Google Guava

/*
 * see: http://code.google.com/p/guava-libraries/
 * grails caching idea: http://refactr.com/blog/2012/05/grails-in-memory-cache-using-googles-guava-library/
 */
@Grapes([
     @Grab("com.google.guava:guava:14.0.1")
])
import java.util.concurrent.TimeUnit
import com.google.common.primitives.Ints
import com.google.common.collect.Iterables
import com.google.common.collect.ImmutableList
import com.google.common.collect.ImmutableMap
import com.google.common.hash.Hashing
import com.google.common.cache.Cache
import com.google.common.cache.CacheBuilder
import com.google.common.cache.CacheLoader

List list = [1,2,3,3]
assert Iterables.frequency(list, 2) == 1
assert Iterables.frequency(list, 3) == 2

String temp = "test"
md5 = Hashing.md5()
String hash = md5.newHasher().putBytes(temp as byte[]).hash()
assert hash != temp
assert hash == "098f6bcd4621d373cade4e832627b4f6"

ImmutableList of = ImmutableList.of("a", "b", "c", "d");
// Same one for map
ImmutableMap map = ImmutableMap.of("key1", "value1", "key2", "value2");
//list of ints
List theList = Ints.asList(1, 2, 3, 4, 522, 5, 6);

//see: https://code.google.com/p/guava-libraries/wiki/CachesExplained
Cache cache = 
CacheBuilder.newBuilder()
  .weakKeys()
  .maximumSize(10000)
  .expireAfterWrite(10, TimeUnit.MINUTES)
  .build( new CacheLoader() {
    @Override
    public String load(Integer key) throws Exception {
      return retreveStringForKey(key);
    }
    @Override
    public Object load(Object o) { return o; } //???
  });

cache.metaClass.propertyMissing { k -> delegate.get(k) }
cache.metaClass.propertyMissing { k, v -> delegate.put(k, v) }
cache["a"] = 9
assert cache.size() == 1
assert cache["a"] == 9