RedissonDemo:Redisson分布式锁简单使用教程

## 简单使用 - 基本 ``` // 1. 创建配置对象 Config = ... // 2. 创建redisson实例 RedissonClient redisson = Redisson.create(config); // 3. 获得锁对象 RLock lock = redisson.getLock("myLock"); // 4. 上锁 lock.lock(); // 做你想做的。。。。 // 5.解锁 lock.unlock(); ``` - 依赖 ```xml <dependency> <groupId>org.redisson</groupId> <artifactId>redisson</artifactId> <version>3.4.3</version> </dependency> ``` - 可运行示例代码 ```java public class RedissonTest { private static Logger logger = LoggerFactory.getLogger(RedissonTest.class); private String address = "redis://localhost:6379"; private int connectionMinimumIdleSize = 10; private int idleConnectionTimeout = 10000; private int pingTimeout = 1000; private int connectTimeout = 10000; private int timeout = 3000; private int retryAttempts = 3; private int retryInterval = 1500; private int reconnectionTimeout = 3000; private int failedAttempts = 3; private String password = null; private int subscriptionsPerConnection = 5; private String clientName = null; private int subscriptionConnectionMinimumIdleSize = 1; private int subscriptionConnectionPoolSize = 50; private int connectionPoolSize = 64; private int database = 0; private boolean dnsMonitoring = false; private int dnsMonitoringInterval = 5000; private int thread; //当前处理核数量 * 2 private String codec = "org.redisson.codec.JsonJacksonCodec"; RedissonClient redisson() throws Exception { Config config = new Config(); config.useSingleServer().setAddress(address) .setConnectionMinimumIdleSize(connectionMinimumIdleSize) .setConnectionPoolSize(connectionPoolSize) .setDatabase(database) .setDnsMonitoring(dnsMonitoring) .setDnsMonitoringInterval(dnsMonitoringInterval) .setSubscriptionConnectionMinimumIdleSize(subscriptionConnectionMinimumIdleSize) .setSubscriptionConnectionPoolSize(subscriptionConnectionPoolSize) .setSubscriptionsPerConnection(subscriptionsPerConnection) .setClientName(clientName) .setFailedAttempts(failedAttempts) .setRetryAttempts(retryAttempts) .setRetryInterval(retryInterval) .setReconnectionTimeout(reconnectionTimeout) .setTimeout(timeout) .setConnectTimeout(connectTimeout) .setIdleConnectionTimeout(idleConnectionTimeout) .setPingTimeout(pingTimeout) .setPassword(password); Codec codec = (Codec) ClassUtils.forName("org.redisson.codec.JsonJacksonCodec", ClassUtils.getDefaultClassLoader()).newInstance(); config.setCodec(codec); config.setThreads(thread); config.setEventLoopGroup(new NioEventLoopGroup()); config.setUseLinuxNativeEpoll(false); return Redisson.create(config); } @Test public void testGetLock() throws Exception { RedissonClient redissonClient = redisson(); RLock lock = redissonClient.getLock("TEST"); try { lock.lock(); logger.info("Request Thread - " + Thread.currentThread().getName() + " locked and begun..."); Thread.sleep(5000); // 5 sec logger.info("Request Thread - " + Thread.currentThread().getName() + " ended successfully..."); } catch (Exception ex) { logger.error("Error occurred"); } finally { lock.unlock(); logger.info("Request Thread - " + Thread.currentThread().getName() + " unlocked..."); } } } ``` ## 集成spring boot - 示例项目地址：[https://github.com/14251104246/RedissonDemo](https://github.com/14251104246/RedissonDemo) - 依赖 ```xml <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.redisson</groupId> <artifactId>redisson</artifactId> <version>3.4.3</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> ``` - 配置 ```java @Configuration public class RedissonConfig { private String address = "redis://localhost:6379"; private int connectionMinimumIdleSize = 10; private int idleConnectionTimeout = 10000; private int pingTimeout = 1000; private int connectTimeout = 10000; private int timeout = 3000; private int retryAttempts = 3; private int retryInterval = 1500; private int reconnectionTimeout = 3000; private int failedAttempts = 3; private String password = null; private int subscriptionsPerConnection = 5; private String clientName = null; private int subscriptionConnectionMinimumIdleSize = 1; private int subscriptionConnectionPoolSize = 50; private int connectionPoolSize = 64; private int database = 0; private boolean dnsMonitoring = false; private int dnsMonitoringInterval = 5000; private int thread; //当前处理核数量 * 2 private String codec = "org.redisson.codec.JsonJacksonCodec"; @Bean(destroyMethod = "shutdown") RedissonClient redisson() throws Exception { Config config = new Config(); config.useSingleServer().setAddress(address) .setConnectionMinimumIdleSize(connectionMinimumIdleSize) .setConnectionPoolSize(connectionPoolSize) .setDatabase(database) .setDnsMonitoring(dnsMonitoring) .setDnsMonitoringInterval(dnsMonitoringInterval) .setSubscriptionConnectionMinimumIdleSize(subscriptionConnectionMinimumIdleSize) .setSubscriptionConnectionPoolSize(subscriptionConnectionPoolSize) .setSubscriptionsPerConnection(subscriptionsPerConnection) .setClientName(clientName) .setFailedAttempts(failedAttempts) .setRetryAttempts(retryAttempts) .setRetryInterval(retryInterval) .setReconnectionTimeout(reconnectionTimeout) .setTimeout(timeout) .setConnectTimeout(connectTimeout) .setIdleConnectionTimeout(idleConnectionTimeout) .setPingTimeout(pingTimeout) .setPassword(password); Codec codec = (Codec) ClassUtils.forName("org.redisson.codec.JsonJacksonCodec", ClassUtils.getDefaultClassLoader()).newInstance(); config.setCodec(codec); config.setThreads(thread); config.setEventLoopGroup(new NioEventLoopGroup()); config.setUseLinuxNativeEpoll(false); return Redisson.create(config); } } ``` ## 分布式锁使用场景 - 场景1 ``` 某集群服务提供一组任务，A请求随机从集群中的机器1任务组中获取一个任务；B请求随机从集群中的机器2任务组中获取一个任务。 在理想的情况下，A从任务组中挑选一个任务，任务组删除该任务，B从剩下的的任务中再挑一个，任务组删除该任务。 同样的，在真实情况下，如果不做任何处理，可能会出现A和B挑中了同一个任务的情况。 ``` - 场景2 ``` 以流量业务场景中例子来说明，手机用户可以在手机App端、网上营业厅、wap手厅进行流量业务的操作 如果发现该用户没有流量账户的时候，会首先给该用户创建一个专门的流量账户，如果用户在app端、网上营业厅端同时操作的时候，可能会给该用户创建2个账户； ``` - 场景3 ``` 一个公共集团账户，下面包含很多账户，给下面账户充