Weight-based cache eviction

gistfile1.java

public class CacheTest {
    private Logger logger = LoggerFactory.getLogger(CacheTest.class);
    public AtomicInteger numEvicted = new AtomicInteger(0);
    private final LoadingCache<String, Integer> testCache = CacheBuilder.newBuilder()
            .maximumWeight(10)
            .weigher(new Weigher<String, Integer>() {
                @Override
                public int weigh(String key, Integer value) {
                    return key.length();
                }
            })
            .removalListener(new RemovalListener<String, Integer>() {
                @Override
                public void onRemoval(RemovalNotification<String, Integer> notification) {
                    logger.info("Removed entry {}->{} with weight {}: {}", new Object[]{
                            notification.getKey(), notification.getValue(),
                            notification.getKey().length(), notification.getCause()});
                    numEvicted.incrementAndGet();
                }
            })
            .build(new CacheLoader<String, Integer>() {
                @Override
                public Integer load(String key) throws Exception {
                    return key.length();
                }
            });

    @Test
    public void testWeightedCache() throws ExecutionException {
        testCache.get("aaaaa");
        testCache.get("bbbb");
        assertEquals(2, testCache.size());
        assertEquals(0, numEvicted.get());
        testCache.get("blah");
        assertEquals(2, testCache.size());
        assertEquals(1, numEvicted.get());
    }
}