public class ByteTool {
/**
* byte to int
*
* @param b
* 待转换的字节数组
* @param offset
* 偏移量，字节数组中开始转换的位置
* @return
*/
public static int byte2int(byte b[], int offset) {
return b[offset + 3] & 0xff | (b[offset + 2] & 0xff) << 8
| (b[offset + 1] & 0xff) << 16 | (b[offset] & 0xff) << 24;
}
public static short byte2short(byte b[], int offset) {
return (short)(b[offset + 1] & 0xff | (b[offset] & 0xff) << 8);
}
/**
* int to byte
*
* @param n待转换的整形变量
* @param buf
* 转换后生成的字节数组
* @param offset
* 偏移量，字节数组中开始存放的位置
*/
public static void int2byte(int n, byte buf[], int offset) {
buf[offset] = (byte) (n >> 24);
buf[offset + 1] = (byte) (n >> 16);
buf[offset + 2] = (byte) (n >> 8);
buf[offset + 3] = (byte) n;
}
/**
* @returntype void
* @param n
* 待转换的short变量
* @param buf
* 转换后存放的byte数组
* @param offset偏移量，字节数组中开始存放的位置
*/
public static void short2byte(int n, byte buf[], int offset) {
buf[offset] = (byte) (n >> 8);
buf[offset + 1] = (byte) n;
}
/**
*
* @param buf
* @return
*/
public static String byte2Hex(byte[] buf) {
StringBuffer sb = new StringBuffer();
//sb.append("{");
for (byte b : buf) {
if (b == 0) {
sb.append("00");
} else if (b == -1) {
sb.append("FF");
} else {
String str = Integer.toHexString(b).toUpperCase();
// sb.append(a);
if (str.length() == 8) {
str = str.substring(6, 8);
} else if (str.length() < 2) {
str = "0" + str;
}
sb.append(str);
}
//sb.append(" ");
}
//sb.append("}");
return sb.toString();
}
public static int unsignedByteToInt(byte b) {
return (int) b & 0xFF;
}
/**
* convert signed one byte into a hexadecimal digit
*
* @param b
* byte
* @return convert result
*/
public static String byteToHex(byte b) {
int i = b & 0xFF;
return Integer.toHexString(i);
}
/**
* convert signed 4 bytes into a 32-bit integer
*
* @param buf
* bytes buffer
* @param pos
* beginning <code>byte</code>> for converting
* @return convert result
*/
public static long unsigned4BytesToInt(byte[] buf, int pos) {
int firstByte = 0;
int secondByte = 0;
int thirdByte = 0;
int fourthByte = 0;
int index = pos;
firstByte = (0x000000FF & ((int) buf[index]));
secondByte = (0x000000FF & ((int) buf[index + 1]));
thirdByte = (0x000000FF & ((int) buf[index + 2]));
fourthByte = (0x000000FF & ((int) buf[index + 3]));
index = index + 4;
return ((long) (firstByte << 24 | secondByte << 16 | thirdByte << 8 | fourthByte)) & 0xFFFFFFFFL;
}
public static long bytes2long(byte[] b) {
int mask = 0xff;
long temp = 0;
long res = 0;
for (int i = 0; i < 8; i++) {
res <<= 8;
temp = b[i] & mask;
res |= temp;
}
return res;
}
public static byte[] long2bytes(long num) {
byte[] b = new byte[8];
for (int i = 0; i < 8; i++) {
b[i] = (byte) (num >>> (56 - i * 8));
}
return b;
}
public static long getLong(byte[] bb, int index) {
return ((((long) bb[index + 0] & 0xff) << 56)
| (((long) bb[index + 1] & 0xff) << 48)
| (((long) bb[index + 2] & 0xff) << 40)
| (((long) bb[index + 3] & 0xff) << 32)
| (((long) bb[index + 4] & 0xff) << 24)
| (((long) bb[index + 5] & 0xff) << 16)
| (((long) bb[index + 6] & 0xff) << 8) | (((long) bb[index + 7] & 0xff) << 0));
}
public static void putLong(byte[] bb, long x, int index) {
bb[index + 0] = (byte) (x >> 56);
bb[index + 1] = (byte) (x >> 48);
bb[index + 2] = (byte) (x >> 40);
bb[index + 3] = (byte) (x >> 32);
bb[index + 4] = (byte) (x >> 24);
bb[index + 5] = (byte) (x >> 16);
bb[index + 6] = (byte) (x >> 8);
bb[index + 7] = (byte) (x >> 0);
}
public static void putShort(byte b[], short s, int index) {
b[index] = (byte) (s >> 8);
