System.out.println(str);
String str1 = new String(str.getBytes("ISO-8859-1"), "utf-8");
System.out.println(str1);
String str2 = new String(str.getBytes("gb2312"), "utf-8");
System.out.println(str2);
String str3 = new String(str.getBytes("gbk"), "utf-8");
System.out.println(str3);
str.getBytes(charsetName);charsetName是原本字符的编码
"utf-8"是将str转换为utf-8编码。