Java integer and network byte order byte[] array conversion relationship detail
- 2020-09-16 07:27:25
- OfStack
This article illustrates the conversion relationship between Java integer and byte[] array in network byte order. To share for your reference, the details are as follows:
The work item requires socket communication between java and c/c++. socket communication is in the form of byte stream or byte packet. The socket sender has to convert the data to byte stream or byte packet while the receiver converts the byte stream and byte packet back to the corresponding data type. If the sender and receiver are of the same language, general 1 only involves the adjustment of the byte order. For java and c/c++ communication, the situation is a little more complicated, mainly because unsigned is not of type java and java and c are not equal in length on some data types.
To address this situation, this article has sorted out the conversion methods between the java data type and the network byte stream or byte packet (equivalent to the byte array). In fact, there is a lot of information on the Internet, but it is often incomplete, and even some errors, so I spent some time to do some verification and collation of the conversion between java integer and byte[] of network byte order. The functions sorted out are as follows:
public class ByteConvert {
// The following Is integer and Network byte ordered byte[] Conversion between arrays
public static byte[] longToBytes(long n) {
byte[] b = new byte[8];
b[7] = (byte) (n & 0xff);
b[6] = (byte) (n >> 8 & 0xff);
b[5] = (byte) (n >> 16 & 0xff);
b[4] = (byte) (n >> 24 & 0xff);
b[3] = (byte) (n >> 32 & 0xff);
b[2] = (byte) (n >> 40 & 0xff);
b[1] = (byte) (n >> 48 & 0xff);
b[0] = (byte) (n >> 56 & 0xff);
return b;
}
public static void longToBytes( long n, byte[] array, int offset ){
array[7+offset] = (byte) (n & 0xff);
array[6+offset] = (byte) (n >> 8 & 0xff);
array[5+offset] = (byte) (n >> 16 & 0xff);
array[4+offset] = (byte) (n >> 24 & 0xff);
array[3+offset] = (byte) (n >> 32 & 0xff);
array[2+offset] = (byte) (n >> 40 & 0xff);
array[1+offset] = (byte) (n >> 48 & 0xff);
array[0+offset] = (byte) (n >> 56 & 0xff);
}
public static long bytesToLong( byte[] array )
{
return ((((long) array[ 0] & 0xff) << 56)
| (((long) array[ 1] & 0xff) << 48)
| (((long) array[ 2] & 0xff) << 40)
| (((long) array[ 3] & 0xff) << 32)
| (((long) array[ 4] & 0xff) << 24)
| (((long) array[ 5] & 0xff) << 16)
| (((long) array[ 6] & 0xff) << 8)
| (((long) array[ 7] & 0xff) << 0));
}
public static long bytesToLong( byte[] array, int offset )
{
return ((((long) array[offset + 0] & 0xff) << 56)
| (((long) array[offset + 1] & 0xff) << 48)
| (((long) array[offset + 2] & 0xff) << 40)
| (((long) array[offset + 3] & 0xff) << 32)
| (((long) array[offset + 4] & 0xff) << 24)
| (((long) array[offset + 5] & 0xff) << 16)
| (((long) array[offset + 6] & 0xff) << 8)
| (((long) array[offset + 7] & 0xff) << 0));
}
