如何在 JFrame/JPanel 中可视化控制台 java

问题描述

我使用 Swing 库制作了一个 Java 程序.现在我想将我的控制台输出重定向到 JFrame 或 JPanel.

I made a Java program using Swing libraries. Now I would like to redirect my console outputs into a JFrame or JPanel.

推荐答案

你需要制作一个OutputStream，将输出重定向到文本区域并实现OutputStream接口的所有必要方法，然后在你的主程序中，将您的标准输出重定向到此流中.我在我的一个程序中使用了类似的东西:

You need to make an OutputStream that re-directs output to the text area and that implements all the necessary methods of the OutputStream interface, and then in your main program, redirect your Standard output into this stream. I've used something like this for one of my programs:

import java.io.IOException;
import java.io.OutputStream;

import javax.swing.JTextArea;
import javax.swing.SwingUtilities;

public class TextAreaOutputStream extends OutputStream {

   private final JTextArea textArea;
   private final StringBuilder sb = new StringBuilder();
   private String title;

   public TextAreaOutputStream(final JTextArea textArea, String title) {
      this.textArea = textArea;
      this.title = title;
      sb.append(title + "> ");
   }

   @Override
   public void flush() {
   }

   @Override
   public void close() {
   }

   @Override
   public void write(int b) throws IOException {

      if (b == '
')
         return;

      if (b == '
') {
         final String text = sb.toString() + "
";
         SwingUtilities.invokeLater(new Runnable() {
            public void run() {
               textArea.append(text);
            }
         });
         sb.setLength(0);
         sb.append(title + "> ");
         return;
      }

      sb.append((char) b);
   }
}

你可以用这个来演示它:

And you can demonstrate it with this:

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.PrintStream;
import javax.swing.*;

@SuppressWarnings("serial")
public class TextAreaOutputStreamTest extends JPanel {

   private JTextArea textArea = new JTextArea(15, 30);
   private TextAreaOutputStream taOutputStream = new TextAreaOutputStream(
         textArea, "Test");

   public TextAreaOutputStreamTest() {
      setLayout(new BorderLayout());
      add(new JScrollPane(textArea, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, 
            JScrollPane.HORIZONTAL_SCROLLBAR_NEVER));
      System.setOut(new PrintStream(taOutputStream));

      int timerDelay = 1000;
      new Timer(timerDelay , new ActionListener() {
         int count = 0;
         @Override
         public void actionPerformed(ActionEvent arg0) {

            // though this outputs via System.out.println, it actually displays
            // in the JTextArea:
            System.out.println("Count is now: " + count + " seconds");
            count++;
         }
      }).start();
   }

   private static void createAndShowGui() {
      JFrame frame = new JFrame("Test");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(new TextAreaOutputStreamTest());
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}

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