Jedis:分布：
public static void main(String[] args) throws IOException {
JedisPoolConfig jedisPoolConfig = new JedisPoolConfig();
jedisPoolConfig.setMaxTotal(20);
jedisPoolConfig.setMaxIdle(10);
jedisPoolConfig.setMinIdle(5);
// timeout，这里既是连接超时又是读写超时，从Jedis 2.8开始有区分connectionTimeout和soTimeout的构造函数
JedisPool jedisPool = new JedisPool(jedisPoolConfig, "192.168.0.60", 6379, 3000, null);
Jedis jedis = null;
try {
//从redis连接池里拿出一个连接执行命令
jedis = jedisPool.getResource();
//******* jedis普通操作示例 ********
/*System.out.println(jedis.set("single1", "zhuge"));
System.out.println(jedis.get("single1"));*/
//******* 管道示例 ********
//管道的命令执行方式：cat redis.txt | redis-cli -h 127.0.0.1 -a password - p 6379 --pipe
/*Pipeline pl = jedis.pipelined();
for (int i = 0; i < 10; i++) {
pl.incr("pipelineKey");
pl.set("zhuge" + i, "zhuge");
}
List<Object> results = pl.syncAndReturnAll();
System.out.println(results);*/
//******* lua脚本示例 ********
//模拟一个商品减库存的原子操作
//lua脚本命令执行方式：redis-cli --eval /tmp/test.lua , 10
jedis.set("product_stock_10016", "15"); //初始化商品10016的库存
String script = " local count = redis.call('get', KEYS[1]) " +
" local a = tonumber(count) " +
" local b = tonumber(ARGV[1]) " +
" if a >= b then " +
" redis.call('set', KEYS[1], count-b) " +
//模拟语法报错回滚操作" bb == 0 " +
" return 1 " +
" end " +
" return 0 ";
Object obj = jedis.eval(script, Arrays.asList("product_stock_10016"), Arrays.asList("10"));
System.out.println(obj);
} catch (Exception e) {
e.printStackTrace();
} finally {
//注意这里不是关闭连接，在JedisPool模式下，Jedis会被归还给资源池。
if (jedis != null)
jedis.close();
}
}
}
public class JedisSentinelTest {
public static void main(String[] args) throws IOException {
JedisPoolConfig config = new JedisPoolConfig();
config.setMaxTotal(20);
config.setMaxIdle(10);
config.setMinIdle(5);
String masterName = "mymaster";
Set<String> sentinels = new HashSet<String>();
sentinels.add(new HostAndPort("192.168.0.60",26379).toString());
sentinels.add(new HostAndPort("192.168.0.60",26380).toString());
sentinels.add(new HostAndPort("192.168.0.60",26381).toString());
//JedisSentinelPool其实本质跟JedisPool类似，都是与redis主节点建立的连接池
//JedisSentinelPool并不是说与sentinel建立的连接池，而是通过sentinel发现redis主节点并与其建立连接
JedisSentinelPool jedisSentinelPool = new JedisSentinelPool(masterName, sentinels, config, 3000, null);
Jedis jedis = null;
try {
jedis = jedisSentinelPool.getResource();
System.out.println(jedis.set("sentinel666", "zhuge"));
System.out.println(jedis.get("sentinel666"));
} catch (Exception e) {
e.printStackTrace();
} finally {
//注意这里不是关闭连接，在JedisPool模式下，Jedis会被归还给资源池。
if (jedis != null)
jedis.close();
}
}
}
CRC 校验：
public class CRC16 {
public static void main(String[] args){
String str="name1";
System.out.println(JedisClusterCRC16.getCRC16(str)%16384);
}
}
二.redis spring boot 集成：
redis 配置文件：
server:
port: 8080
spring:
redis:
database: 0
timeout: 3000
password: zhuge
# sentinel: #哨兵模式
# master: mymaster #主服务器所在集群名称
# nodes: 192.168.0.60:26379,192.168.0.60:26380,192.168.0.60:26381
cluster:
