java 将 System.out 重定向到 JTextPane
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Redirecting System.out to JTextPane
提问by Jakir00
I have a class (shown below) that extends JPaneland contains a JTextPane. I want to redirect System.outand System.errto my JTextPane. My class does not seem to work. When I run it, it does redirect the system prints, but they do not print to my JTextPane. Please help!
我有一个类（如下所示），它扩展JPanel并包含一个JTextPane. 我想重定向System.out和System.err我JTextPane。我的课似乎不起作用。当我运行它时，它会重定向系统打印，但它们不会打印到我的JTextPane. 请帮忙！
Note:The calls are only redirected when the application launches. But any time after launch, the System.outcalls are not redirected to the JTextPane. (ie, if I place a System.out.prinln();in the class, it will be called, but if it is placed in a actionListenerfor later use, it does not redirect).
注意：调用仅在应用程序启动时重定向。但是在启动后的任何时候，System.out调用都不会重定向到JTextPane. （即，如果我System.out.prinln();在类中放置 a ，它将被调用，但如果将其放置在 a 中actionListener供以后使用，则不会重定向）。
public class OSXConsole extends JPanel {
public static final long serialVersionUID = 21362469L;
private JTextPane textPane;
private PipedOutputStream pipeOut;
private PipedInputStream pipeIn;
public OSXConsole() {
super(new BorderLayout());
textPane = new JTextPane();
this.add(textPane, BorderLayout.CENTER);
redirectSystemStreams();
textPane.setBackground(Color.GRAY);
textPane.setBorder(new EmptyBorder(5, 5, 5, 5));
}
private void updateTextPane(final String text) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
Document doc = textPane.getDocument();
try {
doc.insertString(doc.getLength(), text, null);
} catch (BadLocationException e) {
throw new RuntimeException(e);
}
textPane.setCaretPosition(doc.getLength() - 1);
}
});
}
private void redirectSystemStreams() {
OutputStream out = new OutputStream() {
@Override
public void write(final int b) throws IOException {
updateTextPane(String.valueOf((char) b));
}
@Override
public void write(byte[] b, int off, int len) throws IOException {
updateTextPane(new String(b, off, len));
}
@Override
public void write(byte[] b) throws IOException {
write(b, 0, b.length);
}
};
System.setOut(new PrintStream(out, true));
System.setErr(new PrintStream(out, true));
}
}
采纳答案by camickr
Piped streams always confuse me, which is why my Message Console solution doesn't use them. Anyway here is my attempt at a console using piped streams. A couple of differences:
管道流总是让我感到困惑，这就是我的消息控制台解决方案不使用它们的原因。无论如何，这是我在使用管道流的控制台上的尝试。几个不同点：
a) it uses a JTextArea because a JTextArea is more efficient than a JTextPane for just displaying text. Of course if you intend to add attributes to the text then you need a text pane.
a) 它使用 JTextArea，因为 JTextArea 比仅显示文本的 JTextPane 更有效。当然，如果您打算向文本添加属性，那么您需要一个文本窗格。
b) this solution uses Threads. I'm sure I read somewhere that this was necessary to prevent blocking of the output. Anyway it works in my simple test case.
