java - 如何关闭 PDF 文件以重新创建它？ (正在使用的文件)

Question

我有可以创建 PDF 文件的 Java 应用程序。因此，例如，我从我的程序创建了一个简单的文件，我已经构建了打开该文件的代码。所以我创建了文件，我看到了它，然后就可以了。如果我想修改那个文件，我必须关闭这个文件然后重新创建它，如果我不关闭这个文件我有这个错误:

java.io.FileNotFoundException: Archivio_Etichette\_12-4-2015.pdf (Impossibile accedere al file. Il file è utilizzato da un altro processo)
    at java.io.FileOutputStream.open(Native Method)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:171)
    at com.mcsolution.easyMgmt.print.pdf.FoglioFattura.stampaEtichette(FoglioFattura.java:2215)
    at Etichette.PanelBigliettiAdesivi.stampaEtichette(PanelBigliettiAdesivi.java:242)
    at Etichette.PanelBigliettiAdesivi$1.actionPerformed(PanelBigliettiAdesivi.java:273)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
    at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
    at java.awt.Component.processMouseEvent(Component.java:6516)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3320)
    at java.awt.Component.processEvent(Component.java:6281)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4872)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4698)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4698)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:694)
    at java.awt.EventQueue$3.run(EventQueue.java:692)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:708)
    at java.awt.EventQueue$4.run(EventQueue.java:706)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

这是我用来创建PDF的代码

public static void stampaEtichette(String percorsoOperazione, 
            List<Articoli>listaArticoli,
            Integer numeroCella,boolean aprire)throws DocumentException
{
    String folderName = DateUtil.getDataGiornaliera();
    percorsoOperazione = (new StringBuilder()).append(percorsoOperazione).append(""+"_"+folderName).append(".pdf").toString();
    File f = new File(percorsoOperazione);
    try {

        OutputStream os = new FileOutputStream(f);
        Document doc = new Document(PageSize.A4, -74F, -74F, 0F, 0F);
        PdfWriter docWriter = PdfWriter.getInstance(doc, os);
        //  String testo = "Anagrafica Clienti";
        doc.open();
        float[] ciccio = {25f,25f,25f,25f};
        PdfPTable table = new PdfPTable(ciccio);
        table.setSpacingAfter(0f);
        table.setSpacingBefore(0f);

        PdfContentByte cb = docWriter.getDirectContent();
        if(numeroCella!=null){
            for(int i=1; i< numeroCella;i++){
                Paragraph Descrizione = new Paragraph("", FontFactory.getFont("Century Gothic", 7F, Font.BOLD));
                Paragraph Costo = new Paragraph("", FontFactory.getFont("Century Gothic", 10F, Font.BOLD));

                PdfPCell cell = new PdfPCell();
                cell.setVerticalAlignment(5);
                cell.setHorizontalAlignment(1);
                cell.setColspan(1);
                cell.setFixedHeight(84.1F); 
                cell.setBorderWidth(0.0F);
                cell.setPadding(0F);

                Descrizione.setAlignment(1);
                cell.addElement(Descrizione);

                Costo.setAlignment(1);
                cell.addElement(Costo);

                table.addCell(cell);
            }
        }


        doc.add(table);
        doc.close();
        os.close();

    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    catch(IOException exp)
    {
        exp.printStackTrace();
    }
    catch(DocumentException exp2)
    {
        exp2.printStackTrace();
    }

    if(aprire)
    {
        if(Desktop.isDesktopSupported())
        {
            try
            {
                Desktop.getDesktop().open(f.getCanonicalFile());
            }
            catch(IOException ex)
            {
                JOptionPane.showMessageDialog(null, ex.getMessage());
            }
        } else
        {
            JOptionPane.showMessageDialog(null, "Non è stato trovato un software per aprire i file PDF.", "Errore", 0);
        }
    }

    //  return pathimg;

}//fine stampa etichette

错误在这一行

OutputStream os = new FileOutputStream(f);

我该如何解决？

Answer 1

您需要关闭文件。该问题类似于尝试删除或重命名打开的文件:如果您在 Windows 上工作，Windows 将显示此错误:

您遇到了完全相同的问题:在这种情况下，我尝试在 Windows 资源管理器中重命名名为 hello.pdf 的文件。但是，此操作无法完成，因为该文件已在 Adob​​e Acrobat 中打开。 Adobe Reader 和 Adob​​e Acrobat 等工具需要对文件进行随机文件访问，因此将锁定该文件，以便其他进程无法删除、重写、重命名该文件。

解决方案也显示在对话框中:关闭文件并重试。您正在尝试做一些不可能的事情(并且这与您使用 iText 无关或不限于您)。

注意

在处理 iText 项目时，我遇到了您经常描述的相同问题:我编写了一些代码，运行它，查看生成的 PDF，更改代码，运行它，然后遇到相同的异常。为了避免这种情况，我经常创建名称中包含时间戳的文件。例如。 hello-20150411163400.pdf，然后当我在 30 秒后运行相同的代码时 hello-20150411163430.pdf 等等(文件名是根据当前日期和时间)。这样，我就可以避免该异常。