Redisson 是一种基于 Redis 的 Java 驻留集群的分布式对象和服务库,可以为我们提供丰富的分布式锁和线程安全集合的实现。在 Spring Boot 应用程序中使用 Redisson 可以方便地实现分布式应用程序的某些方面,例如分布式锁、分布式集合、分布式事件发布和订阅等。本篇是一个使用 Redisson 实现分布式锁的详细示例,在这个示例中,我们定义了DistributedLock注解,它可以标注在方法上,配合DistributedLockAspect切面以及IDistributedLock分布式锁封装的接口,来实现redisson 分布式锁的 API 调用。
Spring Boot 集成 Redisson
1、在 pom.xml 文件中添加 Redisson 的相关依赖
<dependency>
<groupId>org.redisson</groupId>
<artifactId>redisson-spring-boot-starter</artifactId>
<version>3.16.1</version>
</dependency>
2、在 application.yml 中配置 Redisson单机模式 的连接信息和相关参数
spring:
redis:
host: localhost
port: 6379
password: null
redisson:
codec: org.redisson.codec.JsonJacksonCodec
threads: 4
netty:
threads: 4
single-server-config:
address: "redis://localhost:6379"
password: null
database: 0
3、Redission还支持主从、集群、哨兵配置
//主从模式
spring:
redis:
sentinel:
master: my-master
nodes: localhost:26379,localhost:26389
password: your_password
redisson:
master-slave-config:
master-address: "redis://localhost:6379"
slave-addresses: "redis://localhost:6380,redis://localhost:6381"
password: ${spring.redis.password}
// 集群模式
spring:
redis:
cluster:
nodes: localhost:6379,localhost:6380,localhost:6381,localhost:6382,localhost:6383,localhost:6384
password: your_password
redisson:
cluster-config:
node-addresses: "redis://localhost:6379,redis://localhost:6380,redis://localhost:6381,redis://localhost:6382,redis://localhost:6383,redis://localhost:6384"
password: ${spring.redis.password}
// 哨兵模式
spring:
redis:
sentinel:
master: my-master
nodes: localhost:26379,localhost:26389
password: your_password
redisson:
sentinel-config:
master-name: my-master
sentinel-addresses: "redis://localhost:26379,redis://localhost:26380,redis://localhost:26381"
password: ${spring.redis.password}
本地封装Redisson 分布式锁
1、定义IDistributedLock分布式锁接口
public interface IDistributedLock {
/**
* 获取锁,默认30秒失效,失败一直等待直到获取锁
*
* @param key 锁的key
* @return 锁对象
*/
ILock lock(String key);
/**
* 获取锁,失败一直等待直到获取锁
*
* @param key 锁的key
* @param lockTime 加锁的时间,超过这个时间后锁便自动解锁; 如果lockTime为-1,则保持锁定直到显式解锁
* @param unit {@code lockTime} 参数的时间单位
* @param fair 是否公平锁
* @return 锁对象
*/
ILock lock(String key, long lockTime, TimeUnit unit, boolean fair);
/**
* 尝试获取锁,30秒获取不到超时异常,锁默认30秒失效
*
* @param key 锁的key
* @param tryTime 获取锁的最大尝试时间
* @return
* @throws Exception
*/
ILock tryLock(String key, long tryTime) throws Exception;
/**
* 尝试获取锁,获取不到超时异常
*
* @param key 锁的key
* @param tryTime 获取锁的最大尝试时间
* @param lockTime 加锁的时间
* @param unit {@code tryTime @code lockTime} 参数的时间单位
* @param fair 是否公平锁
* @return
* @throws Exception
*/
ILock tryLock(String key, long tryTime, long lockTime, TimeUnit unit, boolean fair) throws Exception;
/**
* 解锁
*
* @param lock
* @throws Exception
*/
void unLock(Object lock);
/**
* 释放锁
*
* @param lock
* @throws Exception
*/
default void unLock(ILock lock) {
if (lock != null) {
unLock(lock.getLock());
}
}
}
2、IDistributedLock实现类
@Slf4j
@Component
public class RedissonDistributedLock implements IDistributedLock {
@Resource
private RedissonClient redissonClient;
/**
* 统一前缀
*/
@Value("${redisson.lock.prefix:bi:distributed:lock}")
