如何访问打印机的状态？

看看这个PrinterStateReason。还有javax.print。

获取打印机的完整状态是不可能的。打印机有一个能够请求服务的本机驱动程序，但是因为有很多可能的打印机功能，Java 只支持它的一个子集。

您实际上可以通过调用让用户修改状态

PrinterJob pj = PrinterJob.getPrinterJob();
pj.printDialog()

它显示了本机打印机对话框。尽管 javax.print API 中的信息表明可以检查打印机状态，但我无法为我的打印机这样做！（佳能）。

检查代码：

import javax.print.*;
import javax.print.attribute.DocAttributeSet;
import javax.print.attribute.PrintServiceAttributeSet;
import javax.print.attribute.standard.PrinterStateReason;
import javax.print.attribute.standard.PrinterStateReasons;
import javax.print.attribute.standard.Severity;
import javax.print.event.*;
import java.awt.*;
import java.awt.print.PageFormat;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
import java.awt.print.PrinterJob;
import java.io.*;
import java.util.Set;

/**
 * PrintTest
 */
public class PrintTest implements PrintServiceAttributeListener,PrintJobListener,Doc, Printable, PrintJobAttributeListener {

  private static final transient String TEXT = "12345";

  public static void main(String[] args) {
    PrintTest test = new PrintTest();
    test.checkPrinters();
  }

  public void checkPrinters() {
    Thread newThread = new Thread(new Runnable() {
      public void run() {
    PrintService ps = PrinterJob.getPrinterJob().getPrintService();

    DocFlavor[] myFlavors = ps.getSupportedDocFlavors();
    ps.addPrintServiceAttributeListener(PrintTest.this);
    DocPrintJob docJob = ps.createPrintJob();
      docJob.addPrintJobAttributeListener(PrintTest.this, null);
    docJob.addPrintJobListener(PrintTest.this);
    try {
      docJob.print(PrintTest.this,null);
    }
    catch (PrintException e) {
      e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
    }
    } });

    newThread.start();
    /**
    PrintServiceAttributeSet attSet = ps.getAttributes();
    PrinterStateReasons psr = ps.getAttribute(PrinterStateReasons.class);

    if (psr != null) {
      Set<PrinterStateReason> errors = psr.printerStateReasonSet(Severity.REPORT);
      for (PrinterStateReason reason : errors)
        System.out.printf(" Reason : %s",reason.getName());
      System.out.println();
    }          */
  }

  public void attributeUpdate(PrintServiceAttributeEvent psae) {
    System.out.println(psae.getAttributes());
  }

  public void printDataTransferCompleted(PrintJobEvent pje) {
    System.out.println("Transfer completed");
  }

  public void printJobCompleted(PrintJobEvent pje) {
    System.out.println("Completed");
  }

  public void printJobFailed(PrintJobEvent pje) {
    System.out.println("Failed");
    PrinterStateReasons psr = pje.getPrintJob().getPrintService().getAttribute(PrinterStateReasons.class);
    if (psr != null) {
      Set<PrinterStateReason> errors = psr.printerStateReasonSet(Severity.REPORT);
      for (PrinterStateReason reason : errors)
        System.out.printf(" Reason : %s",reason.getName());
      System.out.println();
    }
  }

  public void printJobCanceled(PrintJobEvent pje) {
    System.out.println("Canceled");
  }

  public void printJobNoMoreEvents(PrintJobEvent pje) {
    System.out.println("No more events");
  }

  public void printJobRequiresAttention(PrintJobEvent pje) {
    System.out.println("Job requires attention");
    PrinterStateReasons psr = pje.getPrintJob().getPrintService().getAttribute(PrinterStateReasons.class);
    if (psr != null) {
      Set<PrinterStateReason> errors = psr.printerStateReasonSet(Severity.REPORT);
      for (PrinterStateReason reason : errors)
        System.out.printf(" Reason : %s",reason.getName());
      System.out.println();
    }
  }

