java - 为什么这个 Java Page Printing 代码如此缓慢，还有其他替代方法吗？

问题描述

我正在使用可打印界面。实现 Printable的PrintPanel的确切代码是：

package accessory;

// all necessary imports

public class PrintPanel implements Printable {

BufferedImage printableImages[] = null;
DynPanel printable = null;

public Font printFont = new Font("Arial", Font.BOLD , 10);
public String headerStr = null , footerStr = null;
public boolean draw_pageBorder = false;
public Color borderColor = Color.BLACK;
public int pageBorder_thickness = 2;
public int pageCount = 1;

public PrintPanel(DynPanel panel)
{
printable = panel;
pageCount = 1;
}
public PrintPanel(BufferedImage images[])
{
printableImages = images;
pageCount = images.length;
}
    @Override
   public int print(Graphics g, PageFormat pageFormat, int page) throws PrinterException
{
 System.out.println("entered print command");
 if(page < pageCount )
 {

 //--- Create the Graphics2D object
 Graphics2D g2d = (Graphics2D) g;
 g2d.translate(pageFormat.getImageableX(), pageFormat
         .getImageableY());
 //--- Translate the origin to 0,0 for the top left corner

 int fontHeight = g2d.getFontMetrics().getHeight();
 int fontDescent = g2d.getFontMetrics().getDescent();
 int lineHeight = fontHeight+ fontDescent;

 int fontWidth_header = g2d.getFontMetrics().stringWidth(headerStr);
 int fontWidth_footer = g2d.getFontMetrics().stringWidth(footerStr);
 int remainder_header = (int)Math.ceil( pageFormat.getImageableWidth()  )  - fontWidth_header;
 remainder_header /= 2d;
 int remainder_footer = (int)Math.ceil( pageFormat.getImageableWidth()  )  - fontWidth_footer;
 remainder_footer /= 2d;

  if(draw_pageBorder)
  {

 g2d.setPaint(borderColor);


 g2d.setStroke(new BasicStroke(pageBorder_thickness));
 Rectangle2D.Double border = new Rectangle2D.Double(0, 0, pageFormat
     .getImageableWidth()+4, pageFormat.getImageableHeight()+4);

   g2d.draw(border);
  }
  g2d.setFont(printFont);



 // code for printing DynPanel (JPanel)
 if(printable != null)
 {

      Dimension compSize = printable.getPreferredSize();
         // Make sure we size to the preferred size
         printable.setSize(compSize);
         // Get the the print size
         Dimension printSize = new Dimension();
         printSize.setSize(pageFormat.getImageableWidth(), pageFormat.getImageableHeight());

         // Calculate the scale factor
         double scaleFactor = getScaleFactorToFit(compSize, printSize);
         // Don't want to scale up, only want to scale down
         if (scaleFactor > 1d) {
             scaleFactor = 1d;
         }


         // Calculate the scaled size...
         double scaleWidth = compSize.width * scaleFactor;
         double scaleHeight = compSize.height * scaleFactor;

         // Create a clone of the graphics context.  This allows us to manipulate
         // the graphics context without begin worried about what effects
         // it might have once we're finished
         //Graphics2D g2d = (Graphics2D) g.create();
         // Calculate the x/y position of the component, this will center
         // the result on the page if it can
         double x = ((pageFormat.getImageableWidth() - scaleWidth) / 2d) + pageFormat.getImageableX();
         double y = ((pageFormat.getImageableHeight() - scaleHeight) / 2d) + pageFormat.getImageableY();
 AffineTransform at = new AffineTransform();
 // Translate the offset to out "center" of page
 at.translate(x, y);
 // Set the scaling
 at.scale(scaleFactor, scaleFactor);
 // Apply the transformation
 g2d.transform(at);
 // Print the component

 printable.printAll(g2d);
 }
 else // code for printing BufferedImages 'printableImages'
 {


     try{



            int width = (int) pageFormat.getImageableWidth();
            int height = (int) pageFormat.getImageableHeight();
            int imageWidth  = printableImages[page].getWidth();
            int imageHeight = printableImages[page].getHeight();

            double scaleX = (double)width/imageWidth;
            double scaleY = (double)height/imageHeight;
            AffineTransform scaleTransform = AffineTransform.getScaleInstance(scaleX, scaleY);
            AffineTransformOp bilinearScaleOp = new AffineTransformOp(scaleTransform, AffineTransformOp.TYPE_BILINEAR);

            printableImages[page] = bilinearScaleOp.filter(
                    printableImages[page],
                new BufferedImage(width, height, printableImages[page].getType()));
         System.out.println("Printing IMAGE="+printableImages[page]);

        g2d.drawImage(printableImages[page] ,  (int)pageFormat.getImageableX() , ( (int)pageFormat.getImageableY() + (8 + lineHeight) ),  null);
    } catch (Exception e) {
        // TODO Auto-generated catch block
        System.out.println("ERROR IN PRINTING IMAGE");
        e.printStackTrace();
    }

