Question

java byte 怎么表示16进制

Answer 1

* Convert byte[] to hex string.这里我们可以将byte转换成int，然后利用Integer.toHexString(int)来转换成16进制字符串。
* @param src byte[] data
* @return hex string
*/
public static String bytesToHexString(byte[] src){
StringBuilder stringBuilder = new StringBuilder("");
if (src == null || src.length <= 0) {
return null;
}
for (int i = 0; i < src.length; i++) {
int v = src[i] & 0xFF;
String hv = Integer.toHexString(v);
if (hv.length() < 2) {
stringBuilder.append(0);
}
stringBuilder.append(hv);
}
return stringBuilder.toString();
}
/**
* Convert hex string to byte[]
* @param hexString the hex string
* @return byte[]
*/
public static byte[] hexStringToBytes(String hexString) {
if (hexString == null || hexString.equals("")) {
return null;
}
hexString = hexString.toUpperCase();
int length = hexString.length() / 2;
char[] hexChars = hexString.toCharArray();
byte[] d = new byte[length];
for (int i = 0; i < length; i++) {
int pos = i * 2;
d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
}
return d;
}
/**
* Convert char to byte
* @param c char
* @return byte
*/
private byte charToByte(char c) {
return (byte) "0123456789ABCDEF".indexOf(c);
}

Answer 2

* Convert byte[] to hex string.这里我们可以将byte转换成int，然后利用Integer.toHexString(int)来转换成16进制字符串。
* @param src byte[] data
* @return hex string
*/
public static String bytesToHexString(byte[] src){
StringBuilder stringBuilder = new StringBuilder("");
if (src == null || src.length <= 0) {
return null;
}
for (int i = 0; i < src.length; i++) {
int v = src[i] & 0xFF;
String hv = Integer.toHexString(v);
if (hv.length() < 2) {
stringBuilder.append(0);
}
stringBuilder.append(hv);
}
return stringBuilder.toString();
}
/**
* Convert hex string to byte[]
* @param hexString the hex string
* @return byte[]
*/
public static byte[] hexStringToBytes(String hexString) {
if (hexString == null || hexString.equals("")) {
return null;
}
hexString = hexString.toUpperCase();
int length = hexString.length() / 2;
char[] hexChars = hexString.toCharArray();
byte[] d = new byte[length];
for (int i = 0; i < length; i++) {
int pos = i * 2;
d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
}
return d;
}
/**
* Convert char to byte
* @param c char
* @return byte
*/
private byte charToByte(char c) {
return (byte) "0123456789ABCDEF".indexOf(c);
}

Answer 3

一个byte可以被2个十六进制字符表示
比如 FF 01 12 32 是4个byte

Answer 4

byte a=0x4a;
带上0x就行了