文章--Java设计--分布式锁实现
redis分布式锁实现
整个starter工程目录如下：
pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.redis</groupId>
<version>2.1.0</version>
<packaging>jar</packaging>
<artifactId>redis-spring-boot-starter</artifactId>
<description>redis通用组件</description>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
<version>2.0.9.RELEASE</version>
<exclusions>
<exclusion>
<artifactId>jedis</artifactId>
<groupId>redis.clients</groupId>
</exclusion>
<exclusion>
<artifactId>lettuce-core</artifactId>
<groupId>io.lettuce</groupId>
</exclusion>
</exclusions>
</dependency>
<!-- jedis客户端 -->
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.9.3</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.16.22</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-collections4</artifactId>
<version>4.2</version>
</dependency>
<!-- spring2.X集成redis所需common-pool2，使用jedis必须依赖它-->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-pool2</artifactId>
<version>2.5.0</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.6</version>
</dependency>
</dependencies>
</project>
分布式锁顶级接口DistributedLock
package com.redis.common.lock;
/**
* 分布式锁顶级接口
* 例如：
* RETRY_TIMES=100，SLEEP_MILLIS=100
* RETRY_TIMES * SLEEP_MILLIS = 10000 意味着如果一直获取不了锁，最长会等待10秒后抛超时异常
*
* @author
* @date
*/
public interface DistributedLock {
/**
* 默认超时时间
*/
long TIMEOUT_MILLIS = 5000;
/**
* 重试次数
*/
int RETRY_TIMES = 100;
/**
* 每次重试后等待的时间
*/
long SLEEP_MILLIS = 100;
/**
* 获取锁
*
* @param key key
* @return 成功/失败
*/
boolean lock(String key);
/**
* 获取锁
*
* @param key key
* @param retryTimes 重试次数
* @return 成功/失败
*/
boolean lock(String key, int retryTimes);
/**
* 获取锁
*
* @param key key
* @param retryTimes 重试次数
* @param sleepMillis 获取锁失败的重试间隔
* @return 成功/失败
*/
boolean lock(String key, int retryTimes, long sleepMillis);
/**
* 获取锁
*
* @param key key
* @param expire 获取锁超时时间
* @return 成功/失败
*/
boolean lock(String key, long expire);
/**
* 获取锁
*
* @param key key
* @param expire 获取锁超时时间
* @param retryTimes 重试次数
* @return 成功/失败
*/
boolean lock(String key, long expire, int retryTimes);
/**
* 获取锁
*
* @param key key
* @param expire 获取锁超时时间
* @param retryTimes 重试次数
* @param sleepMillis 获取锁失败的重试间隔
* @return 成功/失败
*/
boolean lock(String key, long expire, int retryTimes, long sleepMillis);
/**
* 释放锁
*
* @param key key值
* @return 释放结果
*/
boolean releaseLock(String key);
}
分布式锁抽象类AbstractDistributedLock
package com.redis.common.lock;
/**
* 分布式锁抽象类
*
* @author
* @date
*/
public abstract class AbstractDistributedLock implements DistributedLock{
@Override
public boolean lock(String key) {
return lock(key, TIMEOUT_MILLIS, RETRY_TIMES, SLEEP_MILLIS);
}
@Override
public boolean lock(String key, int retryTimes) {
return lock(key, TIMEOUT_MILLIS, retryTimes, SLEEP_MILLIS);
}
@Override
public boolean lock(String key, int retryTimes, long sleepMillis) {
return lock(key, TIMEOUT_MILLIS, retryTimes, sleepMillis);
}
@Override
public boolean lock(String key, long expire) {
return lock(key, expire, RETRY_TIMES, SLEEP_MILLIS);
}
@Override
public boolean lock(String key, long expire, int retryTimes) {
return lock(key, expire, retryTimes, SLEEP_MILLIS);
}
}
redis分布式锁实现
package com.redis.common.redis.lock;
/**
* redis分布式锁实现
*
* @author
* @date
*/
@Slf4j
@Component
public class RedisDistributedLock extends AbstractDistributedLock {
@Autowired
private RedisTemplate<String, Object> redisTemplate;
private ThreadLocal<String> lockFlag = new ThreadLocal<>();