 }
 if(headerStr != null)
     g2d.drawString( headerStr , (int)pageFormat.getImageableX() + remainder_header , (int)pageFormat.getImageableY() + (8 + lineHeight));
     if(footerStr != null)
     {
      if(footerStr.equals("print_page_index"))
          g2d.drawString( ("Page "+( page + 1) + " of " + pageCount ) , (int)pageFormat.getImageableX() + remainder_footer , (int)pageFormat.getImageableY() + ((int)pageFormat.getImageableHeight() - lineHeight - 8 ));
      else 
     g2d.drawString( footerStr ,  (int)pageFormat.getImageableX() + remainder_footer , (int)pageFormat.getImageableY() + ((int)pageFormat.getImageableHeight() - lineHeight - 8));
     }
//else System.out.println("EMPTY PRINT");
 //g2d.dispose();
if(printable != null) printable.revalidate();
  //  printable.paint(g2d);
 return Printable.PAGE_EXISTS;
}
else return Printable.NO_SUCH_PAGE;

     }



 }

我正在使用构造函数 PrintPanel(BufferedImage images[])

现在我正在调用具有以下代码的函数 printDocument()：

private void printDocument()
{


javax.swing.SwingUtilities.invokeLater(new Runnable() {
    public void run() {

        System.out.println("Initiating print command..");
        long t1 = System.currentTimeMillis();                
        PrinterJob printJob = PrinterJob.getPrinterJob();
        Book book = new Book();
        PageFormat documentPageFormat = new PageFormat();
        documentPageFormat.setOrientation(PageFormat.PORTRAIT);
       BufferedImage pages[] = new BufferedImage[pane.pageCount];

        for(int count = 0; count < pane.pageCount; count ++ )   
         pages[count] = pane.pages[count].getSnapshot();



        PrintPanel printImage = new PrintPanel(pages);

        printImage.headerStr = "Java Study Frame : " + ( docName != null ? (( docName.replaceAll("\\s+" , "").isEmpty() ? " Untitled JSF Document " : docName ) ) : " Untitled JSF Document " ) ;
        printImage.footerStr = "print_page_index";

       printJob.setJobName("Java Study Frame Print");
       long t2 = System.currentTimeMillis();
        System.out.println("Setting printable. Prev time = " + (t2 - t1)/1000 +" seconds!");
        t1 = System.currentTimeMillis();
        printJob.setPrintable(printImage);
         t2 = System.currentTimeMillis();
        System.out.println("Printable set in " + (t2 - t1)/1000 + " seconds !");

        if (printJob.printDialog()) {
          try {
            printJob.print();
          } catch (Exception PrintException) {
            PrintException.printStackTrace();
          }
        }
    }
});

}

我的问题

在“启动打印命令”打印到控制台后，打印对话框每次出现实际上需要超过 30 秒。 是什么原因造成的？
即使单击打印对话框中的“打印”按钮，在实际生成打印作业之前至少需要 40-50 秒。这是为什么？（我最多打印 1 - 2 页）
超过 setPrintable() 需要 3-6 秒（prev time = 0 seconds and Printable Set is = 3-6 seconds），这意味着语句 printJob.printDialog() 需要时间。可能是什么原因造成的？
正如其他问题所证明的那样，Java 打印似乎很慢。如果是这样，我可以使用任何其他用于 Java 页面打印的 API吗？
即使我只添加了一个 printableImage 函数 print() 似乎也被多次调用（2-3次），控制台上的“输入的打印命令”就证明了这一点。这是对的吗？
尽管整个 printDocument() 是在单独的线程中启动的，但它会挂起我的应用程序。怎么会这样。我在这里做错了什么？

标签： javajava-print

java - 为什么这个 Java Page Printing 代码如此缓慢，还有其他替代方法吗？

问题描述

解决方案

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