jedis操作封装

参考自：Java秒杀系统方案优化-高性能高并发实战

为什么我们要封装jedis？

     1.每次使用需要释放资源，

     2.每次使用需要转换类型

     3.多人开发，key存储可能覆盖   

根据上述问题，封装适合自己项目的操作类

---

针对1、2问题，我们简单封装jedisserver

public class RedisService {
	
	@Autowired
	JedisPool jedisPool;
	
	/**
	 * 获取当个对象
	 * */
	public <T> T get(KeyPrefix prefix, String key,  Class<T> clazz) {
		 Jedis jedis = null;
		 try {
			 jedis =  jedisPool.getResource();
			 //生成真正的key
			 String realKey  = prefix.getPrefix() + key;
			 String  str = jedis.get(realKey);
			 T t =  stringToBean(str, clazz);
			 return t;
		 }finally {
			  returnToPool(jedis);
		 }
	}
	
	/**
	 * 设置对象
	 * */
	public <T> boolean set(KeyPrefix prefix, String key,  T value) {
		 Jedis jedis = null;
		 try {
			 jedis =  jedisPool.getResource();
			 String str = beanToString(value);
			 if(str == null || str.length() <= 0) {
				 return false;
			 }
			//生成真正的key
			 String realKey  = prefix.getPrefix() + key;
			 int seconds =  prefix.expireSeconds();
			 if(seconds <= 0) {
				 jedis.set(realKey, str);
			 }else {
				 jedis.setex(realKey, seconds, str);
			 }
			 return true;
		 }finally {
			  returnToPool(jedis);
		 }
	}
	
	/**
	 * 判断key是否存在
	 * */
	public <T> boolean exists(KeyPrefix prefix, String key) {
		 Jedis jedis = null;
		 try {
			 jedis =  jedisPool.getResource();
			//生成真正的key
			 String realKey  = prefix.getPrefix() + key;
			return  jedis.exists(realKey);
		 }finally {
			  returnToPool(jedis);
		 }
	}
	
	/**
	 * 增加值
	 * */
	public <T> Long incr(KeyPrefix prefix, String key) {
		 Jedis jedis = null;
		 try {
			 jedis =  jedisPool.getResource();
			//生成真正的key
			 String realKey  = prefix.getPrefix() + key;
			return  jedis.incr(realKey);
		 }finally {
			  returnToPool(jedis);
		 }
	}
	
	/**
	 * 减少值
	 * */
	public <T> Long decr(KeyPrefix prefix, String key) {
		 Jedis jedis = null;
		 try {
			 jedis =  jedisPool.getResource();
			//生成真正的key
			 String realKey  = prefix.getPrefix() + key;
			return  jedis.decr(realKey);
		 }finally {
			  returnToPool(jedis);
		 }
	}
	
	private <T> String beanToString(T value) {
		if(value == null) {
			return null;
		}
		Class<?> clazz = value.getClass();
		if(clazz == int.class || clazz == Integer.class) {
			 return ""+value;
		}else if(clazz == String.class) {
			 return (String)value;
		}else if(clazz == long.class || clazz == Long.class) {
			return ""+value;
		}else {
			return JSON.toJSONString(value);
		}
	}

	@SuppressWarnings("unchecked")
	private <T> T stringToBean(String str, Class<T> clazz) {
		if(str == null || str.length() <= 0 || clazz == null) {
			 return null;
		}
		if(clazz == int.class || clazz == Integer.class) {
			 return (T)Integer.valueOf(str);
		}else if(clazz == String.class) {
			 return (T)str;
		}else if(clazz == long.class || clazz == Long.class) {
			return  (T)Long.valueOf(str);
		}else {
			return JSON.toJavaObject(JSON.parseObject(str), clazz);
		}
	}

	private void returnToPool(Jedis jedis) {
		 if(jedis != null) {
			 jedis.close();
		 }
	}

}

针对第三个问题，我们封装KeyPrefix，并且定义了自己的key规则，格式为【模块:前缀key】

public interface KeyPrefix {
		
	public int expireSeconds();
	
	public String getPrefix();
	
}

public abstract class BasePrefix implements KeyPrefix{
	
	private int expireSeconds;
	
	private String prefix;
	
	public BasePrefix(String prefix) {//0代表永不过期
		this(0, prefix);
	}
	
	public BasePrefix( int expireSeconds, String prefix) {
		this.expireSeconds = expireSeconds;
		this.prefix = prefix;
	}
	
	public int expireSeconds() {//默认0代表永不过期
		return expireSeconds;
	}

	public String getPrefix() {
		String className = getClass().getSimpleName();
		return className+":" + prefix;
	}

}

public class MiaoshaUserKey extends BasePrefix{

	public static final int TOKEN_EXPIRE = 3600*24 * 2;
	private MiaoshaUserKey(int expireSeconds, String prefix) {
		super(expireSeconds, prefix);
	}
	public static MiaoshaUserKey token = new MiaoshaUserKey(TOKEN_EXPIRE, "tk");
}