介绍
redis有一个bitMap数据结构，可以看成是一个二进制的数组，数组元素只有0和1。
ps:
这里要注意bitcount范围统计时，计算的是字节数，即一次性计算8位里面，1的个数。只有getbit时后面跟的偏移量才是从(bit位)数起。
通常用redisTemplate操作bitField时要注意返回的是Long，最大只有8个字节，即64位
签到
命令行操作demo
是否签到： setbit key 第几天 是否签到
统计一段时间内的签到天数： bitcount key 开始日期 结束日期
java的Calendar自带获取今天是一年中第几天的方法
那么当天是否签到只要把值往redis一塞就ok了
Calendar calendar = Calendar.getInstance();
calendar.setTime(new Date());
System.out.println(calendar.get(Calendar.DAY_OF_YEAR));
LocalDateTime localDateTime = LocalDateTime.now();
System.out.println(localDateTime.getDayOfYear());
LocalDate localDate = LocalDate.now();
System.out.println(localDate.getDayOfYear());
来一波实际操作demo
demo中是一个月的统计签到次数
import com.alibaba.fastjson.JSON;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.connection.BitFieldSubCommands;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.util.CollectionUtils;
import org.springframework.web.bind.annotation.*;
import javax.annotation.Resource;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
@RestController
@RequestMapping("/bitMap")
public class RedisBitMapController {
private final String userId="155852412069";
@Resource
private RedisTemplate<String, String> redisTemplate;
/**
* 获取 当月签到总次数
* @param
* @return
*/
@GetMapping("/getKey")
public String getRedis() {
String s1 = buildSignKey(userId, LocalDate.now());
Object s = redisTemplate.execute((RedisCallback<Long>) con -> con.bitCount(s1.getBytes()));
return String.valueOf(s);
}
/**
* 模拟签到
* @param signDay yyyy-MM-dd
* @return
*/
@GetMapping("/sign")
public String setBitFild(@RequestParam String signDay) {
LocalDate localDate = formatDay(signDay);
redisTemplate.opsForValue().setBit(buildSignKey(userId, localDate), localDate.getDayOfMonth(), true);
return localDate.getDayOfMonth() + "日签到成功";
}
/**
* 模拟取消签到 用来测试数据用
* @param signDay yyyy-MM-dd
* @return
*/
@GetMapping("/unsign")
public String unsetBitFild(@RequestParam String signDay) {
LocalDate localDate = formatDay(signDay);
redisTemplate.opsForValue().setBit(buildSignKey(userId, localDate), localDate.getDayOfMonth(), false);
return localDate.getDayOfMonth() + "日取消签到成功";
}
/**
* 获取一个当前月份里面 截止到到传入的日期的连续签到的天数
* @param signDay
* @return
*/
@GetMapping("/getSign")
public long getBitFild(@RequestParam String signDay) {
LocalDate localDate = formatDay(signDay);
long continueSignCountDay = getContinueSignCountDay(userId, localDate, 1);
System.out.println(continueSignCountDay);
return continueSignCountDay;
}
/**
* 检测某一天是否签到
* @param signDay
* @return
*/
@GetMapping("/checkSign")
public Boolean checkSign(@RequestParam String signDay) {
LocalDate localDate = formatDay(signDay);
Boolean bit = redisTemplate.opsForValue().getBit(buildSignKey(userId, localDate), localDate.getDayOfMonth());
return bit;
}
public LocalDate formatDay(String signDay) {
DateTimeFormatter format = DateTimeFormatter.ofPattern("yyyy-MM-dd");
return LocalDate.parse(signDay, format);
}
/**
* 获取一个月签到的详情
* @return
*/
@GetMapping("/getsignDetail")
public String setBitFild1() {
Map<String, Boolean> signInfo = getSignInfo(userId, LocalDate.now());
System.out.println(signInfo);
return JSON.toJSONString(signInfo);
}
/**
* 获取一个月的总签到次数
* @return
*/
@GetMapping("getSignSum")
public String getSignSum(@RequestParam("signDay") String signDay){
LocalDate localDate = formatDay(signDay);
String signKey = buildSignKey(userId, localDate);
Long signSum = redisTemplate.execute((RedisCallback<Long>) con -> {
return con.bitCount(signKey.getBytes());
});
return signSum.toString();
}
/**
* 获取当月连续签到最大的天数
* @return
*/
@GetMapping("/getContinueSigns")
public String getContinueSigns(@RequestParam String signDay) {
LocalDate localDate = formatDay(signDay);
List<Map<String, Boolean>> signInfo = getContinueSigns(userId, localDate);
System.out.println(signInfo);
return JSON.toJSONString(signInfo);
}
/**
* 使用bitfield来判断用户连续签到多少天
*
* @param signKey
* @param limit
* @param offset
* @return
*/
public List<Long> bitfiled(String signKey, int limit, int offset) {
List<Long> execute = (List<Long>) redisTemplate.execute((RedisCallback<List<Long>>) con -> con.bitField(
signKey.getBytes(), BitFieldSubCommands.create().
