大家好，我下面有一些代码可以打印我已经写入应用程序（mText）的文本，但是我希望能够选择一个.txt文件并将其打印出来，而不是仅仅在程序中写入内容相反，我如何修改下面的代码来实现这一点？
import java.awt.*;
import java.awt.font.*;
import java.awt.geom.*;
import java.awt.print.*;
import java.text.*;
/**
* The PrintText application expands on the
* PrintExample application in that it images
* text on to the single page printed.
*/
public class PrintText implements Printable {
/**
* The text to be printed.
*/
private static final String mText =
"Four score and seven years ago our fathers brought forth on this "
+ "continent a new nation, conceived in liberty and dedicated to the "
+ "proposition that all men are created equal. Now we are engaged in "
+ "a great civil war, testing whether that nation or any nation so "
+ "conceived and so dedicated can long endure. We are met on a great "
+ "battlefield of that war. We have come to dedicate a portion of "
+ "that field as a final resting-place for those who here gave their "
+ "lives that that nation might live. It is altogether fitting and "
+ "proper that we should do this. But in a larger sense, we cannot "
+ "dedicate, we cannot consecrate, we cannot hallow this ground."
+ "The brave men, living and dead who struggled here have consecrated "
+ "it far above our poor power to add or detract. The world will "
+ "little note nor long remember what we say here, but it can never "
+ "forget what they did here. It is for us the living rather to be "
+ "dedicated here to the unfinished work which they who fought here "
+ "have thus far so nobly advanced. It is rather for us to be here "
+ "dedicated to the great task remaining before us--that from these "
+ "honored dead we take increased devotion to that cause for which "
+ "they gave the last full measure of devotion--that we here highly "
+ "resolve that these dead shall not have died in vain, that this "
+ "nation under God shall have a new birth of freedom, and that "
+ "government of the people, by the people, for the people shall "
+ "not perish from the earth.";
/**
* Our text in a form for which we can obtain a
* AttributedCharacterIterator.
*/
private static final AttributedString mStyledText = new AttributedString(mText);
/**
* Print a single page containing some sample text.
*/
static public void main(String args[]) {
/* Get the representation of the current printer and
* the current print job.
*/
PrinterJob printerJob = PrinterJob.getPrinterJob();
/* Build a book containing pairs of page painters (Printables)
* and PageFormats. This example has a single page containing
* text.
*/
Book book = new Book();
book.append(new PrintText(), new PageFormat());
/* Set the object to be printed (the Book) into the PrinterJob.
* Doing this before bringing up the print dialog allows the
* print dialog to correctly display the page range to be printed
* and to dissallow any print settings not appropriate for the
* pages to be printed.
*/
printerJob.setPageable(book);
/* Show the print dialog to the user. This is an optional step
* and need not be done if the application wants to perform
* 'quiet' printing. If the user cancels the print dialog then false
* is returned. If true is returned we go ahead and print.
*/
boolean doPrint = printerJob.printDialog();
if (doPrint) {
try {
printerJob.print();
} catch (PrinterException exception) {
System.err.println("Printing error: " + exception);
}
}
}
/**
* Print a page of text.
*/
public int print(Graphics g, PageFormat format, int pageIndex) {
/* We'll assume that Jav2D is available.
*/
Graphics2D g2d = (Graphics2D) g;
/* Move the origin from the corner of the Paper to the corner
* of the imageable area.
*/
g2d.translate(format.getImageableX(), format.getImageableY());
/* Set the text color.
*/
g2d.setPaint(Color.black);
/* Use a LineBreakMeasurer instance to break our text into
* lines that fit the imageable area of the page.
*/
Point2D.Float pen = new Point2D.Float();
AttributedCharacterIterator charIterator = mStyledText.getIterator();
LineBreakMeasurer measurer = new LineBreakMeasurer(charIterator, g2d.getFontRenderContext());
float wrappingWidth = (float) format.getImageableWidth();
while (measurer.getPosition() < charIterator.getEndIndex()) {
TextLayout layout = measurer.nextLayout(wrappingWidth);
pen.y += layout.getAscent();
float dx = layout.isLeftToRight()? 0 : (wrappingWidth - layout.getAdvance());
layout.draw(g2d, pen.x + dx, pen.y);
pen.y += layout.getDescent() + layout.getLeading();
}
return Printable.PAGE_EXISTS;
}
}
我在打印其他代码时遇到了一些问题，但上面的代码对我来说成功地工作得很好，这就是我想修改它的原因
我的文件阅读器：
import java.io.*;
class FileReaderDemo {
public static void main(String args[]) throws Exception {
FileReader fr = new FileReader("D:/Documents/testDocToPrintUsingJava.txt");
BufferedReader br = new BufferedReader(fr);
String s;
while((s = br.readLine()) != null) {
System.out.println(s);
}
fr.close();
}
}
下面的当前代码，我对如何使用此代码感到困惑，
import java.awt.*;
import java.awt.font.*;
import java.awt.geom.*;
import java.awt.print.*;
import java.text.*;
import java.io.*;
import javax.swing.*;
import static java.nio.file.StandardOpenOption.*;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.BufferedWriter;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.IOException;
import java.io.BufferedInputStream;
import java.io.Console;
import java.util.Arrays;
import java.io.IOException;
import java.io.DataOutputStream;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.EOFException;
import java.io.FileNotFoundException;
import java.nio.file.Files;
import java.lang.System;
import java.lang.String;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.FileSystemException;
import java.nio.file.InvalidPathException;
import java.nio.file.FileSystemNotFoundException;
import java.lang.IllegalArgumentException;
import java.lang.SecurityException;
import java.nio.channels.FileChannel;
import java.nio.channels.*;
import static java.nio.file.StandardOpenOption.*;
import java.lang.Enum;
import java.nio.charset.Charset;
/**
* The PrintText application expands on the
* PrintExample application in that it images
* text on to the single page printed.
