运行以下（示例）代码

import java.io.*;

public class test {
    public static void main(String[] args) throws Exception {
        byte[] buf = {-27};
        InputStream is = new ByteArrayInputStream(buf);
        BufferedReader r = new BufferedReader(
                new InputStreamReader(is, "ISO-8859-1"));
        String s = r.readLine();
        System.out.println("test.java:9 [byte] (char)" + (char)s.getBytes()[0] + 
                " (int)" + (int)s.getBytes()[0]);
        System.out.println("test.java:10 [char] (char)" + (char)s.charAt(0) + 
                " (int)" + (int)s.charAt(0));
        System.out.println("test.java:11 string below");
        System.out.println(s);
        System.out.println("test.java:13 string above");
    }
}

给我这个输出

test.java:9 [byte]（字符）？（整数）63
test.java:10 [char]（char）？（整数）229
test.java:11下面的字符串
？
test.java:13字符串以上

如何在第9行打印输出中保留正确的字节值（-27）？因此，将收到System.out.println(s)命令的预期输出（å）。