@EnableScheduling
@SpringBootApplication
public class SpringBootApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBootApplication.class);
    }
}

@Component
public class ScheduledTask {

    @Scheduled(cron = "0 * * * * ?")
    public void run() {
        System.out.println("现在时间：" + dateFormat.format(new Date()));
    }
}

package main

import (
	"encoding/hex"
	"encoding/xml"
	"fmt"
	"os"
	"strings"
	"testing"
)

type Node struct {
	Loc string `xml:"loc"`
}

type Root struct {
	XMLName xml.Name `xml:"urlset"`
	Nodes   []Node   `xml:"url"`
}

func main() {
	file, err := os.Open("../public/sitemap.xml")
	if err != nil {
		panic(err)
	}
	defer file.Close()

	var root Root
	decoder := xml.NewDecoder(file)
	if err := decoder.Decode(&root); err != nil {
		panic(err)
	}

	for _, node := range root.Nodes {
		fmt.Println(node.Loc)
	}
}

//注册监听
var observer = NotificationCenter.default.addObserver(forName: Notification.Name(rawValue: "Notify"), object: nil, queue: OperationQueue.main) {_ in
        }
//移除监听
NotificationCenter.default.removeObserver(observer)
//发送通知
NotificationCenter.default.post(name: Notification.Name("Notify"), object: nil)

<key>NSBluetoothPeripheralUsageDescription</key>
<string>Bluetooth is used to communicate with BLE devices.</string>

override func viewDidDisappear(_ animated: Bool) {
    if self.navigationController == nil {
    		// todo 调用蓝牙断开方法
    }
}

#include <stdint.h>
uint8_t crc8(uint8_t *p_buffer, uint16_t buf_size);
uint8_t crc8(uint8_t *p_buffer, uint16_t buf_size)
{
    uint8_t crc = 0;
    uint8_t i=0;
    if(buf_size <= 0)
    {
        return crc;
    }
    while( buf_size-- )
    {
        for (  i = 0x80; i != 0; i /= 2 )
        {
            if ( (crc & 0x80) != 0)
            {
                crc *= 2;
                crc ^= 0x07;
            }
            else
            {
                crc *= 2;
            }

            if ( (*p_buffer & i) != 0 )
            {
                crc ^= 0x07;
            }
        }
        p_buffer++;
    }
    return crc;
}

/* CRC16 implementation acording to CCITT standards */
unsigned short crc16_ccitt_check(const void *buf, int len);
static const unsigned short crc16tab[256]= {
	0x0000,0x1021,0x2042,0x3063,0x4084,0x50a5,0x60c6,0x70e7,
	0x8108,0x9129,0xa14a,0xb16b,0xc18c,0xd1ad,0xe1ce,0xf1ef,
	0x1231,0x0210,0x3273,0x2252,0x52b5,0x4294,0x72f7,0x62d6,
	0x9339,0x8318,0xb37b,0xa35a,0xd3bd,0xc39c,0xf3ff,0xe3de,
	0x2462,0x3443,0x0420,0x1401,0x64e6,0x74c7,0x44a4,0x5485,
	0xa56a,0xb54b,0x8528,0x9509,0xe5ee,0xf5cf,0xc5ac,0xd58d,
	0x3653,0x2672,0x1611,0x0630,0x76d7,0x66f6,0x5695,0x46b4,
	0xb75b,0xa77a,0x9719,0x8738,0xf7df,0xe7fe,0xd79d,0xc7bc,
	0x48c4,0x58e5,0x6886,0x78a7,0x0840,0x1861,0x2802,0x3823,
	0xc9cc,0xd9ed,0xe98e,0xf9af,0x8948,0x9969,0xa90a,0xb92b,
	0x5af5,0x4ad4,0x7ab7,0x6a96,0x1a71,0x0a50,0x3a33,0x2a12,
	0xdbfd,0xcbdc,0xfbbf,0xeb9e,0x9b79,0x8b58,0xbb3b,0xab1a,
	0x6ca6,0x7c87,0x4ce4,0x5cc5,0x2c22,0x3c03,0x0c60,0x1c41,
	0xedae,0xfd8f,0xcdec,0xddcd,0xad2a,0xbd0b,0x8d68,0x9d49,
	0x7e97,0x6eb6,0x5ed5,0x4ef4,0x3e13,0x2e32,0x1e51,0x0e70,
	0xff9f,0xefbe,0xdfdd,0xcffc,0xbf1b,0xaf3a,0x9f59,0x8f78,
	0x9188,0x81a9,0xb1ca,0xa1eb,0xd10c,0xc12d,0xf14e,0xe16f,
	0x1080,0x00a1,0x30c2,0x20e3,0x5004,0x4025,0x7046,0x6067,
	0x83b9,0x9398,0xa3fb,0xb3da,0xc33d,0xd31c,0xe37f,0xf35e,
	0x02b1,0x1290,0x22f3,0x32d2,0x4235,0x5214,0x6277,0x7256,
	0xb5ea,0xa5cb,0x95a8,0x8589,0xf56e,0xe54f,0xd52c,0xc50d,
	0x34e2,0x24c3,0x14a0,0x0481,0x7466,0x6447,0x5424,0x4405,
	0xa7db,0xb7fa,0x8799,0x97b8,0xe75f,0xf77e,0xc71d,0xd73c,
	0x26d3,0x36f2,0x0691,0x16b0,0x6657,0x7676,0x4615,0x5634,
	0xd94c,0xc96d,0xf90e,0xe92f,0x99c8,0x89e9,0xb98a,0xa9ab,
	0x5844,0x4865,0x7806,0x6827,0x18c0,0x08e1,0x3882,0x28a3,
	0xcb7d,0xdb5c,0xeb3f,0xfb1e,0x8bf9,0x9bd8,0xabbb,0xbb9a,
	0x4a75,0x5a54,0x6a37,0x7a16,0x0af1,0x1ad0,0x2ab3,0x3a92,
	0xfd2e,0xed0f,0xdd6c,0xcd4d,0xbdaa,0xad8b,0x9de8,0x8dc9,
	0x7c26,0x6c07,0x5c64,0x4c45,0x3ca2,0x2c83,0x1ce0,0x0cc1,
	0xef1f,0xff3e,0xcf5d,0xdf7c,0xaf9b,0xbfba,0x8fd9,0x9ff8,
	0x6e17,0x7e36,0x4e55,0x5e74,0x2e93,0x3eb2,0x0ed1,0x1ef0
};
  
