spring-data-redis简介

1、简述
Redis是一种nosql数据库，在开发中常用做缓存。Jedis是Redis在Java中的redis- client。spring把专门的数据操作独立封装在spring-data系列中，spring-data-redis自然是针对Redis的独立封装了。

2、使用
2.1 pom.xml

<!-- redis --> <dependency>      <groupId>redis.clients</groupId>      <artifactId>jedis</artifactId>      <version>2.8.2</version>      <type>jar</type>      <scope>compile</scope>  </dependency>  <!-- spring-redis -->  <dependency>      <groupId>org.springframework.data</groupId>      <artifactId>spring-data-redis</artifactId>      <version>1.6.4.RELEASE</version>  </dependency>  

2.2 redis.properties配置

#最大分配的对象数redis.pool.maxTotal=1024#最大能够保持idel状态的对象数redis.pool.maxIdle=200#当池内没有返回对象时，最大等待时间redis.pool.maxWaitMillis=1000#当调用borrow Object方法时，是否进行有效性检查redis.pool.testOnBorrow=true#当调用return Object方法时，是否进行有效性检查redis.pool.testOnReturn=true#连接密码redis.password=#IPredis.ip=xxxx#Portredis.port=6379

2.3 spring-redis.xml配置

<!-- 缓存的层级-->    <context:component-scan base-package="com.xxxx" />    <!-- 引入redis配置 -->    <context:property-placeholder location="classpath:redis.properties" ignore-unresolvable="true"/>    <!-- Jedis 连接池配置 -->    <bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">        <property name="maxTotal" value="${redis.pool.maxTotal}" />        <property name="maxIdle" value="${redis.pool.maxIdle}" />        <property name="maxWaitMillis" value="${redis.pool.maxWaitMillis}" />        <property name="testOnBorrow" value="${redis.pool.testOnBorrow}" />    </bean>    <!-- Jedis ConnectionFactory 数据库连接配置 -->    <bean id="jedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">        <property name="hostName" value="${redis.ip}" />        <property name="port" value="${redis.port}" />        <!--<property name="password" value="${redis.pass}" />-->        <property name="poolConfig" ref="jedisPoolConfig" />    </bean>     <!-- redisTemplate配置，redisTemplate是对Jedis的对redis操作的扩展，有更多的操作，封装使操作更便捷 -->    <bean id="redisTemplate" class="org.springframework.data.redis.core.StringRedisTemplate">        <property name="connectionFactory" ref="jedisConnectionFactory" />    </bean>

redisTemplate已经基本配置完成。接下来可以创建一个Goods类，必须实现或者间接实现Serializable接口。

Redis存储对象是使用序列化，spring-data-redis已经将序列化的功能内置，不需要我们去管，我们只需要调用api就可以使用。SerialVersionUID字段对序列化扩展有用，为了以后扩展或者缩减字段时不会造成反序列化出错。

