Java整数到固定长度的字节数组

Question

How can I convert an integer between 0 and 65k to fixed length of two bytes? 如何将0到65k之间的整数转换为固定长度的两个字节？ as an example 举个例子

2 would be 00000000 00000010 2将是00000000 00000010

~65k would be 11111111 11111111 〜65k将是11111111 11111111

and all that in a byte array 以及所有字节数组

Answer 1

java has the short data type, this is a 2 bytes integer. java具有短数据类型，这是2个字节的整数。 You cast the integer to short. 您将整数强制转换为short。

int a = 1;
short b = (short)a;

If you want the bytes of the integer you can use ByteBuffer 如果您想要整数的字节，则可以使用ByteBuffer

byte[] bytes = ByteBuffer.allocate(2).putShort((short)intnumber).array();

Or if you want the binary format you can just use toBinaryString method of the Integer. 或者，如果您想要二进制格式，则可以只使用Integer的toBinaryString方法。

int x = 2;
System.out.println(Integer.toBinaryString(x));

Answer 2

When x is your number between 0 and 65,535 just use 当x是您介于0到65,535之间的数字时，请使用

new byte[] { (byte) (x >> 8), (byte) x }

to create a byte array containing the value as two bytes in big-endian format. 创建一个字节数组，该字节数组以big-endian格式包含两个字节的值。