我的尝试:

public static byte[] toBytes(final int intVal, final int... intArray) {
    if (intArray == null || (intArray.length == 0)) {
        return ByteBuffer.allocate(4).putInt(intVal).array();
    } else {
        final ByteBuffer bb = ByteBuffer.allocate(4 + (intArray.length * 4)).putInt(intVal);
        for (final int val : intArray) {
            bb.putInt(val);
        }
        return bb.array();
    }
}

用它你可以这样做:

byte[] fourBytes = toBytes(0x01020304);
byte[] eightBytes = toBytes(0x01020304, 0x05060708);

完整的类在这里:https://gist.github.com/superbob/6548493，它支持从short或long初始化

byte[] eightBytesAgain = toBytes(0x0102030405060708L);

如果您正在使用apache-commons

public static byte[] toByteArray(int value) {
    byte result[] = new byte[4];
    return Conversion.intToByteArray(value, 0, result, 0, 4);
}

我的尝试:

public static byte[] toBytes(final int intVal, final int... intArray) {
    if (intArray == null || (intArray.length == 0)) {
        return ByteBuffer.allocate(4).putInt(intVal).array();
    } else {
        final ByteBuffer bb = ByteBuffer.allocate(4 + (intArray.length * 4)).putInt(intVal);
        for (final int val : intArray) {
            bb.putInt(val);
        }
        return bb.array();
    }
}

用它你可以这样做:

byte[] fourBytes = toBytes(0x01020304);
byte[] eightBytes = toBytes(0x01020304, 0x05060708);

完整的类在这里:https://gist.github.com/superbob/6548493，它支持从short或long初始化

byte[] eightBytesAgain = toBytes(0x0102030405060708L);

如何:

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

这个主意不是我的。我是从dzone.com上的一些帖子上截取的。

使用番石榴:

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

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;
}