  public DocFlavor getDocFlavor() {
    return DocFlavor.SERVICE_FORMATTED.PRINTABLE;  //To change body of implemented methods use File | Settings | File Templates.
  }

  public Object getPrintData() throws IOException {
    return this;
  }

  public DocAttributeSet getAttributes() {
    return null;  //To change body of implemented methods use File | Settings | File Templates.
  }

  public Reader getReaderForText() throws IOException {
    return null; //To change body of implemented methods use File | Settings | File Templates.
  }

  public InputStream getStreamForBytes() throws IOException {
    return null;  //To change body of implemented methods use File | Settings | File Templates.
  }

  public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
    return pageIndex == 0 ? PAGE_EXISTS : NO_SUCH_PAGE;  //To change body of implemented methods use File | Settings | File Templates.
  }

  public void attributeUpdate(PrintJobAttributeEvent pjae) {
    System.out.println("Look out");
  }
}

我试图通过故意打开箱子或取出纸张来获得 PrinterReasonsState，但我没有成功。也许其他人可以展示它是如何可能的，但到目前为止，API 似乎提供了更多实际上不可用的功能。

或者简而言之：它不起作用，至少不适用于我的打印机。

有人告诉我可以通过这种方式检查打印机状态：

PrintService printService = PrintServiceLookup.lookupDefaultPrintService();
AttributeSet attributes = printService.getAttributes();
String printerState = attributes.get(PrinterState.class).toString();
String printerStateReason = attributes.get(PrinterStateReason.class).toString();

System.out.println("printerState = " + printerState); // May be IDLE, PROCESSING, STOPPED or UNKNOWN
System.out.println("printerStateReason = " + printerStateReason); // If your printer state returns STOPPED, for example, you can identify the reason 

if (printerState.equals(PrinterState.STOPPED.toString()) {

    if (printerStateReason.equals(PrinterStateReason.TONER_LOW.toString()) {

        System.out.println("Toner level is low.");
    }
}

遗憾的是，我的打印机似乎不支持 printerState，因此我无法对其进行测试。

更新： 我建议不要像这样直接使用 Powershell，而不是查询 WMI“win32_printer”对象，它的 API 更简洁：

Get-Printer | where PrinterStatus -like 'Normal' | fl

查看所有打印机和状态：

Get-Printer | fl Name, PrinterStatus

要查看所有属性：

Get-Printer | fl

您仍然可以在 Java 中使用 ProcessBuilder，如下所述。

更新前：

仅适用于 Windows 的解决方案。在 Windows 中，您可以查询 WMI "win32_printer" 类，因此您可以检查 OS 层上的状态：Win32_Printer 类

在 Java 中，您可以像这样使用 ProcessBuilder 来启动 PowerShell 并像这样执行 PS 脚本：

String printerName = "POS_PRINTER";
ProcessBuilder builder = new ProcessBuilder("powershell.exe", "get-wmiobject -class win32_printer | Select-Object Name, PrinterState, PrinterStatus | where {$_.Name -eq '"+printerName+"'}");

String fullStatus = null;
Process reg;
builder.redirectErrorStream(true);
try {
    reg = builder.start();
    fullStatus = getStringFromInputStream(reg.getInputStream());
    reg.destroy();
} catch (IOException e1) {
    // TODO Auto-generated catch block
    e1.printStackTrace();
}
System.out.print(fullStatus);

将 InputStream 转换为 String 后，您应该得到如下内容：

Name        PrinterState PrinterStatus
----        ------------ -------------
POS_PRINTER            0             3

State 和 Status 应该在各种情况下发生变化（打印机关闭、缺纸、盖子打开……）。

这应该有效，但取决于打印机和驱动程序。我将它与带有 ESDPRT 端口的 EPSON TM 打印机一起使用，我可以获得如下信息：无纸、盖子打开、打印机离线/关闭、打印机暂停。

更全面的答案在这里： -我在类似问题上的 StackOverflow 回答。