b) 此解决方案使用线程。我确定我在某处读到过，这是防止阻塞输出所必需的。无论如何，它适用于我的简单测试用例。
import java.io.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
public class Console implements Runnable
{
JTextArea displayPane;
BufferedReader reader;
private Console(JTextArea displayPane, PipedOutputStream pos)
{
this.displayPane = displayPane;
try
{
PipedInputStream pis = new PipedInputStream( pos );
reader = new BufferedReader( new InputStreamReader(pis) );
}
catch(IOException e) {}
}
public void run()
{
String line = null;
try
{
while ((line = reader.readLine()) != null)
{
// displayPane.replaceSelection( line + "\n" );
displayPane.append( line + "\n" );
displayPane.setCaretPosition( displayPane.getDocument().getLength() );
}
System.err.println("im here");
}
catch (IOException ioe)
{
JOptionPane.showMessageDialog(null,
"Error redirecting output : "+ioe.getMessage());
}
}
public static void redirectOutput(JTextArea displayPane)
{
Console.redirectOut(displayPane);
Console.redirectErr(displayPane);
}
public static void redirectOut(JTextArea displayPane)
{
PipedOutputStream pos = new PipedOutputStream();
System.setOut( new PrintStream(pos, true) );
Console console = new Console(displayPane, pos);
new Thread(console).start();
}
public static void redirectErr(JTextArea displayPane)
{
PipedOutputStream pos = new PipedOutputStream();
System.setErr( new PrintStream(pos, true) );
Console console = new Console(displayPane, pos);
new Thread(console).start();
}
public static void main(String[] args)
{
JTextArea textArea = new JTextArea();
JScrollPane scrollPane = new JScrollPane( textArea );
JFrame frame = new JFrame("Redirect Output");
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.getContentPane().add( scrollPane );
frame.setSize(200, 100);
frame.setVisible(true);
Console.redirectOutput( textArea );
final int i = 0;
Timer timer = new Timer(1000, new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.out.println( new java.util.Date().toString() );
System.err.println( System.currentTimeMillis() );
}
});
timer.start();
}
}
回答by camickr
Message Consoleclass does this for you.
Message Console类会为您执行此操作。
Edit:
编辑：
Here is a simple test class:
这是一个简单的测试类：
import java.io.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
public class MessageConsoleTest
{
public static int counter;
public static void main(String[] args)
throws Exception
{
JTextComponent textComponent = new JTextPane();
JScrollPane scrollPane = new JScrollPane( textComponent );
JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame("Message Console");
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.getContentPane().add( scrollPane );
frame.setSize(400, 120);
frame.setVisible(true);
MessageConsole console = new MessageConsole(textComponent);
console.redirectOut();
console.redirectErr(Color.RED, null);
Timer timer = new Timer(1000, new java.awt.event.ActionListener()
{
public void actionPerformed(java.awt.event.ActionEvent e)
{
System.out.println( new java.util.Date().toString() );
}
});
timer.start();
Thread.sleep(750);
Timer timer2 = new Timer(1000, new java.awt.event.ActionListener()
{
public void actionPerformed(java.awt.event.ActionEvent e)
{
System.err.println( "Error Message: " + ++counter);
}
});
timer2.start();
}
}
回答by eniel.rod
In the following linkyou can find the MessageConsole class that someone mentioned. I implemented a software and used this solution and it works perfect for me. I used the Netbeans design tool, so the code regarding the visual appearance of the JTextPane is a bit cumbersome, so I'm not going to place it here.
在以下链接中，您可以找到有人提到的 MessageConsole 类。我实现了一个软件并使用了这个解决方案，它非常适合我。我用的是Netbeans的设计工具，所以关于JTextPane的视觉外观的代码有点繁琐，这里就不放了。
JTextPane jTextPane = new JTextPane();
MessageConsole console = new MessageConsole(jTextPane);
/*
This parameters are optional, but if you are looking for a solution with JTextPane it is because you need them, at least color.
*/
console.redirectErr(Color.RED, null);
console.redirectOut();
//some event
private void jButton1ActionPerformed(ActionEvent evt) {
/*
In this event I execute a function of my business.
I put it in a thread so that it does not block the graphical interface.
There are many calls to System.out.println() and System.err.println()
*/
BusinessClass bc = new BusinessClass();
Runnable runnable = () -> {
bc.someBusinessFn();
};
thread = new Thread(runnable);
thread.start();
}
//My main method
public static void main(String args[]) {
/* Create and display the GUI */
EventQueue.invokeLater(() -> {
new MyJFrame().setVisible(true);
});
}
Edit
编辑
Sorry, I did not realize that in the response similar to this, they had put the link to the MessageConsole class. I didn't see it and I also wanted to show my solution.
抱歉，我没有意识到在与此类似的响应中，他们已经放置了 MessageConsole 类的链接。我没有看到它，我也想展示我的解决方案。
