public static String ChineseToASCII(byte[] rec) { //从字节读取内容
   ByteArrayInputStream bais = new ByteArrayInputStream(rec);
   DataInputStream dis = new DataInputStream(bais);
   String BTS=null;
   try {
   BTS=new String(rec,"ISO8859-1");//转换编码
   bais.close();
   dis.close();
   } catch (Exception e) {
   e.printStackTrace();
   }
   return BTS;
 }
  /**
   * @param args the command line arguments
   */
  public static void main(String[] args) {
    String source="一二三四五六七八九十";
    System.out.println(source.length());
    String target=ChineseToASCII(source.getBytes());
    System.out.println(target);
    System.out.println(target.length());
  }

compile:
run:
10
???????????ù??°????? ASCII字符如果超过128，则会显示为？，但是其本身的值不变
20
BUILD SUCCESSFUL (total time: 1 second)