2.4 创建redis的增删改查操作

@Componentpublic class RedisCache {    public final static String CAHCENAME="cache";//缓存名    public final static int CAHCETIME=60;//默认缓存时间    //自动注入RedisTemplate    @Autowired    private RedisTemplate<String, String> redisTemplate;    public <T> boolean putCache(String key, T obj) {        final byte[] bkey = key.getBytes();        final byte[] bvalue = ProtoStuffSerializerUtil.serialize(obj);        boolean result = redisTemplate.execute(new RedisCallback<Boolean>() {            @Override            public Boolean doInRedis(RedisConnection connection) throws DataAccessException {                return connection.setNX(bkey, bvalue);            }        });        return result;    }    public <T> boolean setCache(String key, T obj) {        final byte[] bkey = key.getBytes();        final byte[] bvalue = ProtoStuffSerializerUtil.serialize(obj);        boolean result = redisTemplate.execute(new RedisCallback<Boolean>() {            @Override            public Boolean doInRedis(RedisConnection connection) throws DataAccessException {                connection.set(bkey, bvalue);                return true;            }        });        return result;    }    public <T> void putCacheWithExpireTime(String key, T obj, final long expireTime) {        final byte[] bkey = key.getBytes();        final byte[] bvalue = ProtoStuffSerializerUtil.serialize(obj);        redisTemplate.execute(new RedisCallback<Boolean>() {            @Override            public Boolean doInRedis(RedisConnection connection) throws DataAccessException {                connection.setEx(bkey, expireTime, bvalue);                return true;            }        });    }    public <T> boolean putListCache(String key, List<T> objList) {        final byte[] bkey = key.getBytes();        final byte[] bvalue = ProtoStuffSerializerUtil.serializeList(objList);        boolean result = redisTemplate.execute(new RedisCallback<Boolean>() {            @Override            public Boolean doInRedis(RedisConnection connection) throws DataAccessException {                return connection.setNX(bkey, bvalue);            }        });        return result;    }    public <T> boolean putListCacheWithExpireTime(String key, List<T> objList, final long expireTime) {        final byte[] bkey = key.getBytes();        final byte[] bvalue = ProtoStuffSerializerUtil.serializeList(objList);        boolean result = redisTemplate.execute(new RedisCallback<Boolean>() {            @Override            public Boolean doInRedis(RedisConnection connection) throws DataAccessException {                connection.setEx(bkey, expireTime, bvalue);                return true;            }        });        return result;    }    public <T> T getCache(final String key, Class<T> targetClass) {        byte[] result = redisTemplate.execute(new RedisCallback<byte[]>() {            @Override            public byte[] doInRedis(RedisConnection connection) throws DataAccessException {                return connection.get(key.getBytes());            }        });        if (result == null) {            return null;        }        return ProtoStuffSerializerUtil.deserialize(result, targetClass);    }    public <T> List<T> getListCache(final String key, Class<T> targetClass) {        byte[] result = redisTemplate.execute(new RedisCallback<byte[]>() {            @Override            public byte[] doInRedis(RedisConnection connection) throws DataAccessException {                return connection.get(key.getBytes());            }        });        if (result == null) {            return null;        }        return ProtoStuffSerializerUtil.deserializeList(result, targetClass);    }    /**     * 精确删除key     *      * @param key     */    public void deleteCache(String key) {        redisTemplate.delete(key);    }    /**     * 模糊删除key     *      * @param pattern     */    public void deleteCacheWithPattern(String pattern) {        Set<String> keys = redisTemplate.keys(pattern);        redisTemplate.delete(keys);    }    /**     * 清空所有缓存     */    public void clearCache() {        deleteCacheWithPattern(RedisCache.CAHCENAME+"|*");    }}

2.5 get和set操作示例

@Service("goodsService")public class GoodsServiceImpl implements IGoodsService {    private final Logger LOG = LoggerFactory.getLogger(this.getClass());    @Resource    private IElasticService elasticService;    @Autowired    private RedisCache cache;    @Value("${searchUrl}")    private String searchUrl;    @Override    public List<Goods> getGoodsList(int offset, int limit) {        String cacheKey = RedisCache.CAHCENAME + "|getGoodsList|" + offset + "|" + limit;        //先去缓存中取        List<Goods> resultCache = cache.getListCache(cacheKey, Goods.class);        if (resultCache == null) {            //缓存中没有再去数据库取，并插入缓存（缓存时间为60秒）            resultCache = elasticService.getGoodsList(offset, limit);            cache.putListCacheWithExpireTime(cacheKey, resultCache, RedisCache.CAHCETIME);            LOG.info("put cache with key:" + cacheKey);        } else {            LOG.info("get cache with key:" + cacheKey);        }        return resultCache;    }    @Override    public ReportResultSimple searchGoods(String queryData) {        ReportResultSimple result = new ReportResultSimple();        try {            JsonParser jsonParser = new ObjectMapper().readValue(queryData, new TypeReference<JsonParser>() {            });            LOG.info("query begin, query is:[ " + jsonParser.toString() + " ]");            String cacheKey = RedisCache.CAHCENAME + "|" + queryData;            //暂时只对没有search的查询条件做缓存            if (jsonParser.getQuerys() == null) {                //先去缓存中取                result = cache.getCache(cacheKey, ReportResultSimple.class);            }            if (result == null || jsonParser.getQuerys() != null) {                //缓存没有结果,从elasticsearch查询                //                if (jsonParser.getQuerys() == null) {                    cache.putCacheWithExpireTime(cacheKey, result, RedisCache.CAHCETIME);                }            }        } catch (Exception e) {            LOG.error(e.getMessage(), e);            result.setFlag("false");            result.setMsg(e.getMessage());        }        return result;    }}