本篇文章为大家展示了如何在scala中使用redis实现分布式锁,内容简明扼要并且容易理解,绝对能使你眼前一亮,通过这篇文章的详细介绍希望你能有所收获。
首先实现工具类
package utils
import CacheManager
/**
* redis分布式锁
*/
object RedisTool {
//加锁是否成功标志
val LOCK_SUCCESS:String = "OK"
//即当key不存在时,我们进行set操作;若key已经存在,则不做任何操作;
val SET_IF_NOT_EXIST:String = "NX"
//意思是我们要给这个key加一个过期的设置,具体时间由第五个参数决定。
val SET_WITH_EXPIRE_TIME:String = "PX"
val RELEASE_SUCCESS:String = "1"
/**
*
* @param lockKey 锁
* @param requestId 请求标识
* @param expireTime 超期时间
* @param isPersist 临时缓存或者永久缓存
*/
def tryGetDistributedLock(lockKey:String, requestId:String, expireTime:Int,isPersist:Boolean=false){
CacheManager.redisClientPool.withClient(
client => {
//val redisKeyPrefix = CacheManager.getRedisKeyPrefix(isPersist)
client.select(CacheManager.redisDBNum)
val result = client.set(lockKey, requestId, SET_IF_NOT_EXIST, SET_WITH_EXPIRE_TIME, expireTime)
var flag = false
if(LOCK_SUCCESS == result){
flag = true
}
flag
}
)
}
/**
*释放分布式锁
* @param lockKey 锁
* @param requestId 请求标识
* @param expireTime 超期时间
* @param isPersist 临时缓存或者永久缓存
* @return
*/
def releaseDistributedLock(lockKey:String, requestId:String,expireTime: Int = 10,isPersist:Boolean=false) ={
CacheManager.redisClientPool.withClient(
client => {
val redisKeyPrefix = CacheManager.getRedisKeyPrefix(isPersist)
client.select(CacheManager.redisDBNum)
//lua脚本也是单例模式,同样也可以保证同一时刻只有一个线程执行脚本
val lua =
s"""
|local current = redis.call('incrBy',KEYS[1],ARGV[1]);
|if current == tonumber(ARGV[1]) then
| local t = redis.call('ttl',KEYS[1]);
| if t == -1 then
| redis.call('expire',KEYS[1],ARGV[2])
| end;
|end;
|return current;
""".stripMargin
val code = client.scriptLoad(lua).get
val ret = client.evalSHA(code, List(redisKeyPrefix + lockKey),List(requestId,expireTime))
val result = ret.get.asInstanceOf[Object].toString
var flag = false
if(result == RELEASE_SUCCESS){
flag = true
}
flag
}
)
}
}
2、实现CacheManager类
package utils
import com.redis.RedisClientPool
/**
*
*/
object CacheManager {
val redisClientPool = "dev".equalsIgnoreCase(System.getenv("SCALA_ENV")) match {
//开发环境
case true => new RedisClientPool("127.0.0.1", 6379)
//其他环境
case false => new RedisClientPool("10.180.x.y", 6379, 8, 0, Some("root"))
}
val redisDBNum = 10
def getRedisKeyPrefix(isPersist:Boolean) ={
if(isPersist){
//永久缓存前缀
"persist_"
}else{
//临时缓存前缀
"tmp_"
}
}
}
3、调用锁操作
def updateTableInfo(param:String) = {
var resMap = Map[String,Any]()
val lockKey = "mdms.MdmsUtils.updateTableInfo"
//val requestId = UUID.randomUUID().toString().replace("-", "").toUpperCase()
val flag = RedisTool.releaseDistributedLock(lockKey, "1")
if(flag){
try{
//执行你的操作
resMap = Map("code" -> 200 ,"msg" -> "成功")
}catch {
case e:Exception => {
e.printStackTrace()
resMap = Map("code" -> 200101 ,"msg" -> "执行失败")
}
}
}else{
resMap = Map("code" -> 200102 ,"msg" -> "操作冲突,已经被其他人捷足先登啦。")
}
resMap
}
上述内容就是如何在scala中使用redis实现分布式锁,你们学到知识或技能了吗?如果还想学到更多技能或者丰富自己的知识储备,欢迎关注天达云行业资讯频道。