE>.)

 * </UL>

 * <P>

 * A <code>DocPrintJob</code> obtains its print data by means of interface

 * {@link Doc Doc}. A <code>Doc</code> object lets the <code>DocPrintJob</code>

 * determine the doc flavor the client can supply.  A <code>Doc</code> object

 * also lets the <code>DocPrintJob</code> obtain an instance of the doc flavor's

 * representation class, from which the <code>DocPrintJob</code> then obtains

 * the actual print data.

 * <P>

 * <HR>

 * <H3>Client Formatted Print Data</H3>

 * There are two broad categories of print data, client formatted print data

 * and service formatted print data.

 * <P>

 * For <B>client formatted print data</B>, the client determines or knows the

 * print data format.

 * For example the client may have a JPEG encoded image, a URL for

 * HTML code, or a disk file containing plain text in some encoding,

 * possibly obtained from an external source, and

 * requires a way to describe the data format to the print service.

 * <p>

 * The doc flavor's representation class is a conduit for the JPS

 * <code>DocPrintJob</code> to obtain a sequence of characters or

 * bytes from the client. The

 * doc flavor's MIME type is one of the standard media types telling how to

 * interpret the sequence of characters or bytes. For a list of standard media

 * types, see the Internet Assigned Numbers Authority's (IANA's) <A

 * HREF="http://www.iana.org/assignments/media-types/">Media Types

 * Directory</A>. Interface {@link Doc Doc} provides two utility operations,

 * {@link Doc#getReaderForText() getReaderForText} and

 * {@link Doc#getStreamForBytes() getStreamForBytes()}, to help a

 * <code>Doc</code> object's client extract client formatted print data.

 * <P>

 * For client formatted print data, the print data representation class is

 * typically one of the following (although other representation classes are

 * permitted):

 * <UL>

 * <LI>

 * Character array (<CODE>char[]</CODE>) -- The print data consists of the

 * <P>

 * <LI>

 * <code>String</code>  --

 * The print data consists of the Unicode characters in the string.

 * <P>

 * <LI>

 * Character stream ({@link java.io.Reader java.io.Reader})

 * -- The print data consists of the Unicode characters read from the stream

 * up to the end-of-stream.

 * <P>

 * <LI>

 * Byte array (<CODE>byte[]</CODE>) -- The print data consists of the bytes in

 * the array. The bytes are encoded in the character set specified by the doc

 * flavor's MIME type. If the MIME type does not specify a character set, the

 * default character set is US-ASCII.

 * <P>

 * <LI>

 * Byte stream ({@link java.io.InputStream java.io.InputStream}) --

 * The print data consists of the bytes read from the stream up to the

 * end-of-stream. The bytes are encoded in the character set specified by the

 * doc flavor's MIME type. If the MIME type does not specify a character set,

 * the default character set is US-ASCII.

 * <LI>

 * Uniform Resource Locator ({@link java.net.URL URL})

 * -- The print data consists of the bytes read from the URL location.

 * The bytes are encoded in the character set specified by the doc flavor's

 * MIME type. If the MIME type does not specify a character set, the default

 * character set is US-ASCII.

 * <P>

 * When the representation class is a URL, the print service itself accesses

 * and downloads the document directly from its URL address, without involving

 * the client. The service may be some form of network print service which

 * is executing in a different environment.

 * This means you should not use a URL print data flavor to print a

 * document at a restricted URL that the client can see but the printer cannot

 * see. This also means you should not use a URL print data flavor to print a

 * document stored in a local file that is not available at a URL

 * accessible independently of the client.

 * For example, a file that is not served up by an HTTP server or FTP server.

 * To print such documents, let the client open an input stream on the URL

 * or file and use an input stream data flavor.

 * </UL>

 * <p>

 * <HR>

 * <h3>Default and Platform Encodings</h3>

 * <P>

 * For byte print data where the doc flavor's MIME type does not include a

 * <CODE>charset</CODE> parameter, the Java Print Service instance assumes the

 * US-ASCII character set by default. This is in accordance with

 * <A HREF="http://www.ietf.org/rfc/rfc2046.txt">RFC 2046</A>, which says the

 * default character set is US-ASCII. Note that US-ASCII is a subset of

 * UTF-8, so in the future this may be widened if a future RFC endorses

 * UTF-8 as the default in a compatible manner.

 * <p>

 * Also note that this is different than the behaviour of the Java runtime

 * when interpreting a stream of bytes as text data. That assumes the

 * default encoding for the user's locale. Thus, when spooling a file in local

 * encoding to a Java Print Service it is important to correctly specify

 * the encoding. Developers working in the English locales should

 * be particularly conscious of this, as their platform encoding corresponds

 * to the default mime charset. By this coincidence that particular

 * case may work without specifying the encoding of platform data.

