Java输入流编码/字符集

Question

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] (char)? (int)63
test.java:10 [char] (char)? (int)229
test.java:11 string below
?
test.java:13 string above

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