private static final String UNLOCK_LUA;
/*
* 通过lua脚本释放锁,来达到释放锁的原子操作
*/
static {
UNLOCK_LUA = "if redis.call(\"get\",KEYS[1]) == ARGV[1] " +
"then " +
" return redis.call(\"del\",KEYS[1]) " +
"else " +
" return 0 " +
"end ";
}
public RedisDistributedLock(RedisTemplate<String, Object> redisTemplate) {
super();
this.redisTemplate = redisTemplate;
}
@Override
public boolean lock(String key, long expire, int retryTimes, long sleepMillis) {
boolean result = setRedis(key, expire);
// 如果获取锁失败，按照传入的重试次数进行重试
while ((!result) && retryTimes-- > 0) {
try {
log.debug("get redisDistributeLock failed, retrying..." + retryTimes);
Thread.sleep(sleepMillis);
} catch (InterruptedException e) {
log.warn("Interrupted!", e);
Thread.currentThread().interrupt();
}
result = setRedis(key, expire);
}
return result;
}
private boolean setRedis(final String key, final long expire) {
try {
String status = redisTemplate.execute((RedisCallback<String>) connection -> {
Object nativeConnection = connection.getNativeConnection();
String uuid = UUID.randomUUID().toString();
lockFlag.set(uuid);
String result = null;
// 集群模式和单机模式虽然执行脚本的方法一样，但是没有共同的接口，所以只能分开执行
// 集群模式
if (nativeConnection instanceof JedisCluster) {
result = ((JedisCluster) nativeConnection).set(key, uuid, "NX", "PX", expire);
}
// 单机模式
else if (nativeConnection instanceof Jedis) {
result = ((Jedis) nativeConnection).set(key, uuid, "NX", "PX", expire);
}
return result;
});
return !StringUtils.isEmpty(status);
} catch (Exception e) {
log.error("set redisDistributeLock occured an exception", e);
}
return false;
}
@Override
public boolean releaseLock(String key) {
// 释放锁的时候，有可能因为持锁之后方法执行时间大于锁的有效期，此时有可能已经被另外一个线程持有锁，所以不能直接删除
try {
final List<String> keys = new ArrayList<>();
keys.add(key);
final List<String> args = new ArrayList<>();
args.add(lockFlag.get());
// 使用lua脚本删除redis中匹配value的key，可以避免由于方法执行时间过长而redis锁自动过期失效的时候误删其他线程的锁
// spring自带的执行脚本方法中，集群模式直接抛出不支持执行脚本的异常，所以只能拿到原redis的connection来执行脚本
Long result = redisTemplate.execute((RedisCallback<Long>) connection -> {
Object nativeConnection = connection.getNativeConnection();
// 集群模式和单机模式虽然执行脚本的方法一样，但是没有共同的接口，所以只能分开执行
// 集群模式
if (nativeConnection instanceof JedisCluster) {
return (Long) ((JedisCluster) nativeConnection).eval(UNLOCK_LUA, keys, args);
}
// 单机模式
else if (nativeConnection instanceof Jedis) {
return (Long) ((Jedis) nativeConnection).eval(UNLOCK_LUA, keys, args);
}
return 0L;
});
return result != null && result > 0;
} catch (Exception e) {
log.error("release redisDistributeLock occured an exception", e);
} finally {
lockFlag.remove();
}
return false;
}
}
**redis 基本操作 **
package com.redis.common.redis.template;
/**
* Redis Repository
* redis 基本操作 可扩展,基本够用了
*
* @author
*/
@Slf4j
public class RedisRepository {
/**
* 默认编码
*/
private static final Charset DEFAULT_CHARSET = StandardCharsets.UTF_8;
/**
* key序列化
*/
private static final StringRedisSerializer STRING_SERIALIZER = new StringRedisSerializer();
/**
* value 序列化
*/
private static final JdkSerializationRedisSerializer OBJECT_SERIALIZER = new JdkSerializationRedisSerializer();
/**
* Spring Redis Template
*/
private RedisTemplate<String, Object> redisTemplate;
public RedisRepository(RedisTemplate<String, Object> redisTemplate) {
this.redisTemplate = redisTemplate;
this.redisTemplate.setKeySerializer(STRING_SERIALIZER);
this.redisTemplate.setValueSerializer(OBJECT_SERIALIZER);
}
