Jedis

We're going to use java To operate redis

jedis yes Redis Officially recommended java Connect development tools , Use java operation redis middleware

1. newly build maven Project connection test

​ （1） Import jedis rely on

<!-- https://mvnrepository.com/artifact/redis.clients/jedis -->
<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>3.6.3</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.78</version>
</dependency>

​ （2） Coding test

public class TestPing {
    
    public static void main(String[] args) {
    
        //1.new Jedis object 
        Jedis jedis=new Jedis("127.0.0.1",6379);
        //2.jedis All the commands we have learned before redis command 
        System.out.println(jedis.ping());
    }
}

 Control output ：
PONG

2. frequently-used API

testKey

public class TestKey {
    
    public static void main(String[] args) {
    
        Jedis jedis = new Jedis("127.0.0.1", 6379);

        System.out.println(" Empty data ："+jedis.flushDB());
        System.out.println(" Determine whether a key exists ："+jedis.exists("username"));
        System.out.println(" newly added <'username','kuangshen'> The key/value pair ："+jedis.set("username", "kuangshen"));
        System.out.println(" newly added <'password','password'> The key/value pair ："+jedis.set("password", "password"));
        System.out.print(" All keys in the system are as follows ：");
        Set<String> keys = jedis.keys("*");
        System.out.println(keys);
        System.out.println(" Delete key password:"+jedis.del("password"));
        System.out.println(" Judgment key password Whether there is ："+jedis.exists("password"));
        System.out.println(" View key username The type of value stored ："+jedis.type("username"));
        System.out.println(" Random return key One of the spaces ："+jedis.randomKey());
        System.out.println(" rename key："+jedis.rename("username","name"));
        System.out.println(" Take out the modified name："+jedis.get("name"));
        System.out.println(" Search by index ："+jedis.select(0));
        System.out.println(" Delete all... In the currently selected database key："+jedis.flushDB());
        System.out.println(" Return to the current database key Number of ："+jedis.dbSize());
        System.out.println(" Delete all in all databases key："+jedis.flushAll());
    }
}

testString

public class TestString {
    
    public static void main(String[] args) {
    
        Jedis jedis = new Jedis("127.0.0.1", 6379);

        jedis.flushDB();
        System.out.println("=========== Add data ===========");
        System.out.println(jedis.set("key1","value1"));
        System.out.println(jedis.set("key2","value2"));
        System.out.println(jedis.set("key3", "value3"));
        System.out.println(" Delete key key2:"+jedis.del("key2"));
        System.out.println(" Get key key2:"+jedis.get("key2"));
        System.out.println(" modify key1:"+jedis.set("key1", "value1Changed"));
        System.out.println(" obtain key1 Value ："+jedis.get("key1"));
        System.out.println(" stay key3 Then add the value ："+jedis.append("key3", "End"));
        System.out.println("key3 Value ："+jedis.get("key3"));
        System.out.println(" Add multiple key value pairs ："+jedis.mset("key01","value01","key02","value02","key03","value03"));
        System.out.println(" Get multiple key value pairs ："+jedis.mget("key01","key02","key03"));
        System.out.println(" Get multiple key value pairs ："+jedis.mget("key01","key02","key03","key04"));
        System.out.println(" Delete multiple key value pairs ："+jedis.del("key01","key02"));
        System.out.println(" Get multiple key value pairs ："+jedis.mget("key01","key02","key03"));

        jedis.flushDB();
        System.out.println("=========== The new key value pair prevents the original value from being overridden ==============");
        System.out.println(jedis.setnx("key1", "value1"));
        System.out.println(jedis.setnx("key2", "value2"));
        System.out.println(jedis.setnx("key2", "value2-new"));
        System.out.println(jedis.get("key1"));
        System.out.println(jedis.get("key2"));

        System.out.println("=========== Add a key value pair and set the effective time =============");
        System.out.println(jedis.setex("key3", 2, "value3"));
        System.out.println(jedis.get("key3"));
        try {
    
            TimeUnit.SECONDS.sleep(3);
        } catch (InterruptedException e) {
    
            e.printStackTrace();
        }
        System.out.println(jedis.get("key3"));

        System.out.println("=========== To obtain original value , Update to the new value ==========");
        System.out.println(jedis.getSet("key2", "key2GetSet"));
        System.out.println(jedis.get("key2"));

