pdpage.java

非常有用的操作pdf文件的java源码

        {
            page.removeItem( COSName.BLEED_BOX );
        }
        else
        {
            page.setItem( COSName.BLEED_BOX, bleedBox.getCOSArray() );
        }
    }

    /**
     * A rectangle, expressed in default user space units, defining
     * the intended dimensions of the finished page after trimming.
     * The default is the CropBox.
     *
     * @return The TrimBox attribute.
     */
    public PDRectangle getTrimBox()
    {
        PDRectangle retval = null;
        COSArray array = (COSArray)page.getDictionaryObject( COSName.TRIM_BOX );
        if( array != null )
        {
            retval = new PDRectangle( array );
        }
        else
        {
            retval = findCropBox();
        }
        return retval;
    }

    /**
     * This will set the TrimBox for this page.
     *
     * @param trimBox The new TrimBox for this page.
     */
    public void setTrimBox( PDRectangle trimBox )
    {
        if( trimBox == null )
        {
            page.removeItem( COSName.TRIM_BOX );
        }
        else
        {
            page.setItem( COSName.TRIM_BOX, trimBox.getCOSArray() );
        }
    }

    /**
     * A rectangle, expressed in default user space units, defining
     * the extent of the page's meaningful content (including potential
     * white space) as intended by the page's creator  The default isthe CropBox.
     *
     * @return The ArtBox attribute.
     */
    public PDRectangle getArtBox()
    {
        PDRectangle retval = null;
        COSArray array = (COSArray)page.getDictionaryObject( COSName.ART_BOX );
        if( array != null )
        {
            retval = new PDRectangle( array );
        }
        else
        {
            retval = findCropBox();
        }
        return retval;
    }

    /**
     * This will set the ArtBox for this page.
     *
     * @param artBox The new ArtBox for this page.
     */
    public void setArtBox( PDRectangle artBox )
    {
        if( artBox == null )
        {
            page.removeItem( COSName.ART_BOX );
        }
        else
        {
            page.setItem( COSName.ART_BOX, artBox.getCOSArray() );
        }
    }


    //todo BoxColorInfo
    //todo Contents

    /**
     * A value representing the rotation.  This will be null if not set at this level
     * The number of degrees by which the page should
     * be rotated clockwise when displayed or printed. The value must be a multiple
     * of 90.
     *
     * This will get the rotation at this page and not look up the hierarchy.
     * This attribute is inheritable, and findRotation() should probably used.
     * This will return null if no rotation is available at this level.
     *
     * @return The rotation at this level in the hierarchy.
     */
    public Integer getRotation()
    {
        Integer retval = null;
        COSNumber value = (COSNumber)page.getDictionaryObject( COSName.ROTATE );
        if( value != null )
        {
            retval = new Integer( value.intValue() );
        }
        return retval;
    }

    /**
     * This will find the rotation for this page by looking up the hierarchy until
     * it finds them.
     *
     * @return The rotation at this level in the hierarchy.
     */
    public int findRotation()
    {
        int retval = 0;
        Integer rotation = getRotation();
        if( rotation != null )
        {
            retval = rotation.intValue();
        }
        else
        {
            PDPageNode parent = getParent();
            if( parent != null )
            {
                retval = parent.findRotation();
            }
        }

        return retval;
    }

    /**
     * This will set the rotation for this page.
     *
     * @param rotation The new rotation for this page.
     */
    public void setRotation( int rotation )
    {
        page.setItem( COSName.ROTATE, new COSInteger( rotation ) );
    }

    /**
     * This will get the contents of the PDF Page, in the case that the contents
     * of the page is an array then then the entire array of streams will be
     * be wrapped and appear as a single stream.
     *
     * @return The page content stream.
     *
     * @throws IOException If there is an error obtaining the stream.
     */
    public PDStream getContents() throws IOException
    {
        return PDStream.createFromCOS( page.getDictionaryObject( COSName.CONTENTS ) );
    }

    /**
     * This will set the contents of this page.
     *
     * @param contents The new contents of the page.
     */
    public void setContents( PDStream contents )
    {
        page.setItem( COSName.CONTENTS, contents );
    }
    
    /**
     * This will get a list of PDThreadBead objects, which are article threads in the
     * document.  This will return an empty list of there are no thread beads.
     * 
     * @return A list of article threads on this page.
     */
    public List getThreadBeads()
    {
        COSArray beads = (COSArray)page.getDictionaryObject( COSName.B );
        if( beads == null )
        {
            beads = new COSArray();
        }
        List pdObjects = new ArrayList();
        for( int i=0; i<beads.size(); i++)
        {
            COSDictionary beadDic = (COSDictionary)beads.getObject( i );
            PDThreadBead bead = null;
            //in some cases the bead is null
            if( beadDic != null )
            {
                bead = new PDThreadBead( beadDic );
            }
            pdObjects.add( bead );
        }
        return new COSArrayList(pdObjects, beads);
        