/**
* 获取链接工厂
*/
public RedisConnectionFactory getConnectionFactory() {
return this.redisTemplate.getConnectionFactory();
}
/**
* 获取 RedisTemplate对象
*/
public RedisTemplate<String, Object> getRedisTemplate() {
return redisTemplate;
}
/**
* 清空DB
*
* @param node redis 节点
*/
public void flushDB(RedisClusterNode node) {
this.redisTemplate.opsForCluster().flushDb(node);
}
/**
* 添加到带有 过期时间的 缓存
*
* @param key redis主键
* @param value 值
* @param time 过期时间(单位秒)
*/
public void setExpire(final byte[] key, final byte[] value, final long time) {
redisTemplate.execute((RedisCallback<Long>) connection -> {
connection.setEx(key, time, value);
log.debug("[redisTemplate redis]放入 缓存 url:{} ========缓存时间为{}秒", key, time);
return 1L;
});
}
/**
* 添加到带有 过期时间的 缓存
*
* @param key redis主键
* @param value 值
* @param time 过期时间(单位秒)
*/
public void setExpire(final String key, final Object value, final long time) {
redisTemplate.execute((RedisCallback<Long>) connection -> {
RedisSerializer<String> serializer = getRedisSerializer();
byte[] keys = serializer.serialize(key);
byte[] values = OBJECT_SERIALIZER.serialize(value);
connection.setEx(keys, time, values);
return 1L;
});
}
/**
* 一次性添加数组到 过期时间的 缓存，不用多次连接，节省开销
*
* @param keys redis主键数组
* @param values 值数组
* @param time 过期时间(单位秒)
*/
public void setExpire(final String[] keys, final Object[] values, final long time) {
redisTemplate.execute((RedisCallback<Long>) connection -> {
RedisSerializer<String> serializer = getRedisSerializer();
for (int i = 0; i < keys.length; i++) {
byte[] bKeys = serializer.serialize(keys[i]);
byte[] bValues = OBJECT_SERIALIZER.serialize(values[i]);
connection.setEx(bKeys, time, bValues);
}
return 1L;
});
}
/**
* 一次性添加数组到 过期时间的 缓存，不用多次连接，节省开销
*
* @param keys the keys
* @param values the values
*/
public void set(final String[] keys, final Object[] values) {
redisTemplate.execute((RedisCallback<Long>) connection -> {
RedisSerializer<String> serializer = getRedisSerializer();
for (int i = 0; i < keys.length; i++) {
byte[] bKeys = serializer.serialize(keys[i]);
byte[] bValues = OBJECT_SERIALIZER.serialize(values[i]);
connection.set(bKeys, bValues);
}
return 1L;
});
}
/**
* 添加到缓存
*
* @param key the key
* @param value the value
*/
public void set(final String key, final Object value) {
redisTemplate.execute((RedisCallback<Long>) connection -> {
RedisSerializer<String> serializer = getRedisSerializer();
byte[] keys = serializer.serialize(key);
byte[] values = OBJECT_SERIALIZER.serialize(value);
connection.set(keys, values);
log.debug("[redisTemplate redis]放入 缓存 url:{}", key);
return 1L;
});
}
/**
* 查询在这个时间段内即将过期的key
*
* @param key the key
* @param time the time
* @return the list
*/
public List<String> willExpire(final String key, final long time) {
final List<String> keysList = new ArrayList<>();
redisTemplate.execute((RedisCallback<List<String>>) connection -> {
Set<String> keys = redisTemplate.keys(key + "*");
for (String key1 : keys) {
Long ttl = connection.ttl(key1.getBytes(DEFAULT_CHARSET));
if (0 <= ttl && ttl <= 2 * time) {
keysList.add(key1);
}
}
return keysList;
});
return keysList;
}
/**
* 查询在以keyPatten的所有 key
*
* @param keyPatten the key patten
* @return the set
*/
public Set<String> keys(final String keyPatten) {
return redisTemplate.execute((RedisCallback<Set<String>>) connection -> redisTemplate.keys(keyPatten + "*"));
}
/**
* 根据key获取对象
*
* @param key the key
* @return the byte [ ]
