JAVA：如何将消息框与多个输出相结合

Question

我正在学习 Java，并且有一个相当简单的程序，它根据 Collatz Conjecture 返回一系列数字。我可以将它输出到控制台或弹出许多JOptionPane.showMessageDialog() 窗口，每个窗口都有一个。

如何将JOptionPane.showMessageDialog() 组合起来以在一个JOptionPane.showMessageDialog() 中显示所有输出？

代码：

package collatz;

import java.util.Random;
import javax.swing.*;

public class Collatz {

/**
 * Demonstrates the Collatz Cojecture
 * with a randomly generated number
 */

public static void main(String[] args) {
    Random randomGenerator = new Random();
    int n = randomGenerator.nextInt(1000);

    JOptionPane.showMessageDialog(null, "The randomly generated number was: " + n);


    while(n > 1){
        if(n % 2 == 0){
            n = n / 2;
            JOptionPane.showMessageDialog(null, n);
        }
        else{
            n = 3 * n + 1;
            JOptionPane.showMessageDialog(null, n);
        }
    }

    JOptionPane.showMessageDialog(null, n);
    JOptionPane.showMessageDialog(null, "Done.");

}

}

谢谢！

-- ZuluDeltaNiner

Answer 1

跟踪要显示的完整字符串，然后在末尾显示：

public static void main(String[] args) {
    Random randomGenerator = new Random();
    int n = randomGenerator.nextInt(1000);

    StringBuilder output = new StringBUilder("The randomly generated number was: " + n + "\n");

    while(n > 1){
        if(n % 2 == 0){
            n = n / 2;
        }
        else{
            n = 3 * n + 1;
        }
        output.append(n + "\n");
    }

    output.append("Done.");
    JOptionPane.showMessageDialog(null, output);

}