Java整数到字节数组

Question

我得到一个整数: 1695609641

当我使用方法时:

String hex = Integer.toHexString(1695609641);
system.out.println(hex); 

得到:

6510f329

但我想要一个字节数组:

byte[] bytearray = new byte[] { (byte) 0x65, (byte)0x10, (byte)0xf3, (byte)0x29};

我该怎么做？

Answer 1

使用Java NIO的ByteBuffer非常简单:

byte[] bytes = ByteBuffer.allocate(4).putInt(1695609641).array();

for (byte b : bytes) {
   System.out.format("0x%x ", b);
}

输出:

0x65 0x10 0xf3 0x29 

Answer 2

怎么样:

public static final byte[] intToByteArray(int value) {
    return new byte[] {
            (byte)(value >>> 24),
            (byte)(value >>> 16),
            (byte)(value >>> 8),
            (byte)value};
}

这个想法不是我的.我是从dzone.com上的一些帖子中得到的.

Answer 3

BigInteger.valueOf(1695609641).toByteArray()

Answer 4

byte[] IntToByteArray( int data ) {

byte[] result = new byte[4];

result[0] = (byte) ((data & 0xFF000000) >> 24);
result[1] = (byte) ((data & 0x00FF0000) >> 16);
result[2] = (byte) ((data & 0x0000FF00) >> 8);
result[3] = (byte) ((data & 0x000000FF) >> 0);

return result;
}

Answer 5

使用番石榴:

byte[] bytearray = Ints.toByteArray(1695609641);

Answer 6

byte[] conv = new byte[4];
conv[3] = (byte) input & 0xff;
input >>= 8;
conv[2] = (byte) input & 0xff;
input >>= 8;
conv[1] = (byte) input & 0xff;
input >>= 8;
conv[0] = (byte) input;

Answer 7

public static byte[] intToBytes(int x) throws IOException {
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    DataOutputStream out = new DataOutputStream(bos);
    out.writeInt(x);
    out.close();
    byte[] int_bytes = bos.toByteArray();
    bos.close();
    return int_bytes;
}