        System.out.println(" get key2 The string of the value of ："+jedis.getrange("key2", 2, 4));
    }
}

testSet

public class TestSet {
    
    public static void main(String[] args) {
    
        Jedis jedis = new Jedis("127.0.0.1", 6379);
        jedis.flushDB();
        System.out.println("============ Add elements to the collection （ No repetition ）============");
        System.out.println(jedis.sadd("eleSet", "e1","e2","e4","e3","e0","e8","e7","e5"));
        System.out.println(jedis.sadd("eleSet", "e6"));
        System.out.println(jedis.sadd("eleSet", "e6"));
        System.out.println("eleSet All elements of are ："+jedis.smembers("eleSet"));
        System.out.println(" Delete an element e0："+jedis.srem("eleSet", "e0"));
        System.out.println("eleSet All elements of are ："+jedis.smembers("eleSet"));
        System.out.println(" Delete two elements e7 and e6："+jedis.srem("eleSet", "e7","e6"));
        System.out.println("eleSet All elements of are ："+jedis.smembers("eleSet"));
        System.out.println(" Randomly remove an element from the set ："+jedis.spop("eleSet"));
        System.out.println(" Randomly remove an element from the set ："+jedis.spop("eleSet"));
        System.out.println("eleSet All elements of are ："+jedis.smembers("eleSet"));
        System.out.println("eleSet The number of elements contained in ："+jedis.scard("eleSet"));
        System.out.println("e3 Whether in eleSet in ："+jedis.sismember("eleSet", "e3"));
        System.out.println("e1 Whether in eleSet in ："+jedis.sismember("eleSet", "e1"));
        System.out.println("e1 Whether in eleSet in ："+jedis.sismember("eleSet", "e5"));
        System.out.println("=================================");
        System.out.println(jedis.sadd("eleSet1", "e1","e2","e4","e3","e0","e8","e7","e5"));
        System.out.println(jedis.sadd("eleSet2", "e1","e2","e4","e3","e0","e8"));
        System.out.println(" take eleSet1 Delete in e1 And deposit in eleSet3 in ："+jedis.smove("eleSet1", "eleSet3", "e1"));// Move to the collection element 
        System.out.println(" take eleSet1 Delete in e2 And deposit in eleSet3 in ："+jedis.smove("eleSet1", "eleSet3", "e2"));
        System.out.println("eleSet1 The elements in ："+jedis.smembers("eleSet1"));
        System.out.println("eleSet3 The elements in ："+jedis.smembers("eleSet3"));
        System.out.println("============ Set operations =================");
        System.out.println("eleSet1 The elements in ："+jedis.smembers("eleSet1"));
        System.out.println("eleSet2 The elements in ："+jedis.smembers("eleSet2"));
        System.out.println("eleSet1 and eleSet2 Intersection :"+jedis.sinter("eleSet1","eleSet2"));
        System.out.println("eleSet1 and eleSet2 Union :"+jedis.sunion("eleSet1","eleSet2"));
        System.out.println("eleSet1 and eleSet2 The difference between the set :"+jedis.sdiff("eleSet1","eleSet2"));//eleSet1 There is ,eleSet2 There is no 
        jedis.sinterstore("eleSet4","eleSet1","eleSet2");// Find the intersection and save it to dstkey Set 
        System.out.println("eleSet4 The elements in ："+jedis.smembers("eleSet4"));
    }
}