b[index + 1] = (byte) (s >> 0);
}
public static short getShort(byte[] b, int index) {
return (short) (((b[index] << 8) | b[index + 1] & 0xff));
}
public static byte[] subArray(byte[] srcByte,int nStart, int nLength ){
byte[] ret = new byte[nLength];
System.arraycopy(srcByte, nStart, ret, 0, nLength);
return ret;
}
public static void main(String[] args){
byte[] b=new byte[3];
int year_offset=15; //2*2*2*2=16 > 16year[support:2011~2026] 00001011
int month=12; //2*2*2*2=16 > 12months 00000111
int day=31; //2*2*2*2*2=32 > 31days 00011111
int hour=24; //2*2*2*2*2=32 > 24hours 00010001
int min=59; //2*2*2*2*2*2=64 > 60minitues 00001001
// int year_offset=1; //2*2*2*2=16 > 16year[support:2011~2026] 00001011
// int month=1; //2*2*2*2=16 > 12months 00000111
// int day=1; //2*2*2*2*2=32 > 31days 00011111
// int hour=0; //2*2*2*2*2=32 > 24hours 00010001
// int min=0; //2*2*2*2*2*2=64 > 60minitues 00001001
//int temp=(int)(day<<11)+(int)(hour<<6)+(int)(min<<0);
int temp=(day<<11)+(hour<<6)+(min<<0);
System.out.println( "temp="+temp );
b[0] = (byte)((year_offset<<4)|month);
b[1] = (byte)(temp >> 8);
b[2] = (byte)(temp >> 0);
int temp2=(int) (
((((int)b[1])&0xFF) << 8) |
(((int)b[2])&0xFF));
System.out.println( "temp2="+temp2 );
int year_offset_reverse=(byte)((b[0] >> 4)& 0x0F);
int month_reverse=(byte)(b[0] & 0x0F);
int day_reverse=(byte)(temp2>>11);
//0000 0 111 11 00 0000 0x
int hour_reverse=(byte)((byte)((temp2 & 0x07C0) >>6));
//00000 00000 11111
//
int min_reverse=(byte)(((temp2 & 0x003F)));
System.out.println( "year_offset_reverse="+year_offset_reverse );
System.out.println( "month_reverse="+month_reverse );
System.out.println( "day_reverse="+day_reverse );
System.out.println( "hour_reverse="+hour_reverse );
System.out.println( "min_reverse="+min_reverse );
/*
b[0] = (byte)((year_offset<<4)|month);
//day-hour-min ：2bytes :DAY[4BIT]+HOUR[low-4-BIT] - HOUR[hign-2-BIT]+MIN[6BIT]
b[1] = (byte)((day << 3)|hour << 4);
b[2] = (byte)(((min << 2))|hour>> 4);
char year_offset_reverse=(char)(b[0] >> 4);
char month_reverse=(char)(b[0] & 0x0F);
char day_reverse=(char)(b[1] >> 3);
char hour_reverse=(char)((b[2] << 6) | (b[1] & 0x0F));
char min_reverse=(char)(b[1] >> 2);
System.out.println( "year_offset_reverse="+year_offset_reverse );
System.out.println( "month_reverse="+month_reverse );
System.out.println( "day_reverse="+day_reverse );
System.out.println( "hour_reverse="+hour_reverse );
System.out.println( "min_reverse="+min_reverse );
*/
/*
b[0] = (byte)((year_offset<<4)|month);
//day-hour-min ：2bytes :DAY[4BIT]+HOUR[low-4-BIT] - HOUR[hign-2-BIT]+MIN[6BIT]
b[1] = (byte)((day << 3)|hour << 4);
b[2] = (byte)(((min << 2))|hour>> 4);
char year_offset_reverse=(char)(b[0] >> 4);
char month_reverse=(char)(b[0] & 0x0F);
char day_reverse=(char)(b[1] >> 3);
char hour_reverse=(char)((b[2] << 6) | (b[1] & 0x0F));
char min_reverse=(char)(b[1] >> 2);
System.out.println( "year_offset_reverse="+year_offset_reverse );
System.out.println( "month_reverse="+month_reverse );
System.out.println( "day_reverse="+day_reverse );
System.out.println( "hour_reverse="+hour_reverse );
System.out.println( "min_reverse="+min_reverse );
*/
// short s=260;
//
// b[0] = (byte) (s >> 8);
// b[1] = (byte) (s >> 0);
// short s2=(short) (b[0] << 8);
// short SS=(short) (((b[0] << 8) | b[1] & 0xff));
//
// System.out.println(Long.MAX_VALUE);
// byte[] bs = long2bytes(Long.MAX_VALUE);
// System.out.println( bytes2long(bs) );
}
}
