如何使用 iText 添加每页的总页码？

https://stackoverflow.com/questions/759909

java
itext

09-09-2019
|

题

如何用iText添加每页的总页数？

解决方案

处理a的输出 PdfWriter 到一个 bytestream 首先是虚拟页数。
创建一个 PdfReader 从那 bytestream, 呼叫 PdfReader.getNumberOfPages 获取实际页数。
重新创建 PDF 输出，了解页数，并相应地更改页脚。

这很混乱，但如果不采用两次方法，就没有简单的方法可以知道页数。请参阅示例代码有关操作 PDF 的详细信息。

其他提示

可以创建从PdfPageEventHelper继承的类然后覆盖论文两个功能是这样的：

Imports System.Collections.Generic
Imports System.Text

Imports iTextSharp.text.pdf
Imports iTextSharp.text

Namespace PDF_EnteteEtPiedDePage
    Public Class EnteteEtPiedDePage
        Inherits PdfPageEventHelper
        ' This is the contentbyte object of the writer
        Private cb As PdfContentByte

        ' we will put the final number of pages in a template
        Private template As PdfTemplate

        ' this is the BaseFont we are going to use for the header / footer
        Private bf As BaseFont = Nothing

        ' This keeps track of the creation time
        Private PrintTime As DateTime = DateTime.Now

        ' we override the onOpenDocument method
        Public Overrides Sub OnOpenDocument(writer As PdfWriter, document As Document)
            Try
                PrintTime = DateTime.Now
                bf = BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED)
                cb = writer.DirectContent
                template = cb.CreateTemplate(50, 50)
            Catch de As DocumentException
            Catch ioe As System.IO.IOException
            End Try
        End Sub

        Public Overrides Sub OnStartPage(writer As PdfWriter, document As Document)
            MyBase.OnStartPage(writer, document)

            Dim pageSize As Rectangle = document.PageSize

        End Sub

        Public Overrides Sub OnEndPage(writer As PdfWriter, document As Document)
            MyBase.OnEndPage(writer, document)

            Dim pageN As Integer = writer.PageNumber
            Dim text As [String] = "Page " & pageN & " de "
            Dim len As Single = bf.GetWidthPoint(text, 8)

            Dim pageSize As Rectangle = document.PageSize

            cb.SetRGBColorFill(100, 100, 100)

            cb.BeginText()
            cb.SetFontAndSize(bf, 8)
            cb.SetTextMatrix(pageSize.GetLeft(40), pageSize.GetBottom(30))
            cb.ShowText(text)
            cb.EndText()

            cb.AddTemplate(template, pageSize.GetLeft(40) + len, pageSize.GetBottom(30))

            cb.BeginText()
            cb.SetFontAndSize(bf, 8)
            cb.ShowTextAligned(PdfContentByte.ALIGN_RIGHT, "Imprimé le : " & PrintTime.ToShortDateString() & " à " & PrintTime.ToShortTimeString, pageSize.GetRight(40), pageSize.GetBottom(30), 0)
            cb.EndText()
        End Sub

        Public Overrides Sub OnCloseDocument(writer As PdfWriter, document As Document)
            MyBase.OnCloseDocument(writer, document)

            template.BeginText()
            template.SetFontAndSize(bf, 8)
            template.SetTextMatrix(0, 0)
            template.ShowText("" & Convert.ToString((writer.PageNumber - 1)))
            template.EndText()
        End Sub

    End Class
End Namespace

然后后，仅仅设定pdfwriter PageEvent的值是这样的：

Dim PageEventHandler = New EnteteEtPiedDePage()
            aPdfWriter.PageEvent = PageEventHandler

