java - 如何使用 jtable 标题将 jtable 保存在 pdf 上

Question

我可以在 pdf 上保存 jtable，但表没有标题，请帮助我:

  Document document = new Document(PageSize.A4, 50.0f, 50.0f, 10.0f, 50.0f);
            PdfWriter writer = PdfWriter.getInstance((Document)document,      (OutputStream)new FileOutputStream(this.file + ".pdf"));
              document.open();
               PdfContentByte cb1 = writer.getDirectContent();
         // modules table
              PdfTemplate template = cb1.createTemplate(2480.0f, 3500.0f);   
                  Graphics2D g1 =        template.createGraphics((float)this.jTable_Modules2.getWidth(),        (float)this.jTable_Modules2.getHeight());
   //                       this.jTable_Modules2.getViewport().setBackground(Color.WHITE);
             this.jTable_Modules2.print(g1);
                g1.dispose();
            com.itextpdf.text.Image image = com.itextpdf.text.Image.getInstance((PdfTemplate)template);
            image.scalePercent(60.0f);
            image.setAbsolutePosition(80.0f, 458.0f);

             document.add((Element)image);

   document.close();
            JOptionPane.showMessageDialog(null, "Transcript successfully generated");

Answer 1

如this answer所示您可以创建一个新的 JTable 并将其作为组件传递给 getImageFromComponent(...) 及其 header 应用程序:

java.awt.Image img = getImageFromComponent(table.getTableHeader());
addImageToDocument(img);
img = getImageFromComponent(table);
addImageToDocument(img);

如果您不将 JTable 添加到 JScrollPane，如果您这样做，则发送 JScrollPane，例如:

java.awt.Image img = getImageFromComponent(scrollPane);
addImageToDocument(img);

如何添加表格取决于您...我更喜欢 scrollPane 版本:)

<小时/>

另一种方法是迭代 JTable 的数据并使用 PdfPTable。

基于this answer你可以得到这样的东西:

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;

import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.pdf.GrayColor;
import com.itextpdf.text.pdf.PdfPCell;
import com.itextpdf.text.pdf.PdfPTable;
import com.itextpdf.text.pdf.PdfWriter;

public class JTableToPdf {

    private JFrame frame;
    private JTable table;
    private JButton button;
    private Document document;
    private PdfWriter writer;
    private JScrollPane scrollPane;

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new JTableToPdf().createAndShowGui();
            }
        });
    }

    public void openPdf() throws FileNotFoundException, DocumentException {
        document = new Document(PageSize.A4, 30, 30, 30, 30);
        writer = PdfWriter.getInstance(document, new FileOutputStream("myFile2.pdf"));
        document.open();
    }

    public void closePdf() {
        document.close();
    }

    public void addData(PdfPTable pdfTable) throws DocumentException {
        pdfTable.setHeaderRows(1);

        PdfPCell cell = new PdfPCell(new Paragraph(table.getColumnName(0)));
        cell.setBackgroundColor(new GrayColor(0.7f));
        pdfTable.addCell(cell);

        cell = new PdfPCell(new Paragraph(table.getColumnName(1)));
        cell.setBackgroundColor(new GrayColor(0.7f));
        pdfTable.addCell(cell);

        cell = new PdfPCell(new Paragraph(table.getColumnName(2)));
        cell.setBackgroundColor(new GrayColor(0.7f));
        pdfTable.addCell(cell);

        for (int i = 0; i < table.getRowCount(); i++) {
            for (int j = 0; j < table.getColumnCount(); j++) {
                pdfTable.addCell(table.getModel().getValueAt(i, j).toString());
            }
        }

        document.add(pdfTable);
    }

    public void createAndShowGui() {
        frame = new JFrame("PDF creator");

        int rows = 100;
        int cols = 3;

        String data [][] = new String[rows][cols];

        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                data[i][j] = i + "-" + j;
            }
        }

        table = new JTable(data, new String []{"A", "B", "C"});
        table.setBorder(BorderFactory.createLineBorder(Color.RED));
        button = new JButton("Create PDF");

        scrollPane = new JScrollPane(table);

        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    PdfPTable pdfTable = new PdfPTable(table.getColumnCount());
                    openPdf();
                    addData(pdfTable);
                    closePdf();
                } catch (FileNotFoundException e1) {
                    e1.printStackTrace();
                } catch (DocumentException e1) {
                    e1.printStackTrace();
                }
            }
        });

//      frame.add(table.getTableHeader(), BorderLayout.NORTH);
        frame.add(scrollPane, BorderLayout.CENTER);
        frame.add(button, BorderLayout.SOUTH);

        frame.pack();
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

如果您不希望标题在每个页面上重复，只需删除 addData(...) 方法上 for 循环之前的行即可。

<小时/>

第三种方法可以使用 JTable 的 printable 方法，但我这里没有打印机，稍后我将处理这个示例，因为我现在没有太多时间，我不知道如何将其与 iText 集成，所以我必须搜索一下......