*/
public byte[] get(final byte[] key) {
byte[] result = redisTemplate.execute((RedisCallback<byte[]>) connection -> connection.get(key));
log.debug("[redisTemplate redis]取出 缓存 url:{} ", key);
return result;
}
/**
* 根据key获取对象
*
* @param key the key
* @return the string
*/
public Object get(final String key) {
Object resultStr = redisTemplate.execute((RedisCallback<Object>) connection -> {
RedisSerializer<String> serializer = getRedisSerializer();
byte[] keys = serializer.serialize(key);
byte[] values = connection.get(keys);
return OBJECT_SERIALIZER.deserialize(values);
});
log.debug("[redisTemplate redis]取出 缓存 url:{} ", key);
return resultStr;
}
/**
* 根据key获取对象
*
* @param keyPatten the key patten
* @return the keys values
*/
public Map<String, Object> getKeysValues(final String keyPatten) {
log.debug("[redisTemplate redis] getValues() patten={} ", keyPatten);
return redisTemplate.execute((RedisCallback<Map<String, Object>>) connection -> {
RedisSerializer<String> serializer = getRedisSerializer();
Map<String, Object> maps = new HashMap<>(16);
Set<String> keys = redisTemplate.keys(keyPatten + "*");
if (CollectionUtils.isNotEmpty(keys)) {
for (String key : keys) {
byte[] bKeys = serializer.serialize(key);
byte[] bValues = connection.get(bKeys);
Object value = OBJECT_SERIALIZER.deserialize(bValues);
maps.put(key, value);
}
}
return maps;
});
}
/**
* Ops for hash hash operations.
*
* @return the hash operations
*/
public HashOperations<String, String, Object> opsForHash() {
return redisTemplate.opsForHash();
}
/**
* 对HashMap操作
*
* @param key the key
* @param hashKey the hash key
* @param hashValue the hash value
*/
public void putHashValue(String key, String hashKey, Object hashValue) {
log.debug("[redisTemplate redis] putHashValue() key={},hashKey={},hashValue={} ", key, hashKey, hashValue);
opsForHash().put(key, hashKey, hashValue);
}
/**
* 获取单个field对应的值
*
* @param key the key
* @param hashKey the hash key
* @return the hash values
*/
public Object getHashValues(String key, String hashKey) {
log.debug("[redisTemplate redis] getHashValues() key={},hashKey={}", key, hashKey);
return opsForHash().get(key, hashKey);
}
/**
* 根据key值删除
*
* @param key the key
* @param hashKeys the hash keys
*/
public void delHashValues(String key, Object... hashKeys) {
log.debug("[redisTemplate redis] delHashValues() key={}", key);
opsForHash().delete(key, hashKeys);
}
/**
* key只匹配map
*
* @param key the key
* @return the hash value
*/
public Map<String, Object> getHashValue(String key) {
log.debug("[redisTemplate redis] getHashValue() key={}", key);
return opsForHash().entries(key);
}
/**
* 批量添加
*
* @param key the key
* @param map the map
*/
public void putHashValues(String key, Map<String, Object> map) {
opsForHash().putAll(key, map);
}
/**
* 集合数量
*
* @return the long
*/
public long dbSize() {
return redisTemplate.execute(RedisServerCommands::dbSize);
}
/**
* 清空redis存储的数据
*
* @return the string
*/
public String flushDB() {
return redisTemplate.execute((RedisCallback<String>) connection -> {
connection.flushDb();
return "ok";
});
}
/**
* 判断某个主键是否存在
*
* @param key the key
* @return the boolean
*/
public boolean exists(final String key) {
return redisTemplate.execute((RedisCallback<Boolean>) connection -> connection.exists(key.getBytes(DEFAULT_CHARSET)));
}
/**
* 删除key
*
* @param keys the keys
* @return the long
*/
public long del(final String... keys) {
