如何使用javafx8在打印机图像上打印

Question

I have object of javafx.scene.image.Image class. How can I print it on printer using javafx8? Please, note, that I don't want to print some node, for example ImageView. I need to print image. Although it's very simple question I can't find answer in internet. The only code I found is:

PrinterJob job = PrinterJob.createPrinterJob();
if (job != null) {
boolean success = job.printPage(node);
if (success) {
job.endJob();
}
}

However it is about printing the node.

Answer 1

Problem

javafx.print. PrinterJob only prints Node and it's subclasses. Image isn't a subclass of Node. So you have to wrap it in a Node (ImageView) or print from plain Java.

Difference of JavaFX-PrinterJob and AWT-PrinterJob

The main difference is, that the JavaFX PrinterJob was introduced for usage with Node objects. It has set some usefull things as a JavaFX Property like the Jobstatus or the Printer itself. And it is more thread safe as the older AWT PrinterJob. The AWT PrinterJob can print mostly anything you want like Strings, Images, Arc's, etc., because it takes an AWT Graphics Object to draw things on the page.

Solution

Before you can use the plain Java solution, you have to convert your FX-Image to a BufferedImage with SwingFXUtils.fromFXImage() . But there is a bug with *.jpg Files, as described here: https://stackoverflow.com/a/30995307/4170073

The Minimal, Complete, and Verifiable example down below shows a working solution:

import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.awt.print.PageFormat;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
import java.awt.print.PrinterJob;
import javafx.application.Application;
import javafx.embed.swing.SwingFXUtils;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.image.Image;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class ImagePrinter extends Application {

  @Override
  public void start(Stage primaryStage) {

    Image image = new Image("http://www.gnu.org/graphics/gnu-head.png");
    BufferedImage bufferedImage = SwingFXUtils.fromFXImage(image, null);

    Button btn = new Button();
    btn.setText("Print Image");
    btn.setOnAction(new EventHandler<ActionEvent>() {

      @Override
      public void handle(ActionEvent event) {
        printImage(bufferedImage);
      }
    });

    StackPane root = new StackPane();
    root.getChildren().add(btn);

    Scene scene = new Scene(root, 300, 250);

    primaryStage.setTitle("Image Printer");
    primaryStage.setScene(scene);
    primaryStage.show();
  }

  /**
   * @param args the command line arguments
   */
  public static void main(String[] args) {
    launch(args);
  }

  private void printImage(BufferedImage image) {
    PrinterJob printJob = PrinterJob.getPrinterJob();
    printJob.setPrintable(new Printable() {
      @Override
      public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
        // Get the upper left corner that it printable
        int x = (int) Math.ceil(pageFormat.getImageableX());
        int y = (int) Math.ceil(pageFormat.getImageableY());
        if (pageIndex != 0) {
          return NO_SUCH_PAGE;
        }
        graphics.drawImage(image, x, y, image.getWidth(), image.getHeight(), null);
        return PAGE_EXISTS;
      }
    });
    try {
      printJob.print();
    } catch (PrinterException e1) {
      e1.printStackTrace();
    }
  }
}