没有更多的搜索，这里是解决方案。如果他们删除此链接，我将代码发布到我的网站和主机的链接。

iText的页码例如

下面是我使用的代码。它不会增加太多的开销编写的页面输出。

outputStream = new ByteArrayOutputStream();
output = new DataOutputStream(outputStream);
document = new Document();
writer = PdfWriter.getInstance(document, output);
document.open();
contentByte = writer.getDirectContent();
....add stuff
document.close();
writer.close();
byte[] output = outputStream.toByteArray();
PdfReader reader = new PdfReader(output);
//reset the output
outputStream = new ByteArrayOutputStream();
output = new DataOutputStream(outputStream);
document = new Document();
writer = PdfWriter.getInstance(document, output);
document.open();
PdfStamper stamper = new PdfStamper(reader, outputStream);
//add the pages
for (int i = 1; i <= pageCount; i++)
{
    contentByte = stamper.getOverContent(i);
    addParagraph("Page " + i + " of " + pageCount, new Point(500, 30), boldTextFont);  // my own paragraph font
}
stamper.close();

这是一个快速的网络搜索，以提醒自己此;看一看

实施例

在相关方法onEndPage()产生的“X”和onCloseDocument()以产生“Y”，一旦你命中文档的末尾。

下面是一个方便的功能！（上米尔豪斯的做法基于）（这使用iText的版本4.1.6.0）

public static byte[] AddPageNumbers(byte[] pdf)
        {
            PdfReader reader = new PdfReader(pdf);
            var Pages = reader.NumberOfPages;
            MemoryStream ms = new MemoryStream();

            PdfStamper stamper = new PdfStamper(reader, ms);
            for (int i = 1; i <= Pages; i++)
            {
                PdfContentByte overContent;
                Font Signature = FontFactory.GetFont("Calibiri", 9, iTextSharp.text.Font.NORMAL, Color.BLACK);
                overContent = stamper.GetOverContent(i);
                var helv = BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.WINANSI, BaseFont.NOT_EMBEDDED);
                overContent.SaveState();
                overContent.BeginText();
                overContent.SetFontAndSize(helv, 10.0f);
                overContent.SetTextMatrix(PageSize.LETTER.Width / 2 - 20, PageSize.LETTER.Height - (PageSize.LETTER.Height - 20));
                overContent.ShowText("Page " + (i) + " of " + Pages);
                overContent.EndText();
                overContent.RestoreState();
            }
            stamper.Close();            
            return ms.ToArray();
        }

试试这个，因为我也是从这个痛苦，我也有新的这个库中，以便以后很多的麻烦，我得到的结果仅仅只尝试，因为我在评论中提到的应用逻辑的两倍。

class PdfReportServlet extends HttpServlet
{
    public static int total = 0;

    public static int getTotal() 
    {
        return total;
    }

    public static void setTotal(int total) {
        PdfReportServlet .total = total;
    }


    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
    {
        String reportFor = request.getParameter("report");
        if(!"".equals(reportFor))
        {
            if(reportFor.equals("pdf"))
            {
    /* 
       from here logic starts
    */
                response.setContentType("application/pdf");
                Document document = new Document(PageSize.LETTER.rotate());
                try
                {
                    ByteArrayOutputStream bos = new ByteArrayOutputStream();
                    PdfWriter pdfWriter = PdfWriter.getInstance(document, bos);
                    PdfReport pdfReport = new PdfReport();
                    pdfWriter.setPageEvent(pdfReport);
                    document.open();
                    String id = request.getParameter("id");
                    DettagliFamigliaPDFReport.generatePDFReport(document,id);
                    document.close();

                    /*
                     * now again give new references to Document and PdfWriter classes.
                     */

                    document = new Document(PageSize.LETTER.rotate());

                    pdfWriter = PdfWriter.getInstance(document, response.getOutputStream());
                    PDFReport.setTotalPages(getTotal());/*##PAGES_TOTAL here i set total Pages which i get from above logic */
                    PdfReport pdfReport = new PdfReport();
                    pdfWriter.setPageEvent(pdfReport);
                    document.open();
                    id = request.getParameter("id");
                    PDFReport.generatePDFReport(document,id);
                    document.close();

                }
                catch(DocumentException de){
                    de.printStackTrace();
                }
                catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }


}


/*
    Here below i write the class inherits the PdfPageEventHelper class and also having generatePDFReport() method.
*/


public class PDFReport extends PdfPageEventHelper
{
    public static PdfTemplate template;
    public static int totalPages=0;

    public static int getTotalPages() {
        return totalPages;
    }

    public static void setTotalPages(int totalPages) {
        DettagliFamigliaPDFReport.totalPages = totalPages;
    }


    public static void generatePDFReport(Document document,String id)
    {
        // here your data to write on page of pdf.
    }

    @Override
    public void onOpenDocument(PdfWriter writer, Document doc) 
    {
        template = writer.getDirectContent().createTemplate(100, 100);
    }

    int totalPage = 0;
    @Override
    public void onCloseDocument(PdfWriter writer, Document doc) 
    {
        totalPage = writer.getPageNumber() - 1;/* at the end this method calls and you will get total number of pages.*/
        PdfReportServlet.setTotal(totalPage); /* while first time logic of servlet executes then i set the total pages to servlet's variable using this logic.
and second time servlet's logic is executing i passed totalPages to this class variable
where i marked ##PAGES_TOTAL  */
    }

    @Override
    public void onStartPage(PdfWriter writer, Document doc) {
        // Here i write header logic when each time page starts.
    }

    @Override`enter code here`
    public void onEndPage(PdfWriter writer, Document doc) 
    {
        Rectangle rect = writer.getPageSize();
        float width = rect.getWidth()/2;   

        DateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
        Date date = new Date();

        String footerOne = "This document is printed on date "+dateFormat.format(date)+" - Page. "+writer.getPageNumber()+" of "+getTotalPages();

        Paragraph paraOne = new Paragraph(footerOne);

        Font fontFooter = new Font();
        fontFooter.setSize(8);
        fontFooter.setColor(Color.gray);

        paraOne.setFont(fontFooter);

        Phrase footerPhraseOne = new Phrase(paraOne);
        ColumnText.showTextAligned(writer.getDirectContent(),
                Element.ALIGN_CENTER, footerPhraseOne,
                width, 30, 0);
    }
}

这是您的代码片段：

final PdfWriter writer = PdfWriter.getInstance(document, outputStream);
writer.setPageEvent(new PageStamper());

以及编号代码：

import com.itextpdf.text.*;
import com.itextpdf.text.pdf.*;
import com.itextpdf.tool.xml.*;
import com.itextpdf.tool.xml.css.*;

import java.io.IOException;

/**
 * Adds page number to al the pages except the first.
 */
public class PageStamper extends PdfPageEventHelper {
    private static final Logger logger = Logger.getLogger(PageStamper.class);

    @Override
    public void onEndPage(PdfWriter writer, Document document) {
        final int currentPageNumber = writer.getCurrentPageNumber();

        if (currentPageNumber == 1) {
            return;
        }

        try {
            final Rectangle pageSize = document.getPageSize();
            final PdfContentByte directContent = writer.getDirectContent();

            directContent.setColorFill(BaseColor.GRAY);
            directContent.setFontAndSize(BaseFont.createFont(), 10);

            directContent.setTextMatrix(pageSize.getRight(40), pageSize.getBottom(30));
            directContent.showText(String.valueOf(currentPageNumber));

        } catch (DocumentException | IOException e) {
            logger.error("PDF generation error", e);
        }
    }
}

这段代码在这里找到： http://blog.abelsky.com/2014/01/22/adding-page-number-to-itext- generated-pdf/. 。非常感谢你，andy722

至于其他的答案表明，你首先需要创建PDF，然后看你创建的PDF多少页包含然后页脚添加到每个页面。理想的类做，这是PdfStamper，其目的是为了附加元素添加到现有的PDF /现有的PDF页面。