private String prefix;
@Override
public ILock lock(String key) {
return this.lock(key, 0L, TimeUnit.SECONDS, false);
}
@Override
public ILock lock(String key, long lockTime, TimeUnit unit, boolean fair) {
RLock lock = getLock(key, fair);
// 获取锁,失败一直等待,直到获取锁,不支持自动续期
if (lockTime > 0L) {
lock.lock(lockTime, unit);
} else {
// 具有Watch Dog 自动延期机制 默认续30s 每隔30/3=10 秒续到30s
lock.lock();
}
return new ILock(lock, this);
}
@Override
public ILock tryLock(String key, long tryTime) throws Exception {
return this.tryLock(key, tryTime, 0L, TimeUnit.SECONDS, false);
}
@Override
public ILock tryLock(String key, long tryTime, long lockTime, TimeUnit unit, boolean fair)
throws Exception {
RLock lock = getLock(key, fair);
boolean lockAcquired;
// 尝试获取锁,获取不到超时异常,不支持自动续期
if (lockTime > 0L) {
lockAcquired = lock.tryLock(tryTime, lockTime, unit);
} else {
// 具有Watch Dog 自动延期机制 默认续30s 每隔30/3=10 秒续到30s
lockAcquired = lock.tryLock(tryTime, unit);
}
if (lockAcquired) {
return new ILock(lock, this);
}
return null;
}
/**
* 获取锁
*
* @param key
* @param fair
* @return
*/
private RLock getLock(String key, boolean fair) {
RLock lock;
String lockKey = prefix + ":" + key;
if (fair) {
// 获取公平锁
lock = redissonClient.getFairLock(lockKey);
} else {
// 获取普通锁
lock = redissonClient.getLock(lockKey);
}
return lock;
}
@Override
public void unLock(Object lock) {
if (!(lock instanceof RLock)) {
throw new IllegalArgumentException("Invalid lock object");
}
RLock rLock = (RLock) lock;
if (rLock.isLocked()) {
try {
rLock.unlock();
} catch (IllegalMonitorStateException e) {
log.error("释放分布式锁异常", e);
}
}
}
}
3、定义ILock锁对象
import lombok.AllArgsConstructor;
import lombok.Getter;
import java.util.Objects;
/**
* <p>
* RedissonLock 包装的锁对象 实现AutoCloseable接口,在java7的try(with resource)语法,不用显示调用close方法
* </p>
* @since 2023-06-08 16:57
*/
@AllArgsConstructor
public class ILock implements AutoCloseable {
/**
* 持有的锁对象
*/
@Getter
private Object lock;
/**
* 分布式锁接口
*/
@Getter
private IDistributedLock distributedLock;
@Override
public void close() throws Exception {
if(Objects.nonNull(lock)){
distributedLock.unLock(lock);
}
}
}
4、注入IDistributedLock接口使用示例
// 定义接口
public interface IProductSkuSupplierMeasureService {
/**
* 保存SKU供应商供货信息
*
* @param dto
* @return
*
Boolean saveSupplierInfo(ProductSkuSupplierInfoDTO dto);
/**
* 编辑SKU供应商供货信息
*
* @param dto
* @return
*/
Boolean editSupplierInfo(ProductSkuSupplierInfoDTO dto);
}
**手动释放锁示例 **
// 实现类
@Service
public class ProductSkuSupplierMeasureServiceImpl
implements IProductSkuSupplierMeasureService {
@Resource
private IDistributedLock distributedLock;
@Override
@Transactional(rollbackFor = Exception.class)
public Boolean saveSupplierInfo(ProductSkuSupplierInfoDTO dto) {
// 手动释放锁
String sku = dto.getSku();
ILock lock = null;
try {
lock = distributedLock.lock(dto.getSku(),10L, TimeUnit.SECONDS, false);
// 业务代码
} catch (Exception e) {
log.error("保存异常", e);
throw new BaseException(e.getMessage());
} finally {
if (Objects.nonNull(lock)) {
distributedLock.unLock(lock);
}
}
return Boolean.TRUE;
}
}
** 使用try-with-resources 语法糖自动释放锁**
// 实现类
