cosdictionary.java

非常有用的操作pdf文件的java源码

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 * Copyright (c) 2003-2005, www.pdfbox.org
 * 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,
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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package org.pdfbox.cos;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import java.util.Iterator;

import org.pdfbox.exceptions.COSVisitorException;

import org.pdfbox.pdmodel.common.COSObjectable;
import org.pdfbox.util.DateConverter;

/**
 * This class represents a dictionary where name/value pairs reside.
 *
 * @author <a href="[e-mail]">Ben Litchfield</a>
 * @version $Revision: 1.32 $
 */
public class COSDictionary extends COSBase
{
    private static final String PATH_SEPARATOR = "/";
    
    /**
     * These are all of the items in the dictionary.
     */
    private Map items = new HashMap();

    /**
     * Used to store original sequence of keys, for testing.
     */
    private List keys = new ArrayList();

    /**
     * Constructor.
     */
    public COSDictionary()
    {
        //default constructor
    }

    /**
     * Copy Constructor.  This will make a shallow copy of this dictionary.
     *
     * @param dict The dictionary to copy.
     */
    public COSDictionary( COSDictionary dict )
    {
        items = new HashMap( dict.items );
        keys = new ArrayList( dict.keys );
    }
    
    /**
     * @see java.util.Map#containsValue(java.lang.Object)
     * 
     * @param value The value to find in the map.
     * 
     * @return true if the map contains this value.
     */
    public boolean containsValue( Object value )
    {
        boolean contains = items.containsValue( value );
        if( !contains && value instanceof COSObject )
        {
            contains = items.containsValue( ((COSObject)value).getObject());
        }
        return contains;
    }
    
    /**
     * Search in the map for the value that matches the parameter
     * and return the first key that maps to that value.
     * 
     * @param value The value to search for in the map.
     * @return The key for the value in the map or null if it does not exist.
     */
    public COSName getKeyForValue( Object value )
    {
        COSName key = null;
        Iterator iter = items.entrySet().iterator();
        while( key == null && iter.hasNext() )
        {
            Map.Entry next = (Map.Entry)iter.next();
            Object nextValue = next.getValue();
            if( nextValue.equals( value ) ||
                (nextValue instanceof COSObject && 
                 ((COSObject)nextValue).getObject().equals( value))
                )
            {
                key = (COSName)next.getKey();
            }
        }
        
        return key;
    }

    /**
     * This will return the number of elements in this dictionary.
     *
     * @return The number of elements in the dictionary.
     */
    public int size()
    {
        return keys.size();
    }

    /**
     * This will clear all items in the map.
     */
    public void clear()
    {
        items.clear();
        keys.clear();
    }

    /**
     * This will get an object from this dictionary.  If the object is a reference then it will
     * dereference it and get it from the document.  If the object is COSNull then
     * null will be returned.
     *
     * @param key The key to the object that we are getting.
     *
     * @return The object that matches the key.
     */
    public COSBase getDictionaryObject( String key )
    {
        return getDictionaryObject( COSName.getPDFName( key ) );
    }
    
    /**
     * This is a special case of getDictionaryObject that takes multiple keys, it will handle
     * the situation where multiple keys could get the same value, ie if either CS or ColorSpace
     * is used to get the colorspace.
     * This will get an object from this dictionary.  If the object is a reference then it will
     * dereference it and get it from the document.  If the object is COSNull then
     * null will be returned.  
     *
     * @param firstKey The first key to try.
     * @param secondKey The second key to try.
     *
     * @return The object that matches the key.
     */
    public COSBase getDictionaryObject( String firstKey, String secondKey )
    {
        COSBase retval = getDictionaryObject( COSName.getPDFName( firstKey ) );
        if( retval == null )
        {
            retval = getDictionaryObject( COSName.getPDFName( secondKey ) );
        }
        return retval;
    }
    
    /**
     * This is a special case of getDictionaryObject that takes multiple keys, it will handle
     * the situation where multiple keys could get the same value, ie if either CS or ColorSpace
     * is used to get the colorspace.
     * This will get an object from this dictionary.  If the object is a reference then it will
     * dereference it and get it from the document.  If the object is COSNull then
     * null will be returned.  
     *
     * @param keyList The list of keys to find a value.
     *
     * @return The object that matches the key.
     */
    public COSBase getDictionaryObject( String[] keyList )
    {
        COSBase retval = null;
        for( int i=0; i<keyList.length && retval == null; i++ )
        {
            retval = getDictionaryObject( COSName.getPDFName( keyList[i] ) ); 
        }
        return retval;
    }

    /**
     * This will get an object from this dictionary.  If the object is a reference then it will
     * dereference it and get it from the document.  If the object is COSNull then
     * null will be returned.
     *
     * @param key The key to the object that we are getting.
     *
     * @return The object that matches the key.
     */
    public COSBase getDictionaryObject( COSName key )
    {
        COSBase retval = (COSBase)items.get( key );
        if( retval instanceof COSObject )
        {
            retval = ((COSObject)retval).getObject();
        }
        if( retval instanceof COSNull )
        {
            retval = null;
        }
        return retval;
    }

