A concept.
redis is a high performance NOSQL series of non-relational database.
II. Download and install.
1, redis a Chinese network.
2, decompression can be used directly.
* Redis.windows.conf: configuration file.
* Redis-cli.exe: redis client.
* Redis-server.exe: redis server.
III. Command operations.
1, redis data structure: the format of the key value, key string type, value of the five types:
* String type string
* Type hash hash: map format
* List type list: linkedlist format
* Set type set
* Indexed collections sortedset
2, string type string:
* Storage: set key value
* Get: get key
* Delete: del key
3. hash type hash:
* Storage: hset key field value
* 获取： hget key field hgetall key
* Delete: hdel key field
4, the list type list: an element may be added to the head or tail of a list. If they add, is to "squeeze" approach.
* 添加：1、lpush key value 2、rpush key value
* Get: lrange key start end: the scope of acquisition.
* Delete: lpop key rpop key delete elements and returns it.
5, a set of type set: unordered, allowed repeat elements.
* Storage: sadd key value
* Get: smembers key Gets a collection of all the elements.
* Delete; srem key value: Delete a set of elements.
6, ordered set sortedset: do not allow duplicate elements, but orderly. Sort according score
* Storage: zadd key score value
* Get: zrange key start end
* Delete: zrem key value
7, Spoken instructions.
Keys : Search button
* Type key: get key corresponding to the value of the type.
* Del key: delete the specified pairs.
Four. Endurance of.
1, redis is an in-memory database, when redis server is restarted, or restart the computer, data will be lost, so it is necessary to persist to the hard disk
2, redis persistence mechanism:
* RDB: default, does not require configuration. Upon detecting the change of key in a certain time, persistent data.
Edit redis.windows.conf file:
save 900 1
save 300 10
save 60 10000
Meaning: how many seconds, at least the number of key changes, and on persistent one.
* AOF: logging mode, you can record the operation of each command. After each operation command may, persistent data.
Edit redis.windows.conf file:
Set appendonly yes (open aof)
# Appendfsync always: each operation are persistent
appendfsync everysec: once every second persistence
# Appendfsync no: no persistence
Five .Java client Jedis.
* Jedis: a Java tool operation redis database
* Use steps: first import jar two packages: jedis and jedis pool
1, obtaining a connection: Jedis jedis = new Jedis ( "localhost", 6379); Empty default parameters of the machine.
2. Operation: method name and the same command line.
3, close the connection: jedis.close ();
* Other methods:
1, jedis.setex ( "activecode", 20, "rt"): key-value pairs stored and automatically deleted after 20 seconds.
* Jedis connection pool:
1, create a configuration object:
JedisPoolConfig config =new JedisPoolConfig();
config.setMaxTotal(20) ; config.setMaxIdle(10) ...........
2, Jedis create a connection pool object.
JedisPool jp=new JedisPool(config,"localhost",6379)
3, get connected.
Jedis jedis=jp.getResource()
4, use.
5, returned to the pool. jedis.close ();
* Custom jedis tools.
* Redis applications: cache some data does not change often happens with redis.
VI. Case
Requirements: providing index.html page, there is a drop-down list province, after the page is loaded, sending Ajax, load all provinces.