testList

public class TestList {
    
    public static void main(String[] args) {
    
        Jedis jedis = new Jedis("127.0.0.1", 6379);
        jedis.flushDB();
        System.out.println("=========== Add one list===========");
        jedis.lpush("collections", "ArrayList", "Vector", "Stack", "HashMap", "WeakHashMap", "LinkedHashMap");
        jedis.lpush("collections", "HashSet");
        jedis.lpush("collections", "TreeSet");
        jedis.lpush("collections", "TreeMap");
        System.out.println("collections The content of ："+jedis.lrange("collections", 0, -1));//-1 For the last element ,-2 Represents the penultimate element ,end by -1 Means to query all 
        System.out.println("collections Section 0-3 The elements of ："+jedis.lrange("collections",0,3));
        System.out.println("===============================");
        //  Delete the value specified in the list  , The second parameter is the number of deletions （ When there are repetitions ）, after add The value entered is deleted first , It's like getting out of the stack 
        System.out.println(" Delete the specified number of elements ："+jedis.lrem("collections", 2, "HashMap"));
        System.out.println("collections The content of ："+jedis.lrange("collections", 0, -1));
        System.out.println(" Delete the following table 0-3 Elements outside the interval ："+jedis.ltrim("collections", 0, 3));
        System.out.println("collections The content of ："+jedis.lrange("collections", 0, -1));
        System.out.println("collections List out （ Left side ）："+jedis.lpop("collections"));
        System.out.println("collections The content of ："+jedis.lrange("collections", 0, -1));
        System.out.println("collections Additive elements , From the right end of the list , And lpush Corresponding ："+jedis.rpush("collections", "EnumMap"));
        System.out.println("collections The content of ："+jedis.lrange("collections", 0, -1));
        System.out.println("collections List out （ Right end ）："+jedis.rpop("collections"));
        System.out.println("collections The content of ："+jedis.lrange("collections", 0, -1));
        System.out.println(" modify collections Specify subscript 1 The content of ："+jedis.lset("collections", 1, "LinkedArrayList"));
        System.out.println("collections The content of ："+jedis.lrange("collections", 0, -1));
        System.out.println("===============================");
        System.out.println("collections The length of ："+jedis.llen("collections"));
        System.out.println(" obtain collections Subscript to be 2 The elements of ："+jedis.lindex("collections", 2));
        System.out.println("===============================");
        jedis.lpush("sortedList", "3","6","2","0","7","4");
        System.out.println("sortedList Before ordering ："+jedis.lrange("sortedList", 0, -1));
        System.out.println(jedis.sort("sortedList"));
        System.out.println("sortedList After ordering ："+jedis.lrange("sortedList", 0, -1));
    }
}

testHash

public class TestHash {
    
    public static void main(String[] args) {
    
        Jedis jedis = new Jedis("127.0.0.1", 6379);
        jedis.flushDB();
        Map<String,String> map = new HashMap<String,String>();
        map.put("key1","value1");
        map.put("key2","value2");
        map.put("key3","value3");
        map.put("key4","value4");
        // Add the name hash（key） Of hash Elements 
        jedis.hmset("hash",map);
        // The name of Xiang is hash Of hash Add key by key5,value by value5 Elements 
        jedis.hset("hash", "key5", "value5");
        System.out.println(" hash hash All key value pairs of are ："+jedis.hgetAll("hash"));//return Map<String,String>
        System.out.println(" hash hash All the keys of are ："+jedis.hkeys("hash"));//return Set<String>
        System.out.println(" hash hash All values of are ："+jedis.hvals("hash"));//return List<String>
        System.out.println(" take key6 The saved value plus an integer , If key6 Add if not key6："+jedis.hincrBy("hash", "key6", 6));
        System.out.println(" hash hash All key value pairs of are ："+jedis.hgetAll("hash"));
        System.out.println(" take key6 The saved value plus an integer , If key6 Add if not key6："+jedis.hincrBy("hash", "key6", 3));
        System.out.println(" hash hash All key value pairs of are ："+jedis.hgetAll("hash"));
        System.out.println(" Delete one or more key value pairs ："+jedis.hdel("hash", "key2"));
        System.out.println(" hash hash All key value pairs of are ："+jedis.hgetAll("hash"));
        System.out.println(" hash hash The number of key-value pairs ："+jedis.hlen("hash"));
        System.out.println(" Judge hash Whether there is key2："+jedis.hexists("hash","key2"));
        System.out.println(" Judge hash Whether there is key3："+jedis.hexists("hash","key3"));
        System.out.println(" obtain hash The value in ："+jedis.hmget("hash","key3"));
        System.out.println(" obtain hash The value in ："+jedis.hmget("hash","key3","key4"));
    }
}

3. Business

public class TestMulti {
    
    public static void main(String[] args) {
    
        // Create client connection server ,redis The server needs to be turned on 
        Jedis jedis = new Jedis("127.0.0.1", 6379);
        jedis.flushDB();

        JSONObject jsonObject = new JSONObject();
        jsonObject.put("hello", "world");
        jsonObject.put("name", "java");
        // Open transaction 
        Transaction multi = jedis.multi();
        String result = jsonObject.toJSONString();
        // Put an optimistic lock on transactions 
        jedis.watch(result);
        try{
    
            // towards redis Put in a piece of data 
            multi.set("json", result);
            // Save another piece of data 
            multi.set("json2", result);
            // This raises an exception , use 0 As divisor 
            int i = 100/0;
            // If no exception is raised , Execute the command to enter the queue 
            multi.exec();
        }catch(Exception e){
    
            e.printStackTrace();
            // If there is an anomaly , Roll back , Give up the business 
            multi.discard();
        }finally{
    
            System.out.println(jedis.get("json"));
            System.out.println(jedis.get("json2"));
            // Finally shut down the client 
            jedis.close();
        }
    }
}