Question

对于Nable的上一篇文章感到抱歉。我的印象是所有更高级别的iText接口都管理了开始/结束文本平衡，但以下代码仍然失败，并且出现了不平衡的开始/结束文本异常。

你能否建议我做什么（不做）导致这种不平衡。

干杯谢谢，斯蒂芬

package com.opentext.basis.webtop.actions;

import com.opentext.basis.jdbc.BasisResultSet;
import com.opentext.basis.webtop.servlet.*;
import java.io.IOException;
import java.io.InputStream;
import java.io.BufferedInputStream;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletResponse;
import org.apache.log4j.Logger;
import pdf.PDFFooter;
import java.net.URL;
import com.opentext.basis.jdbc.BasisConnection;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Font;
import com.itextpdf.text.FontFactory;
import com.itextpdf.text.Image;
import com.itextpdf.text.Jpeg;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.Chunk;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.ColumnText;
import com.itextpdf.text.pdf.PdfPCell;
import com.itextpdf.text.pdf.PdfPTable;
import com.itextpdf.text.pdf.PdfWriter;

// Referenced classes of package com.opentext.basis.webtop.actions:
//            AbstractRecordAction, ResultSetBean, ActionResponse, WebtopAction

// This action generates a PDF containing all thumbnails for the current set.

public class tnPDF2 extends AbstractRecordAction
implements WebtopAction
{

public tnPDF2()
{
}

public void destroy()
{
    super.destroy();
    mResponse = null;
}

public String getPageName()
{
    if(mResponse != null)
        return mResponse.getPage();
    else
        return null;
}

public String getRedirectUrl()
{
    if(mResponse != null)
        return mResponse.getURL();
    else
        return null;
}

public void doAction(HttpServlet httpservlet, Request request, HttpServletResponse httpservletresponse)
    throws SQLException, WebtopException
{
//
// Get request params.
    Font [] fonts = new Font[2];
    fonts[0] = FontFactory.getFont(FontFactory.HELVETICA, 14, Font.NORMAL);
    fonts[1] = FontFactory.getFont(FontFactory.HELVETICA, 11, Font.NORMAL);
    String s = request.getParameter("s");
    Statement mS;
    BasisResultSet brs = null;
    Document document = new Document();
    PdfWriter writer;
    float[] widths = {0.08f,0.1f, 0.07f, 0.25f,0.08f,0.1f, 0.07f, 0.25f};

    PdfPTable pics= new PdfPTable(widths);
    pics.setWidthPercentage(100);

    httpservletresponse.setHeader("Pragma", "no-cache");
    httpservletresponse.setHeader("Cache-control", "no-cache");
    httpservletresponse.setHeader("Cache-control", "no-store");
    httpservletresponse.setHeader("Expires", "-1");

    try {             
            writer = PdfWriter.getInstance(document,httpservletresponse.getOutputStream());
            writer.setPageEvent(new PDFFooter());

            document.open();

    }
    catch (DocumentException de) {
            System.err.println(de.getMessage());
    }
    catch (Exception e2) {
            System.err.println(e2.getMessage());
    }
    WebtopSession webtopsession = request.getWebtopSession();
    mS = webtopsession.getConnection().createStatement(java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE,java.sql.ResultSet.CONCUR_READ_ONLY);
    String s1 = "select photo_no,title,date_taken,dm_blob from history(" + s + ")";
    brs = (BasisResultSet)mS.executeQuery(s1);
    String sq = brs.getSQLStatement().replaceAll("select.*NATIVE\\('","").replaceAll("'\\) order.*","");
    try {
      Phrase heading =new Phrase("Search results for: " + sq,fonts[0]);
      document.add(heading);
      document.add(Chunk.NEWLINE);
    }
    catch (DocumentException de2) {
            System.err.println(de2.getMessage());
    }
    while (brs.next()){
      String c = brs.getString("photo_no");
      if (c == null)c = "";
      pics.addCell(new Paragraph(c,fonts[1]));
      c = brs.getString("title");
      if (c == null)c = "";
      pics.addCell(new Paragraph(c,fonts[1]));
      c = brs.getString("date_taken");
      if (c == null)c = "";
      pics.addCell(new Paragraph(c,fonts[1]));
//
      InputStream inputstream = null;
      try {
        inputstream = brs.getBinaryStream("dm_blob");
      }
      catch (Exception se) {
            System.err.println("BLOB get error " + se.getMessage());
      }
      if(inputstream == null){
            pics.addCell(new Paragraph("No thumbnail.",fonts[1]));
      } else {
            ArrayList d = new ArrayList();
            BufferedInputStream imgStream = new BufferedInputStream(inputstream);
            int n;
            try {
              while ((n = imgStream.read()) != -1)
                    d.add(new Byte((byte)n));
              imgStream.close();
              byte [] imgData = new byte[d.size()];
              Iterator it = d.iterator();
              int ix = 0;
              while (it.hasNext())
                    imgData[ix++] = ((Byte)it.next()).byteValue();
              Jpeg jpeg = new Jpeg(imgData);
              PdfPCell cl = new PdfPCell();
              cl.setImage(jpeg);
              pics.addCell(jpeg);
            }  
            catch (Exception e3){
              System.err.println(e3.getMessage());
            }
      }
    }
 // add extra empty cell to force odd last pic.
    pics.addCell(new Paragraph(" ",fonts[1]));
    pics.addCell(new Paragraph(" ",fonts[1]));
    pics.addCell(new Paragraph(" ",fonts[1]));
    pics.addCell(new Paragraph(" ",fonts[1]));