下面是一种基于米尔豪斯的例子的详细的示例：

Font smallFont = FontFactory.getFont("Arial", 9, Font.NORMAL);
ByteArrayOutputStream pdfOutputStream = new ByteArrayOutputStream();
Document document = new Document(PageSize.A4, 70, 70, 40, 40);
PdfWriter pdfWriter = PdfWriter.getInstance(document, pdfOutputStream);

document.open();
//CREATE PDF HERE - ADD CONTENT TO DOCUMENT
document.close();

int pageCount = pdfWriter.getPageNumber()-1;
byte[] pdfAsBytes = pdfOutputStream.toByteArray();

//add footer
PdfReader reader = new PdfReader(pdfAsBytes);
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
DataOutputStream output = new DataOutputStream(outputStream);
document = new Document();
document.open();
PdfStamper stamper = new PdfStamper(reader, output);
for (int i = 1; i <= pageCount; i++) {
  ColumnText.showTextAligned(stamper.getOverContent(i), 
    Element.ALIGN_CENTER, new Phrase(i+"/" + pageCount, smallFont), 550, 30, 0);
}
stamper.close();
byte[] finalPdfAsBytes = outputStream.toByteArray();

这是在Java中转换的拉马码（它的一部分至少）

public class test extends PdfPageEventHelper{
    private int _pg = 0;
    private BaseFont font;

    @Override
    public void onEndPage(PdfWriter writer, Document document) {
        _pg++;
        PdfContentByte cb = writer.getDirectContent();
        cb.beginText();
        try {
            Rectangle pageSize = document.getPageSize();
            cb.setFontAndSize(font, 8);
            cb.setTextMatrix(pageSize.getLeft(40), pageSize.getBottom(15));
            String s = "Page " + _pg + "/";
            cb.showText(s);
            cb.addTemplate(template, pageSize.getLeft(40) + font.getWidthPoint(s, 8), pageSize.getBottom(15));
        } catch (Exception exc) {
            logger.warn("got Exception : " + exc.getMessage());
        }
        cb.endText();
    }

    @Override
    public void onOpenDocument(PdfWriter writer, Document document) {
        super.onOpenDocument(writer, document);
        template = writer.getDirectContent().createTemplate(50, 50);
        try {
            font = BaseFont.createFont(BaseFont.COURIER, BaseFont.WINANSI, BaseFont.NOT_EMBEDDED);
        } catch (Exception exc) {
            logger.warn("got Exception : " + exc.getMessage());
        }
    }

    @Override
    public void onCloseDocument(PdfWriter writer, Document document) {
        super.onCloseDocument(writer, document);

        template.beginText();
        try {
            template.setFontAndSize(font, 8);
            template.setTextMatrix(0f, 0f);
            template.showText("" + (writer.getPageNumber() - 1));
        } catch (Exception ex) {
            logger.error(ex);
        }
        template.endText();
    }

}

经过两天的努力！我最终得到的页面总数的PDF计数。其实我的客户要求是为了显示页脚只有PDF的最后一页上。这就是我这样做，希望这将帮助有前途。第1步：创建新类，将继承的 PdfPageEventHelper 就这样。

public class ITextEvents : PdfPageEventHelper
{
public int pageNos { get; set; }

/// <summary>
/// CALLED ON EACH PAGE END PAGE, 
/// </summary>
/// <param name="writer"></param>
/// <param name="document"></param>
public override void OnEndPage(iTextSharp.text.pdf.PdfWriter writer, iTextSharp.text.Document document)
{
//LOGIC: TO SHOW DISCLAIMER ONLY ON LAST PAGE
if (document.PageNumber == pageNos)
{
//Create new Paragraph
Paragraph p = new Paragraph();
//ADD CHUNK IN PARAGRAPH
p.Add(new Chunk("Heading-Text: ", FontFactory.GetFont("Calibri",11,Font.BOLD)));
p.Add(new Chunk("Details sow in footer", FontFactory.GetFont("Calibri", 10)));
//PARAGRAPH TEXT ALIGNMENT. 
p.Alignment = Element.ALIGN_LEFT;
//CREATE PDF TABLE, FOR ADDING NEW CELL AND ROW IN THE PDF
PdfPTable footerTbl = new PdfPTable(1);
//SETING TABLE WIDTH
footerTbl.TotalWidth = 580;
footerTbl.HorizontalAlignment = Element.ALIGN_LEFT;
//ADDING CELL IN THE TABLE
PdfPCell cell = new PdfPCell(p);
//CELL LAYOUT DESIGN
cell.Border = 1;
cell.PaddingLeft = 10;
cell.PaddingRight = 10;
footerTbl.AddCell(cell);
//ADDING TABLE IN THE PDF
footerTbl.WriteSelectedRows(0, -1, 10, 110, writer.DirectContent);
}
}

