带有新行的JTable多个标题

Question

在java swing JTable中，我想使用MessageFormat中的新行打印多个标题。

MessageFormat header = new MessageFormat("Products Details" + '\n' + "xyz suppliers");
MessageFormat footer = new MessageFormat("Page{1,number,integer}");
tbl_country.print(JTable.PrintMode.FIT_WIDTH, header, footer);

我尝试过很多代码，但新行标题不起作用。

Answer 1

最后我找到了使用新的JTable数据行打印多个标题的答案，如下所示： - 我的TablePrintable.java

import javax.swing.table.*;
import java.awt.*;
import java.awt.print.*;
import java.awt.geom.*;
import java.text.MessageFormat;
import javax.swing.JTable;

/**
 * An implementation of <code>Printable</code> for printing
 * <code>JTable</code>s.
 * <p>
 * This implementation spreads table rows naturally in sequence across multiple
 * pages, fitting as many rows as possible per page. The distribution of
 * columns, on the other hand, is controlled by a printing mode parameter passed
 * to the constructor. When <code>JTable.PrintMode.NORMAL</code> is used, the
 * implementation handles columns in a similar manner to how it handles rows,
 * spreading them across multiple pages (in an order consistent with the table's
 * <code>ComponentOrientation</code>). When
 * <code>JTable.PrintMode.FIT_WIDTH</code> is given, the implementation scales
 * the output smaller if necessary, to ensure that all columns fit on the page.
 * (Note that width and height are scaled equally, ensuring that the aspect
 * ratio remains the same).
 * <p>
 * The portion of table printed on each page is headed by the appropriate
 * section of the table's <code>JTableHeader</code>.
 * <p>
 * Header and footer text can be added to the output by providing
 * <code>MessageFormat</code> instances to the constructor. The printing code
 * requests Strings from the formats by calling their <code>format</code> method
 * with a single parameter: an <code>Object</code> array containing a single
 * element of type <code>Integer</code>, representing the current page number.
 * <p>
 * There are certain circumstances where this <code>Printable</code> cannot fit
 * items appropriately, resulting in clipped output. These are:
 * <ul>
 * <li>In any mode, when the header or footer text is too wide to fit completely
 * in the printable area. The implementation prints as much of the text as
 * possible starting from the beginning, as determined by the table's
 * <code>ComponentOrientation</code>.
 * <li>In any mode, when a row is too tall to fit in the printable area. The
 * upper most portion of the row is printed and no lower border is shown.
 * <li>In <code>JTable.PrintMode.NORMAL</code> when a column is too wide to fit
 * in the printable area. The center of the column is printed and no left and
 * right borders are shown.
 * </ul>
 * <p>
 * It is entirely valid for a developer to wrap this <code>Printable</code>
 * inside another in order to create complex reports and documents. They may
 * even request that different pages be rendered into different sized printable
 * areas. The implementation was designed to handle this by performing most of
 * its calculations on the fly. However, providing different sizes works best
 * when <code>JTable.PrintMode.FIT_WIDTH</code> is used, or when only the
 * printable width is changed between pages. This is because when it is printing
 * a set of rows in <code>JTable.PrintMode.NORMAL</code> and the implementation
 * determines a need to distribute columns across pages, it assumes that all of
 * those rows will fit on each subsequent page needed to fit the columns.
 * <p>
 * It is the responsibility of the developer to ensure that the table is not
 * modified in any way after this <code>Printable</code> is created (invalid
 * modifications include changes in: size, renderers, or underlying data). The
 * behavior of this <code>Printable</code> is undefined if the table is changed
 * at any time after creation.
 *
 * @author Shannon Hickey
 * @version 1.41 11/17/05
 */
class MyTablePrintable implements Printable {

    /**
     * The table to print.
     */
    private JTable table;

    /**
     * For quick reference to the table's header.
     */
    private JTableHeader header;

    /**
     * For quick reference to the table's column model.
     */
    private TableColumnModel colModel;

    /**
     * To save multiple calculations of total column width.
     */
    private int totalColWidth;

    /**
     * The printing mode of this printable.
     */
    private JTable.PrintMode printMode;

    /**
     * Provides the header text for the table.
     */
    private MessageFormat[] headerFormat;

    /**
     * Provides the footer text for the table.
     */
    private MessageFormat[] footerFormat;

