Java 打印机监听器：将打印内容保存为 PDF 文件

要持续监听打印机并将文件保存为PDF文件，可以使用Java SE中的javax.print包和iText库。\n\n首先，你需要创建一个PrintService实例来表示要监听的打印机。你可以使用PrintServiceLookup类的静态方法lookupPrintServices来获取可用的打印机列表，然后选择你要监听的打印机。\n\n下面是一个示例代码：\n\njava\nimport javax.print.*;\nimport java.io.FileOutputStream;\nimport com.itextpdf.text.*;\nimport com.itextpdf.text.pdf.*;\n\npublic class PrinterListenerExample {\n\n public static void main(String[] args) throws Exception {\n // 获取可用的打印机列表\n PrintService[] printServices = PrintServiceLookup.lookupPrintServices(null, null);\n \n // 选择要监听的打印机\n PrintService printer = null;\n for (PrintService printService : printServices) {\n if (printService.getName().equals("Your Printer Name")) {\n printer = printService;\n break;\n }\n }\n \n if (printer == null) {\n System.out.println("无法找到要监听的打印机");\n return;\n }\n \n // 创建一个PrintServiceWatcher实例来监听打印事件\n PrintServiceWatcher watcher = new PrintServiceWatcher(printer);\n \n // 启动监听\n watcher.start();\n \n // 等待打印事件\n Thread.sleep(10000);\n \n // 停止监听\n watcher.stop();\n }\n}\n\nclass PrintServiceWatcher {\n\n private PrintService printer;\n private DocPrintJob printJob;\n\n public PrintServiceWatcher(PrintService printer) {\n this.printer = printer;\n }\n\n public void start() throws PrintException {\n // 创建一个打印任务\n printJob = printer.createPrintJob();\n \n // 添加打印事件监听器\n printJob.addPrintJobListener(new PrintJobAdapter() {\n @Override\n public void printDataTransferCompleted(PrintJobEvent event) {\n try {\n // 获取打印数据\n DocPrintJob job = event.getPrintJob();\n DocPrintData printData = job.getPrintData();\n \n // 将打印数据保存为PDF文件\n saveAsPDF(printData);\n } catch (Exception e) {\n e.printStackTrace();\n }\n }\n });\n }\n\n public void stop() {\n // 移除打印事件监听器\n printJob.removePrintJobListener(printJob.getPrintJobListeners()[0]);\n }\n\n private void saveAsPDF(DocPrintData printData) throws Exception {\n // 创建PDF文档对象\n Document document = new Document();\n \n // 创建PDF输出流\n PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("output.pdf"));\n \n // 打开文档\n document.open();\n \n // 将打印数据写入PDF文档\n document.add(new Paragraph(printData.toString()));\n \n // 关闭文档\n document.close();\n \n // 关闭PDF输出流\n writer.close();\n }\n}\n\n\n请注意，上述代码中的"Your Printer Name"处应该替换为你要监听的打印机的名称。\n\n此代码将打印事件监听器添加到PrintService实例的打印任务中，当打印任务完成时，会将打印数据保存为名为"output.pdf"的PDF文件。\n\n希望这可以帮助到你！