<小时/>

唷!我花了一段时间才创建这个结果，但我认为它效果很好(尽管您需要在创建 PDF 后恢复 JTable)。

查看代码注释并告诉我这是否有帮助。我结合使用 PDFPTable 和图像方法来实现这种新方法:

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;

import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Image;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.pdf.PdfPCell;
import com.itextpdf.text.pdf.PdfPTable;
import com.itextpdf.text.pdf.PdfWriter;

public class JTable2Pdf {

    private JFrame frame;
    private JTable table;
    private JButton button;
    private JScrollPane scrollPane;
    private DefaultTableModel model;
    private DefaultTableModel restoreModel;

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new JTable2Pdf().createAndShowGui();
            }
        });
    }

    public void restoreTableView() {
        table.setModel(restoreModel);
        frame.revalidate();
        frame.repaint();
    }

    public void createAndShowGui() {
        frame = new JFrame("PDF creator");
        int rows = 130;
        int cols = 3;

        String data[][] = new String[rows][cols];

        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                data[i][j] = i + "-" + j;
            }
        }

        model = new DefaultTableModel(data, new String[] { "A", "B", "C" });

        restoreModel = new DefaultTableModel(data, new String[] { "A", "B", "C" });

        table = new JTable(model);

        //Just some borders for the table and its header
        table.setBorder(BorderFactory.createLineBorder(Color.RED));
        table.getTableHeader().setBorder(BorderFactory.createLineBorder(Color.RED));

        scrollPane = new JScrollPane(table);

        button = new JButton("Create PDF");

        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    //We create an instance of pdfCreator and pass our JTable as instance
                    PdfCreator pdfCreator = new PdfCreator(table);

                    //We open the pdf and say we want to repeat the header for each page
                    pdfCreator.openPdf(true);
                    //Then we add the header (if we don't add it first, then the 1st row of the table will be the one repeating over the pages
                    pdfCreator.addImageToTable(pdfCreator.getImageFromComponent(table.getTableHeader()));
                    //Then we add the rows to the PDF
                    pdfCreator.getRowsImage();
                    //Finally we close the PDF
                    pdfCreator.closePdf();
                    //And last we restore the table
                    restoreTableView();

                } catch (DocumentException e1) {
                    e1.printStackTrace();
                } catch (FileNotFoundException e1) {
                    e1.printStackTrace();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        });

        frame.add(scrollPane, BorderLayout.CENTER);
        frame.add(button, BorderLayout.SOUTH);

        frame.pack();
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

class PdfCreator {

    private JTable table;
    private Document document;
    private PdfWriter writer;
    private boolean isNewPage;
    private PdfPTable pdfTable;

    public PdfCreator(JTable table) {
        this.table = table;
    }

    //This method opens the PDF, repeatHeader if true, adds the header to each page, otherwise it only adds it to the 1st one
    public void openPdf(boolean repeatHeader) throws FileNotFoundException, DocumentException {
        document = new Document(PageSize.A4, 30, 30, 30, 30);
        writer = PdfWriter.getInstance(document, new FileOutputStream("myFile.pdf"));
        pdfTable = new PdfPTable(1);
        if (repeatHeader) {
            pdfTable.setHeaderRows(1);
        }
        pdfTable.getDefaultCell().setBorder(PdfPCell.NO_BORDER);
        pdfTable.getDefaultCell().setPadding(0);
        document.open();
    }

    //This method closes the document
    public void closePdf() {
        document.close();
    }

    //This method gets the image for each row recursively
    //As this method gets the graphics for the table from 0, 0 to the width and length determined, we need to remove the 1st row of the table
    //each time we go through it and that's why we need to restore the table model later in the code
    public void getRowsImage() throws DocumentException, IOException {
        if (table.getRowCount() > 0) {
            int width = table.getCellRect(0, 0, true).width + table.getCellRect(0, 1, true).width + table.getCellRect(0, 2, true).width;
            int height = table.getCellRect(0, 0, true).height;

            BufferedImage img = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            table.paint(img.getGraphics());
            DefaultTableModel dtm = (DefaultTableModel) table.getModel();
            System.out.println(table.getRowCount() + " - " + isNewPage);

            dtm.removeRow(0);
            addImageToTable(img);
            getRowsImage();
        } else {
            document.add(pdfTable);
        }
    }

    //This gets the image for the table header and / or any other components you need to add to the PDF
    public java.awt.Image getImageFromComponent(JComponent component) throws DocumentException {
        int width = component.getWidth();
        int height = component.getHeight();
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        component.paint(image.getGraphics());
        return image;
    }

    //This method add the image to a PDFPTable which will be added later to the document
    public void addImageToTable(java.awt.Image img) throws IOException, DocumentException {
        Image image = Image.getInstance(writer, img, 1);
        image.scalePercent(100);
        pdfTable.addCell(image);
        System.out.println("printed!");
    }
}

这些是输出:

第一页有边框和重复标题 带边框和重复页眉的第二页

第二页有边框且不重复页眉

第一页无边框且不重复页眉 第二页无边框且不重复页眉

<小时/>

我能够通过移动而不是删除行来更改上述代码，这会产生相同的结果，并且仍然可以正常工作，但您不再需要 restoreTableView() 方法...只需更改 getRowsImage() 方法，如下所示:

public void getRowsImage() throws DocumentException, IOException {
    if (movedRows < table.getRowCount()) {
        int width = table.getCellRect(0, 0, true).width + table.getCellRect(0, 1, true).width + table.getCellRect(0, 2, true).width;
        int height = table.getCellRect(0, 0, true).height;

        BufferedImage img = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        table.paint(img.getGraphics());
        DefaultTableModel dtm = (DefaultTableModel) table.getModel();
        System.out.println(table.getRowCount() + " - " + isNewPage);

        dtm.moveRow(0, 0, table.getRowCount() - 1);
        movedRows++;
        addImageToTable(img);
        getRowsImage();
    } else {
        document.add(pdfTable);
    }
}

并将变量 movedRows = 0 声明为 PdfCreator 类的类成员:)