nodes: 192.168.0.61:8001,192.168.0.62:8002,192.168.0.63:8003,192.168.0.61:8004,192.168.0.62:8005,192.168.0.63:8006
lettuce:
pool:
max-idle: 50
min-idle: 10
max-active: 100
max-wait: 1000
APPlication：
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
@RestController
public class IndexController {
private static final Logger logger = LoggerFactory.getLogger(IndexController.class);
@Autowired
private StringRedisTemplate stringRedisTemplate;
/**
* 测试节点挂了哨兵重新选举新的master节点，客户端是否能动态感知到
*
* @throws InterruptedException
*/
@RequestMapping("/test_sentinel")
public void testSentinel() throws InterruptedException {
int i = 1;
while (true){
try {
stringRedisTemplate.opsForValue().set("zhuge"+i, i+""); //jedis.set(key,value);
System.out.println("设置key："+ "zhuge" + i);
i++;
Thread.sleep(1000);
}catch (Exception e){
logger.error("错误：", e);
}
}
}
}
redis 分布式锁：
配置文件：
server:
port: 8090
spring:
redis:
host: 192.168.0.60
port: 6379
分布式锁的方案：
@RestController
public class IndexController {
private static final Logger logger = LoggerFactory.getLogger(IndexController.class);
@Autowired
private Redisson redisson;
@Autowired
private StringRedisTemplate stringRedisTemplate;
@RequestMapping("/deduct_stock")
public String deductStock() throws InterruptedException {
String lockKey = "product_001";
//String clientId = UUID.randomUUID().toString();
RLock redissonLock = redisson.getLock(lockKey);
try {
//Boolean result = stringRedisTemplate.opsForValue().setIfAbsent(lockKey, "zhuge"); //jedis.setnx(key,value)
//stringRedisTemplate.expire(lockKey,30, TimeUnit.SECONDS);
/*Boolean result = stringRedisTemplate.opsForValue().setIfAbsent(lockKey, clientId, 30, TimeUnit.SECONDS);
if (!result) {
return "1001";
}*/
// 加锁，实现锁续命功能
redissonLock.lock();
int stock = Integer.parseInt(stringRedisTemplate.opsForValue().get("stock")); // jedis.get("stock")
if (stock > 0) {
int realStock = stock - 1;
stringRedisTemplate.opsForValue().set("stock", realStock + ""); // jedis.set(key,value)
System.out.println("扣减成功，剩余库存:" + realStock + "");
} else {
System.out.println("扣减失败，库存不足");
}
}finally {
redissonLock.unlock();
/*if (clientId.equals(stringRedisTemplate.opsForValue().get(lockKey))){
stringRedisTemplate.delete(lockKey);
}*/
}
return "end";
}
@RequestMapping("/redlock")
public String redlock() throws InterruptedException {
String lockKey = "product_001";
//这里需要自己实例化不同redis实例的redisson客户端连接，这里只是伪代码用一个redisson客户端简化了
RLock lock1 = redisson.getLock(lockKey);
RLock lock2 = redisson.getLock(lockKey);
RLock lock3 = redisson.getLock(lockKey);
/**
* 根据多个 RLock 对象构建 RedissonRedLock （最核心的差别就在这里）
*/
RedissonRedLock redLock = new RedissonRedLock(lock1, lock2, lock3);
try {
/**
* 4.尝试获取锁
* waitTimeout 尝试获取锁的最大等待时间，超过这个值，则认为获取锁失败
* leaseTime 锁的持有时间,超过这个时间锁会自动失效（值应设置为大于业务处理的时间，确保在锁有效期内业务能处理完）
*/
boolean res = redLock.tryLock(10, 30, TimeUnit.SECONDS);
if (res) {
//成功获得锁，在这里处理业务
}
} catch (Exception e) {
throw new RuntimeException("lock fail");
} finally {
//无论如何, 最后都要解锁
redLock.unlock();
}
return "end";
}
}