*/
public class PrintText implements Printable {
//Create a file chooser
//final JFileChooser fc = new JFileChooser();
/**
* The text to be printed.
*/
private static final String mText =
"test";
/**
* Our text in a form for which we can obtain a
* AttributedCharacterIterator.
*/
public static void main(String[] args) {
JFileChooser chooser = new JFileChooser();
chooser.showOpenDialog(null);
File file = chooser.getSelectedFile();
String filename = file.getName();
System.out.println("You have selected: " + filename);
}
public static String readFile(String file, String csName)
throws IOException {
Charset cs = Charset.forName(csName);
return readFile(file, cs);
}
public static String readFile(String file, Charset cs)
throws IOException {
// No real need to close the BufferedReader/InputStreamReader
// as they're only wrapping the stream
FileInputStream stream = new FileInputStream(file);
try {
Reader reader = new BufferedReader(new InputStreamReader(stream, cs));
StringBuilder builder = new StringBuilder();
char[] buffer = new char[8192];
int read;
while ((read = reader.read(buffer, 0, buffer.length)) > 0) {
builder.append(buffer, 0, read);
}
return builder.toString();
} finally {
// Potential issue here: if this throws an IOException,
// it will mask any others. Normally I'd use a utility
// method which would log exceptions and swallow them
stream.close();
}
}
private static final AttributedString mStyledText = new AttributedString(mText);
/**
* Print a single page containing some sample text.
*/
static public void main(String args[]) {
/* Get the representation of the current printer and
* the current print job.
*/
PrinterJob printerJob = PrinterJob.getPrinterJob();
/* Build a book containing pairs of page painters (Printables)
* and PageFormats. This example has a single page containing
* text.
*/
Book book = new Book();
book.append(new PrintText(), new PageFormat());
/* Set the object to be printed (the Book) into the PrinterJob.
* Doing this before bringing up the print dialog allows the
* print dialog to correctly display the page range to be printed
* and to dissallow any print settings not appropriate for the
* pages to be printed.
*/
printerJob.setPageable(book);
/* Show the print dialog to the user. This is an optional step
* and need not be done if the application wants to perform
* 'quiet' printing. If the user cancels the print dialog then false
* is returned. If true is returned we go ahead and print.
*/
boolean doPrint = printerJob.printDialog();
if (doPrint) {
try {
printerJob.print();
} catch (PrinterException exception) {
System.err.println("Printing error: " + exception);
}
}
}
/**
* Print a page of text.
*/
public int print(Graphics g, PageFormat format, int pageIndex) {
/* We'll assume that Jav2D is available.
*/
Graphics2D g2d = (Graphics2D) g;
/* Move the origin from the corner of the Paper to the corner
* of the imageable area.
*/
g2d.translate(format.getImageableX(), format.getImageableY());
/* Set the text color.
*/
g2d.setPaint(Color.black);
/* Use a LineBreakMeasurer instance to break our text into
* lines that fit the imageable area of the page.
*/
Point2D.Float pen = new Point2D.Float();
AttributedCharacterIterator charIterator = mStyledText.getIterator();
LineBreakMeasurer measurer = new LineBreakMeasurer(charIterator, g2d.getFontRenderContext());
float wrappingWidth = (float) format.getImageableWidth();
while (measurer.getPosition() < charIterator.getEndIndex()) {
TextLayout layout = measurer.nextLayout(wrappingWidth);
pen.y += layout.getAscent();
float dx = layout.isLeftToRight()? 0 : (wrappingWidth - layout.getAdvance());
layout.draw(g2d, pen.x + dx, pen.y);
pen.y += layout.getDescent() + layout.getLeading();
}
return Printable.PAGE_EXISTS;
}
}