tifffield.java

iText是一个能够快速产生PDF文件的java类库。iText的java类对于那些要产生包含文本

/*
 * 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:
 * 
 * -Redistributions of source code must retain the above copyright notice, this 
 * list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduct the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 * 
 * You acknowledge that Software is not designed,licensed or intended for use in 
 * the design, construction, operation or maintenance of any nuclear facility.
 */
package com.lowagie.text.pdf.codec;

import java.io.Serializable;

/**
 * A class representing a field in a TIFF 6.0 Image File Directory.
 *
 * <p> The TIFF file format is described in more detail in the
 * comments for the TIFFDescriptor class.
 *
 * <p> A field in a TIFF Image File Directory (IFD).  A field is defined
 * as a sequence of values of identical data type.  TIFF 6.0 defines
 * 12 data types, which are mapped internally onto the Java datatypes
 * byte, int, long, float, and double.
 *
 * <p><b> This class is not a committed part of the JAI API.  It may
 * be removed or changed in future releases of JAI.</b>
 *
 * @see TIFFDirectory
 */
public class TIFFField extends Object implements Comparable, Serializable {

    private static final long serialVersionUID = 9088332901412823834L;

	/** Flag for 8 bit unsigned integers. */
    public static final int TIFF_BYTE      =  1;

    /** Flag for null-terminated ASCII strings. */
    public static final int TIFF_ASCII     =  2;

    /** Flag for 16 bit unsigned integers. */
    public static final int TIFF_SHORT     =  3;

    /** Flag for 32 bit unsigned integers. */
    public static final int TIFF_LONG      =  4;

    /** Flag for pairs of 32 bit unsigned integers. */
    public static final int TIFF_RATIONAL  =  5;

    /** Flag for 8 bit signed integers. */
    public static final int TIFF_SBYTE     =  6;

    /** Flag for 8 bit uninterpreted bytes. */
    public static final int TIFF_UNDEFINED =  7;

    /** Flag for 16 bit signed integers. */
    public static final int TIFF_SSHORT    =  8;

    /** Flag for 32 bit signed integers. */
    public static final int TIFF_SLONG     =  9;

    /** Flag for pairs of 32 bit signed integers. */
    public static final int TIFF_SRATIONAL = 10;

    /** Flag for 32 bit IEEE floats. */
    public static final int TIFF_FLOAT     = 11;

    /** Flag for 64 bit IEEE doubles. */
    public static final int TIFF_DOUBLE    = 12;

    /** The tag number. */
    int tag;

    /** The tag type. */
    int type;

    /** The number of data items present in the field. */
    int count;

    /** The field data. */
    Object data;
    
    /** The default constructor. */
    TIFFField() {}

    /**
     * Constructs a TIFFField with arbitrary data.  The data
     * parameter must be an array of a Java type appropriate for the
     * type of the TIFF field.  Since there is no available 32-bit
     * unsigned datatype, long is used. The mapping between types is
     * as follows:
     *
     * <table border=1>
     * <tr>
     * <th> TIFF type </th> <th> Java type </th>
     * <tr>
     * <td><tt>TIFF_BYTE</tt></td>      <td><tt>byte</tt></td>
     * <tr>
     * <td><tt>TIFF_ASCII</tt></td>     <td><tt>String</tt></td>
     * <tr>
     * <td><tt>TIFF_SHORT</tt></td>     <td><tt>char</tt></td>
     * <tr>
     * <td><tt>TIFF_LONG</tt></td>      <td><tt>long</tt></td>
     * <tr>
     * <td><tt>TIFF_RATIONAL</tt></td>  <td><tt>long[2]</tt></td>
     * <tr>
     * <td><tt>TIFF_SBYTE</tt></td>     <td><tt>byte</tt></td>
     * <tr>
     * <td><tt>TIFF_UNDEFINED</tt></td> <td><tt>byte</tt></td>
     * <tr>
     * <td><tt>TIFF_SSHORT</tt></td>    <td><tt>short</tt></td>
     * <tr>
     * <td><tt>TIFF_SLONG</tt></td>     <td><tt>int</tt></td>
     * <tr>
     * <td><tt>TIFF_SRATIONAL</tt></td> <td><tt>int[2]</tt></td>
     * <tr>
     * <td><tt>TIFF_FLOAT</tt></td>     <td><tt>float</tt></td>
     * <tr>
     * <td><tt>TIFF_DOUBLE</tt></td>    <td><tt>double</tt></td>
     * </table>
     */
    public TIFFField(int tag, int type, int count, Object data) {
        this.tag = tag;
        this.type = type;
        this.count = count;
        this.data = data;
    }

    /**
     * Returns the tag number, between 0 and 65535.
     */
    public int getTag() {
        return tag;
    }

    /**
     * Returns the type of the data stored in the IFD.
     * For a TIFF6.0 file, the value will equal one of the
     * TIFF_ constants defined in this class.  For future
     * revisions of TIFF, higher values are possible.
     *
     */
    public int getType() {
        return type;
    }

    /**
     * Returns the number of elements in the IFD.
     */
    public int getCount() {
        return count;
    }

    /**
     * Returns the data as an uninterpreted array of bytes.
     * The type of the field must be one of TIFF_BYTE, TIFF_SBYTE,
     * or TIFF_UNDEFINED;
     *
     * <p> For data in TIFF_BYTE format, the application must take
     * care when promoting the data to longer integral types
     * to avoid sign extension.
     *
     * <p> A ClassCastException will be thrown if the field is not
     * of type TIFF_BYTE, TIFF_SBYTE, or TIFF_UNDEFINED.
     */
    public byte[] getAsBytes() {
        return (byte[])data;
    }

    /**
     * Returns TIFF_SHORT data as an array of chars (unsigned 16-bit
     * integers).
     *
     * <p> A ClassCastException will be thrown if the field is not
     * of type TIFF_SHORT.
     */
    public char[] getAsChars() {
        return (char[])data;
    }

    /**
     * Returns TIFF_SSHORT data as an array of shorts (signed 16-bit
     * integers).
     *
     * <p> A ClassCastException will be thrown if the field is not
     * of type TIFF_SSHORT.
     */
    public short[] getAsShorts() {
        return (short[])data;
    }

    /**
     * Returns TIFF_SLONG data as an array of ints (signed 32-bit
     * integers).
     *
     * <p> A ClassCastException will be thrown if the field is not
     * of type TIFF_SLONG.
     */
    public int[] getAsInts() {
        return (int[])data;
    }

    /**
     * Returns TIFF_LONG data as an array of longs (signed 64-bit
     * integers).
     *
     * <p> A ClassCastException will be thrown if the field is not
     * of type TIFF_LONG.
     */
    public long[] getAsLongs() {
        return (long[])data;
    }

    /**
     * Returns TIFF_FLOAT data as an array of floats. 
     *
     * <p> A ClassCastException will be thrown if the field is not