java - 从控制台输出到 GUI Java 中的 TextArea

Question

我是 Java 的真正初学者，正在尝试将控制台输出重定向到我用 Java (Netbeans) 制作的 GUI 的 TextArea。

这是一个更大项目的一部分，但我首先创建了一个小程序，它将数据输出到控制台和一个仅读取这一行的 GUI。有人可以帮我完成这件事吗？我已经尝试了几种包含append、JFrame等的解决方案，但仍然没有成功。

提前谢谢您!

在控制台上显示文本的程序是:

public class ConsoleToGUI {

    public void run(){
        for (int i = 0; i < 5; i++){
            System.out.println("Test program");
        }
    }

    public static void main(String[] args){
        ConsoleToGUI ctg = new ConsoleToGUI();
        ctg.run();
    }

我用 TextArea 创建的 GUI:

更新下面我发布了三个类(包括GUI代码)，这三个类是我根据dosenfant的解决方案进行调整的，谢谢!然而，我可能仍然做错了什么，因为它还没有工作。请您多多指教!

import java.io.PrintStream;
import javax.swing.*;

public class ConsoleToGUI {

public ConsoleToGUI() {
    DisplayUI gui = new DisplayUI();
    System.setOut(new PrintStream(new RedirectingOutputStream(gui), true));
    gui.start();
}


public void run(){

    for (int i = 0; i < 5; i++){
    JTextArea jTextArea1 = new JTextArea();
    System.out.println("Test program");
    }
}

public static void main(String[] args){
    ConsoleToGUI ctg = new ConsoleToGUI();
    ctg.run();
 }
}  

GUI 类

public class DisplayUI extends javax.swing.JFrame {

/**
 * Creates new form DislapUI
 */
public DisplayUI() {
    initComponents();
}

/**
 * This method is called from within the constructor to initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is always
 * regenerated by the Form Editor.
 */
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    jPanel1 = new javax.swing.JPanel();
    jScrollPane1 = new javax.swing.JScrollPane();
    jTextArea1 = new javax.swing.JTextArea();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jPanel1.setBorder(javax.swing.BorderFactory.createTitledBorder(null, 
    "Console Output: ", 
    javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION, 
    javax.swing.border.TitledBorder.DEFAULT_POSITION, new 
    java.awt.Font("Tahoma", 1, 11), new java.awt.Color(51, 153, 255))); // 
    NOI18N

    jTextArea1.setEditable(false);
    jTextArea1.setColumns(20);
    jTextArea1.setRows(5);
    jScrollPane1.setViewportView(jTextArea1);

    javax.swing.GroupLayout jPanel1Layout = new 
    javax.swing.GroupLayout(jPanel1);
    jPanel1.setLayout(jPanel1Layout);
    jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 348, Short.MAX_VALUE)
            .addContainerGap())
    );
    jPanel1Layout.setVerticalGroup(
        jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(jPanel1Layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 70, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(15, Short.MAX_VALUE))
    );

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addContainerGap())
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
    );

    pack();
}// </editor-fold>                        

/**
 * @param args the command line arguments
 */
public static void main(String args[]) {
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    try {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(DisplayUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(DisplayUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(DisplayUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(DisplayUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new DisplayUI().setVisible(true);
        }
    });
}

public void start() {
    jPanel1.setVisible(true);
}

public void appendText(String text) {
    jTextArea1.append(text);
}

// Variables declaration - do not modify                     
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextArea jTextArea1;
// End of variables declaration                   

}

重定向输出流
导入java.io.IOException； 导入java.io.OutputStream;

public class RedirectingOutputStream extends OutputStream {

    private DisplayUI gui;

    public RedirectingOutputStream(DisplayUI gui) {
        this.gui = gui;
    }

    @Override
    public void write(int b) throws IOException {
        gui.appendText(String.valueOf((char) b));
    }
 }

Answer 1

如果你想在清除JTextArea后写入，可以使用以下内容:

jTextArea.setText("Test program");

如果您希望新文本出现在旧文本之后:

jTextArea.append("Test program");