• Jedis工具类


    1、RedisCache.java

    package cn.itcast.mybatis.dao;


    import java.util.Date;
    import java.util.HashMap;
    import java.util.HashSet;
    import java.util.Map;
    import java.util.Set;

    import org.apache.commons.lang3.StringUtils;

    import redis.clients.jedis.Jedis;
    import redis.clients.jedis.JedisPool;
    import redis.clients.jedis.JedisPoolConfig;

    import com.google.gson.Gson;

    /**
    *
    * @description
    *
    * @author xujie04
    * @version $Id: RedisCacher.java, v 0.1 2015年8月25日 下午5:23:19 xujie04 Exp $
    */

    public class RedisCacher {

    private static int DEFAULT_DB_INDEX = 0;
    private static int DB_INDEX_1 = 1;
    private static JedisPool jedisPool = null;

    private String host;
    private int port;
    private String password;

    private static Gson gson = new Gson();

    private static final String ClassName = "CN";
    private static final String ObjectKey = "OBJK";
    private static final String EXPIRE_SECONDS = "expireSeconds";
    private static final String TIMESTAMP = "timestamp";

    public RedisCacher(String host, int port) {
    this.host = host;
    this.port = port;
    }

    public RedisCacher(String host, int port, String password) {
    this.host = host;
    this.port = port;
    this.password = password;
    }

    /**
    * 初始化redis连接池
    */
    public void init() {
    try {
    if (jedisPool == null) {

    // 配置如下的4个参数就够了。
    JedisPoolConfig config = new JedisPoolConfig();
    // 控制一个pool可分配多少个jedis实例,通过pool.getResource()来获取;
    // 如果赋值为-1,则表示不限制;如果pool已经分配了maxActive个jedis实例,则此时pool的状态为exhausted(耗尽)。
    config.setMaxTotal(100);
    // 控制一个pool最多有多少个状态为idle(空闲的)的jedis实例。
    config.setMaxIdle(10);
    // 表示当borrow(引入)一个jedis实例时,最大的等待时间,如果超过等待时间,则直接抛出JedisConnectionException;
    config.setMaxWaitMillis(10000L);
    // 在borrow一个jedis实例时,是否提前进行validate操作;如果为true,则得到的jedis实例均是可用的;
    config.setTestOnBorrow(true);
    jedisPool = new JedisPool(config, host, port, 10000, password);
    }
    } catch (Exception e) {
    e.printStackTrace();
    }
    }

    /**
    * 获得redis实例
    */
    public Jedis getJedis() {
    try {
    if (jedisPool != null) {
    Jedis resource = jedisPool.getResource();
    resource.select(DEFAULT_DB_INDEX);
    return resource;
    } else {
    return null;
    }
    } catch (Exception e) {
    e.printStackTrace();
    return null;
    }
    }

    public void returnResource(final Jedis jedis) {
    if (jedis != null) {
    jedisPool.returnResource(jedis);
    }
    }

    private String objectToJSONString(Object val, Integer seconds) {
    Map<String, Object> map = new HashMap<String, Object>();
    map.put(ObjectKey, gson.toJson(val));
    map.put(ClassName, val.getClass().getName());
    map.put(EXPIRE_SECONDS, seconds);
    map.put(TIMESTAMP, new Date().getTime());
    return gson.toJson(map);
    }

    @SuppressWarnings("unchecked")
    private Object jsonStringToObject(String value) throws Exception {
    Map<String, Object> map = gson.fromJson(value, new HashMap<String, Object>().getClass());
    Object obj = map.get(ObjectKey);
    if (obj == null) {
    return null;
    }
    Integer seconds = ((Double) map.get(EXPIRE_SECONDS)).intValue();
    if (seconds != null) {
    Long timestamp = ((Double) map.get(TIMESTAMP)).longValue();
    Long now = new Date().getTime();
    if ((timestamp + (seconds.longValue() * 1000)) < now) {
    //过期
    throw new Exception("the value has expire,but not expire in redis...");
    }
    }

    String objStr = (String) obj;
    String className = (String) map.get(ClassName);
    return gson.fromJson(objStr, Class.forName(className));
    }

    //删除
    public void delete(String... keys) {
    Jedis jedis = getJedis();
    try {
    if (jedis != null) {
    if (keys != null) {
    jedis.del(keys);
    }
    }
    } catch (Exception e) {
    e.printStackTrace();
    } finally {
    returnResource(jedis);
    }
    }

    /**
    * 值设置到redis中
    *
    * @param key
    * @param val
    * @param seconds 单位秒
    */
    public void set(String key, Object val, Integer seconds) {
    Jedis jedis = getJedis();
    try {
    if (jedis != null) {
    jedis.set(key, objectToJSONString(val, seconds));
    if (seconds != null) {
    jedis.expire(key, seconds);
    }
    }
    } catch (Exception e) {
    e.printStackTrace();
    } finally {
    returnResource(jedis);
    }
    }

