Java--byte and base type conversions

byteB[]={0x41, (byte) 0xc8,0,0}; //Method 1 Stream input, suitable for me/se environment//default big-endian number, if the small end number, you can first flip the arrayDataInputStream dis=NewDataInputStream (NewBytearrayinputstream (b));floatf=dis.readfloat ();d is.close (); System.out.println (f);//Method 2 Cache input for the SE/EE environmentBytebuffer Buf=bytebuffer.allocatedirect (4);//Direct cache with no additional memory//Buf=buf.order (Byteorder.little_endian);//default big-endian, small end with this lineBuf.put (b); Buf.rewind ();floatF2=buf.getfloat (); SYSTEM.OUT.PRINTLN (F2);

//method Three, custom tool class PackageCn.yuehua.io;/*** byte[] conversion * Using big-endian order, i.e. for 0x11223344,byte[0] save 0x11,byte[1] Save 0x22,byte[2] Save 0x33,byte[3] Save 0x44*/ Public classBytearrayconveter {//Char-byte[2]     Public Static byte[] Getbytearray (Charc) {        byte[] B =New byte[2]; b[0] = (byte) ((C & 0xff00) >> 8); b[1] = (byte) (C & 0X00FF); returnb; }    //gets a char from the index of a byte array at two consecutive bytes     Public Static CharGetChar (byte[] arr,intindex) {        return(Char) (0xff00 & Arr[index] << 8 | (0xFF & Arr[index + 1])); }    //Short converted to byte[2] array     Public Static byte[] Getbytearray ( Shorts) {byte[] B =New byte[2]; b[0] = (byte) ((S & 0xff00) >> 8); b[1] = (byte) (S & 0x00ff); returnb; }    //gets a short from two consecutive bytes at index of the byte array     Public Static  ShortGetshort (byte[] arr,intindex) {        return( Short) (0xff00 & Arr[index] << 8 | (0xFF & Arr[index + 1])); }    //int converted to byte[4] array     Public Static byte[] Getbytearray (inti) {byte[] B =New byte[4]; b[0] = (byte) ((I & 0xff000000) >> 24); b[1] = (byte) ((I & 0x00ff0000) >> 16); b[2] = (byte) ((I & 0x0000ff00) >> 8); b[3] = (byte) (I & 0X000000FF); returnb; }    //gets an int from 4 consecutive bytes at index of the byte array     Public Static intGetInt (byte[] arr,intindex) {        return(0xFF000000 & (Arr[index+0] << 24)) |                (0x00ff0000 & (Arr[index+1] << 16)) |                (0X0000FF00 & (Arr[index+2] << 8)) |                (0X000000FF & Arr[index+3]); }    //float converted to byte[4] array     Public Static byte[] Getbytearray (floatf) {intIntbits = Float.floattointbits (f);//interprets binary strings in float as int integers        returnGetbytearray (intbits); }    //gets a float from 4 consecutive bytes at index of the byte array     Public Static floatGetFloat (byte[] arr,intindex) {        returnfloat.intbitstofloat (arr, index) (GETINT); }    //long converted to byte[8] array     Public Static byte[] Getbytearray (Longl) {byteB[] =New byte[8]; b[0] = (byte) (0xFF & (L >> 56)); b[1] = (byte) (0xFF & (L >> 48)); b[2] = (byte) (0xFF & (L >> 40)); b[3] = (byte) (0xFF & (L >> 32)); b[4] = (byte) (0xFF & (L >> 24)); b[5] = (byte) (0xFF & (L >> 16)); b[6] = (byte) (0xFF & (L >> 8)); b[7] = (byte) (0xFF &l); returnb; }    //gets a long from 8 consecutive bytes from the index of the byte array     Public Static LongGetlong (byte[] arr,intindex) {        return(0xff00000000000000l & (Long) arr[index+0] << 56)) |                (0X00FF000000000000L & (Long) arr[index+1] << 48)) |                (0X0000FF0000000000L & (Long) arr[index+2] << 40)) |                (0X000000FF00000000L & (Long) arr[index+3] << 32)) |                (0X00000000FF000000L & (Long) Arr[index+4] << 24)) |                (0X0000000000FF0000L & (Long) arr[index+5] << 16)) |                (0X000000000000FF00L & (Long) Arr[index+6] << 8)) |                (0X00000000000000FFL & (Long) arr[index+7]); }    //double convert to byte[8] array     Public Static byte[] Getbytearray (Doubled) {LongLongbits =Double.doubletolongbits (d); returnGetbytearray (longbits); }    //gets a double from the index of the byte array at 8 consecutive bytes     Public Static DoubleGetDouble (byte[] arr,intindex) {        returndouble.longbitstodouble (arr, index) (Getlong); }     Public Static voidMain (string[] args) {floatf = 11.9f; byte[] ByteArray =Getbytearray (f); floatAfloat = getfloat (ByteArray, 0);    System.out.println (afloat); }}

Java--byte and base type conversions