how can I save a List of Objects into Redis using only one key - value?

Question

I am trying to do this.

I have a list of objects (Custom objects), I want to save them all in a single register in Redis, is it possible to save them as ajax somehow? I was reading about Jackson but I couldn't figure it how.

So far I only have this

@Autowired
private StringRedisTemplate redisTmpl;

And I can save like this

redisTmpl.opsForValue().set("foo", "bar");

Works pretty good, but instead of Bar , I want to save my list of objects (using this StringRedisTemplate.

Any idea how to do it?

Or maybe using another way? But I need to save all the list in just one key.

Thanks

I'm not a Java dev, but you need to serialize that list into JSON and store the JSON string in the whole key........ — Matías Fidemraizer
– Matías Fidemraizer, Commented Dec 15, 2015 at 8:48
Check out the Spring Data Redis docs, you can use different serializers: docs.spring.io/spring-data/redis/docs/current/reference/html/… — mp911de
– mp911de, Commented Dec 15, 2015 at 10:51
ajax is negotiation protocol not serialization method, I believe you mean JSON instead. — Ali Nikneshan
– Ali Nikneshan, Commented Dec 15, 2015 at 20:09

jpganz18 · Accepted Answer · 2015-12-16 20:22:52Z

5

I Found the way to do it....

To save all the list you can use jackson, on this way

ObjectMapper mapper = new ObjectMapper();
String jsonInString = mapper.writeValueAsString(myList);

And later you just save it on same way

redisTmpl.opsForValue().set("foo", jsonInString);

answered Dec 16, 2015 at 20:22

jpganz18

5,90821 gold badges74 silver badges131 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

samar taj Shaikh Over a year ago

how can i convert the jsonInString object back into an object. Any suggestions ?

Ali Nikneshan · Accepted Answer · 2015-12-15 20:12:04Z

0

If you can serialize your object as JSON, you can store it as string in redis. but for this you may need to create serializer/deserializer methods for your class.

answered Dec 15, 2015 at 20:12

Ali Nikneshan

3,51231 silver badges40 bronze badges

1 Comment

jpganz18 Over a year ago

I am using Jackson for it, and it saves it great, but I cannot get it back in same format (hashmap)

Nebras · Accepted Answer · 2016-01-06 07:55:57Z

0

you should use spring support to convert your values to JSON like below example. It also convert your key to string directly.

<bean id="serializer" class="org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer">
    <constructor-arg>
        <value type="java.lang.Class">your.class.path.to.be.saved.in.redis</value>
    </constructor-arg>
</bean>

<bean id="template" class="org.springframework.data.redis.core.RedisTemplate"
        p:connection-factory-ref="redisConnectionFactory">
    <property name="valueSerializer" ref="serializer"/>
    <property name="keySerializer">
        <bean class="org.springframework.data.redis.serializer.StringRedisSerializer"/>
    </property>
   </bean>

answered Jan 6, 2016 at 7:55

Nebras

6361 gold badge7 silver badges16 bronze badges

1 Comment

Nebras Over a year ago

@jpganz18 you can use the internal support from spring rides data to convert your object into json format by using serializers as mentioned in the answer... if you find this helpful please vote up.

Nikita Koksharov · Accepted Answer · 2017-02-19 13:48:26Z

0

You can try Redisson as well. It supports many codecs like Jackson JSON, Avro, Smile, CBOR, MsgPack, Kryo, FST, LZ4, Snappy and JDK Serialization. It's very easy in use:

List<Object> list = ...
redisson.getBucket("yourKey").set(list);

// or use Redis list object

redisson.getList("yourKey").addAll(list);

edited Feb 19, 2017 at 13:48

answered Sep 14, 2016 at 8:58

Nikita Koksharov

10.8k1 gold badge68 silver badges76 bronze badges

Comments

Lucas Araújo · Accepted Answer · 2019-03-19 23:46:18Z

0

Using redisson you can do this:

ObjectMapper mapper = new ObjectMapper();
RList<MyObject> list = redissonCLient.getList("myKey");
list.add(mapper.writeValueAsString(new MyObject("test")));

The code above will save a Redis List in JSON format with the MyObjects values.

To retrieve the list you can do:

RList<MyObject> list = redissonCLient.getList("myKey");
List<MyObject> myObjects = mapper.readValue(list.toString(), new TypeReference<List<MyObject>>(){});

answered Mar 19, 2019 at 23:46

Lucas Araújo

5871 gold badge6 silver badges19 bronze badges

Collectives™ on Stack Overflow

how can I save a List of Objects into Redis using only one key - value?

5 Answers 5

1 Comment

1 Comment

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

1 Comment

1 Comment

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related