    /**
     * The most recent page index asked to print.
     */
    private int last = -1;

    /**
     * The next row to print.
     */
    private int row = 0;

    /**
     * The next column to print.
     */
    private int col = 0;

    /**
     * Used to store an area of the table to be printed.
     */
    private final Rectangle clip = new Rectangle(0, 0, 0, 0);

    /**
     * Used to store an area of the table's header to be printed.
     */
    private final Rectangle hclip = new Rectangle(0, 0, 0, 0);

    /**
     * Saves the creation of multiple rectangles.
     */
    private final Rectangle tempRect = new Rectangle(0, 0, 0, 0);

    /**
     * Vertical space to leave between table and header/footer text.
     */
    private static final int H_F_SPACE = 8;

    /**
     * Font size for the header text.
     */
    private static final float HEADER_FONT_SIZE = 15.0f;

    /**
     * Font size for the footer text.
     */
    private static final float FOOTER_FONT_SIZE = 10.0f;

    /**
     * The font to use in rendering header text.
     */
    private Font headerFont;

    /**
     * The font to use in rendering footer text.
     */
    private Font footerFont;

    /**
     * Create a new <code>TablePrintable</code> for the given
     * <code>JTable</code>. Header and footer text can be specified using the
     * two <code>MessageFormat</code> parameters. When called upon to provide a
     * String, each format is given the current page number.
     *
     * @param table the table to print
     * @param printMode the printing mode for this printable
     * @param headerFormat a <code>MessageFormat</code> specifying the text to
     * be used in printing a header, or null for none
     * @param footerFormat a <code>MessageFormat</code> specifying the text to
     * be used in printing a footer, or null for none
     * @throws IllegalArgumentException if passed an invalid print mode
     */
    public MyTablePrintable(JTable table,
            JTable.PrintMode printMode,
            MessageFormat[] headerFormat,
            MessageFormat[] footerFormat) {

        this.table = table;

        header = table.getTableHeader();
        colModel = table.getColumnModel();
        totalColWidth = colModel.getTotalColumnWidth();

        if (header != null) {
            // the header clip height can be set once since it's unchanging
            hclip.height = header.getHeight();
        }

        this.printMode = printMode;

        this.headerFormat = headerFormat;
        this.footerFormat = footerFormat;

        // derive the header and footer font from the table's font
        headerFont = table.getFont().deriveFont(Font.BOLD,
                HEADER_FONT_SIZE);
        footerFont = table.getFont().deriveFont(Font.PLAIN,
                FOOTER_FONT_SIZE);
    }

    /**
     * Prints the specified page of the table into the given {@link Graphics}
     * context, in the specified format.
     *
     * @param graphics the context into which the page is drawn
     * @param pageFormat the size and orientation of the page being drawn
     * @param pageIndex the zero based index of the page to be drawn
     * @return PAGE_EXISTS if the page is rendered successfully, or NO_SUCH_PAGE
     * if a non-existent page index is specified
     * @throws PrinterException if an error causes printing to be aborted
     */
    public int print(Graphics graphics, PageFormat pageFormat, int pageIndex)
            throws PrinterException {

        // for easy access to these values
        final int imgWidth = (int) pageFormat.getImageableWidth();
        final int imgHeight = (int) pageFormat.getImageableHeight();

        if (imgWidth <= 0) {
            throw new PrinterException("Width of printable area is too small.");
        }

        // to pass the page number when formatting the header and footer text
        Object[] pageNumber = new Object[]{new Integer(pageIndex + 1)};

        // fetch the formatted header text, if any
        String[] headerText = null;
        if (headerFormat != null) {
            headerText = new String[headerFormat.length];
            for (int i = 0; i < headerFormat.length; i++) {
                headerText[i] = headerFormat[i].format(pageNumber);
            }
        }

        // fetch the formatted footer text, if any
        String[] footerText = null;
        if (footerFormat != null) {
            footerText = new String[footerFormat.length];
            for (int i = 0; i < footerFormat.length; i++) {
                footerText[i] = footerFormat[i].format(pageNumber);
            }
        }

        // to store the bounds of the header and footer text
        Rectangle2D[] hRect = null;
        Rectangle2D[] fRect = null;

        // the amount of vertical space needed for the header and footer text
        int headerTextSpace = 15;
        int footerTextSpace = 0;

        // the amount of vertical space available for printing the table
        int availableSpace = imgHeight;

