Java JTextArea 作为控制台

JTextArea as console

提问by nicki

I have posted two pieces of code below. Both codes work fine individually. Now, when I run the file Easy, and click on the "Start" button, I want the class AddNumber to be implemented. I mean to say that, instead of the AddNumber running on the console, is there any way I could make AddNumber run in the JTextArea i have created in the first class upon clicking the "Start" button? I thought maybe by action listener?(the way we do in case of buttons) But I'm not sure. Is there any other way to make my JTextArea act as a console for the other .java files?

我在下面发布了两段代码。两个代码单独工作正常。现在，当我运行 Easy 文件并单击“开始”按钮时，我希望实现类 AddNumber。我的意思是说，不是在控制台上运行 AddNumber，有什么方法可以让 AddNumber 在我单击“开始”按钮后在第一类中创建的 JTextArea 中运行？我想也许是通过动作监听器？（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);
   }
}

The second class:

第二课：

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);
    }
}

I have seen a few posts talking about PrintStream..but i don't think that applies here. Please help me out. Thanks :)

我看过一些关于 PrintStream 的帖子……但我认为这不适用于这里。请帮帮我。谢谢 ：）

UPDATE: well i found this link: http://www.codeproject.com/Articles/328417/Java-Console-apps-made-easy#HowtousethisJavaConsole1and it works in the sense that it shows "Enter two numbers to be added "...but where can the user provide his input?

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

EDIT: I just had to make a reference of the console in the main method of my class...and it works... well, not exactly as i would've wished to..but partly..the input still has to go from the terminal of the IDE..

编辑：我只需要在我的班级的主要方法中引用控制台......它可以工作......好吧，不完全是我希望的......但部分......输入仍然必须从IDE的终端去..

回答by Mr. Polywhirl

If you do a Google search for: "stdout JTextArea", you will a couple of links to solve your problem.

如果您在 Google 上搜索：“stdout JTextArea”，您将获得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

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

In the last link, buddybobextends java.io.OutputStreamto print standard output to his JTextArea. I included his solution below.

在最后一个链接中，buddybob扩展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

文本区域输出流.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 TextAreaOutputStreamextends the java.io.OutputStreamclass and overrides its write(int)method overload, this class uses a reference to a javax.swing.JTextAreacontrol instance and then appends output to it whenever its write( int b ) method is called.

To use the TextAreaOutputStreamclass, [yo]u should use:

在TextAreaOutputStream扩展了java.io.OutputStream类和覆盖其write(int)方法的过载，这类使用的参考javax.swing.JTextArea控制实例，然后输出附加到它时，它的写（INT B）方法被调用。

要使用这个TextAreaOutputStream类，[你]你应该使用：

Usage

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" );