Jedis set 方法参数的含义

String redis.clients.jedis.Jedis.set(String key, String value, String nxxx, String expx, long time)

Set the string value as value of the key. The string can’t be longer than 1073741824 bytes (1 GB).

Parameters:

key 

value 

nxxx NX|XX, NX -- Only set the key if it does not already exist. XX 
-- Only set the key if it already exist.

expx EX|PX, expire time units: EX = seconds; PX = milliseconds
time expire time in the units of {@param #expx}

Returns:

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