return redisTemplate.execute((RedisCallback<Long>) connection -> {
long result = 0;
for (String key : keys) {
result = connection.del(key.getBytes(DEFAULT_CHARSET));
}
return result;
});
}
/**
* 获取 RedisSerializer
*
* @return the redis serializer
*/
protected RedisSerializer<String> getRedisSerializer() {
return redisTemplate.getStringSerializer();
}
/**
* 对某个主键对应的值加一,value值必须是全数字的字符串
*
* @param key the key
* @return the long
*/
public long incr(final String key) {
return redisTemplate.execute((RedisCallback<Long>) connection -> {
RedisSerializer<String> redisSerializer = getRedisSerializer();
return connection.incr(redisSerializer.serialize(key));
});
}
/**
* redis List 引擎
*
* @return the list operations
*/
public ListOperations<String, Object> opsForList() {
return redisTemplate.opsForList();
}
/**
* redis List数据结构 : 将一个或多个值 value 插入到列表 key 的表头
*
* @param key the key
* @param value the value
* @return the long
*/
public Long leftPush(String key, Object value) {
return opsForList().leftPush(key, value);
}
/**
* redis List数据结构 : 移除并返回列表 key 的头元素
*
* @param key the key
* @return the string
*/
public Object leftPop(String key) {
return opsForList().leftPop(key);
}
/**
* redis List数据结构 :将一个或多个值 value 插入到列表 key 的表尾(最右边)。
*
* @param key the key
* @param value the value
* @return the long
*/
public Long in(String key, Object value) {
return opsForList().rightPush(key, value);
}
/**
* redis List数据结构 : 移除并返回列表 key 的末尾元素
*
* @param key the key
* @return the string
*/
public Object rightPop(String key) {
return opsForList().rightPop(key);
}
/**
* redis List数据结构 : 返回列表 key 的长度 ; 如果 key 不存在，则 key 被解释为一个空列表，返回 0 ; 如果 key 不是列表类型，返回一个错误。
*
* @param key the key
* @return the long
*/
public Long length(String key) {
return opsForList().size(key);
}
/**
* redis List数据结构 : 根据参数 i 的值，移除列表中与参数 value 相等的元素
*
* @param key the key
* @param i the
* @param value the value
*/
public void remove(String key, long i, Object value) {
opsForList().remove(key, i, value);
}
/**
* redis List数据结构 : 将列表 key 下标为 index 的元素的值设置为 value
*
* @param key the key
* @param index the index
* @param value the value
*/
public void set(String key, long index, Object value) {
opsForList().set(key, index, value);
}
/**
* redis List数据结构 : 返回列表 key 中指定区间内的元素，区间以偏移量 start 和 end 指定。
*
* @param key the key
* @param start the start
* @param end the end
* @return the list
*/
public List<Object> getList(String key, int start, int end) {
return opsForList().range(key, start, end);
}
/**
* redis List数据结构 : 批量存储
*
* @param key the key
* @param list the list
* @return the long
*/
public Long leftPushAll(String key, List<String> list) {
return opsForList().leftPushAll(key, list);
}
/**
* redis List数据结构 : 将值 value 插入到列表 key 当中，位于值 index 之前或之后,默认之后。
*
* @param key the key
* @param index the index
* @param value the value
*/
public void insert(String key, long index, Object value) {
opsForList().set(key, index, value);
}
}
redis序列化操作
package com.redis.common.redis.util;
/**
* 此时定义的序列化操作表示可以序列化所有类的对象，当然，这个对象所在的类一定要实现序列化接口
*
* @author
*/
public class RedisObjectSerializer implements RedisSerializer<Object> {
// 做一个空数组，不是null
private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
// 为了方便进行对象与字节数组的转换，所以应该首先准备出两个转换器
private Converter<Object, byte[]> serializingConverter = new SerializingConverter();
private Converter<byte[], Object> deserializingConverter = new DeserializingConverter();
@Override
