Java连接打印机，打印文件夹的所有图片，最后一张图打不出来就使打印机下载固件中

Question

问题遇到的现象和发生背景

package com.company;

import javax.print.*;
import javax.print.attribute.HashDocAttributeSet;
import javax.print.attribute.HashPrintRequestAttributeSet;
import javax.print.attribute.PrintRequestAttributeSet;
import javax.print.attribute.Size2DSyntax;
import javax.print.attribute.standard.*;
import javax.print.event.PrintJobEvent;
import javax.print.event.PrintJobListener;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.Locale;
import java.util.concurrent.TimeUnit;

public class Main {
    private static long j = 1;

    /**
     * 图片路径
     * @param picPath
     */
    public static void  printer(String picPath) {
        // 构建打印请求属性集
        DocFlavor flavor = DocFlavor.INPUT_STREAM.AUTOSENSE;
        // 设置打印格式
        PrintRequestAttributeSet pras = new HashPrintRequestAttributeSet();
        // 查找所有的打印服务
        PrintService[] printServices = PrintServiceLookup.lookupPrintServices(flavor, pras);
        // 这里直接用第一个
        PrintService printService = printServices[0];
        String printName = printService.getName();
        // 判断当前打印机状态
//        Winspool.PRINTER_INFO_2 printerInfo2 = WinspoolUtil.getPrinterInfo2(printName);
//        if (printerInfo2.Status != 0) {
//            return;
//        }
        File picFile = new File(picPath);
        if (!picFile.exists() || !picFile.isFile()) {
            return ;
        }
        PrintService printer = PrintServiceLookup.lookupDefaultPrintService();
        Media[] objs = (Media[]) printer.getSupportedAttributeValues(Media.class, null, null);
        for (Media obj : objs) {
            if (obj instanceof MediaSizeName) {
                System.out.println("纸张型号：" + obj);
            } else if (obj instanceof MediaTray) {
                System.out.println("纸张来源：" + obj.getName());
            }
        }
        String fileName = picFile.getName();
        // 获取图片后缀名，设置打印文件格式
        String suffix = fileName.substring(fileName.lastIndexOf(".") + 1);
        switch (suffix) {
            case "jpg":
            case "jpeg":
                flavor = DocFlavor.INPUT_STREAM.JPEG;
                break;
            case "png":
                flavor = DocFlavor.INPUT_STREAM.PNG;
                break;
            case "pdf":
                flavor = DocFlavor.INPUT_STREAM.PDF;
                break;
            case "gif":
                flavor = DocFlavor.INPUT_STREAM.GIF;
            default:
                break;
        }
        // 设置打印文件名
        pras.add(new JobName(fileName, Locale.CHINA));
        // 设置打印方向
        pras.add(OrientationRequested.LANDSCAPE);
        // 设置打印区域
        MediaPrintableArea mp = new MediaPrintableArea(0, 0, 500 , 900, Size2DSyntax.MM);
        pras.add(mp);
        try {
            FileInputStream fis = new FileInputStream(picFile);
            HashDocAttributeSet das = new HashDocAttributeSet();

            for (long i = 0; i < j; i++) {
                // 使用打印服务生成打印任务
                DocPrintJob job = printService.createPrintJob();
                // 获取需要打印的文档类doc
                SimpleDoc doc = new SimpleDoc(fis, flavor, das);
                // 监听打印任务
                job.addPrintJobListener(new PrintJobListener() {
                    @Override
                    public void printDataTransferCompleted(PrintJobEvent pje) {
                        System.out.println("成功发送任务：" + fileName);
                    }

                    @Override
                    public void printJobCompleted(PrintJobEvent pje) {
                        System.out.println("打印任务完成！");
                    }

                    @Override
                    public void printJobFailed(PrintJobEvent pje) {
                        System.out.println("打印任务失败：" + fileName);
                    }

                    @Override
                    public void printJobCanceled(PrintJobEvent pje) {
                        System.out.println("取消打印任务！");
                    }

                    @Override
                    public void printJobNoMoreEvents(PrintJobEvent pje) {
                        System.out.println("没有更多方法提供打印机调用！");
                    }

                    @Override
                    public void printJobRequiresAttention(PrintJobEvent pje) {
                        System.out.println("纸张已用完");
                    }
                });
                job.print(doc, pras);

            }
        } catch (PrintException e) {
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
    public static void main(String[] args) throws InterruptedException {
        File file = new File("pic");
        File[] files = file.listFiles();
        for (int i = 0; i < files.length; i++) {
            String url = "pic/"+files[i].getName();
            System.out.println(url);
            printer(url);
            TimeUnit.SECONDS.sleep(4);//秒
        }
    }
}

运行结果及报错内容

我的解答思路和尝试过的方法

我想要达到的结果

Answer 1

有啥问题？