/// <summary>
/// THIS METHOD WILL GET TOTAL PDF PAGES COUNT,
/// REQUIREMENT OF THIS METHOD WAS IS TO SHOW FOOTER ON LAST PAGE IN THE PDF. 
/// </summary>
/// <param name="HistoryHTML"></param>
/// <param name="Name"></param>
/// <param name="filePath"></param>
/// <returns></returns>
public int GetTotalPageCount(string HistoryHTML, String Name, string filePath)
{
try
{
using (MemoryStream stream = new System.IO.MemoryStream())
{
StringReader sr = new StringReader(HistoryHTML);
Document pdfDoc = new Document(PageSize.A4, 30f, 30f, 30f, 90f);
PdfWriter writer = PdfWriter.GetInstance(pdfDoc, stream);
pdfDoc.Open();
XMLWorkerHelper.GetInstance().ParseXHtml(writer, pdfDoc, sr);
pdfDoc.Close();

bool exists = System.IO.Directory.Exists(filePath);
if (!exists)
    System.IO.Directory.CreateDirectory(filePath);
System.IO.File.WriteAllBytes((filePath + @"\FileName-" + Name + ".pdf"), stream.ToArray());

string path = AppDomain.CurrentDomain.BaseDirectory + @"FolderPath\" + "FileName-" + Name + ".pdf";

PdfReader pdfReader = new PdfReader(path);
int numberOfPages = pdfReader.NumberOfPages;
pdfReader.Close();
stream.Close();
return numberOfPages;

}
}
catch (Exception ex)
{
CommonFunction.logElmahError(ex);
}
return -1;
}
}

在从流产生pdf文件，调用此方法以获得总页数。

int pageCount = new Common.ITextEvents().GetTotalPageCount(HistoryHTML, Name, Server.MapPath("~/FolderPath"));

为了更好地理解我提供控制器端代码。

public string ExportPDF(string HistoryHTML, String Name)
        {
            int pageCount = new Common.ITextEvents().GetTotalPageCount(HistoryHTML, Name, Server.MapPath("~/FolderPath"));

            using (MemoryStream stream = new System.IO.MemoryStream())
            {
                StringReader sr = new StringReader(HistoryHTML);
                Document pdfDoc = new Document(PageSize.A4, 30f, 30f, 30f, 30f);
                PdfWriter writer = PdfWriter.GetInstance(pdfDoc, stream);
                pdfDoc.Open();

                //APPEND DISCLAIMER TEXT ACCORING TO HIPAA RULES.
                writer.PageEvent = new Common.ITextEvents() { pageNo = pageCount };

                XMLWorkerHelper.GetInstance().ParseXHtml(writer, pdfDoc, sr);
                pdfDoc.Close();

                bool exists = System.IO.Directory.Exists(Server.MapPath("~/FolderPath"));
                if (!exists)
                    System.IO.Directory.CreateDirectory(Server.MapPath("~/FolderPath"));
                System.IO.File.WriteAllBytes(Server.MapPath("~/FolderPath/" + Name + ".pdf"), stream.ToArray());

                return File(stream.ToArray(), "application/pdf", "FileName-" + Name + "-" + Name + ".pdf");
            }
        }

许可以下： CC-BY-SA 和归因

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