Conversion between a numeric type and a byte array

How do we choose to use a string or a number above? Explains the benefits of using numeric types, so the question is, how do you convert between numeric types and byte arrays?

Let's take a look at the conversion between a single numeric type and a byte array, as an example of an integer type:

public static byte[] Inttobytes (int x) {Bytebuffer Intbuffer = bytebuffer.allocate (integer.bytes);    Intbuffer.putint (0, X); return Intbuffer.array ();} public static int bytestoint (byte[] bytes) {return bytestoint (bytes, 0, bytes.length);} public static int bytestoint (byte[] bytes, int offset, int length) {Bytebuffer Intbuffer = bytebuffer.allocate (Integer .    BYTES);    Intbuffer.put (bytes, offset, length);    Intbuffer.flip (); return Intbuffer.getint ();}

Let's look at the conversions between multiple numeric types and byte arrays, with the example of converting between a long and a byte array:

Public static byte[] longsettobytes (Collection<long> ids) {     Int len = ids.size () *long.bytes;    bytebuffer bytebuffer =  Bytebuffer.allocate (len);     int start = 0;    for (Long  id : ids) {        bytebuffer.putlong (start, id);         start += Long.BYTES;    }     return bytebuffer.array ();} Public static set<long> bytestolongset (byte[] bytes) {    return  bytestolongset (bytes, 0, bytes.length);} Public static set<long> bytestolongset (Byte[] bytes, int offset, int  length) {    set<long> ids = new hashset<> ();     byteBuffer bytebuffer = bytebuffer.allocate (length);     bytebuffer.put (Bytes,  offset, length);     bytebuffer.flip ();     int count  = length/long.bytes;    for (int i=0; i<count; i++)  {         ids.add (Bytebuffer.getlong ());    }     return ids;}

Since Bytebuffer supports 5 numeric types, we provide complete support for conversions between numeric types and byte arrays, as shown in:

Conversion between a numeric type and a byte array