pdfoperator.java

非常有用的操作pdf文件的java源码

/**
 * Copyright (c) 2003-2004, 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,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of pdfbox; nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS 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 THE REGENTS OR 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.
 *
 * http://www.pdfbox.org
 *
 */
package org.pdfbox.util;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

/**
 * This class represents an Operator in the content stream.
 *
 * @author <a href="mailto:[e-mail]">Ben Litchfield</a>
 * @version $Revision: 1.14 $
 */
public class PDFOperator
{
    private String theOperator;
    private byte[] imageData;
    private ImageParameters imageParameters;

    private static Map operators = Collections.synchronizedMap( new HashMap() );

    /**
     * Constructor.
     *
     * @param aOperator The operator that this object will represent.
     */
    private PDFOperator( String aOperator )
    {
        theOperator = aOperator;
        if( aOperator.startsWith( "/" ) )
        {
            throw new RuntimeException( "Operators are not allowed to start with / '" + aOperator + "'" );
        }
    }

    /**
     * This is used to create/cache operators in the system.
     *
     * @param operator The operator for the system.
     *
     * @return The operator that matches the operator keyword.
     */
    public static PDFOperator getOperator( String operator )
    {
        PDFOperator operation = null;
        if( operator.equals( "ID" ) || operator.equals( "BI" ) )
        {
            //we can't cache the ID operators.
            operation = new PDFOperator( operator );
        }
        else
        {
            operation = (PDFOperator)operators.get( operator );
            if( operation == null )
            {
                operation = new PDFOperator( operator );
                operators.put( operator, operation );
            }
        }

        return operation;
    }

    /**
     * This will get the operation that this operator represents.
     *
     * @return The string representation of the operation.
     */
    public String getOperation()
    {
        return theOperator;
    }

    /**
     * This will print a string rep of this class.
     *
     * @return A string rep of this class.
     */
    public String toString()
    {
        return "PDFOperator{" + theOperator + "}";
    }

    /**
     * This is the special case for the ID operator where there are just random
     * bytes inlined the stream.
     *
     * @return Value of property imageData.
     */
    public byte[] getImageData()
    {
        return this.imageData;
    }

    /**
     * This will set the image data, this is only used for the ID operator.
     *
     * @param imageDataArray New value of property imageData.
     */
    public void setImageData(byte[] imageDataArray)
    {
        imageData = imageDataArray;
    }

    /**
     * This will get the image parameters, this is only valid for BI operators.
     *
     * @return The image parameters.
     */
    public ImageParameters getImageParameters()
    {
        return imageParameters;
    }

    /**
     * This will set the image parameters, this is only valid for BI operators.
     *
     * @param params The image parameters.
     */
    public void setImageParameters( ImageParameters params)
    {
        imageParameters = params;
    }
}