 * <p>

 * Every instance of the Java virtual machine has a default character encoding

 * determined during virtual-machine startup and typically depends upon the

 * locale and charset being used by the underlying operating system.

 * the same default encoding. Thus clients which want to stream platform

 * encoded text data from the host platform to a Java Print Service instance

 * must explicitly declare the charset and not rely on defaults.

 * <p>

 * The preferred form is the official IANA primary name for an encoding.

 * Applications which stream text data should always specify the charset

 * in the mime type, which necessitates obtaining the encoding of the host

 * platform for data (eg files) stored in that platform's encoding.

 * A CharSet which corresponds to this and is suitable for use in a

 * mime-type for a DocFlavor can be obtained

 * from {@link DocFlavor#hostEncoding DocFlavor.hostEncoding}

 * This may not always be the primary IANA name but is guaranteed to be

 * understood by this VM.

 * For common flavors, the pre-defined *HOST DocFlavors may be used.

 * <p>

 * <p>

 * See <a href="../../java/lang/package-summary.html#charenc">

 * character encodings</a> for more information on the character encodings

 * supported on the Java platform.

 * <p>

 * <HR>

 * <h3>Recommended DocFlavors</h3>

 * <P>

 * The Java Print Service API does not define any mandatorily supported

 * DocFlavors.

 * However, here are some examples of MIME types that a Java Print Service

 * instance might support for client formatted print data.

 * Nested classes inside class DocFlavor declare predefined static

 * constant DocFlavor objects for these example doc flavors; class DocFlavor's

 * constructor can be used to create an arbitrary doc flavor.

 * <UL>

 * <LI>Preformatted text

 * <P>

 * <TABLE BORDER=1 CELLPADDING=0 CELLSPACING=0 SUMMARY="MIME-Types and their descriptions">

 * <TR>

 *  <TH>MIME-Type</TH><TH>Description</TH>

 * </TR>

 * <TR>

 * <TD><CODE>"text/plain"</CODE></TD>

 * <TD>Plain text in the default character set (US-ASCII)</TD>

 * </TR>

 * <TR>

 * <TD><CODE>"text/plain; charset=<I>xxx</I>"</CODE></TD>

 * <TD>Plain text in character set <I>xxx</I></TD>

 * </TR>

 * <TR>

 * <TD><CODE>"text/html"</CODE></TD>

 * <TD>HyperText Markup Language in the default character set (US-ASCII)</TD>

 * </TR>

 * <TR>

 * <TD><CODE>"text/html; charset=<I>xxx</I>"</CODE></TD>

 * <TD>HyperText Markup Language in character set <I>xxx</I></TD>

 * </TR>

 * </TABLE>

 * <P>

 * In general, preformatted text print data is provided either in a character

 * oriented representation class (character array, String, Reader) or in a

 * byte oriented representation class (byte array, InputStream, URL).

 * <P>

 *  <LI>Preformatted page description language (PDL) documents

 *<P>

 * <TABLE BORDER=1 CELLPADDING=0 CELLSPACING=0 SUMMARY="MIME-Types and their descriptions">

 * <TR>

 *  <TH>MIME-Type</TH><TH>Description</TH>

 * </TR>

 *<TR>

 * <TD><CODE>"application/pdf"</CODE></TD>

 * <TD>Portable Document Format document</TD>

 * </TR>

 * <TR>

 * <TD><CODE>"application/postscript"</CODE></TD>

 * <TD>PostScript document</TD>

 * </TR>

 * <TR>

 * <TD><CODE>"application/vnd.hp-PCL"</CODE></TD>

 * <TD>Printer Control Language document</TD>

 * </TR>

 * </TABLE>

 * <P>

 * In general, preformatted PDL print data is provided in a byte oriented

 * representation class (byte array, InputStream, URL).

 * <P>

 *  <LI>Preformatted images

 *<P>

 * <TABLE BORDER=1 CELLPADDING=0 CELLSPACING=0 SUMMARY="MIME-Types and their descriptions">

 * <TR>

 *  <TH>MIME-Type</TH><TH>Description</TH>

 * </TR>

 *

 * <TR>

 * <TD><CODE>"image/gif"</CODE></TD>

 * <TD>Graphics Interchange Format image</TD>

 * </TR>

 * <TR>

 * <TD><CODE>"image/jpeg"</CODE></TD>

 * <TD>Joint Photographic Experts Group image</TD>

 * </TR>

 * <TR>

 * <TD><CODE>"image/png"</CODE></TD>

 * <TD>Portable Network Graphics image</TD>

 * </TR>

 * </TABLE>

 * <P>

 * In general, preformatted image print data is provided in a byte oriented

 * representation class (byte array, InputStream, URL).

