8

I want to use Spring cache @Cacheable to manager cache. And the real cache is redis.

my code like that:

@PostMapping("/post")
@CachePut(value = "abc", key = "#key")
public String putInRedis(@RequestParam String key, @RequestParam String value) {
    saveInDB(key, value);

    return value;
}

@GetMapping("/get")
@Cacheable(value = "abc", key = "#key")
public String queryRedis(@RequestParam String key) {

    return findByKey(key);
}

After I have the post request which is

localhost:8080/post?key=key&value=value

the redis server appear a weird key

127.0.0.1:6379> keys *
1) "abc:\xac\xed\x00\x05t\x00\x03key"
127.0.0.1:6379> GET "abc:\xac\xed\x00\x05t\x00\x03key"
"\xac\xed\x00\x05t\x00\x05value"

Spring caching

weird-redis-key-with-spring-data-jedis

how to set @Cacheable's Serializer like StringRedisTemplate default:

public StringRedisTemplate() {
    RedisSerializer<String> stringSerializer = new StringRedisSerializer();
    setKeySerializer(stringSerializer);
    setValueSerializer(stringSerializer);
    setHashKeySerializer(stringSerializer);
    setHashValueSerializer(stringSerializer);
}

my application.properties:

spring.redis.host=localhost
spring.redis.password=
spring.redis.port=6379

build.gradle

group 'io.freezhan'
version '1.0-SNAPSHOT'

buildscript {
    repositories {
        maven {
            url 'https://plugins.gradle.org/m2/'
        }
    }
    dependencies {
        classpath 'org.springframework.boot:spring-boot-gradle-plugin:1.4.0.RELEASE'
    }
}

task wrapper(type: Wrapper) {
    gradleVersion = '2.13'
    distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
}

apply plugin: 'java'
apply plugin: 'spring-boot'

sourceCompatibility = 1.5

repositories {
    mavenCentral()
}

dependencies {
    compile("org.springframework.boot:spring-boot-starter-web") {
        exclude module: "spring-boot-starter-tomcat"
    }
    compile("org.springframework.boot:spring-boot-starter-data-redis")
    compile("org.springframework.boot:spring-boot-starter-jetty")
    compile("org.springframework.boot:spring-boot-starter-actuator")
    compile 'org.projectlombok:lombok:1.16.10'
    testCompile("junit:junit")
}
Community
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free斩
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3 Answers3

8

Create a redis template

private RedisTemplate<String, ?> createRedisTemplateForEntity() {
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<String, Object>();
        redisTemplate.setConnectionFactory(getRedisConnectionFactory());
        redisTemplate.setHashValueSerializer(new StringRedisSerializer());
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(new StringRedisSerializer());
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        redisTemplate.afterPropertiesSet();

    return redisTemplate;
}

Why is it creating a weird string as key?

The key is created based on the argument attributes present in your method which is annotated as cacheable. This is how spring reads the cache value from redis.

Rohith K
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  • The default RedisTemplate will not appear weird key, because the serializer is StringRedisSerializer. But the default @Cacheable(value = "abc", key = "#key") maybe use defaultSerializer = new JdkSerializationRedisSerializer(); Define own cacheManager and set this redisTemplate will solve my problem. thanks for your answer – free斩 Sep 05 '16 at 06:55
3

The caching - feature of Spring allows to use different cache - implementations. One of them is Redis. It can be used with the class RedisCacheManager. The Spring documentation says:

If Redis is available and configured, the RedisCacheManager is auto-configured.

This is the approach that I propose to influence the Redis - caching - integration:

  1. Define the RedisCacheManager as bean on your own.

  2. Pass the RedisTemplate to the constructor of RedisCacheManager.

I found an example for this on the Internet using a programmmatic configuration. There is also an example using XML-based configuration.

Sled
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mm759
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  • Is there any way implement this in application.properties or yaml file. Don't use to write code~ – free斩 Sep 05 '16 at 07:25
  • I hardly know both, but I think it's not possible. I couldn't find annotations on RedisCacheManager that allow it. – mm759 Sep 05 '16 at 17:12
  • Passing RedisTemplate to the constructor of RedisCacheManager is deprecated now. Any new way to stop the weird key generation? – echoaman May 01 '21 at 22:55
3

like mm759's answer:

  1. Define the RedisCacheManager as bean on your own.

    1. Pass the RedisTemplate to the constructor of RedisCacheManager.

this code will solve my problem:

package io;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.CacheManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.serializer.StringRedisSerializer;

/**
 * Created by freezhan on 16/9/5.
 */
@Configuration
public class CacheConfig {

    @Autowired
    private StringRedisTemplate redisTemplate;

    @Bean
    public CacheManager cacheManager() {
        RedisCacheManager cacheManager = new RedisCacheManager(redisTemplate);
        return cacheManager;
    }

}

and the redis store like this:

enter image description here

free斩
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    its deprecated..now RedisCacheManager not allowing StringRedisTemplate to be in parameter – aswzen Mar 08 '19 at 02:48