get(BitFieldSubCommands.BitFieldType.unsigned(limit)).valueAt(offset)));
return execute;
}
private static String buildSignKey(String uid, LocalDate date) {
return String.format("u:sign:%s:%s", uid, formatDate(date, "yyyyMM"));
}
private static String formatDate(LocalDate date, String pattern) {
return date.format(DateTimeFormatter.ofPattern(pattern));
}
/**
* 获取该用户的当前自然月的签到总数
*
* @param userId
* @param localDate
* @return
*/
public long getContinueSignCountDay(String userId, LocalDate localDate, int offset) {
long signDayCount = 0;
List<Long> list = bitfiled(buildSignKey(userId, localDate), localDate.getDayOfMonth(), offset);
System.out.println(list.get(0));
if (!CollectionUtils.isEmpty(list) && list.size() > 0) {
long result = list.get(0) == null ? 0 : list.get(0);
for (int i = 0; i < localDate.getDayOfMonth(); i++) {
//相等的代表没有签到，左右右移后最右边的1会变成0
if (result >> 1 << 1 == result) {
if (i > 0) {
//当前日期的第一天就没签到，连续签到中断
break;
}
} else {
signDayCount += 1;
}
//将右移两位后的值赋值给result
result >>= 1;
}
}
return signDayCount;
}
/**
* 月签详情 查看哪天签到 哪天未签到
*
* @param userId
* @param date
* @return
*/
public Map<String, Boolean> getSignInfo(String userId, LocalDate date) {
Map<String, Boolean> signMap = new LinkedHashMap<>(date.getDayOfMonth());
List<Long> list = bitfiled(buildSignKey(userId, date), date.lengthOfMonth(), 1);
System.out.println(list.get(0));
if (!CollectionUtils.isEmpty(list) && list.size() > 0) {
// 由低位到高位，为0表示未签，为1表示已签
long result = list.get(0) == null ? 0 : list.get(0);
for (int i = date.lengthOfMonth(); i > 0; i--) {
LocalDate d = date.withDayOfMonth(i);
//在redis中数据存放是从左往右的，即最右边是最近的签到。
//位移的时候是从最右边开始，所以这里从最新的日期开始
signMap.put(formatDate(d, "yyyy-MM-dd"), result >> 1 << 1 != result);
result >>= 1;
}
}
return signMap;
}
public List<Map<String, Boolean>> getContinueSigns(String userId, LocalDate date) {
List<Long> list = bitfiled(buildSignKey(userId, date), date.lengthOfMonth(), 1);
System.out.println(list.get(0));
List<Map<String, Boolean>> maxContinueDays = new ArrayList<>();
if (!CollectionUtils.isEmpty(list) && list.size() > 0) {
// 由低位到高位，为0表示未签，为1表示已签
long result = list.get(0) == null ? 0 : list.get(0);
List<Map<String, Boolean>> tmpMaxContinueDays = new ArrayList<>();
for (int i = date.lengthOfMonth(); i > 0; i--) {
//在redis中数据存放是从左往右的，即最右边是最近的签到。
//位移的时候是从最右边开始，所以这里从最新的日期开始
LocalDate currentLocalDate = date.withDayOfMonth(i);
if(result >> 1 << 1 == result){
if(maxContinueDays.size() < tmpMaxContinueDays.size()){
maxContinueDays.clear();
maxContinueDays.addAll(tmpMaxContinueDays);
}
tmpMaxContinueDays.clear();
}else {
//因为是倒着找过来的，所以这里连续的签到日期是最后一个最大连续签到日期
//如果想要最早的，只需要把上面maxContinueDays.size() < tmpMaxContinueDays.size()改成 <= 即可
String currentDayStr = formatDate(currentLocalDate, "yyyy-MM-dd");
Boolean isSign = result >> 1 << 1 != result;
Map<String, Boolean> tmpMap = new HashMap<>();
tmpMap.put(currentDayStr, isSign);
tmpMaxContinueDays.add(tmpMap);
}
result >>= 1;
}
}
return maxContinueDays;
}
}
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