我有一个JTable用于捕获用户输入，稍后将在点击“打印”按钮时打印。我有一个图像，我想成为标题，另一个图像是一个页脚。显示这一点的图像可以找到here。我按照oracle documents here中找到的示例进行了操作。我希望它完全按照TablePrintdemo3 here中的方式完成。
请允许我在这里发布课程。 这是我的第一堂课：
public class Product {
String productDescription;
Double productPrice;
//dummy properties
Integer productQuantity;
Double productTotalAmount;
public Product() {
this.productDescription = "";
this.productPrice = 0.0;
this.productTotalAmount = 0.0;
this.productQuantity = 0;
}//getters and setters here
}
第二类是自定义模型，如下所示：
public class ProductTableModel extends AbstractTableModel {
private final List<String> columnNames;
private final List<Product> products;
public ProductTableModel() {
String[] header = new String[] {
"Quantity",
"Description",
"Unity Price",
"Total Price"
};
this.columnNames = Arrays.asList(header);
this.products = new ArrayList<>();
}
@Override
public Class<?> getColumnClass(int columnIndex) {
switch (columnIndex) {
case 0: return Integer.class;
case 1: return String.class;
case 2: return Double.class;
case 3: return Double.class;
default: throw new ArrayIndexOutOfBoundsException(columnIndex);
}
}
@Override
public Object getValueAt(int rowIndex, int columnIndex) {
Product product = this.getProduct(rowIndex);
switch (columnIndex) {
case 0: return product.getProductQuantity();
case 1: return product.getProductDescription();
case 2: return product.getProductPrice();
case 3: return product.getProductTotalAmount();
default: throw new ArrayIndexOutOfBoundsException(columnIndex);
}
}
@Override
public boolean isCellEditable(int rowIndex, int columnIndex) {
return true;
}
@Override
public void setValueAt(Object aValue, int rowIndex, int columnIndex) {
if (columnIndex < 0 || columnIndex >= getColumnCount()) {
throw new ArrayIndexOutOfBoundsException(columnIndex);
} else {
Product product = this.getProduct(rowIndex);
switch (columnIndex) {
case 0: product.setProductQuantity((Integer)aValue); break;
case 1: product.setProductDescription((String)aValue); break;
case 2: product.setProductPrice((Double)aValue); break;
case 3: product.setProductTotalAmount((Double)aValue); break;
}
fireTableCellUpdated(rowIndex, columnIndex);
}
}
@Override
public int getRowCount() {
return this.products.size();
}
@Override
public int getColumnCount() {
return this.columnNames.size();
}
@Override
public String getColumnName(int columnIndex) {
return this.columnNames.get(columnIndex);
}
public void setColumnNames(List<String> columnNames) {
if (columnNames != null) {
this.columnNames.clear();
this.columnNames.addAll(columnNames);
fireTableStructureChanged();
}
}
public List<String> getColumnNames() {
return Collections.unmodifiableList(this.columnNames);
}
public void addProducts(Product product) {
int rowIndex = this.products.size();
this.products.add(product);
fireTableRowsInserted(rowIndex, rowIndex);
}
public void addProducts(List<Product> productList) {
if (!productList.isEmpty()) {
int firstRow = this.products.size();
this.products.addAll(productList);
int lastRow = this.products.size() - 1;
fireTableRowsInserted(firstRow, lastRow);
}
}
public void addEmptyRow(){
products.add(new Product());
this.fireTableRowsInserted(products.size()-1, products.size()-1);
}
public void insertProduct(Product product, int rowIndex) {
this.products.add(rowIndex, product);
fireTableRowsInserted(rowIndex, rowIndex);
}
public void deleteProduct(int rowIndex) {
if (this.products.remove(this.products.get(rowIndex))) {
fireTableRowsDeleted(rowIndex, rowIndex);
}
}
public Product getProduct(int rowIndex) {
return this.products.get(rowIndex);
}
public List<Product> getProducts() {
return Collections.unmodifiableList(this.products);
}
public void clearTableModelData() {
if (!this.products.isEmpty()) {
int lastRow = products.size() - 1;
this.products.clear();
fireTableRowsDeleted(0, lastRow);
}
}
}
第三课是我的如下：
public class NiceTablePrinting extends MainClass{
@Override
protected JTable initializeTable(TableModel model) {
return new NicePrintingJTable(model);
}
private static class NicePrintingJTable extends JTable {
public NicePrintingJTable(TableModel model) {
super(model);
}
/**
* Overridden to return a fancier printable, that wraps the default.