public byte[] serialize(Object obj) {
// 这个时候没有要序列化的对象出现，所以返回的字节数组应该就是一个空数组
if (obj == null) {
return EMPTY_BYTE_ARRAY;
}
// 将对象变为字节数组
return this.serializingConverter.convert(obj);
}
@Override
public Object deserialize(byte[] data) {
// 此时没有对象的内容信息
if (data == null || data.length == 0) {
return null;
}
return this.deserializingConverter.convert(data);
}
}
缓存管理属性设置
package com.redis.common.redis.properties;
/**
* @author
* @date
*/
@Setter
@Getter
@ConfigurationProperties(prefix = "redis.cache-manager")
public class CacheManagerProperties {
private List<CacheConfig> configs;
@Setter
@Getter
public static class CacheConfig {
/**
* cache key
*/
private String key;
/**
* 过期时间，sec
*/
private long second = 60;
}
}
redis 配置类
package com.redis.common.redis;
/**
* redis 配置类
*
* @author
* @date
*/
@ConditionalOnClass(RedisRepository.class)
@EnableConfigurationProperties({RedisProperties.class, CacheManagerProperties.class})
@EnableCaching
public class RedisAutoConfigure {
@Autowired
private CacheManagerProperties cacheManagerProperties;
/**
* RedisTemplate配置
* @param factory
*/
@Bean
public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
redisTemplate.setConnectionFactory(factory);
RedisSerializer stringSerializer = new StringRedisSerializer();
RedisSerializer redisObjectSerializer = new RedisObjectSerializer();
redisTemplate.setKeySerializer(stringSerializer);
redisTemplate.setHashKeySerializer(stringSerializer);
redisTemplate.setValueSerializer(redisObjectSerializer);
redisTemplate.afterPropertiesSet();
return redisTemplate;
}
/**
* Redis repository redis repository.
*
* @param redisTemplate the redis template
* @return the redis repository
*/
@Bean
@ConditionalOnMissingBean
public RedisRepository redisRepository(RedisTemplate<String, Object> redisTemplate) {
return new RedisRepository(redisTemplate);
}
@Bean(name = "cacheManager")
@Primary
public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory) {
RedisCacheConfiguration difConf = getDefConf().entryTtl(Duration.ofHours(1));
//自定义的缓存过期时间配置
int configSize = cacheManagerProperties.getConfigs() == null ? 0 : cacheManagerProperties.getConfigs().size();
Map<String, RedisCacheConfiguration> redisCacheConfigurationMap = new HashMap<>(configSize);
if (configSize > 0) {
cacheManagerProperties.getConfigs().forEach(e -> {
RedisCacheConfiguration conf = getDefConf().entryTtl(Duration.ofSeconds(e.getSecond()));
redisCacheConfigurationMap.put(e.getKey(), conf);
});
}
return RedisCacheManager.builder(redisConnectionFactory)
.cacheDefaults(difConf)
.withInitialCacheConfigurations(redisCacheConfigurationMap)
.build();
}
@Bean
public KeyGenerator keyGenerator() {
return (target, method, objects) -> {
StringBuilder sb = new StringBuilder();
sb.append(target.getClass().getName());
sb.append(":" + method.getName() + ":");
for (Object obj : objects) {
sb.append(obj.toString());
}
return sb.toString();
};
}
private RedisCacheConfiguration getDefConf() {
return RedisCacheConfiguration.defaultCacheConfig()
.disableCachingNullValues()
.computePrefixWith(cacheName -> "cache".concat(":").concat(cacheName).concat(":"))
.serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(new StringRedisSerializer()))
.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(new RedisObjectSerializer()));
}
}
spring.factories文件
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
com.redis.common.redis.RedisAutoConfigure