        // if there's header text, find out how much space is needed for it
        // and subtract that from the available space
        if (headerText != null) {
            graphics.setFont(headerFont);
            hRect = new Rectangle2D[headerText.length];
            for (int i = 0; i < headerText.length; i++) {
                hRect[i] = graphics.getFontMetrics().getStringBounds(headerText[i], graphics);
                headerTextSpace += (int) Math.ceil(hRect[i].getHeight());
            }
            availableSpace -= headerTextSpace + H_F_SPACE;
        }

        // if there's footer text, find out how much space is needed for it
        // and subtract that from the available space
        if (footerText != null) {
            graphics.setFont(footerFont);
            fRect = new Rectangle2D[footerText.length];
            for (int i = 0; i < footerText.length; i++) {
                fRect[i] = graphics.getFontMetrics().getStringBounds(footerText[i], graphics);
                footerTextSpace += (int) Math.ceil(fRect[i].getHeight());
            }
            availableSpace -= footerTextSpace + H_F_SPACE;
        }

        if (availableSpace <= 0) {
            throw new PrinterException("Height of printable area is too small.");
        }

        // depending on the print mode, we may need a scale factor to
        // fit the table's entire width on the page
        double sf = 1.0D;
        if (printMode == JTable.PrintMode.FIT_WIDTH
                && totalColWidth > imgWidth) {

            // if not, we would have thrown an acception previously
            assert imgWidth > 0;

            // it must be, according to the if-condition, since imgWidth > 0
            assert totalColWidth > 1;

            sf = (double) imgWidth / (double) totalColWidth;
        }

        // dictated by the previous two assertions
        assert sf > 0;

        // This is in a loop for two reasons:
        // First, it allows us to catch up in case we're called starting
        // with a non-zero pageIndex. Second, we know that we can be called
        // for the same page multiple times. The condition of this while
        // loop acts as a check, ensuring that we don't attempt to do the
        // calculations again when we are called subsequent times for the
        // same page.
        while (last < pageIndex) {
            // if we are finished all columns in all rows
            if (row >= table.getRowCount() && col == 0) {
                return NO_SUCH_PAGE;
            }

            // rather than multiplying every row and column by the scale factor
            // in findNextClip, just pass a width and height that have already
            // been divided by it
            int scaledWidth = (int) (imgWidth / sf);
            int scaledHeight = (int) ((availableSpace - hclip.height) / sf);

            // calculate the area of the table to be printed for this page
            findNextClip(scaledWidth, scaledHeight);

            last++;
        }

        // translate into the co-ordinate system of the pageFormat
        Graphics2D g2d = (Graphics2D) graphics;
        g2d.translate(pageFormat.getImageableX(), pageFormat.getImageableY());

        // to save and store the transform
        AffineTransform oldTrans;

        // if there's footer text, print it at the bottom of the imageable area
        if (footerText != null) {
            oldTrans = g2d.getTransform();

            g2d.translate(0, imgHeight - footerTextSpace);
            for (int i = 0; i < footerText.length; i++) {
                printText(g2d, footerText[i], fRect[i], footerFont, i, imgWidth);
            }

            g2d.setTransform(oldTrans);
        }

        // if there's header text, print it at the top of the imageable area
        // and then translate downwards
        if (headerText != null) {
            for (int i = 0; i < headerText.length; i++) {
                printText(g2d, headerText[i], hRect[i], headerFont, i, imgWidth);
            }

            g2d.translate(0, headerTextSpace + H_F_SPACE);
        }

        // constrain the table output to the available space
        tempRect.x = 0;
        tempRect.y = 0;
        tempRect.width = imgWidth;
        tempRect.height = availableSpace;
        g2d.clip(tempRect);

        // if we have a scale factor, scale the graphics object to fit
        // the entire width
        if (sf != 1.0D) {
            g2d.scale(sf, sf);

            // otherwise, ensure that the current portion of the table is
            // centered horizontally
        } else {
            int diff = (imgWidth - clip.width) / 2;
            g2d.translate(diff, 0);
        }

        // store the old transform and clip for later restoration
        oldTrans = g2d.getTransform();
        Shape oldClip = g2d.getClip();

        // if there's a table header, print the current section and
        // then translate downwards
        if (header != null) {
            hclip.x = clip.x;
            hclip.width = clip.width;

            g2d.translate(-hclip.x, 0);
            g2d.clip(hclip);
            header.print(g2d);