    try {
            document.add(pics);
    }
    catch (DocumentException de2) {
            System.err.println(de2.getMessage());
    }
    document.close();
}

private ActionResponse mResponse;
private static final Logger gLog = Logger.getLogger("tnPDF2");
}

这是PDFFooter代码（包含此代码，原始文件在document.close（）处失败）：

package pdf;

import java.awt.Color;

import java.util.*;
import java.text.SimpleDateFormat;

import com.itextpdf.text.Document;
import com.itextpdf.text.Element;
import com.itextpdf.text.ExceptionConverter;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfPTable;
import com.itextpdf.text.pdf.PdfPageEventHelper;
import com.itextpdf.text.pdf.PdfTemplate;
import com.itextpdf.text.pdf.PdfWriter;



public class PDFFooter extends PdfPageEventHelper
{
       public PdfPTable table;
        /** The Graphic state */

        /** A template that will hold the total number of pages. */
        public PdfTemplate tpl;
        /** The font that will be used. */
        public BaseFont helv;
        public void onOpenDocument(PdfWriter writer, Document document) {
            try {
                    // initialization of the header table
                table = new PdfPTable(1);
                table.getDefaultCell().setHorizontalAlignment(Element.ALIGN_RIGHT);
                table.getDefaultCell().setBorderWidth(0);

                Calendar dt = Calendar.getInstance();
                SimpleDateFormat f2 = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
                table.addCell(f2.format(dt.getTime()));


                // initialization of the template
                tpl = writer.getDirectContent().createTemplate(100, 100);
                tpl.setBoundingBox(new Rectangle(-20, -20, 100, 100));
                // initialization of the font
                helv = BaseFont.createFont("Helvetica", BaseFont.WINANSI, false);
            }
            catch(Exception e) {
                throw new ExceptionConverter(e);
            }
        }    


    public void onEndPage(PdfWriter writer, Document document) {
    PdfContentByte cb = writer.getDirectContent();
    cb.saveState();
    // write the headertable
    table.setTotalWidth(document.right() - document.left());
    table.writeSelectedRows(0, -1, document.left(), document.getPageSize().getHeight() , cb);
    // compose the footer
    String text = "Page " + writer.getPageNumber() + " of ";
    float textSize = helv.getWidthPoint(text, 12);
    float textBase = document.bottom() - 20;
    cb.beginText();
    cb.setFontAndSize(helv, 12);

    float adjust = helv.getWidthPoint("0", 12);
    cb.setTextMatrix(document.right() - textSize - adjust, textBase);
    cb.showText(text);
    cb.endText();
    cb.addTemplate(tpl, document.right() - adjust, textBase);
    cb.saveState();


}



/**
 * @see com.itextpdf.text.pdf.PdfPageEventHelper#onCloseDocument(com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)
 */
public void onCloseDocument(PdfWriter writer, Document document) {
   tpl.beginText();
   tpl.setFontAndSize(helv, 12);
   tpl.setTextMatrix(0, 0);
   tpl.showText("" + (writer.getPageNumber() - 1));
   tpl.endText();
}

Answer 1

我按照建议更改了页面末尾代码并重新编译，问题就消失了。

我不相信代码更改实际上解决了问题。我相信用后来的itext.jar重新编译是真正的修复。

感谢您的反馈。

导致此代码中的开始/结束文本不平衡的原因是什么？

1 个答案: