String str = "中文";
     System.out.println(new String(new String((str.getBytes("GBK")),"iso8859-1").getBytes("iso8859-1"),"gbk"));
     System.out.println(new String(new String((str.getBytes("GBK")),"utf-8").getBytes("utf-8"),"gbk"));两种转换方式是否结果都是显示“中文”?为什么?