@Service
public class ProductSkuSupplierMeasureServiceImpl
implements IProductSkuSupplierMeasureService {
@Resource
private IDistributedLock distributedLock;
@Override
@Transactional(rollbackFor = Exception.class)
public Boolean editSupplierInfo(ProductSkuSupplierInfoDTO dto) {
String sku = dto.getSku();
// try-with-resources 语法糖自动释放锁
try(ILock lock = distributedLock.lock(dto.getSku(),10L, TimeUnit.SECONDS, false)) {
if(Objects.isNull(lock)){
throw new IdempotencyException("Duplicate request for method still in process");
}
// 业务代码
} catch (Exception e) {
log.error("异常", e);
throw new BaseException(e.getMessage());
}
return Boolean.TRUE;
}
}
5、使用AOP切面实现分布式锁的绑定
** 定义DistributedLock注解**
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DistributedLock {
/**
* 保证业务接口的key的唯一性,否则失去了分布式锁的意义 锁key
* 支持使用spEl表达式
*/
String key();
/**
* 保证业务接口的key的唯一性,否则失去了分布式锁的意义 锁key 前缀
*/
String keyPrefix() default "";
/**
* 是否在等待时间内获取锁,如果在等待时间内无法获取到锁,则返回失败
*/
boolean tryLok() default false;
/**
* 获取锁的最大尝试时间 ,会尝试tryTime时间获取锁,在该时间内获取成功则返回,否则抛出获取锁超时异常,tryLok=true时,该值必须大于0。
*
*/
long tryTime() default 0;
/**
* 加锁的时间,超过这个时间后锁便自动解锁
*/
long lockTime() default 30;
/**
* tryTime 和 lockTime的时间单位
*/
TimeUnit unit() default TimeUnit.SECONDS;
/**
* 是否公平锁,false:非公平锁,true:公平锁
*/
boolean fair() default false;
}
** 定义DistributedLockAspect Lock切面**
@Aspect
@Slf4j
public class DistributedLockAspect {
@Resource
private IDistributedLock distributedLock;
/**
* SpEL表达式解析
*/
private SpelExpressionParser spelExpressionParser = new SpelExpressionParser();
/**
* 用于获取方法参数名字
*/
private DefaultParameterNameDiscoverer nameDiscoverer = new DefaultParameterNameDiscoverer();
@Pointcut("@annotation(com.yt.bi.common.redis.distributedlok.annotation.DistributedLock)")
public void distributorLock() {
}
@Around("distributorLock()")
public Object around(ProceedingJoinPoint pjp) throws Throwable {
// 获取DistributedLock
DistributedLock distributedLock = this.getDistributedLock(pjp);
// 获取 lockKey
String lockKey = this.getLockKey(pjp, distributedLock);
ILock lockObj = null;
try {
// 加锁,tryLok = true,并且tryTime > 0时,尝试获取锁,获取不到超时异常
if (distributedLock.tryLok()) {
if(distributedLock.tryTime() <= 0){
throw new IdempotencyException("tryTime must be greater than 0");
}
lockObj = this.distributedLock.tryLock(lockKey, distributedLock.tryTime(), distributedLock.lockTime(), distributedLock.unit(), distributedLock.fair());
} else {
lockObj = this.distributedLock.lock(lockKey, distributedLock.lockTime(), distributedLock.unit(), distributedLock.fair());
}
if (Objects.isNull(lockObj)) {
throw new IdempotencyException("Duplicate request for method still in process");
}
return pjp.proceed();
} catch (Exception e) {
throw e;
} finally {
// 解锁
this.unLock(lockObj);
}
}
/**
* @param pjp
* @return
* @throws NoSuchMethodException
*/
private DistributedLock getDistributedLock(ProceedingJoinPoint pjp) throws NoSuchMethodException {
String methodName = pjp.getSignature().getName();
Class clazz = pjp.getTarget().getClass();
Class<?>[] par = ((MethodSignature) pjp.getSignature()).getParameterTypes();