public static byte[] intToBytes(int n) {
byte[] b = new byte[4];
b[3] = (byte) (n & 0xff);
b[2] = (byte) (n >> 8 & 0xff);
b[1] = (byte) (n >> 16 & 0xff);
b[0] = (byte) (n >> 24 & 0xff);
return b;
}
public static void intToBytes( int n, byte[] array, int offset ){
array[3+offset] = (byte) (n & 0xff);
array[2+offset] = (byte) (n >> 8 & 0xff);
array[1+offset] = (byte) (n >> 16 & 0xff);
array[offset] = (byte) (n >> 24 & 0xff);
}
public static int bytesToInt(byte b[]) {
return b[3] & 0xff
| (b[2] & 0xff) << 8
| (b[1] & 0xff) << 16
| (b[0] & 0xff) << 24;
}
public static int bytesToInt(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 byte[] uintToBytes( long n )
{
byte[] b = new byte[4];
b[3] = (byte) (n & 0xff);
b[2] = (byte) (n >> 8 & 0xff);
b[1] = (byte) (n >> 16 & 0xff);
b[0] = (byte) (n >> 24 & 0xff);
return b;
}
public static void uintToBytes( long n, byte[] array, int offset ){
array[3+offset] = (byte) (n );
array[2+offset] = (byte) (n >> 8 & 0xff);
array[1+offset] = (byte) (n >> 16 & 0xff);
array[offset] = (byte) (n >> 24 & 0xff);
}
public static long bytesToUint(byte[] array) {
return ((long) (array[3] & 0xff))
| ((long) (array[2] & 0xff)) << 8
| ((long) (array[1] & 0xff)) << 16
| ((long) (array[0] & 0xff)) << 24;
}
public static long bytesToUint(byte[] array, int offset) {
return ((long) (array[offset+3] & 0xff))
| ((long) (array[offset+2] & 0xff)) << 8
| ((long) (array[offset+1] & 0xff)) << 16
| ((long) (array[offset] & 0xff)) << 24;
}
public static byte[] shortToBytes(short n) {
byte[] b = new byte[2];
b[1] = (byte) ( n & 0xff);
b[0] = (byte) ((n >> 8) & 0xff);
return b;
}
public static void shortToBytes(short n, byte[] array, int offset ) {
array[offset+1] = (byte) ( n & 0xff);
array[offset] = (byte) ((n >> 8) & 0xff);
}
public static short bytesToShort(byte[] b){
return (short)( b[1] & 0xff
|(b[0] & 0xff) << 8 );
}
public static short bytesToShort(byte[] b, int offset){
return (short)( b[offset+1] & 0xff
|(b[offset] & 0xff) << 8 );
}
public static byte[] ushortToBytes(int n) {
byte[] b = new byte[2];
b[1] = (byte) ( n & 0xff);
b[0] = (byte) ((n >> 8) & 0xff);
return b;
}
public static void ushortToBytes(int n, byte[] array, int offset ) {
array[offset+1] = (byte) ( n & 0xff);
array[offset] = (byte) ((n >> 8) & 0xff);
}
public static int bytesToUshort(byte b[]) {
return b[1] & 0xff
| (b[0] & 0xff) << 8;
}
public static int bytesToUshort(byte b[], int offset) {
return b[offset+1] & 0xff
| (b[offset] & 0xff) << 8;
}
public static byte[] ubyteToBytes( int n ){
byte[] b = new byte[1];
b[0] = (byte) (n & 0xff);
return b;
}
public static void ubyteToBytes( int n, byte[] array, int offset ){
array[0] = (byte) (n & 0xff);
}
public static int bytesToUbyte( byte[] array ){
return array[0] & 0xff;
}
public static int bytesToUbyte( byte[] array, int offset ){
return array[offset] & 0xff;
}
// char The type, float , double The type and byte[] The transformation relationship between arrays needs further study and implementation.
