SpringBoot Practical Development (VI)--RedisTemplate processes Hash-type data

Table of contents

1. Add key-value pairs in the form of map collection

2. Get key-value pairs in variables

3. Check whether the specified field in the hash table exists

4. Get whether the specified map key in the variable has a value. If the map key exists, get the value. If there is no, return null.

5. Add hashMap value

6. Set only if hashKey does not exist

7. Delete one or more hash table fields

8. Add incremental increment to the integer value of the specified field in the hash table key

9. Get all fields in hash table

10. Get the number of fields in the hash table

11. Get multiple values ​​present in the hash table

12. Match to get key-value pairs, in order to get all key pairs

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@SpringBootTest




class SpringBootQuick01ApplicationTests {



 



    @Autowired




    private RedisTemplate redisTemplate;



 



    @Test




    void get() {



        HashOperations hashOperations = ();



    }



 



}

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Redishash is aStringA mapping table of type field and value, hash is particularly suitable for storing objects;

Each hash in Redis can store 2^32 - 1Key-value pairs(More than 4 billion);

1. Add key-value pairs in the form of map collection

().putAll(key, maps); // Map<String, String> maps
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2. Get key-value pairs in variables

Map<Object, Object> ().entries(key);
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3. Viewhash tableWhether the specified field exists

Boolean ().hasKey(key, field);
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4. Get whether the specified map key in the variable has a value. If the map key exists, get the value. If there is no, return null.

().get(key, field);
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5. Add hashMap value

().put(key, hashKey, value);
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6. Set only if hashKey does not exist

Boolean ().putIfAbsent(key, hashKey, value);
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7. Delete one or more hash table fields

Long ().delete(key, fields); // Object... fields
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8. Add incremental increment to the integer value of the specified field in the hash table key

public Double hIncrByDouble(String key, Object field, double delta) {



    return ().increment(key, field, delta);



}



 




public Long hashIncrBy(String key, Object field, long increment) {



    return ().increment(key, field, increment);



}

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9. Get all fields in hash table

().keys(key);
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10. Get the number of fields in the hash table

().size(key);
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11. Get multiple values ​​present in the hash table

List<Object> ().values(key);
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12. Match to get key-value pairs, in order to get all key pairs

public Cursor<Entry<Object, Object>> hashScan(String key, ScanOptions options) {



    return ().scan(key, options);



}

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