long 占 8 个字节，在网络传输时经常用到！
public static byte[] LongToBytes(long values) {
byte[] buffer = new byte[8];
for (int i = 0; i < 8; i++) {
int offset = 64 - (i + 1) * 8;
buffer[i] = (byte) ((values >> offset) & 0xff);
}
return buffer;
}
public static long BytesToLong(byte[] buffer) {
long values = 0;
for (int i = 0; i < 8; i++) {
values <<= 8; values|= (buffer[i] & 0xff);
}
return values;
}
--------------------------转
public static byte[]
getBytes(short data)
{
byte[]
bytes =
new byte[2];
bytes[0] = (
byte)
(data & 0xff);
bytes[1] = (
byte)
((data & 0xff00) >> 8);
return bytes;
}
public static byte[]
getBytes(
char data)
{
byte[]
bytes =
new byte[2];
bytes[0] = (
byte)
(data);
bytes[1] = (
byte)
(data >> 8);
return bytes;
}
public static byte[]
getBytes(
int data)
{
byte[]
bytes =
new byte[4];
bytes[0] = (
byte)
(data & 0xff);
bytes[1] = (
byte)
((data & 0xff00) >> 8);
bytes[2] = (
byte)
((data & 0xff0000) >> 16);
bytes[3] = (
byte)
((data & 0xff000000) >> 24);
return bytes;
}
public static byte[]
getBytes(
long data)
{
byte[]
bytes =
new byte[8];
bytes[0] = (
byte)
(data & 0xff);
bytes[1] = (
byte)
((data >> 8) & 0xff);
bytes[2] = (
byte)
((data >> 16) & 0xff);
bytes[3] = (
byte)
((data >> 24) & 0xff);
bytes[4] = (
byte)
((data >> 32) & 0xff);
bytes[5] = (
byte)
((data >> 40) & 0xff);
bytes[6] = (
byte)
((data >> 48) & 0xff);
bytes[7] = (
byte)
((data >> 56) & 0xff);
return bytes;
}
public static byte[]
getBytes(
float data)
{
int intBits
= Float.
floatToIntBits(data);
return getBytes(intBits);
}
public static byte[]
getBytes(
double data)
{
long intBits
= Double.
doubleToLongBits(data);
return getBytes(intBits);
}
public static byte[]
getBytes(String data, String charsetName)
{
Charset charset = Charset.
forName(charsetName);
return data.getBytes(charset);
}
public static byte[]
getBytes(String data)
{
return getBytes(data, "GBK");
}
public static short getShort(
byte[]
bytes)
{
return (
short)
((0xff & bytes[0]) | (0xff00 & (bytes[1] << 8)));
}
public static char getChar(
byte[]
bytes)
{
return (
char)
((0xff & bytes[0]) | (0xff00 & (bytes[1] << 8)));
}
public static int getInt(
byte[]
bytes)
{
return (0xff
& bytes[0]) | (0xff00 & (bytes[1] << 8)) | (0xff0000 & (bytes[2] << 16)) | (0xff000000 & (bytes[3] << 24));
}
public static long getLong(
byte[]
bytes)
{
return(0xffL
& (
long)bytes[0]) | (0xff00L &
((
long)bytes[1] << 8)) | (0xff0000L
& ((
long)bytes[2] << 16)) | (0xff000000L
& ((
long)bytes[3] << 24))
| (0xff00000000L & ((
long)bytes[4]
<< 32)) | (0xff0000000000L & ((
long)bytes[5]
<< 40)) | (0xff000000000000L & ((
long)bytes[6]
<< 48)) | (0xff00000000000000L & ((
long)bytes[7]
<< 56));
}
public static float getFloat(
byte[]
bytes)
{
return Float.
intBitsToFloat(
getInt(bytes));
}
public static double getDouble(
byte[]
bytes)
{
long l
=
getLong(bytes);
System.
out.println(l);
return Double.
longBitsToDouble(l);
}
public static String
getString(
byte[] bytes, String
charsetName)
{
return new String(bytes,
Charset.
forName(charsetName));
}
public static String
getString(
byte[] bytes)
{
return getString(bytes, "GBK");
}