}
The test procedure is as follows:
public class ByteConvertTest {
public static String byte2Hex(byte[] buf)
{
StringBuffer strbuf = new StringBuffer();
strbuf.append("{");
for (byte b : buf)
{
if (b == 0)
{
strbuf.append("00");
}
else if (b == -1)
{
strbuf.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;
}
strbuf.append(str);
}
strbuf.append(" ");
}
strbuf.append("}");
return strbuf.toString();
}
public static byte[] longToBytes(long n) {
byte[] b = new byte[8];
b[7] = (byte) (n & 0xff);
b[6] = (byte) (n >> 8 & 0xff);
b[5] = (byte) (n >> 16 & 0xff);
b[4] = (byte) (n >> 24 & 0xff);
b[3] = (byte) (n >> 32 & 0xff);
b[2] = (byte) (n >> 40 & 0xff);
b[1] = (byte) (n >> 48 & 0xff);
b[0] = (byte) (n >> 56 & 0xff);
return b;
}
public static long bytesToLong( byte[] array )
{
return ((((long) array[ 0] & 0xff) << 56)
| (((long) array[ 1] & 0xff) << 48)
| (((long) array[ 2] & 0xff) << 40)
| (((long) array[ 3] & 0xff) << 32)
| (((long) array[ 4] & 0xff) << 24)
| (((long) array[ 5] & 0xff) << 16)
| (((long) array[ 6] & 0xff) << 8)
| (((long) array[ 7] & 0xff) ));
}
public static int bytesToInt(byte b[]) {
return b[3] & 0xff
| (b[2] & 0xff) << 8
| (b[1] & 0xff) << 16
| (b[0] & 0xff) << 24;
}
public static long bytesToUint(byte[] array) {
return ((long) (array[3] & 0xff))
| ((long) (array[2] & 0xff)) << 8
| ((long) (array[1] & 0xff)) << 16
| ((long) (array[0] & 0xff)) << 24;
}
public static byte[] uintToBytes( long n )
{
byte[] b = new byte[4];
b[3] = (byte) (n & 0xff);
b[2] = (byte) (n >> 8 & 0xff);
b[1] = (byte) (n >> 16 & 0xff);
b[0] = (byte) (n >> 24 & 0xff);
return b;
}
public static byte[] shortToBytes(short n) {
byte[] b = new byte[2];
b[1] = (byte) ( n & 0xff);
b[0] = (byte) ((n >> 8) & 0xff);
return b;
}
public static short bytesToShort(byte[] b){
return (short)( b[1] & 0xff
|(b[0] & 0xff) << 8 );
}
static void testShortConvert(){
System.out.println("=================== short convert =============");
System.out.println("byte2Hex(shortToBytes((short)0x11f2))"+byte2Hex(shortToBytes((short)0x11f2)));
System.out.print("println 0x11f2:");
System.out.println((short)0x11f2);
System.out.println("byte2Hex(shortToBytes((short)0xf1f2))"+byte2Hex(shortToBytes((short)0xf1f2)));
System.out.print("println 0xf1f2:");
System.out.println((short)0xf1f2);
System.out.print("println bytesToShort(shortToBytes((short)0x11f2)):");
System.out.println((short)bytesToShort(shortToBytes((short)0x11f2)));
System.out.print("println bytesToShort(shortToBytes((short)0xf1f2)):");
System.out.println((short)bytesToShort(shortToBytes((short)0xf1f2)));
}
public static byte[] ushortToBytes(int n) {
byte[] b = new byte[2];
b[1] = (byte) (n & 0xff);
b[0] = (byte) (n >> 8 & 0xff);
return b;
}
public static int bytesToUshort(byte b[]) {
return b[1] & 0xff
| (b[0] & 0xff) << 8;
}
static void testUshortConvert(){
System.out.println("=================== Ushort convert =============");
System.out.println("byte2Hex(ushortToBytes(0x11f2))"+byte2Hex(ushortToBytes(0x11f2)));
System.out.print("println 0x11f2:");
System.out.println(0x11f2);
System.out.println("byte2Hex(ushortToBytes(0xf1f2))"+byte2Hex(ushortToBytes(0xf1f2)));
System.out.print("println 0xf1f2:");
System.out.println(0xf1f2);
System.out.print("println bytesToUshort(ushortToBytes(0x11f2)):");
System.out.println(bytesToUshort(ushortToBytes(0x11f2)));
System.out.print("println bytesToUshort(ushortToBytes(0xf1f2)):");
System.out.println(bytesToUshort(ushortToBytes(0xf1f2)));
}
public static byte[] ubyteToBytes( int n ){
byte[] b = new byte[1];
b[0] = (byte) (n & 0xff);
return b;
}
