在 java swing JTable 中，我想使用 MessageFormat 中的新行打印多个 header 。
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);
我尝试了很多代码，但新行标题不起作用。
最佳答案
最后我找到了用新的 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);
}
}
单击打印按钮时进行打印
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
关于java - JTable 多个标题与换行符，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46076333/