打印慢的原因
java的RasterPrinterJob会执行很多次printPage方法
他应该是按块填充的, 如果页面元素非常复杂, 那么printPage方法可能会执行十几次.
而如果你用了如下代码中流式打印的方式, 每页pdf单独实现Printable接口, 重写print方法.
private static class FinePrintableDemo implements Printable {
public FinePrintableDemo(PDDocument document, int index) {
this.index = index;
this.printable = new PDFPrintable(document);
}
private int index;
private PDFPrintable printable;
@Override
public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
long start1 = System.currentTimeMillis();
int res = printable.print(graphics, pageFormat, index);
long end1 = System.currentTimeMillis();
System.out.println("打印第 " + (index + 1) + "页 耗时 : " + (end1 - start1) +" 毫秒 ");
return res;
}
}
会发现print方法同样被执行了十几次, 造成一个带背景的pdf打印耗时十几秒.
慢在哪
慢在每次都重复解析同一页pdf内容. 打了断点后会发现每页都在PDFStreamEngine.processStream
public void renderPageToGraphics(int pageIndex, Graphics2D graphics, float scale) throws IOException {
PDPage page = this.document.getPage(pageIndex);
this.transform(graphics, page, scale);
PDRectangle cropBox = page.getCropBox();
graphics.clearRect(0, 0, (int)cropBox.getWidth(), (int)cropBox.getHeight());
PageDrawerParameters parameters = new PageDrawerParameters(this, page);
PageDrawer drawer = this.createPageDrawer(parameters);
drawer.drawPage(graphics, cropBox);
}
这个方法每次都会消耗1s左右.
怎么解决
最好的方式自然是改pdfbox源码, 不用每次都重新生成解析pdf文件. 不过那样稍微有点麻烦.
还有个更简单的方式, 既然pdf会被反复解析, 那么我们在print之前把pdf转成图片, 然后直接打印图片即可.
即使RasterPrinterJob.printPage执行十几次, 也不过在绘制Image, 时间会非常短.
因此我们将代码稍微改造下, 在printable.print方法中直接打印图片.
private static class FinePrintableDemo implements Printable {
private BufferedImage image;
public FinePrintableDemo(PDDocument document, int index) {
// 获取pdf文件, 将其中指定的页面转成图片.
PDFRenderer renderer = new PDFRenderer(document);
try {
this.image = renderer.renderImage(index, 1, ImageType.RGB);
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
long start1 = System.currentTimeMillis();
Graphics2D g2d = (Graphics2D) graphics.create();
Paint paint = g2d.getPaint();
int width = this.image.getWidth();
int height = this.image.getHeight();
Shape shape = new Rectangle2D.Double(0, 0, width, height);
g2d.setPaint(createPaint(shape, StableUtils.isNotSupportARGB(g2d), image, width, height));
g2d.fill(shape);
g2d.setPaint(paint);
g2d.dispose();
long end1 = System.currentTimeMillis();
System.out.println("打印第 " + (pageIndex + 1) + "页 耗时 : " + (end1 - start1) +" 毫秒 ");
return Printable.PAGE_EXISTS;
}
private Paint createPaint(Shape shape, boolean isNotSupportARGB, BufferedImage image, int width, int height) {
Rectangle2D rec2D = shape.getBounds2D();
if ((int) rec2D.getWidth() <= 0) {
rec2D.setRect(rec2D.getX(), rec2D.getY(), rec2D.getWidth() + 40, rec2D.getHeight());
}
if ((int) rec2D.getHeight() <= 0) {
rec2D.setRect(rec2D.getX(), rec2D.getY(), rec2D.getWidth(), rec2D.getHeight() + 40);
}
BufferedImage buffered = new BufferedImage((int) rec2D.getWidth(), (int) rec2D.getHeight(), isNotSupportARGB ? BufferedImage.TYPE_INT_RGB : BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = buffered.createGraphics();
GraphHelper.paintImage(g2, (int) rec2D.getWidth(), (int) rec2D.getHeight(), image,
Constants.IMAGE_CENTER , Constants.LEFT, Constants.TOP, width, height, isNotSupportARGB);
g2.dispose();
return new TexturePaint(buffered, rec2D);
}
}
这一次print方法同样被执行了十几次, 但是每次也就十几毫秒, 文件很快就被打印出来了.
