java里面byte数组和String字符串转换

//string 转 byte[]
String str = "问题";
byte[] srtbyte = str.getBytes();
// byte[] 转 string
String res = new String(srtbyte);
System.out.println(res);

当然还有可以设定 ​​编码方式​​ 的

String str = "问题";
 byte[] srtbyte = null;
 try {
 srtbyte = str.getBytes("UTF-8");
 String res = new String(srtbyte,"UTF-8");
 System.out.println(res);
 } catch (UnsupportedEncodingException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }