Map an object to a hash with Spring Data Redis

Question

Say I have a User class

class User {
 private Long id
 private String username
 private String password
}

I read a few articles/tutorials regarding storing repositories with redis in hash.

However they all have one key for the whole "table", what put into redis looks like following:

user 1 {id:1,username:'',password:''}
user 2 {id:1,username:'',password:''}

they all had id as the hash key in this case.

What I wanted to achieve is to use each field as a hash key, like below:

user:1 id 1
user:1 username ''
user:1 password ''

And after quite a lot of time searching, I found Jackson2HashMapper could be the help. But there is no articles/documentations on how to use this mapper exactly.

Have anyone else faced similar situations?

• VonC: What was the answer to stackoverflow.com/q/48294485/6309 that you just deleted?
• Qiaosen Huang: @VonC it turns out you should avoid setting header 'X-Artifactory-Override-Base-Url' in nginx
• VonC: Great! adding that as an answer and accepting it would help others with the same problem ;)

Answer 1

i just use like this:

@Bean
public HashMapper<Object, byte[], byte[]> hashMapper() {
 return new ObjectHashMapper();
}
@Component
public class HashMapping<T> {
 @NonNull
 private StringRedisTemplate stringRedisTemplate;
 @NonNull
 private HashMapper<Object, byte[], byte[]> hashMapper;
 public void writeHash(String key, T t) {
 checkNotNull(key, "hash key cannot be null");
 checkNotNull(t, "hash value cannot be null");
 stringRedisTemplate.execute((RedisCallback<Void>) connection -> {
 Map<byte[], byte[]> mappedHash = hashMapper.toHash(t);
 connection.hMSet(key.getBytes(), mappedHash);
 return null;
 });
 }
 public T loadHash(String key) {
 checkNotNull(key, "hash key cannot be null");
 Map<byte[], byte[]> loadedHash = 
stringRedisTemplate.getConnectionFactory()
 .getConnection().hGetAll(key.getBytes());
 return (T) hashMapper.fromHash(loadedHash);
 }
}