Spring oauth2 token store supported by redis

I had to make a demo for Spring oauth2 with redis store for tokens. Started with the sparklr2 (with tonr2) sample app from here. They are demo apps to show oauth2 powered by spring. Sparklr is the server and tonr is the client. This link has the details. Wanted to replace, the same JVM, in memory backed token store with one that uses redis. Could have used redis template directly. Decided to use spring cache, so that we can change to MemCache, Eh or other cache by change in configuration files.

Cloned the project and added a CacheTokenStore, CacheTokenConfig.java and properties

Using SpringCache, since redis api is more than store/ evict, used the Cache interface to talk to the Cache objects.

CacheTokenStore.java started of as a copy of InMemoryTokenStore. The basic solution and same methods like getTokenCount are there; commented out member variables, replaced with calls to redis.

• Is this a good approach to use Cache interface?

• Any other code comments?

```
package org.springframework.security.oauth.examples.sparklr.config;

import java.util.ArrayList;
import java.util.Collection;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cache.Cache;
import org.springframework.cache.CacheManager;
import org.springframework.cache.concurrent.ConcurrentMapCache;
import org.springframework.cache.support.SimpleCacheManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.data.redis.cache.DefaultRedisCachePrefix;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.cache.RedisCachePrefix;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springf

Disclaimer: I don't know squat about sparklr2, tonr2, and very little about oauth and Redis. I do have a couple of admittedly superficial remarks though.

Hardcoded 1 and 2 values

Why hardcode 1 and 2 to select between in-memory or cache as the store?
The numbers alone are meaningless,
and you could easily replace them with constants,
or put both into an enum.

Use the enhanced for-each loop when possible

Instead of this:

for (int i = 0; i < CACHE_NAMES.length; i++) {
    ConcurrentMapCache cmc = new ConcurrentMapCache(CACHE_NAMES[i]);
    caches.add(cmc);
}

Use an enhanced for-each loop:

for (String name : CACHE_NAMES) {
    ConcurrentMapCache cmc = new ConcurrentMapCache(name);
    caches.add(cmc);
}

Long.compare

You can simplify this:

return (diff == 0 ? 0 : ((diff < 0) ? -1 : 1));

Using Long.compare:

return Long.compare(diff, 0);

Other minor things

This is a bit unusual way to place annotations:

private @Value("${redis.host-name}") String redisHostName;

I'm used to this form instead:

@Value("${redis.host-name}")
    private String redisHostName;

StackExchange Code Review Q#88498, answer score: 4