java - JTextArea 作为控制台

Question

我在下面发布了两段代码。两种代码都可以单独使用。现在，当我运行文件 Easy 并单击“开始”按钮时，我希望实现类 AddNumber。我的意思是说，除了在控制台上运行 AddNumber，有什么方法可以让 AddNumber 在单击“开始”按钮后在第一个类中创建的 JTextArea 中运行？我想也许是通过 Action 监听器？(我们在按钮的情况下所做的方式)但我不确定。有没有其他方法可以让我的 JTextArea 充当其他 .java 文件的控制台？

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;


public class Easy extends JFrame{

    JTextArea text=new JTextArea();
    JPanel panel=new JPanel(new GridLayout(2,2));

    JButton button1 =new JButton("Start");

    public Easy(){

        panel.add(text);

        panel.add(button1);
        add(panel,BorderLayout.CENTER);

        button1.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent ae){
            //add code to call the other class and make the JTextArea act as a console
            }
        });
   }

   public static void main(String arg[]){
       Easy frame=new Easy();
       frame.setSize(300,100);
       frame.setVisible(true);
   }
}

第二类:

import java.util.Scanner;

class AddNumber
{
    public static void main(String args[])
    {
        int x, y, z;
        System.out.println("Enter two numbers to be added ");
        Scanner in = new Scanner(System.in);
        x = in.nextInt();
        y = in.nextInt();
        z = x + y;
        System.out.println("Sum of entered numbers = "+z);
    }
}

我看到一些帖子谈论 PrintStream.. 但我认为这不适用于此处。请帮帮我。谢谢:)

更新:好吧，我找到了这个链接:http://www.codeproject.com/Articles/328417/Java-Console-apps-made-easy#HowtousethisJavaConsole1它的工作原理是它显示“输入两个要相加的数字”......但是用户可以在哪里提供他的输入？

编辑:我只需要在我的类的主要方法中引用控制台......它工作......好吧，不完全像我希望的那样......但部分......输入仍然必须从 IDE 的终端..

Answer 1

如果您在 Google 上搜索:“stdout JTextArea”，您将找到几个链接来解决您的问题。

• http://www.coderanch.com/t/458147/GUI/java/Redirect-output-stderr-stdout-JTextArea
• Redirecting System.out to JTextPane
• http://www.jcreator.com/forums/index.php?showtopic=773

在最后一个链接中，buddybob 扩展了 java.io.OutputStream 以将标准输出打印到他的 JTextArea。我在下面包含了他的解决方案。

TextAreaOutputStream.java

/*
*
* @(#) TextAreaOutputStream.java
*
*/

import java.io.IOException;
import java.io.OutputStream;
import javax.swing.JTextArea;

/**
* An output stream that writes its output to a javax.swing.JTextArea
* control.
*
* @author  Ranganath Kini
* @see      javax.swing.JTextArea
*/
public class TextAreaOutputStream extends OutputStream {
    private JTextArea textControl;

    /**
     * Creates a new instance of TextAreaOutputStream which writes
     * to the specified instance of javax.swing.JTextArea control.
     *
     * @param control   A reference to the javax.swing.JTextArea
     *                  control to which the output must be redirected
     *                  to.
     */
    public TextAreaOutputStream( JTextArea control ) {
        textControl = control;
    }

    /**
     * Writes the specified byte as a character to the
     * javax.swing.JTextArea.
     *
     * @param   b   The byte to be written as character to the
     *              JTextArea.
     */
    public void write( int b ) throws IOException {
        // append the data as characters to the JTextArea control
        textControl.append( String.valueOf( ( char )b ) );
    }  
}

The TextAreaOutputStream extends the java.io.OutputStream class and overrides its write(int) method overload, this class uses a reference to a javax.swing.JTextArea control instance and then appends output to it whenever its write( int b ) method is called.

To use the TextAreaOutputStream class, [yo]u should use:

用法

// Create an instance of javax.swing.JTextArea control
JTextArea txtConsole = new JTextArea();

// Now create a new TextAreaOutputStream to write to our JTextArea control and wrap a
// PrintStream around it to support the println/printf methods.
PrintStream out = new PrintStream( new TextAreaOutputStream( txtConsole ) );

// redirect standard output stream to the TextAreaOutputStream
System.setOut( out );

// redirect standard error stream to the TextAreaOutputStream
System.setErr( out );

// now test the mechanism
System.out.println( "Hello World" );