    }
    
    /**
     * This will set the list of thread beads.
     * 
     * @param beads A list of PDThreadBead objects or null.
     */
    public void setThreadBeads( List beads )
    {
        page.setItem( COSName.B, COSArrayList.converterToCOSArray( beads ) );
    }
    
    /**
     * Get the metadata that is part of the document catalog.  This will 
     * return null if there is no meta data for this object.
     * 
     * @return The metadata for this object.
     */
    public PDMetadata getMetadata()
    {
        PDMetadata retval = null;
        COSStream stream = (COSStream)page.getDictionaryObject( COSName.METADATA );
        if( stream != null )
        {
            retval = new PDMetadata( stream );
        }
        return retval;
    }
    
    /**
     * Set the metadata for this object.  This can be null.
     * 
     * @param meta The meta data for this object.
     */
    public void setMetadata( PDMetadata meta )
    {
        page.setItem( COSName.METADATA, meta );
    }
    
    /**
     * Convert this page to an output image.
     * 
     * @return A graphical representation of this page.
     * 
     * @throws IOException If there is an error drawing to the image.
     */
    public BufferedImage convertToImage() throws IOException
    {
        int scaling = 2;
        int rotation = findRotation();
        PDRectangle mBox = findMediaBox();
        int width = (int)(mBox.getWidth());//*2);
        int height = (int)(mBox.getHeight());//*2);
        if( rotation == 90 || rotation == 270 )
        {
            int tmp = width;
            width = height;
            height = tmp;
        }
        Dimension pageDimension = new Dimension( width, height );
        
        //note we are doing twice as many pixels because
        //the default size is not really good resolution,
        //so create an image that is twice the size
        //and let the client scale it down.
        BufferedImage retval = 
            new BufferedImage( width*scaling, height*scaling, BufferedImage.TYPE_BYTE_INDEXED );
        Graphics2D graphics = (Graphics2D)retval.getGraphics();
        graphics.setColor( Color.WHITE );
        graphics.fillRect(0,0,width*scaling, height*scaling);
        graphics.scale( scaling, scaling );
        PageDrawer drawer = new PageDrawer();
        drawer.drawPage( graphics, this, pageDimension );
        
        
        return retval;
    }
    
    /**
     * Get the page actions.
     * 
     * @return The Actions for this Page 
     */
    public PDPageAdditionalActions getActions()
    {
        COSDictionary addAct = (COSDictionary) page.getDictionaryObject(COSName.AA);
        if (addAct == null)
        {
            addAct = new COSDictionary();
            page.setItem(COSName.AA, addAct);
        }        
        return new PDPageAdditionalActions(addAct);
    }
    
    /**
     * Set the page actions.
     * 
     * @param actions The actions for the page.
     */
    public void setActions( PDPageAdditionalActions actions )
    {
        page.setItem( COSName.AA, actions );
    }
    
    /**
     * This will return a list of the Annotations for this page.
     *
     * @return List of the PDAnnotation objects.
     * 
     * @throws IOException If there is an error while creating the annotations.
     */
    public List getAnnotations() throws IOException
    {
        COSArrayList retval = null;
        COSArray annots = (COSArray)page.getDictionaryObject(COSName.ANNOTS); 
        if (annots == null) 
        {
            annots = new COSArray();
            page.setItem(COSName.ANNOTS, annots);
            retval = new COSArrayList(new ArrayList(), annots);
        }
        else
        {        
            List actuals = new ArrayList();
        
            for (int i=0; i < annots.size(); i++) 
            {
                COSBase item = annots.getObject(i);
                actuals.add( PDAnnotation.createAnnotation( item ) );
            }
            retval = new COSArrayList(actuals, annots);
        }
        return retval;
    }
    
    /**
     * This will set the list of annotations.
     * 
     * @param annots The new list of annotations. 
     */
    public void setAnnotations( List annots )
    {
        page.setItem( COSName.ANNOTS, COSArrayList.converterToCOSArray( annots ) );
    }
    
    /**
     * {@inheritDoc}
     */
    public int print(Graphics graphics, PageFormat pageFormat, int pageIndex)
        throws PrinterException
    {
        int retval = Printable.PAGE_EXISTS;
        try
        {
            PageDrawer drawer = new PageDrawer();
            PDRectangle pageSize = findMediaBox();
            drawer.drawPage( graphics, this, pageSize.createDimension() );
        }
        catch( IOException io )
        {
            throw new PrinterIOException( io );
        }
        return retval;
    }
    
    /**
     * {@inheritDoc}
     */
    public boolean equals( Object other )
    {
        return other instanceof PDPage && ((PDPage)other).getCOSObject() == this.getCOSObject();
    }
    
    /**
     * {@inheritDoc}
     */
    public int hashCode()
    {
        return this.getCOSDictionary().hashCode();
    }
}