 * <P>

 *  <LI>Preformatted autosense print data

 *   <P>

 * <TABLE BORDER=1 CELLPADDING=0 CELLSPACING=0 SUMMARY="MIME-Types and their descriptions">

 * <TR>

 *  <TH>MIME-Type</TH><TH>Description</TH>

 * </TR>

 *

 * <TR>

 * <TD><CODE>"application/octet-stream"</CODE></TD>

 * <TD>The print data format is unspecified (just an octet stream)</TD>

 * </TABLE>

 * <P>

 * The printer decides how to interpret the print data; the way this

 * "autosensing" works is implementation dependent. In general, preformatted

 * autosense print data is provided in a byte oriented representation class

 * (byte array, InputStream, URL).

 * </UL>

 * <P>

 * <HR>

 * <H3>Service Formatted Print Data</H3>

 * <P>

 * For <B>service formatted print data</B>, the Java Print Service instance

 * determines the print data format. The doc flavor's representation class

 * denotes an interface whose methods the <code>DocPrintJob</code> invokes to

 * determine the content to be printed -- such as a renderable image

 * interface or a Java printable interface.

 * The doc flavor's MIME type is the special value

 * <CODE>"application/x-java-jvm-local-objectref"</CODE> indicating the client

 * will supply a reference to a Java object that implements the interface

 * named as the representation class.

 * This MIME type is just a placeholder; what's

 * important is the print data representation class.

 * <P>

 * For service formatted print data, the print data representation class is

 * typically one of the following (although other representation classes are

 * permitted). Nested classes inside class DocFlavor declare predefined static

 * constant DocFlavor objects for these example doc flavors; class DocFlavor's

 * constructor can be used to create an arbitrary doc flavor.

 * <UL>

 * <LI>

 * Renderable image object -- The client supplies an object that implements

 * interface

 * {@link java.awt.image.renderable.RenderableImage RenderableImage}. The

 * printer calls methods

 * in that interface to obtain the image to be printed.

 * <P>

 * <LI>

 * Printable object -- The client supplies an object that implements interface

 * {@link java.awt.print.Printable Printable}.

 * The printer calls methods in that interface to obtain the pages to be

 * printed, one by one.

 * For each page, the printer supplies a graphics context, and whatever the

 * client draws in that graphics context gets printed.

 * <P>

 * <LI>

 * Pageable object -- The client supplies an object that implements interface

 * {@link java.awt.print.Pageable Pageable}. The printer calls

 * methods in that interface to obtain the pages to be printed, one by one.

 * For each page, the printer supplies a graphics context, and whatever

 * the client draws in that graphics context gets printed.

 * </UL>

 * <P>

 * <HR>

 * <P>

 * <HR>

 * <H3>Pre-defined Doc Flavors</H3>

 * A Java Print Service instance is not <B><I>required</I></B> to support the

 * following print data formats and print data representation classes.  In

 * fact, a developer using this class should <b>never</b> assume that a

 * particular print service supports the document types corresponding to

 * these pre-defined doc flavors.  Always query the print service

 * to determine what doc flavors it supports.  However,

 * developers who have print services that support these doc flavors are

 * encouraged to refer to the predefined singleton instances created here.

 * <UL>

 * <LI>

 * Plain text print data provided through a byte stream. Specifically, the

 * following doc flavors are recommended to be supported:

 * <BR>&#183;&nbsp;&nbsp;

 * <CODE>("text/plain", "java.io.InputStream")</CODE>

 * <BR>&#183;&nbsp;&nbsp;

 * <CODE>("text/plain; charset=us-ascii", "java.io.InputStream")</CODE>

 * <BR>&#183;&nbsp;&nbsp;

 * <CODE>("text/plain; charset=utf-8", "java.io.InputStream")</CODE>

 * <P>

 * <LI>

 * Renderable image objects. Specifically, the following doc flavor is

 * recommended to be supported:

 * <BR>&#183;&nbsp;&nbsp;

 * <CODE>("application/x-java-jvm-local-objectref", "java.awt.image.renderable.RenderableImage")</CODE>

 * </UL>

 * <P>

 * A Java Print Service instance is allowed to support any other doc flavors

 * (or none) in addition to the above mandatory ones, at the implementation's

 * choice.

 * <P>

 * Support for the above doc flavors is desirable so a printing client can rely

 * on being able to print on any JPS printer, regardless of which doc flavors

 * the printer supports. If the printer doesn't support the client's preferred

 * doc flavor, the client can at least print plain text, or the client can

 * convert its data to a renderable image and print the image.

 * <P>

 * Furthermore, every Java Print Service instance must fulfill these

 * requirements for processing plain text print data:

 * <UL>

 * <LI>

 * The character pair carriage return-line feed (CR-LF) means

 * "go to column 1 of the next line."

 * <LI>

 * A carriage return (CR) character standing by itself means

 * "go to column 1 of the next line."

