程序运行后，运行效果如下图所示

import javax.swing.*;
public class Java_2 {
    public static void main(String args[]) {
        StringBuffer buf = new StringBuffer("你好!祝你成功!");
        String output = "buf = " + buf.toString()
                + "\nCharacter at 0: " + buf.charAt(0)
                + "\nCharacter at 4: " + buf.charAt(4);
        //*********Found********** 
        char charArray[] = _______________ char[buf.length()]; 
        //*********Found********** 
        buf.____________________(0, buf.length(), charArray, 0);
        output += "\n\n在字符串缓存中的字符是: ";
        //*********Found********** 
        for (int i = 0; i < ______________________; ++i) {
            output += charArray[ i];
        }
        buf.setCharAt(0, '您');
        buf.setCharAt(6, '材');
        output += "\n\nbuf = " + buf.toString();
        //*********Found********** 
        buf.______________________;
        output += "\n\nbuf = " + buf.toString();
        JOptionPane.showMessageDialog(null, output,
                "字符串缓存的字符相关方法示范",
                JOptionPane.INFORMATION_MESSAGE);
        System.exit(0);
    }
}