unsigned short crc16_ccitt_check(const void *buf, int len)
{
	register int counter;
	register unsigned short crc = 0;
	unsigned char * data = (unsigned char *)buf;
	for( counter = 0; counter < len; counter++)
		crc = (crc<<8) ^ crc16tab[((crc>>8) ^ *data++) & 0x00FF];
	return crc;
}

#include <stdio.h>
#include <stdint.h>

uint32_t soft_crc32(const void *__data, int data_size, uint32_t crc);
void soft_crc32_init(void);


#define TABLE_SIZE 256

static uint32_t crc_table[TABLE_SIZE];
static const unsigned int rcrc32 = 0xEDB88320;

void soft_crc32_init(void)
{
	unsigned int crc = 0;
	unsigned char i;
	unsigned int j;

	for (j = 0; j < TABLE_SIZE; j++) {
		crc = 0;
		for (i = 0x01; i != 0x00; i <<= 1) {
			if ((crc & 0x00000001) != 0) {
				crc >>= 1;
				crc ^= rcrc32;
			} else {
				crc >>= 1;
			}
			if ((j & i) != 0)
				crc ^= rcrc32;
		}
		crc_table[j] = crc;
		//printf("%08x\r\n", crc);
	}
}

uint32_t soft_crc32(const void *__data, int data_size, uint32_t crc)
{
	const uint8_t *data =(const uint8_t *) __data;
	unsigned int result = crc;
	unsigned char crc_H8;
	soft_crc32_init();
	//printf("soft_crc32 data_size= %d\r\n", data_size);
	while (data_size--) {
		crc_H8 = (unsigned char)(result & 0x000000FF);
		result >>= 8;
		result ^= crc_table[crc_H8 ^ (*data)];
		data++;
	}

	return result;
}

for i in 0 ... 3 {
  print(i)// 0,1,2,3
}
for i in 0 ..< 3 {
  print(i)// 0,1,2
}
// 倒序遍历
for i in (0...3).reversed() {
  print(i)// 3,2,1,0
}
// 条件遍历
for i in 0...3 where i % 2 == 0 {
  print(i)// 0,2
}

let arr = [1,2,3]
// 元素遍历
for a in arr {
    print(a)
}
// 索引遍历
for i in 0..<arr.count {
    print(arr[i])
}
// forEach
arr.forEach { a in
    print(a)
}
// 迭代器遍历
for (index, element) in arr.enumerated() {
    print(index, element)// 0 1, 1 2, 2 3
}

val nsdata = ("Hello" as NSString).dataUsingEncoding(NSUTF8StringEncoding)

val hello = "Hello"
NSData.create(bytes = hello.cstr.ptr, length = hello.length)

// 实现1
if (nsdata != null) {
    val byteArray = ByteArray(nsdata.length.toInt())
    byteArray.usePinned {
        memcpy(it.addressOf(0), nsdata.bytes, nsdata.length)
    }
}
// 实现2
val byteArray = ByteArray(data.length.toInt())
byteArray.apply {
  usePinned {
  		memcpy(it.addressOf(0), data.bytes, data.length)
	}
}
// 实现3
val byteArray = data.bytes?.readBytes(data.length.toInt())

var nsdata: NSData
byteArray?.usePinned {
    nsdata = NSData.dataWithBytes(it.addressOf(0), it.get().size.toULong())
}