    /**
    * 新增将hash值设置到redis中
    *
    * @param key
    * @param val
    * @param seconds 单位秒
    */
    public void hset(String key, String field, String val, Integer seconds) {
    Jedis jedis = getJedis();
    try {
    if (jedis != null) {
    jedis.select(DB_INDEX_1);
    jedis.hset(key, field, val);
    if (seconds != null) {
    jedis.expire(key, seconds);
    }
    }
    } catch (Exception e) {
    e.printStackTrace();
    } finally {
    returnResource(jedis);
    }
    }

    /**
    * 获取值
    *
    * @param key
    * @return
    */
    public Object get(String key) {
    Jedis jedis = getJedis();
    try {
    if (jedis != null) {
    String str = jedis.get(key);
    if (StringUtils.isEmpty(str)) {
    return null;
    }
    return jsonStringToObject(str);
    }
    return null;
    } catch (Exception e) {
    if (jedis.exists(key)) {
    delete(key);
    }
    return null;
    } finally {
    returnResource(jedis);
    }
    }

    /**
    *根据key field 获取hash值
    *
    * @param key
    * @param field
    * @return
    */
    public String hget(String key, String field) {
    Jedis jedis = getJedis();
    try {
    if (jedis != null) {
    jedis.select(DB_INDEX_1);
    String str = jedis.hget(key, field);
    if (StringUtils.isEmpty(str)) {
    return null;
    }
    return str;
    }
    return null;
    } catch (Exception e) {
    if (jedis.exists(key)) {
    delete(key);
    }
    return null;
    } finally {
    returnResource(jedis);
    }
    }

    /**
    * 获取hash值
    *
    * @param key
    * @return
    */
    public Map<String, String> hgetAll(String key) {
    Jedis jedis = getJedis();
    Map<String, String> str = new HashMap<String, String>();
    try {
    if (jedis != null) {
    jedis.select(DB_INDEX_1);
    str = jedis.hgetAll(key);
    if (StringUtils.isEmpty(str.toString())) {
    return null;
    }
    return str;
    }
    return str;
    } catch (Exception e) {
    if (jedis.exists(key)) {
    delete(key);
    }
    return null;
    } finally {
    returnResource(jedis);
    }
    }

    /**
    * 获取key模糊查询得到的数组
    *
    * @param key
    * @return
    */
    public Set<String> keys(String key) {
    Jedis jedis = getJedis();
    Set<String> str = new HashSet<String>();
    try {
    if (jedis != null) {
    jedis.select(DB_INDEX_1);
    str = jedis.keys(key);
    if (null == str || str.size() == 0) {
    return null;
    }
    return str;
    }
    return str;
    } catch (Exception e) {
    if (jedis.exists(key)) {
    delete(key);
    }
    return null;
    } finally {
    returnResource(jedis);
    }
    }

    public String getHost() {
    return host;
    }

    public void setHost(String host) {
    this.host = host;
    }

    public int getPort() {
    return port;
    }

    public void setPort(int port) {
    this.port = port;
    }

    public String getPassword() {
    return password;
    }

    public void setPassword(String password) {
    this.password = password;
    }
    }

    2、CacheManager.java

    package cn.itcast.mybatis.dao;

    import java.util.Map;
    import java.util.Set;

    /**
    *
    * @description
    *
    * @author xujie04
    * @version $Id: CacheManager.java, v 0.1 2015年8月26日 上午10:36:05 xujie04 Exp $
    */
    public interface CacheManager {
    /**
    *
    * @param key 缓存对象的key
    * @param val 缓存的对象
    * @param expireSeconds 有效时间
    */
    public void set(String key, Object val, Integer expireSeconds);

    public Object get(String key);

    public void delete(String key);

    public void hset(String key, String field, String val, Integer seconds);

    public String hget(String key, String field);

    public Map<String, String> hgetAll(String key);

    public Set<String> keys(String key);

    }

    3、CacheManagerImpl.java

    package cn.itcast.mybatis.dao;


    import java.util.Map;
    import java.util.Set;

    import javax.annotation.PostConstruct;

    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.stereotype.Component;

    /**
    *
    * @description
    *
    * @author xujie04
    * @version $Id: CacheManagerImpl.java, v 0.1 2015年8月26日 上午10:35:58 xujie04 Exp $
    */
    @Component
    public class CacheManagerImpl implements CacheManager {

    private RedisCacher cacher;

    @Value("${redis.ip}")
    private String host;

    @Value("${redis.port}")
    private int port;
    @Value("${redis.password}")
    private String password;

    @PostConstruct
    public void init() {
    cacher = new RedisCacher(host, port, password);
    cacher.init();
    }

    @Override
    public void set(String key, Object val, Integer expireSeconds) {
    cacher.set(key, val, expireSeconds);
    }

    @Override
    public Object get(String key) {
    return cacher.get(key);
    }

    @Override
    public void delete(String key) {
    cacher.delete(key);
    }

    @Override
    public void hset(String key, String field, String val, Integer seconds) {
    cacher.hset(key, field, val, seconds);
    }

    @Override
    public String hget(String key, String field) {
    return cacher.hget(key, field);
    }

    @Override
    public Map<String, String> hgetAll(String key) {
    return cacher.hgetAll(key);
    }


    @Override
    public Set<String> keys(String key) {
    return cacher.keys(key);
    }

    }

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  • 原文地址:https://www.cnblogs.com/muliu/p/6050939.html
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