 * <LI>

 * A line feed (LF) character standing by itself means

 * "go to column 1 of the next line."

 * <LI>

 * </UL>

 * <P>

 * The client must itself perform all plain text print data formatting not

 * addressed by the above requirements.

 * <P>

 * <H3>Design Rationale</H3>

 * <P>

 * Class DocFlavor in package javax.print.data is similar to class

 * {@link java.awt.datatransfer.DataFlavor DataFlavor}. Class

 * <code>DataFlavor</code>

 * is not used in the Java Print Service (JPS) API

 * for three reasons which are all rooted in allowing the JPS API to be

 * shared by other print services APIs which may need to run on Java profiles

 * which do not include all of the Java Platform, Standard Edition.

 * <OL TYPE=1>

 * <LI>

 * The JPS API is designed to be used in Java profiles which do not support

 * AWT.

 * <P>

 * <LI>

 * The implementation of class <code>java.awt.datatransfer.DataFlavor</code>

 * does not guarantee that equivalent data flavors will have the same

 * serialized representation. DocFlavor does, and can be used in services

 * which need this.

 * <P>

 * <LI>

 * The implementation of class <code>java.awt.datatransfer.DataFlavor</code>

 * includes a human presentable name as part of the serialized representation.

 * This is not appropriate as part of a service matching constraint.

 * </OL>

 * <P>

 * Class DocFlavor's serialized representation uses the following

 * canonical form of a MIME type string. Thus, two doc flavors with MIME types

 * that are not identical but that are equivalent (that have the same

 * canonical form) may be considered equal.

 * <UL>

 * <LI> The media type, media subtype, and parameters are retained, but all

 *      comments and whitespace characters are discarded.

 * <LI> The media type, media subtype, and parameter names are converted to

 *      lowercase.

 * <LI> The parameter values retain their original case, except a charset

 *      parameter value for a text media type is converted to lowercase.

 * <LI> Quote characters surrounding parameter values are removed.

 * <LI> Quoting backslash characters inside parameter values are removed.

 * <LI> The parameters are arranged in ascending order of parameter name.

 * </UL>

 * <P>

 * Class DocFlavor's serialized representation also contains the

 * fully-qualified class <I>name</I> of the representation class

 * (a String object), rather than the representation class itself

 * (a Class object). This allows a client to examine the doc flavors a

 * Java Print Service instance supports without having

 * to load the representation classes, which may be problematic for

 * limited-resource clients.

 * <P>

 *

 * @author  Alan Kaminsky

 */

public class DocFlavor implements Serializable, Cloneable {

    private static final long serialVersionUID = -4512080796965449721L;

    /**

     * A String representing the host operating system encoding.

     * This will follow the conventions documented in

     * <a href="http://www.ietf.org/rfc/rfc2278.txt">

     * <i>RFC&nbsp;2278:&nbsp;IANA Charset Registration Procedures</i></a>

     * except where historical names are returned for compatibility with

     * previous versions of the Java platform.

     * The value returned from method is valid only for the VM which

     * returns it, for use in a DocFlavor.

     * This is the charset for all the "HOST" pre-defined DocFlavors in

     * the executing VM.

     */

    public static final String hostEncoding;

    static {

        hostEncoding =

            (String)java.security.AccessController.doPrivileged(

                  new sun.security.action.GetPropertyAction("file.encoding"));

    }

    /**

     * MIME type.

     */

    private transient MimeType myMimeType;

    /**

     * Representation class name.

     * @serial

     */

    private String myClassName;

    /**

     * String value for this doc flavor. Computed when needed and cached.

     */

    private transient String myStringValue = null;

    /**

     * Constructs a new doc flavor object from the given MIME type and

     * representation class name. The given MIME type is converted into

     * canonical form and stored internally.

     *

     * @param  mimeType   MIME media type string.

     * @param  className  Fully-qualified representation class name.

     *

     * @exception  NullPointerException

     *     (unchecked exception) Thrown if <CODE>mimeType</CODE> is null or

     *     <CODE>className</CODE> is null.

     * @exception  IllegalArgumentException

     *     (unchecked exception) Thrown if <CODE>mimeType</CODE> does not

     *     obey the syntax for a MIME media type string.

     */

    public DocFlavor(String mimeType, String className) {

        if (className == null) {

            throw new NullPointerException();

        }

        myMimeType = new MimeType (mimeType);

        myClassName = className;

    }

    /**

     * Returns this doc flavor object's MIME type string based on the

     * canonical form. Each parameter value is enclosed in quotes.

     * @return the mime type

     */

    public String getMimeType() {

        return myMimeType.getMimeType();

    }

    /**

     * Returns this doc flavor object's media type (from the MIME type).

     * @return the media type

     */

    public String getMediaType() {

        return myMimeType.getMediaType();

    }