    /**
     * This will set an item in the dictionary.  If value is null then the result
     * will be the same as removeItem( key ).
     *
     * @param key The key to the dictionary object.
     * @param value The value to the dictionary object.
     */
    public void setItem( COSName key, COSBase value )
    {
        if( value == null )
        {
            removeItem( key );
        }
        else
        {
            if (!items.containsKey(key))
            {
                // insert only if not already there
                keys.add(key);
            }
            items.put( key, value );
        }
    }

    /**
     * This will set an item in the dictionary.  If value is null then the result
     * will be the same as removeItem( key ).
     *
     * @param key The key to the dictionary object.
     * @param value The value to the dictionary object.
     */
    public void setItem( COSName key, COSObjectable value )
    {
        COSBase base = null;
        if( value != null )
        {
            base = value.getCOSObject();
        }
        setItem( key, base );
    }

    /**
     * This will set an item in the dictionary.  If value is null then the result
     * will be the same as removeItem( key ).
     *
     * @param key The key to the dictionary object.
     * @param value The value to the dictionary object.
     */
    public void setItem( String key, COSObjectable value )
    {
        setItem( COSName.getPDFName( key ), value );
    }

    /**
     * This will set an item in the dictionary.
     *
     * @param key The key to the dictionary object.
     * @param value The value to the dictionary object.
     */
    public void setBoolean( String key, boolean value )
    {
        setItem( COSName.getPDFName( key ), COSBoolean.getBoolean( value ) );
    }

    /**
     * This will set an item in the dictionary.
     *
     * @param key The key to the dictionary object.
     * @param value The value to the dictionary object.
     */
    public void setBoolean( COSName key, boolean value )
    {
        setItem( key , COSBoolean.getBoolean( value ) );
    }

    /**
     * This will set an item in the dictionary.  If value is null then the result
     * will be the same as removeItem( key ).
     *
     * @param key The key to the dictionary object.
     * @param value The value to the dictionary object.
     */
    public void setItem( String key, COSBase value )
    {
        setItem( COSName.getPDFName( key ), value );
    }

    /**
     * This is a convenience method that will convert the value to a COSName
     * object.  If it is null then the object will be removed.
     *
     * @param key The key to the object,
     * @param value The string value for the name.
     */
    public void setName( String key, String value )
    {
        setName( COSName.getPDFName( key ), value );
    }

    /**
     * This is a convenience method that will convert the value to a COSName
     * object.  If it is null then the object will be removed.
     *
     * @param key The key to the object,
     * @param value The string value for the name.
     */
    public void setName( COSName key, String value )
    {
        COSName name = null;
        if( value != null )
        {
            name = COSName.getPDFName( value );
        }
        setItem( key, name );
    }
    
    /**
     * Set the value of a date entry in the dictionary.
     * 
     * @param key The key to the date value.
     * @param date The date value.
     */
    public void setDate( String key, Calendar date )
    {
        setDate( COSName.getPDFName( key ), date );
    }
    
    /**
     * Set the date object.
     * 
     * @param key The key to the date.
     * @param date The date to set.
     */
    public void setDate( COSName key, Calendar date )
    {
        setString( key, DateConverter.toString( date ) );
    }
    
    /**
     * Set the value of a date entry in the dictionary.
     * 
     * @param embedded The embedded dictionary.
     * @param key The key to the date value.
     * @param date The date value.
     */
    public void setEmbeddedDate( String embedded, String key, Calendar date )
    {
        setEmbeddedDate( embedded, COSName.getPDFName( key ), date );
    }
    
    /**
     * Set the date object.
     * 
     * @param embedded The embedded dictionary.
     * @param key The key to the date.
     * @param date The date to set.
     */
    public void setEmbeddedDate( String embedded, COSName key, Calendar date )
    {
        COSDictionary dic = (COSDictionary)getDictionaryObject( embedded );
        if( dic == null && date != null )
        {
            dic = new COSDictionary();
            setItem( embedded, dic );
        }
        if( dic != null )
        {
            dic.setDate( key, date );
        }
    }

    /**
     * This is a convenience method that will convert the value to a COSString
     * object.  If it is null then the object will be removed.
     *
     * @param key The key to the object,
     * @param value The string value for the name.
     */
    public void setString( String key, String value )
    {
        setString( COSName.getPDFName( key ), value );
    }

    /**
     * This is a convenience method that will convert the value to a COSString
     * object.  If it is null then the object will be removed.
     *
     * @param key The key to the object,
     * @param value The string value for the name.
     */
    public void setString( COSName key, String value )
    {
        COSString name = null;
        if( value != null )
        {
            name = new COSString( value );
        }
        setItem( key, name );
    }
    
    /**
     * This is a convenience method that will convert the value to a COSString
     * object.  If it is null then the object will be removed.
     *
     * @param embedded The embedded dictionary to set the item in.
     * @param key The key to the object,
     * @param value The string value for the name.
     */
    public void setEmbeddedString( String embedded, String key, String value )
    {
        setEmbeddedString( embedded, COSName.getPDFName( key ), value );
    }