* Ignores the given header and footer. Renders its own header.Always
* uses the page number as the footer.
*/
@Override
public Printable getPrintable(PrintMode printMode,
MessageFormat headerFormat,
MessageFormat footerFormat) {
MessageFormat pageNumber = new MessageFormat("- {0} -");
/* Fetch the default printable */
Printable delegate = per.getPrintable(printMode,null,pageNumber);
/* Return a fancy printable that wraps the default */
return new NicePrintable(delegate);
}
}
private static class NicePrintable implements Printable {
Printable delegate;
//
BufferedImage header;
BufferedImage footer;
//
boolean imagesLoaded;
{
try{
header=ImageIO.read(getClass().getResource("images/header.PNG"));
footer=ImageIO.read(getClass().getResource("images/footer.PNG"));
imagesLoaded=true;
}
catch(IOException ex)
{
ex.printStackTrace();
}
imagesLoaded=false;
}
public NicePrintable(Printable delegate) {
this.delegate = delegate;
}
@Override
public int print(Graphicsg,PageFormatpf,intpi)throwsPrinterException
{
if(!imagesLoaded){
return delegate.print(g, pf, pi);
}
//top origin
int x=(int)pf.getImageableX();
int y=(int)pf.getImageableY();
//
int iw=(int)pf.getImageableWidth();
int ih=(int)pf.getImageableHeight();
//image header
int hh= header.getHeight();
int hw=header.getWidth();
//image footer
int fh=footer.getHeight();
int fw=footer.getWidth();
int fY=ih-fh-10;
int fX=x;
//calculating the area to print the table
int tableX=10;
int tableY=hh +10;
int tableW=iw-20;
int tableH=ih-hh-10-fh-10;
/* create a new page format representing the shrunken area to print the table into */
PageFormat format = new PageFormat() {
@Override
public double getImageableX() {return tableX;}
@Override
public double getImageableY() {return tableY;}
@Override
public double getImageableWidth() {return tableW;}
@Override
public double getImageableHeight() {return tableH;}
};
/*
* We'll use a copy of the graphics to print the table to. This protects
* us against changes that the delegate printable could make to the graphics
* object.
*/
Graphics gCopy = g.create();
/* print the table into the shrunken area */
int retVal = delegate.print(gCopy, format, pi);
/* if there's no pages left, return */
if (retVal == NO_SUCH_PAGE) {
return retVal;
}
/* dispose of the graphics copy */
gCopy.dispose();
//draw the images
g.drawImage(header, x, y, hw, hh, null);
g.drawImage(footer, fX, fY, fw, fh, null);
return Printable.PAGE_EXISTS;
}
}
}
第四节如下：
public class MainClass {
private JTable table;
JFrame frame;
JButton print;
JScrollPane sp;
ProductTableModel model;
public MainClass(){
frame= new JFrame("Test Printing");
frame.setLayout(new java.awt.BorderLayout());
frame.setVisible(true);
///create table
model=new ProductTableModel();
table=this.initializeTable(model);
model.addEmptyRow();
table.setPreferredScrollableViewportSize(newjava.awt.Dimension(300,300));
sp= new javax.swing.JScrollPane(table);
frame.add(sp);
//button
print= new JButton("Print");
frame.add(print,BorderLayout.SOUTH);
frame.pack();
print.addActionListener((ActionEvent e) -> {
try {
printTable();
} catch (PrinterException ex) {
Logger.getLogger(MainClass.class.getName()).log(Level.SEVERE, null, ex);
}
});
}
protected JTable initializeTable(TableModel model) {
return new JTable(model);
}
public void printTable() throws PrinterException {
table.print(JTable.PrintMode.NORMAL, null, null, true, null, true);
}
public static void main(String [] args){
MainClass cl= new MainClass();
}
}
我希望按照TablePrintdemo3中的方式设置我的东西。现在我看不出我哪里出错了。请协助。
问题是它只打印表格 - 没有页眉和页脚图像。