public static void main(String[] args) {

final double cacheSizeInGB = 1.0;

// Create cache backed by off-heap store

// In this case store will use ByteBuffers backed by byte[].

HTreeMap cache = DBMaker.newCache(cacheSizeInGB);

// Other alternative is to use Direct ByteBuffers.

// In this case the memory is not released if cache is not correctly closed.

// cache = DBMaker.newCacheDirect(cacheSizeInGB);

//generates random key and values

Random r = new Random();

//used to print store statistics

Store store = Store.forEngine(cache.getEngine());

// insert some stuff in cycle

for(long counter=1; counter<1e8; counter++){

long key = r.nextLong();

byte[] value = new byte[1000];

r.nextBytes(value);

cache.put(key,value);

if(counter%1e5==0){

System.out.printf("Map size: %,d, counter %,d, store size: %,d, store free size: %,d\n",

cache.sizeLong(), counter, store.getCurrSize(), store.getFreeSize());

}

}

// and release memory. Only necessary with `DBMaker.newCacheDirect()`

cache.close();

}