Java - 如何在沒有任何GUI或命令提示符彈出的情況下完全靜默地運行我的應用程序？

Question

我寫了這個打印應用程序，它是在Windows 8.1 64位上從Python27啓動的。我的問題是它的公共位置上的一個Kiosk，當Python27啓動Java時，它有一個帶有關閉圖標的Windows命令提示符（某些用戶單擊命令提示符處的關閉圖標並且作業未完成）

問題：無需在Kiosk中公開/彈出任何命令提示符，以靜默方式運行以下代碼？

import java.awt.print.PrinterException; 
import java.awt.print.PrinterJob; 
import java.io.File; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.net.URL; 
import javax.print.DocPrintJob; 
import javax.print.PrintService; 
import org.apache.pdfbox.pdmodel.PDDocument; 
import org.apache.pdfbox.printing.PDFPageable; 

public class JPrint { 

    public static boolean saveFile(URL url, String file) throws IOException { 
    boolean download_status = false; 

    System.out.println("[OK] - 1"); 
    InputStream in = url.openStream(); 
    FileOutputStream fos = new FileOutputStream(new File(file)); 
    System.out.println("[OK] - 2"); 
    int length = -1; 
    byte[] buffer = new byte[1024]; 

    while ((length = in.read(buffer)) > -1) { 
     fos.write(buffer, 0, length); 
    } 
    fos.close(); 
    in.close(); 

    download_status = true; 
    System.out.println("[OK] - 3"); 
    return download_status; 
    } 

    public static void main(String[] args) throws IOException, PrinterException { 
    String downloaded_filename = "C:/pdf.pdf"; 
    String download_pdf_from = "http://www.example.com/index/print?kiosk=1"; 
    String downloaded_filename_open_as_pdf = "C:\\pdf.pdf"; 
    String printerNameDesired = "HP Photosmart 5520 series"; 

    // Get printers 
    PrintService[] services = PrinterJob.lookupPrintServices(); 
    DocPrintJob docPrintJob = null; 
      for (int i = 0; i < services.length; i++) { 
      System.out.println(services[i]); 
      } 

    try{ 
     URL url = new URL(download_pdf_from); 

     if(saveFile(url, downloaded_filename)) { 
     try { 
      PDDocument pdf = PDDocument.load(new File(downloaded_filename_open_as_pdf)); 
      PrinterJob job = PrinterJob.getPrinterJob(); 
      for (int i = 0; i < services.length; i++) { 
      if (services[i].getName().equalsIgnoreCase(printerNameDesired)) { 
      docPrintJob = services[i].createPrintJob(); 
      } 
      } 

      job.setPrintService(docPrintJob.getPrintService()); 
      job.setPageable(new PDFPageable(pdf)); 
      //docPrintJob = service[i].createPrintJob(); 
      job.print(); 

     } catch (Exception e) { 
      System.out.println("[FAIL]" + e); 
     }  
     } else { 
     System.out.println("[FAIL] - download fail"); 
     }  
    } catch (Exception ae) { 
     System.out.println("[FAIL]" + ae); 
    } 


    } 
} 

Answer 1

更改您的Python代碼以使用「javaw」而不是「java」啓動Java應用程序。

請注意，這隻在Windows上需要。在其他平臺上，「java」命令不會啓動命令shell。

有關詳細信息，請參閱：

• Difference between java/javaw/javaws

• 甲骨文手冊頁在Windows上的 「java」 命令。

---

既然你是從Python中調用Java應用程序是這樣的：

Popen(['java', 
     '-cp', 
     'C:/Python27/pdfbox-app-2.0.0-RC3.jar;C:/Python27/jprint.jar', 
     'JPrint']) 

直進修複方法就是改變java到javaw;即

Popen(['javaw', 
     '-cp', 
     'C:/Python27/pdfbox-app-2.0.0-RC3.jar;C:/Python27/jprint.jar', 
     'JPrint']) 

@eryksun指出，就可以實現通過告訴Popen重寫應用程序的默認啓動的標誌同樣的目的;例如

DETACHED_PROCESS = 8 
Popen(['java', 
     '-cp', 
     'C:/Python27/pdfbox-app-2.0.0-RC3.jar;C:/Python27/jprint.jar', 
     'JPrint'], 
     creationflags=DETACHED_PROCESS)