            // restore the original transform and clip
            g2d.setTransform(oldTrans);
            g2d.setClip(oldClip);

            // translate downwards
            g2d.translate(0, hclip.height);
        }

        // print the current section of the table
        g2d.translate(-clip.x, -clip.y);
        g2d.clip(clip);
        table.print(g2d);

        // restore the original transform and clip
        g2d.setTransform(oldTrans);
        g2d.setClip(oldClip);

        // draw a box around the table
        g2d.setColor(Color.BLACK);
        g2d.drawRect(0, 0, clip.width, hclip.height + clip.height);

        return PAGE_EXISTS;
    }

    /**
     * A helper method that encapsulates common code for rendering the header
     * and footer text.
     *
     * @param g2d the graphics to draw into
     * @param text the text to draw, non null
     * @param rect the bounding rectangle for this text, as calculated at the
     * given font, non null
     * @param font the font to draw the text in, non null
     * @param imgWidth the width of the area to draw into
     */
    private void printText(Graphics2D g2d,
            String text,
            Rectangle2D rect,
            Font font,
            int textIndex,
            int imgWidth) {

        //int tx = -(int)(Math.ceil(rect.getWidth()) - imgWidth); // for right allign
        int tx = 0; // for left allign

        int ty = textIndex * (int) Math.ceil(Math.abs(rect.getY()));
        g2d.setColor(Color.BLACK);
        g2d.setFont(font);
        g2d.drawString(text, tx, ty);
    }

    /**
     * Calculate the area of the table to be printed for the next page. This
     * should only be called if there are rows and columns left to print.
     *
     * To avoid an infinite loop in printing, this will always put at least one
     * cell on each page.
     *
     * @param pw the width of the area to print in
     * @param ph the height of the area to print in
     */
    private void findNextClip(int pw, int ph) {
        final boolean ltr = table.getComponentOrientation().isLeftToRight();

        // if we're ready to start a new set of rows
        if (col == 0) {
            if (ltr) {
                // adjust clip to the left of the first column
                clip.x = 0;
            } else {
                // adjust clip to the right of the first column
                clip.x = totalColWidth;
            }

            // adjust clip to the top of the next set of rows
            clip.y += clip.height;

            // adjust clip width and height to be zero
            clip.width = 0;
            clip.height = 0;

            // fit as many rows as possible, and at least one
            int rowCount = table.getRowCount();
            int rowHeight = table.getRowHeight(row);
            do {
                clip.height += rowHeight;

                if (++row >= rowCount) {
                    break;
                }

                rowHeight = table.getRowHeight(row);
            } while (clip.height + rowHeight <= ph);
        }

        // we can short-circuit for JTable.PrintMode.FIT_WIDTH since
        // we'll always fit all columns on the page
        if (printMode == JTable.PrintMode.FIT_WIDTH) {
            clip.x = 0;
            clip.width = totalColWidth;
            return;
        }

        if (ltr) {
            // adjust clip to the left of the next set of columns
            clip.x += clip.width;
        }

        // adjust clip width to be zero
        clip.width = 0;

        // fit as many columns as possible, and at least one
        int colCount = table.getColumnCount();
        int colWidth = colModel.getColumn(col).getWidth();
        do {
            clip.width += colWidth;
            if (!ltr) {
                clip.x -= colWidth;
            }

            if (++col >= colCount) {
                // reset col to 0 to indicate we're finished all columns
                col = 0;

                break;
            }

            colWidth = colModel.getColumn(col).getWidth();
        } while (clip.width + colWidth <= pw);

    }

} 

打印时打印按钮

String name = lblCompanyName.getText();
        String address = lblAddress.getText();

        try {
            PrinterJob job = PrinterJob.getPrinterJob();

            MessageFormat[] header = new MessageFormat[3];

            header[0] = new MessageFormat("line 1");
            header[1] = new MessageFormat("                    " + name);
            header[2] = new MessageFormat("                  " + address);

            MessageFormat[] footer = new MessageFormat[2];
            footer[0] = new MessageFormat("");
            footer[1] = new MessageFormat("-{1}-");
            job.setPrintable(new MyTablePrintable(table, JTable.PrintMode.FIT_WIDTH, header, footer));
            job.printDialog();
            job.print();

        } catch (Exception ex) {
        }

结果