大小端byte与int互转

java部分来自：https://blog.csdn.net/a22422931/article/details/64929815

/**
 * 以大端模式将int转成byte[]
 */
public static byte[] intToBytesBig(int value) {
    byte[] src = new byte[4];
    src[0] = (byte) ((value >> 24) & 0xFF);
    src[1] = (byte) ((value >> 16) & 0xFF);
    src[2] = (byte) ((value >> 8) & 0xFF);
    src[3] = (byte) (value & 0xFF);
    return src;
}

/**
 * 以小端模式将int转成byte[]
 *
 * @param value
 * @return
 */
public static byte[] intToBytesLittle(int value) {
    byte[] src = new byte[4];
    src[3] = (byte) ((value >> 24) & 0xFF);
    src[2] = (byte) ((value >> 16) & 0xFF);
    src[1] = (byte) ((value >> 8) & 0xFF);
    src[0] = (byte) (value & 0xFF);
    return src;
}

/**
 * 以大端模式将byte[]转成int
 */
public static int bytesToIntBig(byte[] src, int offset) {
    int value;
    value = (int) (((src[offset] & 0xFF) << 24)
            | ((src[offset + 1] & 0xFF) << 16)
            | ((src[offset + 2] & 0xFF) << 8)
            | (src[offset + 3] & 0xFF));
    return value;
}

/**
 * 以小端模式将byte[]转成int
 */
public static int bytesToIntLittle(byte[] src, int offset) {
    int value;
    value = (int) ((src[offset] & 0xFF)
            | ((src[offset + 1] & 0xFF) << 8)
            | ((src[offset + 2] & 0xFF) << 16)
            | ((src[offset + 3] & 0xFF) << 24));
    return value;
}

本段java来自同事：

    public static int bytesToInt(byte[] src) {
        ByteBuffer buffer = ByteBuffer.wrap(src);
//        buffer.order(ByteOrder.nativeOrder());//获取系统
//        buffer.order(ByteOrder.BIG_ENDIAN);//大端
        buffer.order(ByteOrder.LITTLE_ENDIAN);//小端
        return buffer.getInt();
    }

以下为小端go代码：

// Int2Byte 将int写入指定长度的[]byte
func Int2Byte(data, len int) (ret []byte) {
	ret = make([]byte, len)
	var tmp int = 0xff
	var index uint = 0
	for index = 0; index < uint(len); index++ {
		ret[index] = byte((tmp << (index * 8) & data) >> (index * 8))
	}
	return ret
}

// Byte2Int 从[]byte中读取长度
func Byte2Int(data []byte) int {
	var ret int = 0
	var len int = len(data)
	var i uint = 0
	for i = 0; i < uint(len); i++ {
		ret = ret | (int(data[i]) << (i * 8))
	}
	return ret
}

以下go代码来自：https://www.zhihu.com/question/327537211/answer/703010418

package main

import (
	"encoding/binary"
	"fmt"
)

func main() {
	bytes := []byte{0x78, 0x56, 0x34, 0x12}
	fmt.Printf("0x%x\n", binary.LittleEndian.Uint32(bytes))
	fmt.Printf("0x%x\n", binary.BigEndian.Uint32(bytes))
}