尝试将文本文件读入JTextArea [英] Trying to read a text file into a JTextArea
问题描述
我正在尝试打开一个文本文件并将其值添加到 String
变量中,然后设置为 JTextArea
。无论我做什么,它总是在textarea中什么都不返回。
我希望它改变文本,就像你点击清除按钮时一样,但是我想把它改成它所生成的 Test.txt
文件中的内容。
I'm trying to open a text file and add its value into a String
variable to then set in a JTextArea
. No matter what I do it always returns nothing in the textarea.
I want it change the text like it does when you hit the clear button, but I want to change it to what's in the Test.txt
file it makes.
package texteditor;
import java.awt.FlowLayout;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.StringSelection;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JTextArea;
public class GUI extends JFrame {
//GUI Variables
private JButton save;
private JButton clear;
private JButton copy;
private JButton paste;
private JButton open;
private JTextArea textField;
private StringSelection stringSelection;
private Clipboard clipboard;
String textFieldWritable;
public GUI() {
super("Text Editor");
//Sets Layout
setLayout(new FlowLayout());
save = new JButton("Save");
add(save);
clear = new JButton("Clear");
add(clear);
open = new JButton("Open");
add(open);
textField = new JTextArea(10, 35);
add(textField);
handler handle = new handler();
save.addActionListener(handle);
clear.addActionListener(handle);
}
private class handler implements ActionListener {
@Override
public void actionPerformed(ActionEvent event) {
if (event.getSource() == save) {
textFieldWritable = String.format("%s", textField.getText());
try {
FileWriter fileWrite = new FileWriter("Text.txt");
PrintWriter printWrite = new PrintWriter(fileWrite);
printWrite.println(textFieldWritable);
printWrite.close();
} catch (IOException e) {
JOptionPane.showMessageDialog(null,
"Error, File Already Exists!", "Error",
JOptionPane.ERROR_MESSAGE);
}
} else if (event.getSource() == clear) {
textField.setText("");
} else if (event.getSource() == open) {
try {
FileReader fileReader = new FileReader("Text.txt");
BufferedReader bufferedReader = new BufferedReader(fileReader);
String inputFile = "";
String textFieldReadable = bufferedReader.readLine();
while (textFieldReadable != null) {
inputFile += textFieldReadable;
textFieldReadable = bufferedReader.readLine();
}
System.out.println("inputFile");
} catch (FileNotFoundException ex) {
System.out.println("no such file exists");
} catch (IOException ex) {
System.out.println("unkownerror");
}
}
}
}
}
推荐答案
对我来说,看起来你从未将你读过的文字设置到文本区域。
To me, it looks like you never set the text you've read to the text area.
try {
FileReader fileReader = new FileReader("Text.txt");
BufferedReader bufferedReader = new BufferedReader(fileReader);
String inputFile = "";
String textFieldReadable = bufferedReader.readLine();
while (textFieldReadable != null){
inputFile += textFieldReadable;
textFieldReadable = bufferedReader.readLine();
}
System.out.println("inputFile");
// Opps //
textField.setText(inputFile);
}
catch (FileNotFoundException ex) {
System.out.println("no such file exists");
}
catch (IOException ex) {
System.out.println("unkownerror");
}
就我个人而言,我只使用 JTextComponent
并传递一个 Reader
并允许它自己阅读。
Personally, I'd just use the functionality provide by JTextComponent
and pass it a Reader
and allow it to read itself.
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileReader;
import java.io.Reader;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TextAreaReadTest {
public static void main(String[] args) {
new TextAreaReadTest();
}
public TextAreaReadTest() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JTextArea textArea;
public TestPane() {
setLayout(new BorderLayout());
textArea = new JTextArea(10, 80);
add(new JScrollPane(textArea));
JButton read = new JButton("Read");
read.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Reader reader = null;
try {
reader = new FileReader(new File("D:/SWANH.txt"));
textArea.read(reader, "The force is strong with this one");
} catch (Exception exp) {
exp.printStackTrace();
} finally {
try {
reader.close();
} catch (Exception exp) {
}
}
}
});
add(read, BorderLayout.SOUTH);
}
}
}
这篇关于尝试将文本文件读入JTextArea的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!