public static int bytesToUbyte( byte[] array ){
return array[0] & 0xff;
}
static void testUbyteConvert(){
System.out.println("=================== Ubyte convert =============");
System.out.println("byte2Hex(ubyteToBytes(0x1112))"+byte2Hex(ubyteToBytes(0x1112)));
System.out.print("println 0x1112:");
System.out.println(0x1112);
System.out.println("byte2Hex(ubyteToBytes(0xf2))"+byte2Hex(ubyteToBytes(0xf2)));
System.out.print("println 0xf2:");
System.out.println(0xf2);
System.out.print("println bytesToUbyte(ubyteToBytes(0x1112)):");
System.out.println(bytesToUbyte(ubyteToBytes(0x1112)));
System.out.print("println bytesToUbyte(ubyteToBytes(0xf1f2)):");
System.out.println(bytesToUbyte(ubyteToBytes(0xf1f2)));
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
byte[] array = new byte[4];
array[3] = (byte) 0xF4;
array[2] = 0x13;
array[1] = 0x12;
array[0] = 0x11;
System.out.println("=================== Integer bytes =============");
System.out.println("the bytes is:"+byte2Hex(array) );
System.out.print("println bytesToInt :");
System.out.println( bytesToInt(array));
System.out.printf("printf bytesToInt :%X\n", bytesToInt(array));
System.out.println("=================== long bytes =============");
byte[] longBytes = new byte[8];
longBytes[7] = (byte) 0xf7;
longBytes[6] = (byte) 0x16;
longBytes[5] = (byte) 0xf5;
longBytes[4] = (byte) 0x14;
longBytes[3] = (byte) 0xf3;
longBytes[2] = (byte) 0x12;
longBytes[1] = (byte) 0xf1;
longBytes[0] = (byte) 0x10;
System.out.println( "the bytes is:"+byte2Hex(longBytes) );
System.out.printf("printf bytesToLong:%X\n",bytesToLong(longBytes));
System.out.println("=================byte to long ================");
byte b = (byte)0xf1;
System.out.print("Println the byte:");
System.out.println(b);
System.out.printf("Printf the byte:%X\n",b);
long l = b;
System.out.print("Println byte to long:");
System.out.println(l);
System.out.printf("printf byte to long:%X\n",l);
System.out.println("================= uint Bytes ================");
byte[] uint = new byte[4];
uint[3] = (byte) 0xf3;
uint[2] = (byte) 0x12;
uint[1] = (byte) 0xf1;
uint[0] = (byte) 0xFF;
System.out.println( "the bytes is:"+byte2Hex(uint) );
System.out.printf("printf bytesToUint:%X\n",bytesToUint(uint));
System.out.print("Println bytesToUint:");
System.out.println(bytesToUint(uint));
System.out.println("byte2Hex(uintToBytes(0x11f2f3f4f5f6f7f8l)):"+byte2Hex(uintToBytes(0x11f2f3f4f5f6f7f8l)));
System.out.println("===============Long Integer==============");
System.out.print("println 0x11f2f3f4f5f6f7f8l:");
System.out.println(0x11f2f3f4f5f6f7f8l);
System.out.printf("Printf 0x11f2f3f4f5f6f7f8l:%X\n",0x11f2f3f4f5f6f7f8l);
System.out.println("println byte2Hex(longToBytes(0x11f2f3f4f5f6f7f8l))"+byte2Hex(longToBytes(0x11f2f3f4f5f6f7f8l)));
// Notice, this row down here, it doesn't get it right uint .
System.out.printf("printf bytesToUint(longToBytes(0x11f2f3f4f5f6f7f8l):%X\n",bytesToUint(longToBytes(0x11f2f3f4f5f6f7f8l)));
System.out.println("===============bytesToLong(longToBytes())==============");
System.out.println(bytesToLong(longToBytes(0x11f2f3f4f5f6f7f8l)));
System.out.printf("%X\n",bytesToLong(longToBytes(0x11f2f3f4f5f6f7f8l)));
testShortConvert();
testUshortConvert();
testUbyteConvert();
}
}
For more information about java, please refer to: Java Character and string Manipulation Skills Summary, Java Mathematical manipulation Skills Summary, Java Data Structure and Algorithm Tutorial, Java DOM Node Manipulation Skills Summary and Java Array manipulation Skills Summary.
I hope this article has been helpful in java programming.