Java 以后如何在循环中使用变量
我不确定这是否可行，我很新，希望你们中的一些人能对此有所了解，我有一个函数，可以读取txt文件的所有内容，然后在终端窗口中打印出来，但是我希望能够将文本文件的数据存储在一个变量中，以便我以后可以使用它。这可能吗 以下是代码的剪报位：Java 以后如何在循环中使用变量,java,Java,我不确定这是否可行，我很新，希望你们中的一些人能对此有所了解，我有一个函数，可以读取txt文件的所有内容，然后在终端窗口中打印出来，但是我希望能够将文本文件的数据存储在一个变量中，以便我以后可以使用它。这可能吗 以下是代码的剪报位： String mText; while((mText = br.readLine()) != null) { //Displays the contents of the file in terminal
String mText;
while((mText = br.readLine()) != null) {
//Displays the contents of the file in terminal
System.out.println(mText);
}
import java.awt.*;
import java.awt.font.*;
import java.awt.geom.*;
import java.awt.print.*;
import java.text.*;
import java.io.*;
import javax.swing.*;
public class PrintText implements Printable {
private static String mText;
// Below the code will allow the user to select a file and then print out the contents of the file
public static void main(String[] args) throws IOException {
//selects the file
JFileChooser chooser = new JFileChooser();
chooser.showOpenDialog(null);
File file = chooser.getSelectedFile();
String filename = file.getName();
//System.out.println("You have selected: " + filename); testing to see if file seleected was right
String path = file.getAbsolutePath();
//Reads contents of file into terminal
//FileReader fr = new FileReader("filename");
// FileReader fr = new FileReader("D:/Documents/" + "filename"));
FileReader fr = new FileReader(path);
BufferedReader br = new BufferedReader(fr);
String mText;
while((mText = br.readLine()) != null) {
//Displays the contents of the file in terminal
System.out.println(mText);
}
//fr.close();
}
//private static final String mText =
// "This is a test to see if this text will be printed "; //This works perfectly fine
AttributedString mStyledText = new AttributedString(mText);
/**
* Print a single page containing some sample text.
*/
static public void printer(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;
}
}
import java.awt.*；
导入java.awt.font.*；
导入java.awt.geom.*；
导入java.awt.print.*；
导入java.text.*；
导入java.io.*；
导入javax.swing.*；
公共类PrintText实现了可打印的{
私有静态字符串多行文字；
//下面的代码将允许用户选择一个文件，然后打印出文件的内容
公共静态void main（字符串[]args）引发IOException{
//选择文件
JFileChooser chooser=新的JFileChooser（）；
chooser.showOpenDialog（空）；
File File=chooser.getSelectedFile（）；
字符串文件名=file.getName（）；
//System.out.println（“您已选择：“+filename”）；测试所选文件是否正确
字符串路径=file.getAbsolutePath（）；
//将文件内容读入终端
//FileReader fr=新的FileReader（“文件名”）；
//FileReader fr=新的FileReader（“D:/Documents/“+”filename”）；
FileReader fr=新的FileReader（路径）；
BufferedReader br=新的BufferedReader（fr）；
字符串多行文字；
而（（mText=br.readLine（））！=null）{
//在终端中显示文件的内容
System.out.println（多行文字）；
}
//fr.close（）；
}
//私有静态最终字符串多行文字=
//“这是一个测试，看看这个文本是否会被打印出来”；//这很好用
AttributedString mStyledText=新的AttributedString（多行文字）；
/**
*打印包含一些示例文本的单个页面。
*/
静态公用无效打印机（字符串参数[]）{
/*获取当前打印机和打印机的表示形式
*当前打印作业。
*/
PrinterJob PrinterJob=PrinterJob.getPrinterJob（）；
/*创建一本包含成对页面绘制者的书（可打印）
*和页面格式。此示例有一个包含
*文本。
*/
书=新书（）；
book.append（新的PrintText（），新的PageFormat（））；
/*将要打印的对象（书本）设置为PrinterJob。
*在打开“打印”对话框之前执行此操作将允许
*“打印”对话框以正确显示要打印的页面范围
*以及不允许任何不适合的打印设置
*要打印的页面。
*/
printerJob.setPageable（书本）；
/*向用户显示打印对话框。这是可选步骤
*如果应用程序想要执行，则不需要执行
*“安静”打印。如果用户取消打印对话框，则为false
*返回。如果返回true，则继续打印。
*/
布尔doPrint=printerJob.printDialog（）；
if（doPrint）{
试一试{
printerJob.print（）；
}捕获（PrinterException异常）{
System.err.println（“打印错误：+异常”）；
}
}
}
/**
*打印一页文本。
*/
公共整型打印（图形g、页面格式、整型页面索引）{
/*我们假设Jav2D是可用的。
*/
Graphics2D g2d=（Graphics2D）g；
/*将原点从纸张的一角移动到另一角
*可成像区域的面积。
*/
translate（format.getImageableX（），format.getImageableY（））；
/*设置文本颜色。
*/
g2d.setPaint（颜色：黑色）；
/*使用LineBreakMeasurer实例将文本拆分为
*适合页面可成像区域的行。
*/
Point2D.Float pen=新的Point2D.Float（）；
AttributedCharacterIterator charIterator=mStyledText.getIterator（）；
LineBreakMeasurer measurer=新的LineBreakMeasurer（charIterator，g2d.getFontRenderContext（））；
float wrappingWidth=（float）format.getImageableWidth（）；
while（measurer.getPosition（）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 java.util.List;
import java.util.ArrayList;
public class PrintText implements Printable {
/** private static String mText;
// Below the code will allow the user to select a file and then print out the contents of the file
public static void main(String[] args) throws IOException {
//selects the file
JFileChooser chooser = new JFileChooser();
chooser.showOpenDialog(null);
File file = chooser.getSelectedFile();
String filename = file.getName();
//System.out.println("You have selected: " + filename); testing to see if file seleected was right
String path = file.getAbsolutePath();
//Reads contents of file into terminal
//FileReader fr = new FileReader("filename");
// FileReader fr = new FileReader("D:/Documents/" + "filename"));
FileReader fr = new FileReader(path);
BufferedReader br = new BufferedReader(fr);
List<String> list = new ArrayList<String>();
while((mText = br.readLine()) != null) {
//Displays the contents of the file in terminal
System.out.println(mText);
list.add(mText);
}
//fr.close();
}
*/
private static final String mText =
"This is a test to see if this text will be printed "; //This works perfectly fine
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;
}
}
import java.awt.*；
导入java.awt.font.*；
导入java.awt.geom.*；
导入java.awt.print.*；
导入java.text.*；
导入java.io.*；
导入javax.swing.*；
导入java.util.List；
导入java.util.ArrayList；
公共类PrintText实现了可打印的{
/**私有静态字符串多行文字；
//下面的代码将允许用户选择一个文件，然后打印出文件的内容
公共静态void main（字符串[]args）引发IOException{
//选择文件
JFileChooser chooser=新的JFileChooser（）；
chooser.showOpenDialog（空）；
File File=chooser.getSelectedFile（）；
字符串文件名=file.getName（）；
//System.out.println（“您有
String mText = null;
List<String> list = new ArrayList<String>();
while((mText = br.readLine()) != null) {
//Displays the contents of the file in terminal
System.out.println(mText);
list.add(mText);
}
StringBuilder sb= new StringBuilder();
String mText;
while ((mText = br.readLine()) != null) {
//Displays the contents of the file in terminal
System.out.println(mText);
sb.append(mText).append('\n');
}
// now the whole content of the BufferedReader is stored in sb.