完整代码如下
package com.fr.base; import com.fr.stable.Constants;
import com.fr.stable.StableUtils;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.ImageType;
import org.apache.pdfbox.rendering.PDFRenderer; import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Shape;
import java.awt.TexturePaint;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.awt.print.Book;
import java.awt.print.PageFormat;
import java.awt.print.Paper;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
import java.awt.print.PrinterJob;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream; public class doStreamImagePrint { public static void main(String[] args) throws IOException, PrinterException {
PrinterJob job = PrinterJob.getPrinterJob(); int width = 595;
int height = 842;
int marginLeft = 0;
int marginRight = 0;
int marginTop = 0;
int marginBottom = 0; Paper paper = new Paper();
paper.setSize(width, height);
// 设置边距
paper.setImageableArea(marginLeft, marginRight, width - (marginLeft + marginRight), height - (marginTop + marginBottom));
// 自定义页面设置
PageFormat pageFormat = new PageFormat();
// 设置页面横纵向
pageFormat.setOrientation(PageFormat.PORTRAIT);
pageFormat.setPaper(paper); // 构建一个有size的空book, book里都是引用. 实际打印哪一页就从远程获取哪一页
Book printBook = new Book();
// 真正打印的时候, 每页的printable都new pdfprintable.print();
printBook.append(convertPDFToPrint("D:\\bg.pdf", 0), pageFormat);
printBook.append(convertPDFToPrint("D:\\bg.pdf", 0), pageFormat); job.setPageable(printBook);
job.print();
} private static FinePrintableDemo convertPDFToPrint(String path, int index) throws IOException {
InputStream in = new FileInputStream(path);
PDDocument document = PDDocument.load(in);
return new FinePrintableDemo(document, index);
} private static class FinePrintableDemo implements Printable { private BufferedImage image; public FinePrintableDemo(PDDocument document, int index) {
// 获取pdf文件, 将其中指定的页面转成图片.
PDFRenderer renderer = new PDFRenderer(document);
try {
this.image = renderer.renderImage(index, 1, ImageType.RGB);
} catch (IOException e) {
e.printStackTrace();
} } @Override
public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
long start1 = System.currentTimeMillis();
Graphics2D g2d = (Graphics2D) graphics.create();
Paint paint = g2d.getPaint(); int width = this.image.getWidth();
int height = this.image.getHeight(); Shape shape = new Rectangle2D.Double(0, 0, width, height);
g2d.setPaint(createPaint(shape, StableUtils.isNotSupportARGB(g2d), image, width, height));
g2d.fill(shape);
g2d.setPaint(paint);
g2d.dispose();
long end1 = System.currentTimeMillis();
System.out.println("打印第 " + (pageIndex + 1) + "页 耗时 : " + (end1 - start1) +" 毫秒 ");
return Printable.PAGE_EXISTS;
} private Paint createPaint(Shape shape, boolean isNotSupportARGB, BufferedImage image, int width, int height) {
Rectangle2D rec2D = shape.getBounds2D();
if ((int) rec2D.getWidth() <= 0) {
rec2D.setRect(rec2D.getX(), rec2D.getY(), rec2D.getWidth() + 40, rec2D.getHeight());
}
if ((int) rec2D.getHeight() <= 0) {
rec2D.setRect(rec2D.getX(), rec2D.getY(), rec2D.getWidth(), rec2D.getHeight() + 40);
}
BufferedImage buffered = new BufferedImage((int) rec2D.getWidth(), (int) rec2D.getHeight(), isNotSupportARGB ? BufferedImage.TYPE_INT_RGB : BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = buffered.createGraphics();
GraphHelper.paintImage(g2, (int) rec2D.getWidth(), (int) rec2D.getHeight(), image,
Constants.IMAGE_CENTER , Constants.LEFT, Constants.TOP, width, height, isNotSupportARGB); g2.dispose(); return new TexturePaint(buffered, rec2D);
}
} }