Method lockMethod = clazz.getMethod(methodName, par);
DistributedLock distributedLock = lockMethod.getAnnotation(DistributedLock.class);
return distributedLock;
}
/**
* 解锁
*
* @param lockObj
*/
private void unLock(ILock lockObj) {
if (Objects.isNull(lockObj)) {
return;
}
try {
this.distributedLock.unLock(lockObj);
} catch (Exception e) {
log.error("分布式锁解锁异常", e);
}
}
/**
* 获取 lockKey
*
* @param pjp
* @param distributedLock
* @return
*/
private String getLockKey(ProceedingJoinPoint pjp, DistributedLock distributedLock) {
String lockKey = distributedLock.key();
String keyPrefix = distributedLock.keyPrefix();
if (StringUtils.isBlank(lockKey)) {
throw new IdempotencyException("Lok key cannot be empty");
}
if (lockKey.contains("#")) {
this.checkSpEL(lockKey);
MethodSignature methodSignature = (MethodSignature) pjp.getSignature();
// 获取方法参数值
Object[] args = pjp.getArgs();
lockKey = getValBySpEL(lockKey, methodSignature, args);
}
lockKey = StringUtils.isBlank(keyPrefix) ? lockKey : keyPrefix + lockKey;
return lockKey;
}
/**
* 解析spEL表达式
*
* @param spEL
* @param methodSignature
* @param args
* @return
*/
private String getValBySpEL(String spEL, MethodSignature methodSignature, Object[] args) {
// 获取方法形参名数组
String[] paramNames = nameDiscoverer.getParameterNames(methodSignature.getMethod());
if (paramNames == null || paramNames.length < 1) {
throw new IdempotencyException("Lok key cannot be empty");
}
Expression expression = spelExpressionParser.parseExpression(spEL);
// spring的表达式上下文对象
EvaluationContext context = new StandardEvaluationContext();
// 给上下文赋值
for (int i = 0; i < args.length; i++) {
context.setVariable(paramNames[i], args[i]);
}
return expression.getValue(context).toString();
}
/**
* SpEL 表达式校验
*
* @param spEL
* @return
*/
private void checkSpEL(String spEL) {
try {
ExpressionParser parser = new SpelExpressionParser();
parser.parseExpression(spEL, new TemplateParserContext());
} catch (Exception e) {
log.error("spEL表达式解析异常", e);
throw new IdempotencyException("Invalid SpEL expression [" + spEL + "]");
}
}
}
定义分布式锁注解版启动元注解
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Import({DistributedLockAspect.class})
public @interface EnableDistributedLock {
}
6、AOP切面实现分布式锁的绑定使用示例
** 启动类添加@EnableDistributedLock启用注解支持**
@SpringBootApplication
@EnableDistributedLock
public class BiCenterGoodsApplication {
public static void main(String[] args) {
SpringApplication.run(BiCenterGoodsApplication.class, args);
}
}
**@DistributedLock标注需要使用分布式锁的方法 **
@ApiOperation("编辑SKU供应商供货信息")
@PostMapping("/editSupplierInfo")
//@DistributedLock(key = "#dto.sku + '-' + #dto.skuId", lockTime = 10L, keyPrefix = "sku-")
@DistributedLock(key = "#dto.sku", lockTime = 10L, keyPrefix = "sku-")
public R<Boolean> editSupplierInfo(@RequestBody @Validated ProductSkuSupplierInfoDTO dto) {
return R.ok(productSkuSupplierMeasureService.editSupplierInfo(dto));
}
#dto.sku是 SpEL表达式。Spring中支持的它都支持的。比如调用静态方法,三目表达式。SpEL 可以使用方法中的任何参数。SpEL表达式参考
从原理到实践,分析 Redis 分布式锁的多种实现方案(一)
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