Java - Convert int to Byte Array of 4 Bytes?
JavaByteBufferJava Problem Overview
> Possible Duplicate:
> Convert integer into byte array (Java)
I need to store the length of a buffer, in a byte array 4 bytes large.
Pseudo code:
private byte[] convertLengthToByte(byte[] myBuffer)
{
int length = myBuffer.length;
byte[] byteLength = new byte[4];
//here is where I need to convert the int length to a byte array
byteLength = length.toByteArray;
return byteLength;
}
What would be the best way of accomplishing this? Keeping in mind I must convert that byte array back to an integer later.
Java Solutions
Solution 1 - Java
You can convert yourInt
to bytes by using a ByteBuffer
like this:
return ByteBuffer.allocate(4).putInt(yourInt).array();
Beware that you might have to think about the byte order when doing so.
Solution 2 - Java
public static byte[] my_int_to_bb_le(int myInteger){
return ByteBuffer.allocate(4).order(ByteOrder.LITTLE_ENDIAN).putInt(myInteger).array();
}
public static int my_bb_to_int_le(byte [] byteBarray){
return ByteBuffer.wrap(byteBarray).order(ByteOrder.LITTLE_ENDIAN).getInt();
}
public static byte[] my_int_to_bb_be(int myInteger){
return ByteBuffer.allocate(4).order(ByteOrder.BIG_ENDIAN).putInt(myInteger).array();
}
public static int my_bb_to_int_be(byte [] byteBarray){
return ByteBuffer.wrap(byteBarray).order(ByteOrder.BIG_ENDIAN).getInt();
}
Solution 3 - Java
This should work:
public static final byte[] intToByteArray(int value) {
return new byte[] {
(byte)(value >>> 24),
(byte)(value >>> 16),
(byte)(value >>> 8),
(byte)value};
}
Code taken from here.
Edit An even simpler solution is given in this thread.
Solution 4 - Java
int integer = 60;
byte[] bytes = new byte[4];
for (int i = 0; i < 4; i++) {
bytes[i] = (byte)(integer >>> (i * 8));
}